Add processor for collecting links from content

and putting them into the header via the functionality offered by
`libimagentrylink`.

lib/entry/libimagentrymarkdown/Cargo.toml

@@ -19,6 +19,8 @@ hoedown = "5.0.0"
 url = "1.2"
 error-chain = "0.10"
 
-libimagstore = { version = "0.4.0", path = "../../../lib/core/libimagstore" }
+libimagstore     = { version = "0.4.0", path = "../../../lib/core/libimagstore" }
-libimagerror = { version = "0.4.0", path = "../../../lib/core/libimagerror" }
+libimagerror     = { version = "0.4.0", path = "../../../lib/core/libimagerror" }
+libimagentrylink = { version = "0.4.0", path = "../../../lib/entry/libimagentrylink/" }
+libimagutil      = { version = "0.4.0", path = "../../../lib/etc/libimagutil/" }
 

lib/entry/libimagentrymarkdown/src/error.rs

@@ -17,11 +17,25 @@
 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 //
 
+use url::Url;
+
+use libimagstore::storeid::StoreId;
+
 error_chain! {
     types {
         MarkdownError, MarkdownErrorKind, ResultExt, Result;
     }
 
+    links {
+        StoreError(::libimagstore::error::StoreError, ::libimagstore::error::StoreErrorKind);
+        LinkError(::libimagentrylink::error::LinkError, ::libimagentrylink::error::LinkErrorKind);
+        RefError(::libimagentryref::error::RefError, ::libimagentryref::error::RefErrorKind);
+    }
+
+    foreign_links {
+        UrlParserError(::url::ParseError);
+    }
+
     errors {
         MarkdownRenderError {
             description("Markdown render error")
@@ -33,6 +47,20 @@ error_chain! {
             display("Link parsing error")
         }
 
+        StoreGetError(id: StoreId) {
+            description("Failed to get entry from store")
+            display("Failed to get entry '{}' from store", id)
+        }
+
+        UndecidableLinkType(s: String) {
+            description("Failed to qualify link type")
+            display("The Type of the link '{}' cannot be recognized", s)
+        }
+
+        UrlProcessingError(u: Url) {
+            description("Failed to properly processing URL")
+            display("The URL '{:?}' could not be processed properly", u)
+        }
     }
 }
 

lib/entry/libimagentrymarkdown/src/lib.rs

@@ -39,9 +39,19 @@ extern crate hoedown;
 extern crate url;
 extern crate libimagstore;
 extern crate libimagerror;
+extern crate libimagentrylink;
+extern crate libimagutil;
 #[macro_use] extern crate error_chain;
 
+#[cfg(test)]
+extern crate env_logger;
+
+#[allow(unused)]
+#[macro_use]
+extern crate log;
+
 pub mod error;
 pub mod html;
 pub mod link;
+pub mod processor;
 

lib/entry/libimagentrymarkdown/src/link.rs

@@ -48,6 +48,7 @@ pub struct UrlLink {
     pub link: Url,
 }
 
+#[derive(Debug)]
 struct LinkExtractor {
     links: Vec<Link>,
 }
@@ -76,6 +77,10 @@ impl Render for LinkExtractor {
         let link  = link.and_then(|l| l.to_str().ok()).map(String::from);
         let content = content.and_then(|l| l.to_str().ok()).map(String::from);
 
+        trace!("Processing...");
+        trace!("link    = {:?}", link);
+        trace!("content = {:?}", content);
+
         match (link, content) {
             (Some(link), Some(content)) => {
                 self.links.push(Link { link: link, title: content });
@@ -94,6 +99,7 @@ impl Render for LinkExtractor {
 pub fn extract_links(buf: &str) -> Vec<Link> {
     let mut le = LinkExtractor::new();
     le.render(&Markdown::new(buf));
+    trace!("Extracted: {:?}", le);
     le.links()
 }
 

