//
// 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
//

extern crate clap;
#[macro_use] extern crate log;
extern crate toml;
extern crate toml_query;
#[macro_use] extern crate is_match;
#[macro_use] extern crate version;

extern crate libimagrt;
extern crate libimagerror;
extern crate libimagtodo;

use std::process::{Command, Stdio};
use std::io::stdin;

use toml::Value;

use libimagrt::runtime::Runtime;
use libimagrt::setup::generate_runtime_setup;
use libimagtodo::task::TaskStore;
use libimagerror::trace::{MapErrTrace, trace_error, trace_error_exit};

mod ui;

use ui::build_ui;
fn main() {
    let rt = generate_runtime_setup("imag-todo",
                                    &version!()[..],
                                    "Interface with taskwarrior",
                                    build_ui);

    match rt.cli().subcommand_name() {
        Some("tw-hook") => tw_hook(&rt),
        Some("list") => list(&rt),
        None => {
            warn!("No command");
        },
        _ => unreachable!(),
    } // end match scmd
} // end main

fn tw_hook(rt: &Runtime) {
    let subcmd = rt.cli().subcommand_matches("tw-hook").unwrap();
    if subcmd.is_present("add") {
        let stdin = stdin();
        let stdin = stdin.lock(); // implements BufRead which is required for `FileLockEntry::import_task_from_reader()`

        match rt.store().import_task_from_reader(stdin) {
            Ok((_, line, uuid)) => println!("{}\nTask {} stored in imag", line, uuid),
            Err(e) => trace_error_exit(&e, 1),
        }
    } else if subcmd.is_present("delete") {
        // The used hook is "on-modify". This hook gives two json-objects
        // per usage und wants one (the second one) back.
        let stdin         = stdin();
        rt.store().delete_tasks_by_imports(stdin.lock()).map_err_trace().ok();
    } else {
        // Should not be possible, as one argument is required via
        // ArgGroup
        unreachable!();
    }
}

fn list(rt: &Runtime) {
    use toml_query::read::TomlValueReadExt;

    let subcmd  = rt.cli().subcommand_matches("list").unwrap();
    let verbose = subcmd.is_present("verbose");

    // Helper for toml_query::read::TomlValueReadExt::read() return value, which does only
    // return Result<T> instead of Result<Option<T>>, which is a real inconvenience.
    //
    let no_identifier = |e: &::toml_query::error::Error| -> bool {
        is_match!(e.kind(), &::toml_query::error::ErrorKind::IdentifierNotFoundInDocument(_))
    };

    let res = rt.store().all_tasks() // get all tasks
        .map(|iter| { // and if this succeeded
            // filter out the ones were we can read the uuid
            let uuids : Vec<_> = iter.filter_map(|storeid| {
                match rt.store().retrieve(storeid) {
                    Ok(fle) => {
                        match fle.get_header().read(&String::from("todo.uuid")) {
                            Ok(Some(&Value::String(ref u))) => Some(u.clone()),
                            Ok(Some(_)) => {
                                warn!("Header type error");
                                None
                            },
                            Ok(None) => {
                                warn!("Header missing field");
                                None
                            },
                            Err(e) => {
                                if !no_identifier(&e) {
                                    trace_error(&e);
                                }
                                None
                            }
                        }
                    },
                    Err(e) => {
                        trace_error(&e);
                        None
                    },
                }
            })
            .collect();

            // compose a `task` call with them, ...
            let outstring = if verbose { // ... if verbose
                let output = Command::new("task")
                    .stdin(Stdio::null())
                    .args(&uuids)
                    .spawn()
                    .unwrap_or_else(|e| {
                        trace_error(&e);
                        panic!("Failed to execute `task` on the commandline. I'm dying now.");
                    })
                    .wait_with_output()
                    .unwrap_or_else(|e| panic!("failed to unwrap output: {}", e));

                String::from_utf8(output.stdout)
                    .unwrap_or_else(|e| panic!("failed to execute: {}", e))
            } else { // ... else just join them
                uuids.join("\n")
            };

            // and then print that
            println!("{}", outstring);
        });

    res.map_err_trace().ok();
}