use data;

use handlebars_iron::{HandlebarsEngine, MemorySource, Template};
use iron::headers::ContentType;
use iron::modifiers::Header;
use iron::{self, Iron, Plugin, Chain, Request, Response, IronResult, status};
use rusqlite::Connection;
use std::collections::BTreeMap;
use persistent::Write;
use handlebars_iron::handlebars::to_json;
use serde_json;
use params;
use error::LinoError;
use chrono;
use logger::Logger;
use iron_sessionstorage::{self, SessionStorage, SessionRequestExt};
use iron_sessionstorage::backends::SignedCookieBackend;
use rand::{OsRng, Rng};

#[derive(Debug)]
pub struct State {
    pub connection: Connection,
}
impl iron::typemap::Key for State {
    type Value = State;
}

#[derive(Debug, Clone, Serialize)]
struct UserId(u64);
impl iron_sessionstorage::Value for UserId {
    fn get_key() -> &'static str {
        "user_id"
    }
    fn into_raw(self) -> String {
        format!("{}", self.0)
    }
    fn from_raw(value: String) -> Option<Self> {
        value.parse().ok().map(|i| UserId(i))
    }
}

fn user_id(r: &mut Request) -> IronResult<UserId> {
    if let Some(user_id) = r.session().get::<UserId>()? {
        return Ok(user_id);
    }

    let mut rng = OsRng::new().map_err(|e| {
        // This is ugly, but I don't know how to annotate the expression.
        let e: LinoError = From::from(e);
        e
    })?;
    let user_id = UserId(rng.next_u64());
    r.session().set(user_id.clone())?;
    Ok(user_id)
}

fn make_result(r: &mut Request) -> IronResult<serde_json::Map<String, serde_json::value::Value>> {
    let mut result = serde_json::Map::new();
    result.insert("user_id".to_string(), to_json(&user_id(r)?));
    Ok(result)
}

fn get_param(r: &mut Request, param: &str) -> IronResult<String> {
    let map = itry!(r.get_ref::<params::Params>());
    match map.get(param) {
        Some(&params::Value::String(ref v)) => Ok(v.to_string()),
        _ => Err(From::from(LinoError::NotFound(param.to_string()))),
    }
}

fn make_renderer() -> HandlebarsEngine {
    let mut e = HandlebarsEngine::new();

    let mut templates = BTreeMap::new();
    templates.insert(
        "base".to_string(),
        include_str!("data/templates/base.hbs").to_string(),
    );
    templates.insert(
        "quotes".to_string(),
        include_str!("data/templates/quotes.hbs").to_string(),
    );
    templates.insert(
        "add".to_string(),
        include_str!("data/templates/add.hbs").to_string(),
    );
    templates.insert(
        "add_post".to_string(),
        include_str!("data/templates/add_post.hbs").to_string(),
    );
    templates.insert(
        "approve".to_string(),
        include_str!("data/templates/approve.hbs").to_string(),
    );
    templates.insert(
        "vote".to_string(),
        include_str!("data/templates/vote.hbs").to_string(),
    );

    e.add(Box::new(MemorySource(templates)));
    if let Err(r) = e.reload() {
        panic!("Error loading templates: {}", r)
    }
    e
}

fn quotes(r: &mut Request) -> IronResult<Response> {
    let mut result = make_result(r)?;
    let quote_id = get_param(r, "id").ok().and_then(
        |id| id.parse::<i64>().ok(),
    );
    let ordering = get_param(r, "order").unwrap_or("".to_string());

    let quotes = {
        let mu = r.get::<Write<State>>().unwrap();
        let state = mu.lock().unwrap();
        match quote_id {
            Some(id) => vec![data::get_quote(&state.connection, id)?],
            None => data::get_quotes(&state.connection, &ordering)?,
        }
    };
    let quotes = quotes.into_iter().collect::<Vec<_>>();
    result.insert("quotes".to_string(), to_json(&quotes));
    Ok(Response::with((
        status::Ok,
        Header(ContentType::html()),
        Template::new("quotes", result),
    )))
}

