imag/libimagstore/src/store.rs

use std::collections::HashMap;
use std::fs::{File, remove_file};
use std::ops::Drop;
use std::path::PathBuf;
use std::result::Result as RResult;
use std::sync::Arc;
use std::sync::RwLock;
use std::collections::BTreeMap;
use std::io::{Seek, SeekFrom};
use std::convert::From;
use std::convert::Into;
use std::sync::Mutex;
use std::ops::Deref;
use std::ops::DerefMut;
use std::fmt::Formatter;
use std::fmt::Debug;
use std::fmt::Error as FMTError;

use toml::{Table, Value};
use regex::Regex;
use glob::glob;
use walkdir::WalkDir;
use walkdir::Iter as WalkDirIter;

use error::{ParserErrorKind, ParserError};
use error::{StoreError as SE, StoreErrorKind as SEK};
use storeid::{IntoStoreId, StoreId, StoreIdIterator};
use lazyfile::LazyFile;

use hook::aspect::Aspect;
use hook::error::HookErrorKind;
use hook::result::HookResult;
use hook::accessor::{ MutableHookDataAccessor,
            StoreIdAccessor};
use hook::position::HookPosition;
use hook::Hook;
use libimagerror::trace::trace_error;

use libimagerror::into::IntoError;

use self::glob_store_iter::*;

/// The Result Type returned by any interaction with the store that could fail
pub type Result<T> = RResult<T, SE>;


#[derive(Debug, PartialEq)]
enum StoreEntryStatus {
    Present,
    Borrowed
}

/// A store entry, depending on the option type it is either borrowed currently
/// or not.
#[derive(Debug)]
struct StoreEntry {
    id: StoreId,
    file: LazyFile,
    status: StoreEntryStatus,
}

pub enum StoreObject {
    Id(StoreId),
    Collection(PathBuf),
}

pub struct Walk {
    dirwalker: WalkDirIter,
}

impl Walk {

    fn new(mut store_path: PathBuf, mod_name: &str) -> Walk {
        store_path.push(mod_name);
        Walk {
            dirwalker: WalkDir::new(store_path).into_iter(),
        }
    }
}

impl ::std::ops::Deref for Walk {
    type Target = WalkDirIter;

    fn deref(&self) -> &Self::Target {
        &self.dirwalker
    }
}

impl Iterator for Walk {
    type Item = StoreObject;

    fn next(&mut self) -> Option<Self::Item> {
        while let Some(something) = self.dirwalker.next() {
            match something {
                Ok(next) => if next.file_type().is_dir() {
                                return Some(StoreObject::Collection(next.path().to_path_buf()))
                            } else if next.file_type().is_file() {
                                return Some(StoreObject::Id(next.path().to_path_buf().into()))
                            },
                Err(e) => {
                    warn!("Error in Walker");
                    debug!("{:?}", e);
                    return None;
                }
            }
        }

        return None;
    }
}


impl StoreEntry {

    fn new(id: StoreId) -> StoreEntry {
        StoreEntry {
            id: id.clone(),
            file: LazyFile::Absent(id.into()),
            status: StoreEntryStatus::Present,
        }
    }

    /// The entry is currently borrowed, meaning that some thread is currently
    /// mutating it
    fn is_borrowed(&self) -> bool {
        self.status == StoreEntryStatus::Borrowed
    }

    fn get_entry(&mut self) -> Result<Entry> {
        if !self.is_borrowed() {
            let file = self.file.get_file_mut();
            if let Err(err) = file {
                if err.err_type() == SEK::FileNotFound {
                    Ok(Entry::new(self.id.clone()))
                } else {
                    Err(err)
                }
            } else {
                // TODO:
                let mut file = file.unwrap();
                let entry = Entry::from_file(self.id.clone(), &mut file);
                file.seek(SeekFrom::Start(0)).ok();
                entry
            }
        } else {
            Err(SE::new(SEK::EntryAlreadyBorrowed, None))
        }
    }

    fn write_entry(&mut self, entry: &Entry) -> Result<()> {
        if self.is_borrowed() {
            use std::io::Write;
            let file = try!(self.file.create_file());

            assert_eq!(self.id, entry.location);
            try!(file.set_len(0)
                .map_err(|e| SE::new(SEK::FileError, Some(Box::new(e)))));
            file.write_all(entry.to_str().as_bytes())
                .map_err(|e| SE::new(SEK::FileError, Some(Box::new(e))))
        } else {
            Ok(())
        }
    }
}

/// The Store itself, through this object one can interact with IMAG's entries
pub struct Store {
    location: PathBuf,

    /**
     * Configuration object of the store
     */
    configuration: Option<Value>,

    /*
     * Registered hooks
     */

    store_unload_aspects  : Arc<Mutex<Vec<Aspect>>>,

    pre_create_aspects    : Arc<Mutex<Vec<Aspect>>>,
    post_create_aspects   : Arc<Mutex<Vec<Aspect>>>,
    pre_retrieve_aspects  : Arc<Mutex<Vec<Aspect>>>,
    post_retrieve_aspects : Arc<Mutex<Vec<Aspect>>>,
    pre_update_aspects    : Arc<Mutex<Vec<Aspect>>>,
    post_update_aspects   : Arc<Mutex<Vec<Aspect>>>,
    pre_delete_aspects    : Arc<Mutex<Vec<Aspect>>>,
    post_delete_aspects   : Arc<Mutex<Vec<Aspect>>>,

    /**
     * Internal Path->File cache map
     *
     * Caches the files, so they remain flock()ed
     *
     * Could be optimized for a threadsafe HashMap
     */
    entries: Arc<RwLock<HashMap<StoreId, StoreEntry>>>,
}

impl Store {

    /// Create a new Store object
    pub fn new(location: PathBuf, store_config: Option<Value>) -> Result<Store> {
        use std::fs::create_dir_all;
        use configuration::*;

        debug!("Validating Store configuration");
        if !config_is_valid(&store_config) {
            return Err(SE::new(SEK::ConfigurationError, None));
        }

        debug!("Building new Store object");
        if !location.exists() {
            debug!("Creating store path");
            let c = create_dir_all(location.clone());
            if c.is_err() {
                debug!("Failed");
                return Err(SE::new(SEK::StorePathCreate,
                                           Some(Box::new(c.unwrap_err()))));
            }
        } else if location.is_file() {
            debug!("Store path exists as file");
            return Err(SE::new(SEK::StorePathExists, None));
        }

        let store_unload_aspects = get_store_unload_aspect_names(&store_config)
            .into_iter().map(|n| {
                let cfg = AspectConfig::get_for(&store_config, n.clone());
                Aspect::new(n, cfg)
            }).collect();

        let pre_create_aspects = get_pre_create_aspect_names(&store_config)
            .into_iter().map(|n| {
                let cfg = AspectConfig::get_for(&store_config, n.clone());
                Aspect::new(n, cfg)
            }).collect();

        let post_create_aspects = get_post_create_aspect_names(&store_config)
            .into_iter().map(|n| {
                let cfg = AspectConfig::get_for(&store_config, n.clone());
                Aspect::new(n, cfg)
            }).collect();

        let pre_retrieve_aspects = get_pre_retrieve_aspect_names(&store_config)
            .into_iter().map(|n| {
                let cfg = AspectConfig::get_for(&store_config, n.clone());
                Aspect::new(n, cfg)
            }).collect();

        let post_retrieve_aspects = get_post_retrieve_aspect_names(&store_config)
            .into_iter().map(|n| {
                let cfg = AspectConfig::get_for(&store_config, n.clone());
                Aspect::new(n, cfg)
            }).collect();

        let pre_update_aspects = get_pre_update_aspect_names(&store_config)
            .into_iter().map(|n| {
                let cfg = AspectConfig::get_for(&store_config, n.clone());
                Aspect::new(n, cfg)
            }).collect();

        let post_update_aspects = get_post_update_aspect_names(&store_config)
            .into_iter().map(|n| {
                let cfg = AspectConfig::get_for(&store_config, n.clone());
                Aspect::new(n, cfg)
            }).collect();

        let pre_delete_aspects = get_pre_delete_aspect_names(&store_config)
            .into_iter().map(|n| {
                let cfg = AspectConfig::get_for(&store_config, n.clone());
                Aspect::new(n, cfg)
            }).collect();

        let post_delete_aspects = get_post_delete_aspect_names(&store_config)
            .into_iter().map(|n| {
                let cfg = AspectConfig::get_for(&store_config, n.clone());
                Aspect::new(n, cfg)
            }).collect();

