use std::io;
use std::io::prelude::*;
use std::fs::File;

extern crate telegram_bot;
use telegram_bot::{Api, Message, MessageType, ParseMode};
extern crate time;
extern crate regex;
use self::regex::Regex;
use super::rustc_serialize::json;

use feature::FeatureResult;
use feature::Feature;

#[derive(RustcDecodable)]
pub struct Anime {
    name: String,
    score: f64,
}

pub struct TopAnime {
    animes: Vec<Anime>,
    last_update: f64,
}

impl Feature for TopAnime {
    fn name(&self) -> &'static str {
        "TopAnime"
    }
    fn init(&mut self) {}
    fn handle(&mut self, a: Api, m: Message) -> Result<FeatureResult, String> {
        if let MessageType::Text(s) = m.msg {
            let re = Regex::new(r"(?i)luggas top ([0-9]{1,3}) anime").unwrap();
            let cap = re.captures(&s);
            let s_num = match cap {
                Some(s) => s.at(1),
                None => return Ok(FeatureResult::Skip),
            };
            let s_num = match s_num {
                Some(s) => s,
                None => return Ok(FeatureResult::Skip),
            };

            // parse to int
            let num = match s_num.parse::<i32>() {
                Ok(n) => n,
                Err(e) => {
                    println!("{}", e);
                    return Ok(FeatureResult::Skip);
                }
            };
            let start = time::precise_time_ns();
            if let Err(e) = self.update_animes() {
                println!("{}", e);
                return Ok(FeatureResult::Skip);
            }
            println!("(benchm) updating animes: {}ms",
                     (time::precise_time_ns() - start) / 1000000);

            let mut msg = String::new();
            for i in 0..num {
                let i = i as usize;
                if self.animes.len() <= i {
                    break;
                }
                let mut pref = "";
                if i % 2 == 0 {
                    pref = "*";
                }
                msg.push_str(&format!("{}{}. {} ({}%){}\n",
                                      pref,
                                      i + 1,
                                      self.animes[i].name,
                                      self.animes[i].score,
                                      pref));
            }
            println!("(benchm) anime before send: {}ms",
                     (time::precise_time_ns() - start) / 1000000);
            if let Err(e) = a.send_message(m.chat.id(),
                                           msg,
                                           Some(ParseMode::Markdown),
                                           None,
                                           Some(m.message_id),
                                           None) {
                println!("{}", e);
            }
            println!("(benchm) anime: {}ms",
                     (time::precise_time_ns() - start) / 1000000);
            return Ok(FeatureResult::Handled);
        }
        Ok(FeatureResult::Skip)
    }
}

impl TopAnime {
    pub fn new() -> TopAnime {
        let mut t = TopAnime {
            animes: vec![],
            last_update: 0f64,
        };
        t.init();
        t
    }
    fn update_animes(&mut self) -> Result<(), io::Error> {
        let now = time::precise_time_s();
        if now - self.last_update < 3600.0f64 {
            return Ok(());
        }
        let mut f = try!(File::open("data/animescore.json"));
        let mut buf = String::new();
        try!(f.read_to_string(&mut buf));
        let v: Vec<Anime> = match json::decode(&buf) {
            Ok(v) => v,
            Err(e) => return Err(io::Error::new(io::ErrorKind::InvalidData, format!("{}", e))),
        };
        self.animes = v;
        self.last_update = now;
        Ok(())
    }
}