extern crate toml;
extern crate crossbeam;
extern crate discord;
extern crate rand;
extern crate pvn;
extern crate echobox;

use std::collections::BTreeMap;
use toml::Table;

mod modules;
use modules::Module;
use modules::loader::{ModuleLoader, ModuleLoaderError};

mod event;
use event::Envelope;

use std::sync::Arc;
use std::sync::mpsc;
use std::sync::mpsc::Sender;

mod helpers;

#[macro_use]
extern crate log;

pub struct Tenquestionmarks {
    modules: BTreeMap<String, Box<Module>>
}

impl Tenquestionmarks {
    pub fn with_modules (modules: BTreeMap<String, Box<Module>>) -> Tenquestionmarks {
        let tqm = Tenquestionmarks {
            modules: modules
        };

        for (_, module) in &tqm.modules {
            module.register(&tqm);
        }

        tqm
    }

    pub fn from_configuration (configuration: Table) -> Result<Tenquestionmarks, ModuleLoaderError> {
        let loader = ModuleLoader::new();
        let modules = loader.load_from_configuration(configuration)?;
        Result::Ok(Tenquestionmarks::with_modules(modules))
    }

    pub fn run (&self) {
        crossbeam::scope(|scope| {
            // Our event channel.
            // Modules push events to tenquestionmarks using this channel.
            let (ref sender, ref receiver) = mpsc::channel();

            // Module threads.
            // Each Module will produce events which tenquestionmarks will push
            // into all other Modules.
            // tenquestionmarks propagates all events to each Module through these
            // channels.
            let senders: BTreeMap<&str, Sender<Arc<Envelope>>> = self.modules.iter().map(|(key, module)| {
                let module_sender = sender.clone();
                let (sender, receiver) = mpsc::channel();
                info!("Spawning thread for \"{}\"", key);
                scope.spawn(move || {
                    module.run(module_sender, receiver);
                    info!("Thread for \"{}\" is exiting", key);
                });
                (&key[..], sender)
            }).collect();

            // tenquestionmarks main event loop.
            // tenquestionmarks receives events produced by Modules and pushes them
            // into all other Modules
            loop {
                match receiver.recv() {
                    Ok(envelope) => {
                        let arc_envelope = Arc::new(envelope);
                        for (key, sender) in &senders {
                            match sender.send(arc_envelope.clone()) {
                                Err(err) => debug!("Failed to dispatch event to module \"{}\": {:?}", key, err),
                                Ok(_) => {}
                            }
                        }
                    },
                    Err(err) => { error!("Failed to receive event in main event loop: {:?}", err); }
                }
            }
        });
    }
}

pub struct Message {
    content: String,
    author: User,
    channel: Option<Channel>
}

impl Message {
    fn reply (&self, message: &str) {
        match self.channel {
            Some(ref channel) => channel.send(message),
            None => self.author.send(message)
        }
    }
}

pub struct Channel {
    name: String,
    description: String,
    topic: String,
    sender: Box<MessageSender>
}

impl Channel {
    pub fn send (&self, message: &str) {
        self.sender.send_message(message);
    }
}

pub struct User {
    name: String,
    sender: Box<MessageSender>
}

impl User {
    pub fn send (&self, message: &str) {
        self.sender.send_message(message);
    }
}

pub trait MessageSender : Sync + Send {
    fn send_message (&self, _: &str) {}
}