        let store = Store {
            location: location.clone(),
            configuration: store_config,

            store_unload_aspects  : Arc::new(Mutex::new(store_unload_aspects)),

            pre_create_aspects    : Arc::new(Mutex::new(pre_create_aspects)),
            post_create_aspects   : Arc::new(Mutex::new(post_create_aspects)),
            pre_retrieve_aspects  : Arc::new(Mutex::new(pre_retrieve_aspects)),
            post_retrieve_aspects : Arc::new(Mutex::new(post_retrieve_aspects)),
            pre_update_aspects    : Arc::new(Mutex::new(pre_update_aspects)),
            post_update_aspects   : Arc::new(Mutex::new(post_update_aspects)),
            pre_delete_aspects    : Arc::new(Mutex::new(pre_delete_aspects)),
            post_delete_aspects   : Arc::new(Mutex::new(post_delete_aspects)),
            entries: Arc::new(RwLock::new(HashMap::new())),
        };

        debug!("Store building succeeded");
        Ok(store)
    }

    /// Get the store configuration
    pub fn config(&self) -> Option<&Value> {
        self.configuration.as_ref()
    }

    fn storify_id(&self, id: StoreId) -> StoreId {
        debug!("Create new store id out of: {:?} and {:?}", self.location, id);
        let mut new_id = self.location.clone();
        new_id.push(id);
        debug!("Created: '{:?}'", new_id);
        StoreId::from(new_id)
    }

    /// Creates the Entry at the given location (inside the entry)
    pub fn create<'a, S: IntoStoreId>(&'a self, id: S) -> Result<FileLockEntry<'a>> {
        let id = self.storify_id(id.into_storeid());
        if let Err(e) = self.execute_hooks_for_id(self.pre_create_aspects.clone(), &id) {
            if e.is_aborting() {
                return Err(e)
                    .map_err(Box::new)
                    .map_err(|e| SEK::PreHookExecuteError.into_error_with_cause(e))
                    .map_err(Box::new)
                    .map_err(|e| SEK::CreateCallError.into_error_with_cause(e))
            } else {
                trace_error(&e);
            }
        }

        let mut hsmap = match self.entries.write() {
            Err(_) => return Err(SE::new(SEK::LockPoisoned, None))
                .map_err(Box::new)
                .map_err(|e| SEK::CreateCallError.into_error_with_cause(e)),
            Ok(s) => s,
        };

        if hsmap.contains_key(&id) {
            return Err(SE::new(SEK::EntryAlreadyExists, None))
                .map_err(Box::new)
                .map_err(|e| SEK::CreateCallError.into_error_with_cause(e))
        }
        hsmap.insert(id.clone(), {
            let mut se = StoreEntry::new(id.clone());
            se.status = StoreEntryStatus::Borrowed;
            se
        });

        let mut fle = FileLockEntry::new(self, Entry::new(id));
        self.execute_hooks_for_mut_file(self.post_create_aspects.clone(), &mut fle)
            .map_err(|e| SE::new(SEK::PostHookExecuteError, Some(Box::new(e))))
            .map(|_| fle)
            .map_err(Box::new)
            .map_err(|e| SEK::CreateCallError.into_error_with_cause(e))
    }

    /// Borrow a given Entry. When the `FileLockEntry` is either `update`d or
    /// dropped, the new Entry is written to disk
    ///
    /// Implicitely creates a entry in the store if there is no entry with the id `id`. For a
    /// non-implicitely-create look at `Store::get`.
    pub fn retrieve<'a, S: IntoStoreId>(&'a self, id: S) -> Result<FileLockEntry<'a>> {
        let id = self.storify_id(id.into_storeid());
        if let Err(e) = self.execute_hooks_for_id(self.pre_retrieve_aspects.clone(), &id) {
            if e.is_aborting() {
                return Err(e)
                    .map_err(Box::new)
                    .map_err(|e| SEK::PreHookExecuteError.into_error_with_cause(e))
                    .map_err(Box::new)
                    .map_err(|e| SEK::RetrieveCallError.into_error_with_cause(e))
            } else {
                trace_error(&e);
            }
        }

        self.entries
            .write()
            .map_err(|_| SE::new(SEK::LockPoisoned, None))
            .and_then(|mut es| {
                let mut se = es.entry(id.clone()).or_insert_with(|| StoreEntry::new(id.clone()));
                let entry = se.get_entry();
                se.status = StoreEntryStatus::Borrowed;
                entry
            })
            .map(|e| FileLockEntry::new(self, e))
            .and_then(|mut fle| {
                self.execute_hooks_for_mut_file(self.post_retrieve_aspects.clone(), &mut fle)
                    .map_err(|e| SE::new(SEK::HookExecutionError, Some(Box::new(e))))
                    .and(Ok(fle))
            })
            .map_err(Box::new)
            .map_err(|e| SEK::RetrieveCallError.into_error_with_cause(e))
    }

    /// Get an entry from the store if it exists.
    ///
    /// This executes the {pre,post}_retrieve_aspects hooks.
    pub fn get<'a, S: IntoStoreId + Clone>(&'a self, id: S) -> Result<Option<FileLockEntry<'a>>> {
        if !self.storify_id(id.clone().into_storeid()).exists() {
            debug!("Does not exist: {:?}", id.clone().into_storeid());
            return Ok(None);
        }
        self.retrieve(id).map(Some)
            .map_err(Box::new)
            .map_err(|e| SEK::GetCallError.into_error_with_cause(e))
    }

    /// Same as `Store::get()` but also tries older versions of the entry, returning an iterator
    /// over all versions of the entry.
    pub fn get_all_versions<'a, S: IntoStoreId>(&'a self, id: S) -> Result<StoreIdIterator>
    {
        // get PathBuf component from storeid, but not version component
        fn path_component<S: IntoStoreId>(id: S) -> Result<PathBuf> {
            let p : PathBuf = id.into_storeid().into();
            match p.to_str() {
                Some(s) => {
                    let mut split       = s.split("~");
                    let path_element    = match split.next() {
                        Some(s) => s,
                        None => return Err(SE::new(SEK::StorePathError, None))
                            .map_err(Box::new)
                            .map_err(|e| SEK::GetAllVersionsCallError.into_error_with_cause(e)),
                    };

                    Ok(PathBuf::from(path_element))
                },

                None => Err(SE::new(SEK::StorePathError, None))
                    .map_err(Box::new)
                    .map_err(|e| SEK::GetAllVersionsCallError.into_error_with_cause(e)),
            }
        }

        fn build_glob_pattern(mut pb: PathBuf) -> Option<String> {
            pb.push("~*.*.*");
            pb.to_str().map(String::from)
        }

        match path_component(id).map(build_glob_pattern) {
            Err(e) => Err(SE::new(SEK::StorePathError, Some(Box::new(e))))
                .map_err(Box::new)
                .map_err(|e| SEK::GetAllVersionsCallError.into_error_with_cause(e)),
            Ok(None) => Err(SE::new(SEK::StorePathError, None))
                .map_err(Box::new)
                .map_err(|e| SEK::GetAllVersionsCallError.into_error_with_cause(e)),
            Ok(Some(pattern)) => {
                glob(&pattern[..])
                    .map(|paths| GlobStoreIdIterator::new(paths).into())
                    .map_err(|e| SE::new(SEK::GlobError, Some(Box::new(e))))
                    .map_err(Box::new)
                    .map_err(|e| SEK::GetAllVersionsCallError.into_error_with_cause(e))
            }
        }

    }

    /// Iterate over all StoreIds for one module name
    pub fn retrieve_for_module(&self, mod_name: &str) -> Result<StoreIdIterator> {
        let mut path = self.path().clone();
        path.push(mod_name);

        path.to_str()
            .ok_or(SE::new(SEK::EncodingError, None))
            .and_then(|path| {
                let path = [ path, "/**/*" ].join("");
                debug!("glob()ing with '{}'", path);
                glob(&path[..]).map_err(|e| SE::new(SEK::GlobError, Some(Box::new(e))))
            })
            .map(|paths| GlobStoreIdIterator::new(paths).into())
            .map_err(|e| SE::new(SEK::GlobError, Some(Box::new(e))))
            .map_err(Box::new)
            .map_err(|e| SEK::RetrieveForModuleCallError.into_error_with_cause(e))
    }

