use modules::EventLoop;
use toml::value::Table;

use std::sync::Arc;
use std::sync::mpsc::Receiver;
use transformable_channels::mpsc::ExtSender;

use regex;
use regex::Regex;

use event::{Event, Envelope};
use rand;

pub struct RandomModule {
    pattern: Regex,
    responses: Vec<String>
}

impl RandomModule {
    pub fn new (_: &Table, configuration: &Table) -> Box<EventLoop> {
        let pattern = configuration.get("pattern")
                                   .and_then(|value| value.as_str())
                                   .map(String::from)
                                   .or_else(|| configuration.get("prefix")
                                                            .and_then(|value| value.as_str())
                                                            .map(|value| format!("^{}", regex::escape(value))))
                                   .and_then(|value| Regex::new(&value).ok())
                                   .expect("Invalid value for pattern");

        let responses = configuration.get("responses")
                                     .and_then(|value| value.as_array())
                                     .map(|value| value.to_vec())
                                     .unwrap_or(vec![])
                                     .into_iter()
                                     .map(|value| { String::from(value.as_str().unwrap()) })
                                     .collect();

        Box::new(RandomModule {
            pattern: pattern,
            responses: responses
        })
    }
}

impl EventLoop for RandomModule {
    fn run(&self, _: Box<ExtSender<Event>>, receiver: Receiver<Arc<Envelope>>) {
        let mut rng = rand::thread_rng();

        loop {
            match receiver.recv() {
                Ok(envelope) => {
                    if let Event::Message { ref message } = envelope.event {
                        debug!("Received message from module {:?}... {:?}", envelope.from, message.content);
                        if let Some(captures) = self.pattern.captures(&message.content) {
                            let mut response = String::new();
                            captures.expand(&rand::sample(&mut rng, &self.responses, 1)[0], &mut response);
                            message.reply(&response);
                        }
                    }
                }
                Err(error) => { error!("Error {:?}", error) }
            }
        }
    }
}