use regex::Regex;
use std::cmp::max;
use std::error::Error;
use std::fmt;
use std::fs::File as FsFile;
use std::io;
use std::io::Read;
use std::ops::Deref;
use std::path::Path;

use command_runner::CommandRunner;
use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};
use resources::Resource;

pub struct WordpressTranslation<'a, C, D, R> where C: Deref<Target=str> + fmt::Display, D: AsRef<str> + fmt::Display, R: 'a + CommandRunner {
  path: D,
  language: C,
  command_runner: &'a R
}

impl<'a, C, R> WordpressTranslation<'a, C, String, R> where C: Deref<Target=str> + fmt::Display, R: CommandRunner {
  pub fn new<D: AsRef<str> + fmt::Display>(path: D, language: C, command_runner: &'a R) -> Self {
    WordpressTranslation {
      path: Path::new(path.as_ref()).join("wp-content/languages").to_string_lossy().to_string(),
      language: language,
      command_runner: command_runner
    }
  }
}

/*
https://translate.wordpress.org/projects/wp/4.7.x/de/default/export-translations?format=po > /home/de_adrianheine_blog/WordPress/wp-content/languages/de_DE.po
https://translate.wordpress.org/projects/wp/4.7.x/de/default/export-translations?format=mo > /home/de_adrianheine_blog/WordPress/wp-content/languages/de_DE.mo

https://translate.wordpress.org/projects/wp/4.7.x/cc/de/default/export-translations?format=po > /home/de_adrianheine_blog/WordPress/wp-content/languages/continents-cities-de_DE.po
https://translate.wordpress.org/projects/wp/4.7.x/cc/de/default/export-translations?format=mo > /home/de_adrianheine_blog/WordPress/wp-content/languages/continents-cities-de_DE.mo

https://translate.wordpress.org/projects/wp/4.7.x/admin/de/default/export-translations?format=po > /home/de_adrianheine_blog/WordPress/wp-content/languages/admin-de_DE.po
https://translate.wordpress.org/projects/wp/4.7.x/admin/de/default/export-translations?format=mo > /home/de_adrianheine_blog/WordPress/wp-content/languages/admin-de_DE.mo

https://translate.wordpress.org/projects/wp/4.7.x/admin/network/de/default/export-translations?format=po > /home/de_adrianheine_blog/WordPress/wp-content/languages/admin-network-de_DE.po
https://translate.wordpress.org/projects/wp/4.7.x/admin/network/de/default/export-translations?format=mo > /home/de_adrianheine_blog/WordPress/wp-content/languages/admin-network-de_DE.mo
*/
impl<'a, C, D, R> WordpressTranslation<'a, C, D, R> where C: Deref<Target=str> + fmt::Display, D: AsRef<str> + fmt::Display, R: CommandRunner {
  fn get_pairs(&self) -> Vec<(String, String)> {
    let mut res = vec![];
    for &(in_slug, out_slug) in [("", ""), ("cc/", "continents-cities-"), ("admin/", "admin-"), ("admin/network/", "admin-network-")].into_iter() {
      for format in ["po", "mo"].into_iter() {
        res.push((format!("https://translate.wordpress.org/projects/wp/4.7.x/{}{}/default/export-translations?format={}", in_slug, self.language, format), format!("{}/{}de_DE.{}", self.path, out_slug, format)))
      }
    }
    res
  }
}

impl<'a, C, D, R> Symbol for WordpressTranslation<'a, C, D, R> where C: Deref<Target=str> + fmt::Display, D: AsRef<str> + fmt::Display, R: CommandRunner {
  fn target_reached(&self) -> Result<bool, Box<Error>> {
    let mut newest = String::new();
    let match_date = Regex::new("(?m)^\"PO-Revision-Date: (.+)\\+0000\\\\n\"$").unwrap();
    for (_, target) in self.get_pairs() {
      let file = FsFile::open(target.clone());
      // Check if file exists
      if let Err(e) = file {
        return if e.kind() == io::ErrorKind::NotFound {
          Ok(false)
        } else {
          Err(Box::new(e))
        };
      }
      if target.ends_with(".po") {
        let mut content = String::new();
        try!(file.unwrap().read_to_string(&mut content));
        let file_date = &match_date.captures(&content).unwrap()[1];
        newest = max(newest, file_date.to_string());
      }
    }
    let upstream = try!(self.command_runner.get_output("curl", &["https://api.wordpress.org/core/version-check/1.7/?version=4.7.5&locale=de_DE"]));
    Ok(try!(String::from_utf8(upstream)).contains(&format!(r###"language":"de_DE","version":"4.7.5","updated":"{}"###, newest)))
  }

  fn execute(&self) -> Result<(), Box<Error>> {
    for (source, target) in self.get_pairs() {
      try!(self.command_runner.run_successfully("curl", &["--compressed", "-o", &target, &source]));
    }
    Ok(())
  }

  fn get_prerequisites(&self) -> Vec<Resource> {
    vec![ Resource::new("dir", self.path.as_ref()) ]
  }

  fn as_action<'b>(&'b self, runner: &'b SymbolRunner) -> Box<Action + 'b> {
    Box::new(SymbolAction::new(runner, self))
  }

  fn into_action<'b>(self: Box<Self>, runner: &'b SymbolRunner) -> Box<Action + 'b> where Self: 'b {
    Box::new(OwnedSymbolAction::new(runner, *self))
  }
}

impl<'a, C, D, R> fmt::Display for WordpressTranslation<'a, C, D, R> where C: Deref<Target=str> + fmt::Display, D: AsRef<str> + fmt::Display, R: CommandRunner {
  fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error>{
    write!(f, "WordpressTranslation {}", self.path)
  }
}