    // Walk the store tree for the module
    pub fn walk<'a>(&'a self, mod_name: &str) -> Walk {
        Walk::new(self.path().clone(), mod_name)
    }

    /// Return the `FileLockEntry` and write to disk
    pub fn update<'a>(&'a self, mut entry: FileLockEntry<'a>) -> Result<()> {
        if let Err(e) = self.execute_hooks_for_mut_file(self.pre_update_aspects.clone(), &mut entry) {
            if e.is_aborting() {
                return Err(e)
                    .map_err(Box::new)
                    .map_err(|e| SEK::PreHookExecuteError.into_error_with_cause(e))
                    .map_err(Box::new)
                    .map_err(|e| SEK::UpdateCallError.into_error_with_cause(e));
            } else {
                trace_error(&e);
            }
        }

        if let Err(e) = self._update(&entry) {
            return Err(e)
                .map_err(Box::new)
                .map_err(|e| SEK::UpdateCallError.into_error_with_cause(e));
        }

        self.execute_hooks_for_mut_file(self.post_update_aspects.clone(), &mut entry)
            .map_err(|e| SE::new(SEK::PreHookExecuteError, Some(Box::new(e))))
            .map_err(Box::new)
            .map_err(|e| SEK::UpdateCallError.into_error_with_cause(e))
    }

    /// Internal method to write to the filesystem store.
    ///
    /// # Assumptions
    /// This method assumes that entry is dropped _right after_ the call, hence
    /// it is not public.
    fn _update<'a>(&'a self, entry: &FileLockEntry<'a>) -> Result<()> {
        let mut hsmap = match self.entries.write() {
            Err(_) => return Err(SE::new(SEK::LockPoisoned, None)),
            Ok(e) => e,
        };

        let mut se = try!(hsmap.get_mut(&entry.location).ok_or(SE::new(SEK::IdNotFound, None)));

        assert!(se.is_borrowed(), "Tried to update a non borrowed entry.");

        debug!("Verifying Entry");
        try!(entry.entry.verify());

        debug!("Writing Entry");
        try!(se.write_entry(&entry.entry));
        se.status = StoreEntryStatus::Present;

        Ok(())
    }

    /// Retrieve a copy of a given entry, this cannot be used to mutate
    /// the one on disk
    pub fn retrieve_copy<S: IntoStoreId>(&self, id: S) -> Result<Entry> {
        let id = self.storify_id(id.into_storeid());
        let entries = match self.entries.write() {
            Err(_) => {
                return Err(SE::new(SEK::LockPoisoned, None))
                    .map_err(Box::new)
                    .map_err(|e| SEK::RetrieveCopyCallError.into_error_with_cause(e));
            },
            Ok(e) => e,
        };

        // if the entry is currently modified by the user, we cannot drop it
        if entries.get(&id).map(|e| e.is_borrowed()).unwrap_or(false) {
            return Err(SE::new(SEK::IdLocked, None))
                    .map_err(Box::new)
                    .map_err(|e| SEK::RetrieveCopyCallError.into_error_with_cause(e));
        }

        StoreEntry::new(id).get_entry()
    }

    /// Delete an entry
    pub fn delete<S: IntoStoreId>(&self, id: S) -> Result<()> {
        let id = self.storify_id(id.into_storeid());
        if let Err(e) = self.execute_hooks_for_id(self.pre_delete_aspects.clone(), &id) {
            if e.is_aborting() {
                return Err(e)
                    .map_err(|e| SE::new(SEK::PreHookExecuteError, Some(Box::new(e))))
                    .map_err(Box::new)
                    .map_err(|e| SEK::DeleteCallError.into_error_with_cause(e))
            } else {
                trace_error(&e);
            }
        }

        let mut entries = match self.entries.write() {
            Err(_) => return Err(SE::new(SEK::LockPoisoned, None))
                .map_err(Box::new)
                .map_err(|e| SEK::DeleteCallError.into_error_with_cause(e)),
            Ok(e) => e,
        };

        // if the entry is currently modified by the user, we cannot drop it
        if entries.get(&id).map(|e| e.is_borrowed()).unwrap_or(false) {
            return Err(SE::new(SEK::IdLocked, None))
                .map_err(Box::new)
                .map_err(|e| SEK::DeleteCallError.into_error_with_cause(e));
        }

        // remove the entry first, then the file
        entries.remove(&id);
        if let Err(e) = remove_file(&id) {
            return Err(SE::new(SEK::FileError, Some(Box::new(e))))
                .map_err(Box::new)
                .map_err(|e| SEK::DeleteCallError.into_error_with_cause(e));
        }

        self.execute_hooks_for_id(self.post_delete_aspects.clone(), &id)
            .map_err(|e| SE::new(SEK::PreHookExecuteError, Some(Box::new(e))))
            .map_err(Box::new)
            .map_err(|e| SEK::DeleteCallError.into_error_with_cause(e))
    }

    /// Move an entry
    pub fn save_as(&self, entry: FileLockEntry, new_id: StoreId) -> Result<()> {
        unimplemented!()
    }

    /// Move an entry without loading
    pub fn move_by_id(&self, old_id: StoreId, new_id: StoreId) -> Result<()> {
        unimplemented!()
    }

    /// Gets the path where this store is on the disk
    pub fn path(&self) -> &PathBuf {
        &self.location
    }

    pub fn register_hook(&mut self,
                         position: HookPosition,
                         aspect_name: &str,
                         mut h: Box<Hook>)
        -> Result<()>
    {
        debug!("Registering hook: {:?}", h);
        debug!("     in position: {:?}", position);
        debug!("     with aspect: {:?}", aspect_name);

        let guard = match position {
                HookPosition::StoreUnload  => self.store_unload_aspects.clone(),

                HookPosition::PreCreate    => self.pre_create_aspects.clone(),
                HookPosition::PostCreate   => self.post_create_aspects.clone(),
                HookPosition::PreRetrieve  => self.pre_retrieve_aspects.clone(),
                HookPosition::PostRetrieve => self.post_retrieve_aspects.clone(),
                HookPosition::PreUpdate    => self.pre_update_aspects.clone(),
                HookPosition::PostUpdate   => self.post_update_aspects.clone(),
                HookPosition::PreDelete    => self.pre_delete_aspects.clone(),
                HookPosition::PostDelete   => self.post_delete_aspects.clone(),
            };

        let mut guard = match guard.deref().lock().map_err(|_| SE::new(SEK::LockError, None)) {
            Err(e) => return Err(SE::new(SEK::HookRegisterError, Some(Box::new(e)))),
            Ok(g) => g,
        };

        for mut aspect in guard.deref_mut() {
            if aspect.name().clone() == aspect_name.clone() {
                self.get_config_for_hook(h.name()).map(|config| h.set_config(config));
                aspect.register_hook(h);
                return Ok(());
            }
        }

        let annfe = SE::new(SEK::AspectNameNotFoundError, None);
        Err(SE::new(SEK::HookRegisterError, Some(Box::new(annfe))))
    }

    fn get_config_for_hook(&self, name: &str) -> Option<&Value> {
        match self.configuration {
            Some(Value::Table(ref tabl)) => {
                tabl.get("hooks")
                    .map(|hook_section| {
                        match *hook_section {
                            Value::Table(ref tabl) => tabl.get(name),
                            _ => None
                        }
                    })
                    .unwrap_or(None)
            },
            _ => None,
        }
    }

    fn execute_hooks_for_id(&self,
                            aspects: Arc<Mutex<Vec<Aspect>>>,
                            id: &StoreId)
        -> HookResult<()>
    {
        match aspects.lock() {
            Err(_) => return Err(HookErrorKind::HookExecutionError.into()),
            Ok(g) => g
        }.iter().fold(Ok(()), |acc, aspect| {
            debug!("[Aspect][exec]: {:?}", aspect);
            acc.and_then(|_| (aspect as &StoreIdAccessor).access(id))
        }).map_err(Box::new).map_err(|e| HookErrorKind::HookExecutionError.into_error_with_cause(e))
    }

    fn execute_hooks_for_mut_file(&self,
                                  aspects: Arc<Mutex<Vec<Aspect>>>,
                                  fle: &mut FileLockEntry)
        -> HookResult<()>
    {
        match aspects.lock() {
            Err(_) => return Err(HookErrorKind::HookExecutionError.into()),
            Ok(g) => g
        }.iter().fold(Ok(()), |acc, aspect| {
            debug!("[Aspect][exec]: {:?}", aspect);
            acc.and_then(|_| aspect.access_mut(fle))
        }).map_err(Box::new).map_err(|e| HookErrorKind::HookExecutionError.into_error_with_cause(e))
    }