fn add_get(r: &mut Request) -> IronResult<Response> {
    let date = chrono::offset::Local::now().format("%Y-%m-%d").to_string();
    let mut result = make_result(r)?;
    result.insert("date".to_string(), to_json(&date));
    Ok(Response::with((
        status::Ok,
        Header(ContentType::html()),
        Template::new("add", result),
    )))
}

fn add_post(r: &mut Request) -> IronResult<Response> {
    let result = make_result(r)?;
    let nick = get_param(r, "nick")?;
    let date = get_param(r, "date")?;
    let quote = get_param(r, "quote")?;

    macro_rules! check {
      ($i:ident) => (
        if $i.is_empty() {
          return Err(From::from(LinoError::BadRequest(
              format!("missing parameter: {}", stringify!($i)))));
        }
      )
    }
    check!(nick);
    check!(date);
    check!(quote);

    {
        let mu = r.get::<Write<State>>().unwrap();
        let state = mu.lock().unwrap();
        data::new_quote(&state.connection, &date, &nick, &quote)?;
    }

    Ok(Response::with((
        status::Ok,
        Header(ContentType::html()),
        Template::new("add_post", result)
    )))
}

fn approve(r: &mut Request) -> IronResult<Response> {
    let mut result = make_result(r)?;
    let quote_id = get_param(r, "id").ok().and_then(
        |id| id.parse::<i64>().ok(),
    );
    let action = get_param(r, "action").unwrap_or("".to_string());

    let quotes = {
        let mu = r.get::<Write<State>>().unwrap();
        let state = mu.lock().unwrap();
        if let Some(quote_id) = quote_id {
            info!("Approval for quote({}): {}", quote_id, action);
            if action == "approve" {
                data::approve_quote(&state.connection, quote_id)?;
            } else if action == "reject" {
                data::delete_quote(&state.connection, quote_id)?;
            } else {
                return Err(From::from(
                    LinoError::BadRequest(format!("invalid action: {}", action)),
                ));
            }
        }
        data::get_pending_quotes(&state.connection)?
    };
    result.insert("quotes".to_string(), to_json(&quotes));
    Ok(Response::with((
        status::Ok,
        Header(ContentType::html()),
        Template::new("approve", result),
    )))
}

pub fn vote(r: &mut Request) -> IronResult<Response> {
    let quote_id = get_param(r, "id").and_then(|id| {
        id.parse::<i64>().map_err(|e| {
            From::from(LinoError::BadRequest(format!("id: {}", e)))
        })
    })?;
    let vote = get_param(r, "vote").and_then(|id| {
        id.parse::<i32>().map_err(|e| {
            From::from(LinoError::BadRequest(format!("vote: {}", e)))
        })
    })?;
    if vote < 1 || vote > 5 {
        return Err(From::from(LinoError::BadRequest("bad vote".to_string())));
    }

    let quote = {
        let mu = r.get::<Write<State>>().unwrap();
        let state = mu.lock().unwrap();
        data::new_vote(&state.connection, quote_id, vote)?;
        data::get_quote(&state.connection, quote_id)?
    };

    let mut result = make_result(r)?;
    result.insert("quote".to_string(), to_json(&quote));

    Ok(Response::with((
        status::Ok,
        Header(ContentType::html()),
        Template::new("vote", result),
    )))
}

pub fn serve(state: State, port: u16) {
    let router =
        router!(
        index: get "/" => quotes,
        add_get: get "/add.jsp" => add_get,
        add_post: post "/add.jsp" => add_post,
        quotes_jsp: get "/quotes.jsp" => quotes,
        view_quote: get "/view_quote" => quotes,
        approve: get "/approve.jsp" => approve,
        vote: get "/vote" => vote,
    );

    let mut chain = Chain::new(router);
    let (logger_before, logger_after) = Logger::new(None);
    chain.link_before(logger_before);
    let key = data::get_key(&state.connection, "session").expect("session key");
    chain.link_around(SessionStorage::new(SignedCookieBackend::new(key)));
    chain.link_after(make_renderer());
    chain.link(Write::<State>::both(state));
    chain.link_after(logger_after);

    let bind_address = format!("{}:{}", "::", port);
    let _server = Iron::new(chain).http(bind_address.as_str());
    info!("Serving on {}", bind_address);
}