use iron;
use iron::error::{HttpResult};
use iron::headers::ContentType;
use iron::modifiers::{Header, Redirect};
use iron::status;
use iron::{Iron, IronError, Request, IronResult, Response, Chain, Listening, Plugin, Url};
use iron_sessionstorage::SessionStorage;
use iron_sessionstorage::backends::SignedCookieBackend;
use iron_sessionstorage::traits::*;
use iron_sessionstorage;
use params::{Params, Value};
use regex::Regex;
use render;
use router::Router;
use staticfile::Static;
use systemd::journal;
use systemd::unit;
use persistent::Read;

#[derive(Clone, Default, Debug)]
struct Context {
    base_url: String
}
impl iron::typemap::Key for Context {
    type Value = Context;
}

#[derive(Default, Debug, Clone)]
struct Login {
    user: String,
}

impl iron_sessionstorage::Value for Login {
    fn get_key() -> &'static str {
        "login"
    }
    fn into_raw(self) -> String {
        self.user
    }
    fn from_raw(v: String) -> Option<Self> {
        Some(Login{ user: v })
    }
}

fn overview(r: &mut Request) -> IronResult<Response> {
    let mut _value = try!(r.session().get::<Login>());

    let units = unit::get_units("*").unwrap();

    let sections = ["service", "timer", "socket", "target", "slice", "mount",
                    "path"];
    let units_by_section = sections.iter().map(|&s| {
        (s.to_owned(),
         units.iter().filter(|&u| &u.type_ == s).collect::<Vec<&unit::Unit>>())
    }).collect::<Vec<_>>();

    // let res = Ok(Response::with((status::Ok,
    //                              Header(ContentType::html()),
    //                              render_message(&format!("Hello, {} ({})",
    //                                                      name,
    //                                                      session_value.0),
    //                                             &units))));

    // info!("Updating session value. Current value: {}", session_value.0);
    // session_value.0.push('a');
    // try!(r.session().set(session_value));
    let renderer = make_renderer(r)?;
    Ok(Response::with((status::Ok,
                       Header(ContentType::html()),
                       renderer.system_status(&units_by_section))))
}

fn journal(r: &mut Request) -> IronResult<Response> {
    let unit = iexpect!(r.extensions
                        .get::<Router>()
                        .unwrap()
                        .find("unit"), status::BadRequest);
    let re = Regex::new(r"[-_\w\d]*").unwrap();
    if !re.is_match(unit) {
        return Ok(Response::with(
            (status::BadRequest,
             format!("Unit ({}) does not match {}",
                     unit, re))));
    }
    Ok(Response::with((status::Ok,
                       itry!(journal::get_log(unit, 100)))))
}

fn unit_status(r: &mut Request) -> IronResult<Response> {
    let unit_name = iexpect!(r.extensions
                             .get::<Router>()
                             .unwrap()
                             .find("unit"), status::BadRequest).to_string();
    let re = Regex::new(r"[-_\w\d]*").unwrap();
    if !re.is_match(&unit_name) {
        return Ok(Response::with(
            (status::BadRequest,
             format!("Unit ({}) does not match {}",
                     unit_name, re))));
    }
    let ref unit = itry!(unit::get_units(&unit_name))[0];
    let log = itry!(journal::get_log(&unit_name, 15));
    let renderer = make_renderer(r)?;
    Ok(Response::with((status::Ok,
                       Header(ContentType::html()),
                       renderer.unit_status(&unit, &log))))
}

fn get_logged_in_user(r: &mut Request) -> IronResult<Option<Login>> {
    let login = r.session().get::<Login>()?;
    // Session storage doesn't have a way to delete its cookie,
    // so we set the username to empty on logout.
    if let &Some(Login { ref user }) = &login {
        if user.is_empty() {
            return Ok(None)
        }
    }
    Ok(login)
}

fn login(r: &mut Request) -> IronResult<Response> {
    let renderer = make_renderer(r)?;
    Ok(Response::with((status::Ok,
                       Header(ContentType::html()),
                      renderer.login_page())))
}

fn login_submit(r: &mut Request) -> IronResult<Response> {
    let login = {
        let map = r.get_ref::<Params>().unwrap();
        let user = match map.get("username") {
            Some(&Value::String(ref v)) => v,
            _ => panic!("no username in params: {:?}", map)
        };
        let password = match map.get("password") {
            Some(&Value::String(ref v)) => v,
            _ => panic!("no password in params: {:?}", map)
        };
        Login { user: user.clone() }
    };

    info!("User logged in: {:?}", login);
    r.session().set(login)?;
    let url = Url::parse("http://localhost:8080/").unwrap();
    Ok(Response::with((status::Found,
                       Redirect(url))))
}

fn logout(r: &mut Request) -> IronResult<Response> {
    r.session().set::<Login>(Default::default());
    let url = Url::parse("http://localhost:8080/").unwrap();
    Ok(Response::with((status::Found,
                       Redirect(url))))
}

fn make_renderer(r: &mut Request) -> IronResult<render::Renderer> {
    let user = get_logged_in_user(r)?.map(|u| u.user);
    Ok(render::Renderer {
        user: user
    })
}

pub fn serve(port: u16) -> HttpResult<Listening> {
    // TODO: Use a real secret.
    let secret = b"secret2".to_vec();
    let router = router!(
        root: get "/" => overview,
        login: get "/login" => login,
        login_submit: post "/login" => login_submit,
        logout: get "/logout" => logout,
        details: get "/status/:unit" => unit_status,
        journal: get "/journal/:unit" => journal,
        css: get "/static/main.css" => Static::new(""),
    );
    let mut chain = Chain::new(router);
    let context = Context {
        base_url: String::from("http://localhost:8080/"),
    };
    chain.link_around(SessionStorage::new(SignedCookieBackend::new(secret)));
    chain.link(Read::<Context>::both(context));
    let bind_address = format!("{}:{}", "::", port);
    Iron::new(chain).http(bind_address.as_str())
}