}

impl Debug for Store {

    fn fmt(&self, fmt: &mut Formatter) -> RResult<(), FMTError> {
        try!(write!(fmt, " --- Store ---\n"));
        try!(write!(fmt, "\n"));
        try!(write!(fmt, " - location               : {:?}\n", self.location));
        try!(write!(fmt, " - configuration          : {:?}\n", self.configuration));
        try!(write!(fmt, " - pre_create_aspects     : {:?}\n", self.pre_create_aspects    ));
        try!(write!(fmt, " - post_create_aspects    : {:?}\n", self.post_create_aspects   ));
        try!(write!(fmt, " - pre_retrieve_aspects   : {:?}\n", self.pre_retrieve_aspects  ));
        try!(write!(fmt, " - post_retrieve_aspects  : {:?}\n", self.post_retrieve_aspects ));
        try!(write!(fmt, " - pre_update_aspects     : {:?}\n", self.pre_update_aspects    ));
        try!(write!(fmt, " - post_update_aspects    : {:?}\n", self.post_update_aspects   ));
        try!(write!(fmt, " - pre_delete_aspects     : {:?}\n", self.pre_delete_aspects    ));
        try!(write!(fmt, " - post_delete_aspects    : {:?}\n", self.post_delete_aspects   ));
        try!(write!(fmt, "\n"));
        try!(write!(fmt, "Entries:\n"));
        try!(write!(fmt, "{:?}", self.entries));
        try!(write!(fmt, "\n"));
        Ok(())
    }

}

impl Drop for Store {

    /**
     * Unlock all files on drop
     *
     * TODO: Unlock them
     */
    fn drop(&mut self) {
        let store_id = StoreId::from(self.location.clone());
        if let Err(e) = self.execute_hooks_for_id(self.store_unload_aspects.clone(), &store_id) {
            debug!("Store-load hooks execution failed. Cannot create store object.");
            warn!("Store Unload Hook error: {:?}", e);
        }

        debug!("Dropping store");
    }

}

/// A struct that allows you to borrow an Entry
#[derive(Debug)]
pub struct FileLockEntry<'a> {
    store: &'a Store,
    entry: Entry,
}

impl<'a> FileLockEntry<'a, > {
    fn new(store: &'a Store, entry: Entry) -> FileLockEntry<'a> {
        FileLockEntry {
            store: store,
            entry: entry,
        }
    }
}

impl<'a> Deref for FileLockEntry<'a> {
    type Target = Entry;

    fn deref(&self) -> &Self::Target {
        &self.entry
    }
}

impl<'a> DerefMut for FileLockEntry<'a> {
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.entry
    }
}

impl<'a> Drop for FileLockEntry<'a> {
    /// This will silently ignore errors, use `Store::update` if you want to catch the errors
    fn drop(&mut self) {
        let _ = self.store._update(self);
    }
}

/// `EntryContent` type
pub type EntryContent = String;

/// `EntryHeader`
///
/// This is basically a wrapper around `toml::Table` which provides convenience to the user of the
/// library.
#[derive(Debug, Clone)]
pub struct EntryHeader {
    header: Value,
}

pub type EntryResult<V> = RResult<V, ParserError>;

#[derive(Debug, Clone, PartialEq, Eq)]
enum Token {
    Key(String),
    Index(usize),
}

/**
 * Wrapper type around file header (TOML) object
 */
impl EntryHeader {

    pub fn new() -> EntryHeader {
        EntryHeader {
            header: build_default_header()
        }
    }

    pub fn header(&self) -> &Value {
        &self.header
    }

    fn from_table(t: Table) -> EntryHeader {
        EntryHeader {
            header: Value::Table(t)
        }
    }

    pub fn parse(s: &str) -> EntryResult<EntryHeader> {
        use toml::Parser;

        let mut parser = Parser::new(s);
        parser.parse()
            .ok_or(ParserErrorKind::TOMLParserErrors.into())
            .and_then(verify_header_consistency)
            .map(EntryHeader::from_table)
    }

    pub fn verify(&self) -> Result<()> {
        match self.header {
            Value::Table(ref t) => verify_header(&t),
            _ => Err(SE::new(SEK::HeaderTypeFailure, None)),
        }
    }

    /**
     * Insert a header field by a string-spec
     *
     * ```ignore
     *  insert("something.in.a.field", Boolean(true));
     * ```
     *
     * If an array field was accessed which is _out of bounds_ of the array available, the element
     * is appended to the array.
     *
     * Inserts a Boolean in the section "something" -> "in" -> "a" -> "field"
     * A JSON equivalent would be
     *
     *  {
     *      something: {
     *          in: {
     *              a: {
     *                  field: true
     *              }
     *          }
     *      }
     *  }
     *
     * Returns true if header field was set, false if there is already a value
     */
    pub fn insert(&mut self, spec: &str, v: Value) -> Result<bool> {
        self.insert_with_sep(spec, '.', v)
    }

    pub fn insert_with_sep(&mut self, spec: &str, sep: char, v: Value) -> Result<bool> {
        let tokens = match EntryHeader::tokenize(spec, sep) {
            Err(e) => return Err(e),
            Ok(t) => t
        };

        let destination = match tokens.iter().last() {
            None => return Err(SE::new(SEK::HeaderPathSyntaxError, None)),
            Some(d) => d,
        };

        let path_to_dest = tokens[..(tokens.len() - 1)].into(); // N - 1 tokens

        // walk N-1 tokens
        let value = match EntryHeader::walk_header(&mut self.header, path_to_dest) {
            Err(e) => return Err(e),
            Ok(v) => v
        };

        // There is already an value at this place
        if EntryHeader::extract(value, destination).is_ok() {
            return Ok(false);
        }

        match *destination {
            Token::Key(ref s) => { // if the destination shall be an map key
                match *value {
                    /*
                     * Put it in there if we have a map
                     */
                    Value::Table(ref mut t) => {
                        t.insert(s.clone(), v);
                    }

                    /*
                     * Fail if there is no map here
                     */
                    _ => return Err(SE::new(SEK::HeaderPathTypeFailure, None)),
                }
            },

            Token::Index(i) => { // if the destination shall be an array
                match *value {

                    /*
                     * Put it in there if we have an array
                     */
                    Value::Array(ref mut a) => {
                        a.push(v); // push to the end of the array

                        // if the index is inside the array, we swap-remove the element at this
                        // index
                        if a.len() < i {
                            a.swap_remove(i);
                        }
                    },

                    /*
                     * Fail if there is no array here
                     */
                    _ => return Err(SE::new(SEK::HeaderPathTypeFailure, None)),
                }
            },
        }

        Ok(true)
    }

    /**
     * Set a header field by a string-spec
     *
     * ```ignore
     *  set("something.in.a.field", Boolean(true));
     * ```
     *
     * Sets a Boolean in the section "something" -> "in" -> "a" -> "field"
     * A JSON equivalent would be
     *
     *  {
     *      something: {
     *          in: {
     *              a: {
     *                  field: true
     *              }
     *          }
     *      }
     *  }
     *
     * If there is already a value at this place, this value will be overridden and the old value
     * will be returned
     */
    pub fn set(&mut self, spec: &str, v: Value) -> Result<Option<Value>> {
        self.set_with_sep(spec, '.', v)
    }

    pub fn set_with_sep(&mut self, spec: &str, sep: char, v: Value) -> Result<Option<Value>> {
        let tokens = match EntryHeader::tokenize(spec, sep) {
            Err(e) => return Err(e),
            Ok(t) => t,
        };
        debug!("tokens = {:?}", tokens);

        let destination = match tokens.iter().last() {
            None => return Err(SE::new(SEK::HeaderPathSyntaxError, None)),
            Some(d) => d
        };
        debug!("destination = {:?}", destination);

        let path_to_dest = tokens[..(tokens.len() - 1)].into(); // N - 1 tokens
        // walk N-1 tokens
        let value = match EntryHeader::walk_header(&mut self.header, path_to_dest) {
            Err(e) => return Err(e),
            Ok(v) => v
        };
        debug!("walked value = {:?}", value);

        match *destination {
            Token::Key(ref s) => { // if the destination shall be an map key->value
                match *value {
                    /*
                     * Put it in there if we have a map
                     */
                    Value::Table(ref mut t) => {
                        debug!("Matched Key->Table");
                        return Ok(t.insert(s.clone(), v));
                    }