lib/entry/libimagentrymarkdown/src/processor.rs

@@ -0,0 +1,211 @@
+//
+// imag - the personal information management suite for the commandline
+// Copyright (C) 2015, 2016 Matthias Beyer <mail@beyermatthias.de> and contributors
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; version
+// 2.1 of the License.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+//
+
+use error::MarkdownError as ME;
+use error::MarkdownErrorKind as MEK;
+use error::*;
+use link::extract_links;
+
+use libimagentrylink::external::ExternalLinker;
+use libimagentrylink::internal::InternalLinker;
+use libimagentryref::refstore::RefStore;
+use libimagentryref::flags::RefFlags;
+use libimagstore::store::Entry;
+use libimagstore::store::Store;
+use libimagstore::storeid::StoreId;
+use libimagutil::iter::FoldResult;
+
+use std::path::PathBuf;
+
+use url::Url;
+
+/// A link Processor which collects the links from a Markdown and passes them on to
+/// `libimagentrylink` functionality
+///
+/// The processor can be configured to
+///
+///  * Process internal links (from store entry to store entry)
+///  * Process internal links with automatically creating targets
+///     If an internal link is encountered, the corrosponding target must be present in the store.
+///     If it is not, it will either be created or the processing fails
+///  * Process external links (from store entry to URL)
+///  * Process refs (from store entry to files on the filesystem and outside of the store)
+///  (default: false)
+///
+///  # Note
+///
+///  There's no LinkProcessor::new() function, please use `LinkProcessor::default()`.
+///
+pub struct LinkProcessor {
+    process_internal_links: bool,
+    create_internal_targets: bool,
+    process_external_links: bool,
+    process_refs: bool
+}
+
+impl LinkProcessor {
+
+    /// Switch internal link processing on/off
+    ///
+    /// Internal links are links which are simply `dirctory/file`, but not `/directory/file`, as
+    /// beginning an id with `/` is discouraged in imag.
+    pub fn process_internal_links(mut self, b: bool) -> Self {
+        self.process_internal_links = b;
+        self
+    }
+
+    /// Switch internal link target creation on/off
+    ///
+    /// If a link points to a non-existing imag entry, a `false` here will cause the processor to
+    /// return an error from `process()`. A `true` setting will create the entry and then fetch it
+    /// to link it to the processed entry.
+    pub fn create_internal_targets(mut self, b: bool) -> Self {
+        self.create_internal_targets = b;
+        self
+    }
+
+    /// Switch external link processing on/off
+    ///
+    /// An external link must start with `https://` or `http://`.
+    pub fn process_external_links(mut self, b: bool) -> Self {
+        self.process_external_links = b;
+        self
+    }
+
+    /// Switch ref processing on/off
+    ///
+    /// A Ref is to be expected beeing a link with `file::///` at the beginning.
+    pub fn process_refs(mut self, b: bool) -> Self {
+        self.process_refs = b;
+        self
+    }
+
+    /// Process an Entry for its links
+    ///
+    /// # Warning
+    ///
+    /// When `LinkProcessor::create_internal_targets()` was called to set the setting to true, this
+    /// function returns all errors returned by the Store.
+    ///
+    pub fn process<'a>(&self, entry: &mut Entry, store: &'a Store) -> Result<()> {
+        let text = entry.to_str();
+        trace!("Processing: {:?}", entry.get_location());
+        extract_links(&text)
+            .into_iter()
+            .fold_result::<_, MarkdownError, _>(|link| {
+                trace!("Processing {:?}", link);
+                match LinkQualification::qualify(&link.link) {
+                    LinkQualification::InternalLink => {
+                        if !self.process_internal_links {
+                            return Ok(());
+                        }
+
+                        let spath      = Some(store.path().clone());
+                        let id         = StoreId::new(spath, PathBuf::from(&link.link))?;
+                        let mut target = if self.create_internal_targets {
+                            try!(store.retrieve(id))
+                        } else {
+                            store.get(id.clone())?
+                                .ok_or(ME::from_kind(MEK::StoreGetError(id)))?
+                        };
+
+                        entry.add_internal_link(&mut target).map_err(From::from)
+                    },
+                    LinkQualification::ExternalLink(url) => {
+                        if !self.process_external_links {
+                            return Ok(());
+                        }
+
+                        entry.add_external_link(store, url).map_err(From::from)
+                    },
+                    LinkQualification::RefLink(url) => {
+                        if !self.process_refs {
+                            return Ok(());
+                        }
+
+                        let flags = RefFlags::default()
+                            .with_content_hashing(false)
+                            .with_permission_tracking(false);
+                        trace!("URL            = {:?}", url);
+                        trace!("URL.path()     = {:?}", url.path());
+                        trace!("URL.host_str() = {:?}", url.host_str());
+                        let path = url.host_str().unwrap_or_else(|| url.path());
+                        let path = PathBuf::from(path);
+                        let mut target = try!(RefStore::create(store, path, flags));
+
+                        entry.add_internal_link(&mut target).map_err(From::from)
+                    },
+                    LinkQualification::Undecidable(e) => {
+                        // error
+                        Err(e).chain_err(|| MEK::UndecidableLinkType(link.link.clone()))
+                    },
+                }
+            })
+    }
+
+}
+
+/// Enum to tell what kind of link a string of text is
+enum LinkQualification {
+    InternalLink,
+    ExternalLink(Url),
+    RefLink(Url),
+    Undecidable(ME),
+}
+
+impl LinkQualification {
+    fn qualify(text: &str) -> LinkQualification {
+        match Url::parse(text) {
+            Ok(url) => {
+                if url.scheme() == "file" {
+                    return LinkQualification::RefLink(url)
+                }
+
+                // else we assume the following, as other stuff gets thrown out by
+                // url::Url::parse() as Err(_)
+                //
+                // if url.scheme() == "https" || url.scheme() == "http" {
+                    return LinkQualification::ExternalLink(url);
+                // }
+            },
+
+            Err(e) => {
+                match e {
+                    ::url::ParseError::RelativeUrlWithoutBase => {
+                        LinkQualification::InternalLink
+                    },
+
+                    _ => LinkQualification::Undecidable(ME::from(e)),
+                }
+            }
+        }
+    }
+}
+
+impl Default for LinkProcessor {
+    fn default() -> Self {
+        LinkProcessor {
+            process_internal_links: true,
+            create_internal_targets: false,
+            process_external_links: true,
+            process_refs: false
+        }
+    }
+}
+