                    /*
                     * Fail if there is no map here
                     */
                    _ => {
                        debug!("Matched Key->NON-Table");
                        return Err(SE::new(SEK::HeaderPathTypeFailure, None));
                    }
                }
            },

            Token::Index(i) => { // if the destination shall be an array
                match *value {

                    /*
                     * Put it in there if we have an array
                     */
                    Value::Array(ref mut a) => {
                        debug!("Matched Index->Array");
                        a.push(v); // push to the end of the array

                        // if the index is inside the array, we swap-remove the element at this
                        // index
                        if a.len() > i {
                            debug!("Swap-Removing in Array {:?}[{:?}] <- {:?}", a, i, a[a.len()-1]);
                            return Ok(Some(a.swap_remove(i)));
                        }

                        debug!("Appended");
                        return Ok(None);
                    },

                    /*
                     * Fail if there is no array here
                     */
                    _ => {
                        debug!("Matched Index->NON-Array");
                        return Err(SE::new(SEK::HeaderPathTypeFailure, None));
                    },
                }
            },
        }

        Ok(None)
    }

    /**
     * Read a header field by a string-spec
     *
     * ```ignore
     *  let value = read("something.in.a.field");
     * ```
     *
     * Reads a Value in the section "something" -> "in" -> "a" -> "field"
     * A JSON equivalent would be
     *
     *  {
     *      something: {
     *          in: {
     *              a: {
     *                  field: true
     *              }
     *          }
     *      }
     *  }
     *
     * If there is no a value at this place, None will be returned. This also holds true for Arrays
     * which are accessed at an index which is not yet there, even if the accessed index is much
     * larger than the array length.
     */
    pub fn read(&self, spec: &str) -> Result<Option<Value>> {
        self.read_with_sep(spec, '.')
    }

    pub fn read_with_sep(&self, spec: &str, splitchr: char) -> Result<Option<Value>> {
        let tokens = match EntryHeader::tokenize(spec, splitchr) {
            Err(e) => return Err(e),
            Ok(t) => t,
        };

        let mut header_clone = self.header.clone(); // we clone as READing is simpler this way
        // walk N-1 tokens
        match EntryHeader::walk_header(&mut header_clone, tokens) {
            Err(e) => match e.err_type() {
                // We cannot find the header key, as there is no path to it
                SEK::HeaderKeyNotFound => Ok(None),
                _ => Err(e),
            },
            Ok(v) => Ok(Some(v.clone())),
        }
    }

    pub fn delete(&mut self, spec: &str) -> Result<Option<Value>> {
        let tokens = match EntryHeader::tokenize(spec, '.') {
            Err(e) => return Err(e),
            Ok(t) => t
        };

        let destination = match tokens.iter().last() {
            None => return Err(SE::new(SEK::HeaderPathSyntaxError, None)),
            Some(d) => d
        };
        debug!("destination = {:?}", destination);

        let path_to_dest = tokens[..(tokens.len() - 1)].into(); // N - 1 tokens
        // walk N-1 tokens
        let mut value = match EntryHeader::walk_header(&mut self.header, path_to_dest) {
            Err(e) => return Err(e),
            Ok(v) => v
        };
        debug!("walked value = {:?}", value);

        match *destination {
            Token::Key(ref s) => { // if the destination shall be an map key->value
                match *value {
                    Value::Table(ref mut t) => {
                        debug!("Matched Key->Table, removing {:?}", s);
                        return Ok(t.remove(s));
                    },
                    _ => {
                        debug!("Matched Key->NON-Table");
                        return Err(SE::new(SEK::HeaderPathTypeFailure, None));
                    }
                }
            },

            Token::Index(i) => { // if the destination shall be an array
                match *value {
                    Value::Array(ref mut a) => {
                        // if the index is inside the array, we swap-remove the element at this
                        // index
                        if a.len() > i {
                            debug!("Removing in Array {:?}[{:?}]", a, i);
                            return Ok(Some(a.remove(i)));
                        } else {
                            return Ok(None);
                        }
                    },
                    _ => {
                        debug!("Matched Index->NON-Array");
                        return Err(SE::new(SEK::HeaderPathTypeFailure, None));
                    },
                }
            },
        }

        Ok(None)
    }

    fn tokenize(spec: &str, splitchr: char) -> Result<Vec<Token>> {
        use std::str::FromStr;

        spec.split(splitchr)
            .map(|s| {
                usize::from_str(s)
                    .map(Token::Index)
                    .or_else(|_| Ok(Token::Key(String::from(s))))
            })
            .collect()
    }

    fn walk_header(v: &mut Value, tokens: Vec<Token>) -> Result<&mut Value> {
        use std::vec::IntoIter;

        fn walk_iter<'a>(v: Result<&'a mut Value>, i: &mut IntoIter<Token>) -> Result<&'a mut Value> {
            let next = i.next();
            v.and_then(move |value| {
                if let Some(token) = next {
                    walk_iter(EntryHeader::extract(value, &token), i)
                } else {
                    Ok(value)
                }
            })
        }

        walk_iter(Ok(v), &mut tokens.into_iter())
    }

    fn extract_from_table<'a>(v: &'a mut Value, s: &str) -> Result<&'a mut Value> {
        match *v {
            Value::Table(ref mut t) => {
                t.get_mut(&s[..])
                    .ok_or(SE::new(SEK::HeaderKeyNotFound, None))
            },
            _ => Err(SE::new(SEK::HeaderPathTypeFailure, None)),
        }
    }

    fn extract_from_array(v: &mut Value, i: usize) -> Result<&mut Value> {
        match *v {
            Value::Array(ref mut a) => {
                if a.len() < i {
                    Err(SE::new(SEK::HeaderKeyNotFound, None))
                } else {
                    Ok(&mut a[i])
                }
            },
            _ => Err(SE::new(SEK::HeaderPathTypeFailure, None)),
        }
    }

    fn extract<'a>(v: &'a mut Value, token: &Token) -> Result<&'a mut Value> {
        match *token {
            Token::Key(ref s)  => EntryHeader::extract_from_table(v, s),
            Token::Index(i)    => EntryHeader::extract_from_array(v, i),
        }
    }

}

impl Into<Table> for EntryHeader {

    fn into(self) -> Table {
        match self.header {
            Value::Table(t) => t,
            _ => panic!("EntryHeader is not a table!"),
        }
    }

}

impl From<Table> for EntryHeader {

    fn from(t: Table) -> EntryHeader {
        EntryHeader { header: Value::Table(t) }
    }

}

fn build_default_header() -> Value { // BTreeMap<String, Value>
    let mut m = BTreeMap::new();

    m.insert(String::from("imag"), {
        let mut imag_map = BTreeMap::<String, Value>::new();

        imag_map.insert(String::from("version"), Value::String(String::from(version!())));
        imag_map.insert(String::from("links"), Value::Array(vec![]));

        Value::Table(imag_map)
    });

    Value::Table(m)
}
fn verify_header(t: &Table) -> Result<()> {
    if !has_main_section(t) {
        Err(SE::from(ParserErrorKind::MissingMainSection.into_error()))
    } else if !has_imag_version_in_main_section(t) {
        Err(SE::from(ParserErrorKind::MissingVersionInfo.into_error()))
    } else if !has_only_tables(t) {
        debug!("Could not verify that it only has tables in its base table");
        Err(SE::from(ParserErrorKind::NonTableInBaseTable.into_error()))
    } else {
        Ok(())
    }
}

fn verify_header_consistency(t: Table) -> EntryResult<Table> {
    verify_header(&t)
        .map_err(Box::new)
        .map_err(|e| ParserErrorKind::HeaderInconsistency.into_error_with_cause(e))
        .map(|_| t)
}

fn has_only_tables(t: &Table) -> bool {
    debug!("Verifying that table has only tables");
    t.iter().all(|(_, x)| if let Value::Table(_) = *x { true } else { false })
}

fn has_main_section(t: &Table) -> bool {
    t.contains_key("imag") &&
        match t.get("imag") {
            Some(&Value::Table(_)) => true,
            Some(_)                => false,
            None                   => false,
        }
}

fn has_imag_version_in_main_section(t: &Table) -> bool {
    use semver::Version;

    match *t.get("imag").unwrap() {
        Value::Table(ref sec) => {
            sec.get("version")
                .and_then(|v| {
                    match *v {
                        Value::String(ref s) => Some(Version::parse(&s[..]).is_ok()),
                        _                    => Some(false),
                    }
                })
            .unwrap_or(false)
        }
        _ => false,
    }
}

/**
 * An Entry of the store
 *
 * Contains location, header and content part.
 */
#[derive(Debug, Clone)]
pub struct Entry {
    location: StoreId,
    header: EntryHeader,
    content: EntryContent,
}

impl Entry {

    pub fn new(loc: StoreId) -> Entry {
        Entry {
            location: loc,
            header: EntryHeader::new(),
            content: EntryContent::new()
        }
    }

    pub fn from_file<S: IntoStoreId>(loc: S, file: &mut File) -> Result<Entry> {
        let text = {
            use std::io::Read;
            let mut s = String::new();
            try!(file.read_to_string(&mut s));
            s
        };
        Self::from_str(loc, &text[..])
    }

    pub fn from_str<S: IntoStoreId>(loc: S, s: &str) -> Result<Entry> {
        debug!("Building entry from string");
        lazy_static! {
            static ref RE: Regex = Regex::new(r"(?smx)
                ^---$
                (?P<header>.*) # Header
                ^---$\n
                (?P<content>.*) # Content
            ").unwrap();
        }

        let matches = match RE.captures(s) {
            None    => return Err(SE::new(SEK::MalformedEntry, None)),
            Some(s) => s,
        };

        let header = match matches.name("header") {
            None    => return Err(SE::new(SEK::MalformedEntry, None)),
            Some(s) => s
        };

        let content = matches.name("content").unwrap_or("");

        debug!("Header and content found. Yay! Building Entry object now");
        Ok(Entry {
            location: loc.into_storeid(),
            header: try!(EntryHeader::parse(header)),
            content: content.into(),
        })
    }

    pub fn to_str(&self) -> String {
        format!("---{header}---\n{content}",
                header  = ::toml::encode_str(&self.header.header),
                content = self.content)
    }

    pub fn get_location(&self) -> &StoreId {
        &self.location
    }

    pub fn get_header(&self) -> &EntryHeader {
        &self.header
    }

    pub fn get_header_mut(&mut self) -> &mut EntryHeader {
        &mut self.header
    }

    pub fn get_content(&self) -> &EntryContent {
        &self.content
    }

    pub fn get_content_mut(&mut self) -> &mut EntryContent {
        &mut self.content
    }

    pub fn verify(&self) -> Result<()> {
        self.header.verify()
    }

}

mod glob_store_iter {
    use std::fmt::{Debug, Formatter};
    use std::fmt::Error as FmtError;
    use glob::Paths;
    use storeid::StoreId;
    use storeid::StoreIdIterator;

    pub struct GlobStoreIdIterator {
        paths: Paths,
    }

    impl Debug for GlobStoreIdIterator {

        fn fmt(&self, fmt: &mut Formatter) -> Result<(), FmtError> {
            write!(fmt, "GlobStoreIdIterator")
        }

    }

    impl Into<StoreIdIterator> for GlobStoreIdIterator {

        fn into(self) -> StoreIdIterator {
            StoreIdIterator::new(Box::new(self))
        }

    }

    impl GlobStoreIdIterator {

        pub fn new(paths: Paths) -> GlobStoreIdIterator {
            GlobStoreIdIterator {
                paths: paths,
            }
        }

    }

    impl Iterator for GlobStoreIdIterator {
        type Item = StoreId;

        fn next(&mut self) -> Option<StoreId> {
            self.paths.next().and_then(|o| {
                match o {
                    Ok(o) => Some(o),
                    Err(e) => {
                        debug!("GlobStoreIdIterator error: {:?}", e);
                        None
                    },
                }
            }).map(|p| StoreId::from(p))
        }

    }

}


#[cfg(test)]
mod test {
    extern crate env_logger;

    use std::collections::BTreeMap;
    use super::EntryHeader;
    use super::Token;

    use toml::Value;

    #[test]
    fn test_imag_section() {
        use super::has_main_section;

        let mut map = BTreeMap::new();
        map.insert("imag".into(), Value::Table(BTreeMap::new()));

        assert!(has_main_section(&map));
    }

    #[test]
    fn test_imag_invalid_section_type() {
        use super::has_main_section;

        let mut map = BTreeMap::new();
        map.insert("imag".into(), Value::Boolean(false));

        assert!(!has_main_section(&map));
    }

    #[test]
    fn test_imag_abscent_main_section() {
        use super::has_main_section;

        let mut map = BTreeMap::new();
        map.insert("not_imag".into(), Value::Boolean(false));

        assert!(!has_main_section(&map));
    }

    #[test]
    fn test_main_section_without_version() {
        use super::has_imag_version_in_main_section;

        let mut map = BTreeMap::new();
        map.insert("imag".into(), Value::Table(BTreeMap::new()));

        assert!(!has_imag_version_in_main_section(&map));
    }

    #[test]
    fn test_main_section_with_version() {
        use super::has_imag_version_in_main_section;

        let mut map = BTreeMap::new();
        let mut sub = BTreeMap::new();
        sub.insert("version".into(), Value::String("0.0.0".into()));
        map.insert("imag".into(), Value::Table(sub));

        assert!(has_imag_version_in_main_section(&map));
    }

    #[test]
    fn test_main_section_with_version_in_wrong_type() {
        use super::has_imag_version_in_main_section;

        let mut map = BTreeMap::new();
        let mut sub = BTreeMap::new();
        sub.insert("version".into(), Value::Boolean(false));
        map.insert("imag".into(), Value::Table(sub));

        assert!(!has_imag_version_in_main_section(&map));
    }

    #[test]
    fn test_verification_good() {
        use super::verify_header_consistency;

        let mut header = BTreeMap::new();
        let sub = {
            let mut sub = BTreeMap::new();
            sub.insert("version".into(), Value::String(String::from("0.0.0")));

            Value::Table(sub)
        };

        header.insert("imag".into(), sub);

        assert!(verify_header_consistency(header).is_ok());
    }

    #[test]
    fn test_verification_invalid_versionstring() {
        use super::verify_header_consistency;

        let mut header = BTreeMap::new();
        let sub = {
            let mut sub = BTreeMap::new();
            sub.insert("version".into(), Value::String(String::from("000")));

            Value::Table(sub)
        };

        header.insert("imag".into(), sub);

        assert!(!verify_header_consistency(header).is_ok());
    }


    #[test]
    fn test_verification_current_version() {
        use super::verify_header_consistency;

        let mut header = BTreeMap::new();
        let sub = {
            let mut sub = BTreeMap::new();
            sub.insert("version".into(), Value::String(String::from(version!())));

            Value::Table(sub)
        };

        header.insert("imag".into(), sub);

        assert!(verify_header_consistency(header).is_ok());
    }

    static TEST_ENTRY : &'static str = "---
[imag]
version = \"0.0.3\"
---
Hai";

    #[test]
    fn test_entry_from_str() {
        use super::Entry;
        use std::path::PathBuf;
        println!("{}", TEST_ENTRY);
        let entry = Entry::from_str(PathBuf::from("/test/foo~1.3"),
                                    TEST_ENTRY).unwrap();

        assert_eq!(entry.content, "Hai");
    }

    #[test]
    fn test_entry_to_str() {
        use super::Entry;
        use std::path::PathBuf;
        println!("{}", TEST_ENTRY);
        let entry = Entry::from_str(PathBuf::from("/test/foo~1.3"),
                                    TEST_ENTRY).unwrap();
        let string = entry.to_str();

        assert_eq!(TEST_ENTRY, string);
    }

    #[test]
    fn test_walk_header_simple() {
        let tokens = EntryHeader::tokenize("a", '.').unwrap();
        assert!(tokens.len() == 1, "1 token was expected, {} were parsed", tokens.len());
        assert!(tokens.iter().next().unwrap() == &Token::Key(String::from("a")),
                "'a' token was expected, {:?} was parsed", tokens.iter().next());

        let mut header = BTreeMap::new();
        header.insert(String::from("a"), Value::Integer(1));

        let mut v_header = Value::Table(header);
        let res = EntryHeader::walk_header(&mut v_header, tokens);
        assert_eq!(&mut Value::Integer(1), res.unwrap());
    }

    #[test]
    fn test_walk_header_with_array() {
        let tokens = EntryHeader::tokenize("a.0", '.').unwrap();
        assert!(tokens.len() == 2, "2 token was expected, {} were parsed", tokens.len());
        assert!(tokens.iter().next().unwrap() == &Token::Key(String::from("a")),
                "'a' token was expected, {:?} was parsed", tokens.iter().next());

        let mut header = BTreeMap::new();
        let ary = Value::Array(vec![Value::Integer(1)]);
        header.insert(String::from("a"), ary);


        let mut v_header = Value::Table(header);
        let res = EntryHeader::walk_header(&mut v_header, tokens);
        assert_eq!(&mut Value::Integer(1), res.unwrap());
    }

    #[test]
    fn test_walk_header_extract_array() {
        let tokens = EntryHeader::tokenize("a", '.').unwrap();
        assert!(tokens.len() == 1, "1 token was expected, {} were parsed", tokens.len());
        assert!(tokens.iter().next().unwrap() == &Token::Key(String::from("a")),
                "'a' token was expected, {:?} was parsed", tokens.iter().next());

        let mut header = BTreeMap::new();
        let ary = Value::Array(vec![Value::Integer(1)]);
        header.insert(String::from("a"), ary);

        let mut v_header = Value::Table(header);
        let res = EntryHeader::walk_header(&mut v_header, tokens);
        assert_eq!(&mut Value::Array(vec![Value::Integer(1)]), res.unwrap());
    }

    /**
     * Creates a big testing header.
     *
     * JSON equivalent:
     *
     * ```json
     * {
     *      "a": {
     *          "array": [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 ]
     *      },
     *      "b": {
     *          "array": [ "string1", "string2", "string3", "string4" ]
     *      },
     *      "c": {
     *          "array": [ 1, "string2", 3, "string4" ]
     *      },
     *      "d": {
     *          "array": [
     *              {
     *                  "d1": 1
     *              },
     *              {
     *                  "d2": 2
     *              },
     *              {
     *                  "d3": 3
     *              },
     *          ],
     *
     *          "something": "else",
     *
     *          "and": {
     *              "something": {
     *                  "totally": "different"
     *              }
     *          }
     *      }
     * }
     * ```
     *
     * The sections "a", "b", "c", "d" are created in the respective helper functions
     * create_header_section_a, create_header_section_b, create_header_section_c and
     * create_header_section_d.
     *
     * These functions can also be used for testing.
     *
     */
    fn create_header() -> Value {
        let a = create_header_section_a();
        let b = create_header_section_b();
        let c = create_header_section_c();
        let d = create_header_section_d();

        let mut header = BTreeMap::new();
        header.insert(String::from("a"), a);
        header.insert(String::from("b"), b);
        header.insert(String::from("c"), c);
        header.insert(String::from("d"), d);

        Value::Table(header)
    }

    fn create_header_section_a() -> Value {
        // 0..10 is exclusive 10
        let a_ary = Value::Array((0..10).map(|x| Value::Integer(x)).collect());

        let mut a_obj = BTreeMap::new();
        a_obj.insert(String::from("array"), a_ary);
        Value::Table(a_obj)
    }

    fn create_header_section_b() -> Value {
        let b_ary = Value::Array((0..9)
                                 .map(|x| Value::String(format!("string{}", x)))
                                 .collect());

        let mut b_obj = BTreeMap::new();
        b_obj.insert(String::from("array"), b_ary);
        Value::Table(b_obj)
    }

    fn create_header_section_c() -> Value {
        let c_ary = Value::Array(
            vec![
                Value::Integer(1),
                Value::String(String::from("string2")),
                Value::Integer(3),
                Value::String(String::from("string4"))
            ]);

        let mut c_obj = BTreeMap::new();
        c_obj.insert(String::from("array"), c_ary);
        Value::Table(c_obj)
    }

    fn create_header_section_d() -> Value {
        let d_ary = Value::Array(
            vec![
                {
                    let mut tab = BTreeMap::new();
                    tab.insert(String::from("d1"), Value::Integer(1));
                    tab
                },
                {
                    let mut tab = BTreeMap::new();
                    tab.insert(String::from("d2"), Value::Integer(2));
                    tab
                },
                {
                    let mut tab = BTreeMap::new();
                    tab.insert(String::from("d3"), Value::Integer(3));
                    tab
                },
            ].into_iter().map(Value::Table).collect());

        let and_obj = Value::Table({
            let mut tab = BTreeMap::new();
            let something_tab = Value::Table({
                let mut tab = BTreeMap::new();
                tab.insert(String::from("totally"), Value::String(String::from("different")));
                tab
            });
            tab.insert(String::from("something"), something_tab);
            tab
        });

        let mut d_obj = BTreeMap::new();
        d_obj.insert(String::from("array"), d_ary);
        d_obj.insert(String::from("something"), Value::String(String::from("else")));
        d_obj.insert(String::from("and"), and_obj);
        Value::Table(d_obj)
    }

    #[test]
    fn test_walk_header_big_a() {
        test_walk_header_extract_section("a", &create_header_section_a());
    }

    #[test]
    fn test_walk_header_big_b() {
        test_walk_header_extract_section("b", &create_header_section_b());
    }

    #[test]
    fn test_walk_header_big_c() {
        test_walk_header_extract_section("c", &create_header_section_c());
    }

    #[test]
    fn test_walk_header_big_d() {
        test_walk_header_extract_section("d", &create_header_section_d());
    }

    fn test_walk_header_extract_section(secname: &str, expected: &Value) {
        let tokens = EntryHeader::tokenize(secname, '.').unwrap();
        assert!(tokens.len() == 1, "1 token was expected, {} were parsed", tokens.len());
        assert!(tokens.iter().next().unwrap() == &Token::Key(String::from(secname)),
                "'{}' token was expected, {:?} was parsed", secname, tokens.iter().next());

        let mut header = create_header();
        let res = EntryHeader::walk_header(&mut header, tokens);
        assert_eq!(expected, res.unwrap());
    }

    #[test]
    fn test_walk_header_extract_numbers() {
        test_extract_number("a", 0, 0);
        test_extract_number("a", 1, 1);
        test_extract_number("a", 2, 2);
        test_extract_number("a", 3, 3);
        test_extract_number("a", 4, 4);
        test_extract_number("a", 5, 5);
        test_extract_number("a", 6, 6);
        test_extract_number("a", 7, 7);
        test_extract_number("a", 8, 8);
        test_extract_number("a", 9, 9);

        test_extract_number("c", 0, 1);
        test_extract_number("c", 2, 3);
    }

    fn test_extract_number(sec: &str, idx: usize, exp: i64) {
        let tokens = EntryHeader::tokenize(&format!("{}.array.{}", sec, idx)[..], '.').unwrap();
        assert!(tokens.len() == 3, "3 token was expected, {} were parsed", tokens.len());
        {
            let mut iter = tokens.iter();

            let tok = iter.next().unwrap();
            let exp = Token::Key(String::from(sec));
            assert!(tok == &exp, "'{}' token was expected, {:?} was parsed", sec, tok);

            let tok = iter.next().unwrap();
            let exp = Token::Key(String::from("array"));
            assert!(tok == &exp, "'array' token was expected, {:?} was parsed", tok);

            let tok = iter.next().unwrap();
            let exp = Token::Index(idx);
            assert!(tok == &exp, "'{}' token was expected, {:?} was parsed", idx, tok);
        }

        let mut header = create_header();
        let res = EntryHeader::walk_header(&mut header, tokens);
        assert_eq!(&mut Value::Integer(exp), res.unwrap());
    }

    #[test]
    fn test_header_read() {
        let v = create_header();
        let h = match v {
            Value::Table(t) => EntryHeader::from_table(t),
            _ => panic!("create_header() doesn't return a table!"),
        };

        assert!(if let Ok(Some(Value::Table(_)))  = h.read("a") { true } else { false });
        assert!(if let Ok(Some(Value::Array(_)))   = h.read("a.array") { true } else { false });
        assert!(if let Ok(Some(Value::Integer(_))) = h.read("a.array.1") { true } else { false });
        assert!(if let Ok(Some(Value::Integer(_))) = h.read("a.array.9") { true } else { false });

        assert!(if let Ok(Some(Value::Table(_))) = h.read("c") { true } else { false });
        assert!(if let Ok(Some(Value::Array(_)))  = h.read("c.array") { true } else { false });
        assert!(if let Ok(Some(Value::String(_))) = h.read("c.array.1") { true } else { false });
        assert!(if let Ok(None) = h.read("c.array.9") { true } else { false });

        assert!(if let Ok(Some(Value::Integer(_))) = h.read("d.array.0.d1") { true } else { false });
        assert!(if let Ok(None) = h.read("d.array.0.d2") { true } else { false });
        assert!(if let Ok(None) = h.read("d.array.0.d3") { true } else { false });

        assert!(if let Ok(None) = h.read("d.array.1.d1") { true } else { false });
        assert!(if let Ok(Some(Value::Integer(_))) = h.read("d.array.1.d2") { true } else { false });
        assert!(if let Ok(None) = h.read("d.array.1.d3") { true } else { false });

        assert!(if let Ok(None) = h.read("d.array.2.d1") { true } else { false });
        assert!(if let Ok(None) = h.read("d.array.2.d2") { true } else { false });
        assert!(if let Ok(Some(Value::Integer(_))) = h.read("d.array.2.d3") { true } else { false });

        assert!(if let Ok(Some(Value::String(_))) = h.read("d.something") { true } else { false });
        assert!(if let Ok(Some(Value::Table(_))) = h.read("d.and") { true } else { false });
        assert!(if let Ok(Some(Value::Table(_))) = h.read("d.and.something") { true } else { false });
        assert!(if let Ok(Some(Value::String(_))) = h.read("d.and.something.totally") { true } else { false });
    }

    #[test]
    fn test_header_set_override() {
        let _ = env_logger::init();
        let v = create_header();
        let mut h = match v {
            Value::Table(t) => EntryHeader::from_table(t),
            _ => panic!("create_header() doesn't return a table!"),
        };

        println!("Testing index 0");
        assert_eq!(h.read("a.array.0").unwrap().unwrap(), Value::Integer(0));

        println!("Altering index 0");
        assert_eq!(h.set("a.array.0", Value::Integer(42)).unwrap().unwrap(), Value::Integer(0));

        println!("Values now: {:?}", h);

        println!("Testing all indexes");
        assert_eq!(h.read("a.array.0").unwrap().unwrap(), Value::Integer(42));
        assert_eq!(h.read("a.array.1").unwrap().unwrap(), Value::Integer(1));
        assert_eq!(h.read("a.array.2").unwrap().unwrap(), Value::Integer(2));
        assert_eq!(h.read("a.array.3").unwrap().unwrap(), Value::Integer(3));
        assert_eq!(h.read("a.array.4").unwrap().unwrap(), Value::Integer(4));
        assert_eq!(h.read("a.array.5").unwrap().unwrap(), Value::Integer(5));
        assert_eq!(h.read("a.array.6").unwrap().unwrap(), Value::Integer(6));
        assert_eq!(h.read("a.array.7").unwrap().unwrap(), Value::Integer(7));
        assert_eq!(h.read("a.array.8").unwrap().unwrap(), Value::Integer(8));
        assert_eq!(h.read("a.array.9").unwrap().unwrap(), Value::Integer(9));
    }

    #[test]
    fn test_header_set_new() {
        let _ = env_logger::init();
        let v = create_header();
        let mut h = match v {
            Value::Table(t) => EntryHeader::from_table(t),
            _ => panic!("create_header() doesn't return a table!"),
        };

        assert!(h.read("a.foo").is_ok());
        assert!(h.read("a.foo").unwrap().is_none());

        {
            let v = h.set("a.foo", Value::Integer(42));
            assert!(v.is_ok());
            assert!(v.unwrap().is_none());

            assert!(if let Ok(Some(Value::Table(_))) = h.read("a") { true } else { false });
            assert!(if let Ok(Some(Value::Integer(_))) = h.read("a.foo") { true } else { false });
        }

        {
            let v = h.set("new", Value::Table(BTreeMap::new()));
            assert!(v.is_ok());
            assert!(v.unwrap().is_none());

            let v = h.set("new.subset", Value::Table(BTreeMap::new()));
            assert!(v.is_ok());
            assert!(v.unwrap().is_none());

            let v = h.set("new.subset.dest", Value::Integer(1337));
            assert!(v.is_ok());
            assert!(v.unwrap().is_none());

            assert!(if let Ok(Some(Value::Table(_))) = h.read("new") { true } else { false });
            assert!(if let Ok(Some(Value::Table(_))) = h.read("new.subset") { true } else { false });
            assert!(if let Ok(Some(Value::Integer(_))) = h.read("new.subset.dest") { true } else { false });
        }
    }


    #[test]
    fn test_header_insert_override() {
        let _ = env_logger::init();
        let v = create_header();
        let mut h = match v {
            Value::Table(t) => EntryHeader::from_table(t),
            _ => panic!("create_header() doesn't return a table!"),
        };

        println!("Testing index 0");
        assert_eq!(h.read("a.array.0").unwrap().unwrap(), Value::Integer(0));

        println!("Altering index 0");
        assert_eq!(h.insert("a.array.0", Value::Integer(42)).unwrap(), false);
        println!("...should have failed");

        println!("Testing all indexes");
        assert_eq!(h.read("a.array.0").unwrap().unwrap(), Value::Integer(0));
        assert_eq!(h.read("a.array.1").unwrap().unwrap(), Value::Integer(1));
        assert_eq!(h.read("a.array.2").unwrap().unwrap(), Value::Integer(2));
        assert_eq!(h.read("a.array.3").unwrap().unwrap(), Value::Integer(3));
        assert_eq!(h.read("a.array.4").unwrap().unwrap(), Value::Integer(4));
        assert_eq!(h.read("a.array.5").unwrap().unwrap(), Value::Integer(5));
        assert_eq!(h.read("a.array.6").unwrap().unwrap(), Value::Integer(6));
        assert_eq!(h.read("a.array.7").unwrap().unwrap(), Value::Integer(7));
        assert_eq!(h.read("a.array.8").unwrap().unwrap(), Value::Integer(8));
        assert_eq!(h.read("a.array.9").unwrap().unwrap(), Value::Integer(9));
    }

    #[test]
    fn test_header_insert_new() {
        let _ = env_logger::init();
        let v = create_header();
        let mut h = match v {
            Value::Table(t) => EntryHeader::from_table(t),
            _ => panic!("create_header() doesn't return a table!"),
        };

        assert!(h.read("a.foo").is_ok());
        assert!(h.read("a.foo").unwrap().is_none());

        {
            let v = h.insert("a.foo", Value::Integer(42));
            assert!(v.is_ok());
            assert_eq!(v.unwrap(), true);

            assert!(if let Ok(Some(Value::Table(_))) = h.read("a") { true } else { false });
            assert!(if let Ok(Some(Value::Integer(_))) = h.read("a.foo") { true } else { false });
        }

        {
            let v = h.insert("new", Value::Table(BTreeMap::new()));
            assert!(v.is_ok());
            assert_eq!(v.unwrap(), true);

            let v = h.insert("new.subset", Value::Table(BTreeMap::new()));
            assert!(v.is_ok());
            assert_eq!(v.unwrap(), true);

            let v = h.insert("new.subset.dest", Value::Integer(1337));
            assert!(v.is_ok());
            assert_eq!(v.unwrap(), true);

            assert!(if let Ok(Some(Value::Table(_))) = h.read("new") { true } else { false });
            assert!(if let Ok(Some(Value::Table(_))) = h.read("new.subset") { true } else { false });
            assert!(if let Ok(Some(Value::Integer(_))) = h.read("new.subset.dest") { true } else { false });
        }
    }

    #[test]
    fn test_header_delete() {
        let _ = env_logger::init();
        let v = create_header();
        let mut h = match v {
            Value::Table(t) => EntryHeader::from_table(t),
            _ => panic!("create_header() doesn't return a table!"),
        };

        assert!(if let Ok(Some(Value::Table(_)))   = h.read("a") { true } else { false });
        assert!(if let Ok(Some(Value::Array(_)))   = h.read("a.array") { true } else { false });
        assert!(if let Ok(Some(Value::Integer(_))) = h.read("a.array.1") { true } else { false });
        assert!(if let Ok(Some(Value::Integer(_))) = h.read("a.array.9") { true } else { false });

        assert!(if let Ok(Some(Value::Integer(1))) = h.delete("a.array.1") { true } else { false });
        assert!(if let Ok(Some(Value::Integer(9))) = h.delete("a.array.8") { true } else { false });
        assert!(if let Ok(Some(Value::Array(_)))   = h.delete("a.array") { true } else { false });
        assert!(if let Ok(Some(Value::Table(_)))   = h.delete("a") { true } else { false });

    }

}