mod aggregator;
mod types;
mod plugin;
mod util;
mod log;

use aggregator::MemberEvent;
use log::Logger;
use twilight_gateway::{Intents, Shard, ShardId};
use twilight_http::Client;
pub use types::SystemThreadCommand;
use crate::SystemUiEvent;
use std::{collections::HashMap, num::NonZeroU64, sync::Arc};
use tokio::sync::Mutex;
use plugin::get_plugins;

use std::sync::mpsc::Sender as ThreadSender;
use types::{Member, Response, System};
use std::iter::once;

pub struct Manager;
impl Manager {
    pub async fn start(system_name: String, system_config: crate::config::System, ui_sender : ThreadSender<(String, SystemUiEvent)>) {
        let gateway_intents = Intents::GUILD_MEMBERS | Intents::GUILD_PRESENCES | Intents::GUILD_MESSAGES | Intents::MESSAGE_CONTENT;
        let system = System {
            followed_user: NonZeroU64::try_from(system_config.reference_user_id.parse::<u64>().unwrap()).unwrap().into(),
            command_prefix: "!".to_string(),
            members: system_config.members.iter().map(|member| Member {
                discord_token: member.discord_token.clone(),
                user_id: Arc::new(Mutex::new(None)),
                message_pattern: member.message_pattern.clone(),
                shard: Arc::new(Mutex::new(Shard::new(
                    ShardId::ONE,
                    member.discord_token.clone(),
                    gateway_intents.clone(),
                ))),
                client: Arc::new(Mutex::new(Client::new(member.discord_token.clone())))
            }).collect(),
            message_cache: Arc::new(Mutex::new(HashMap::new())),
        };

        let mut message_receiver = aggregator::MessageAggregator::start(&system);
        let logger = Logger::new(system_name.clone(), system_config.clone(), ui_sender.clone());

        let (all_plugins, by_command) = get_plugins();

        'member_event: loop {
            match message_receiver.recv().await {
                None => (),
                Some(MemberEvent::GatewayConnect(member_token, user_id)) => {
                    for member in &system.members {
                        if member.discord_token == member_token {
                            {*member.user_id.lock().await = Some(user_id)};
                        }
                    }
                    logger.log_connect(member_token).await;
                },
                Some(MemberEvent::GatewayError(member_token)) => {
                    logger.log_err(Some(member_token), "Non-fatal gateway error".to_string()).await;
                },
                Some(MemberEvent::GatewayDisconnect(member_token)) => {
                    logger.log_disconnect(member_token).await;
                },
                Some(MemberEvent::Message(message, seen_by)) => {
                    if let Some(command_string) = message.content.strip_prefix(&system.command_prefix) {
                        let mut words = command_string.split_whitespace();
                        if let Some(first_word) = words.next() {
                            if let Some((command, plugin)) = by_command
                                .get(first_word)
                                .map(|command| Some(command))
                                .unwrap_or_else(|| by_command.get(first_word.get(0..1).unwrap())) {
                                    logger.log_line(None, format!("Handling command: {command:?}")).await;
                                    let args : Vec<_> = match command {
                                        plugin::PluginCommand::Word(_) => words.collect(),
                                        plugin::PluginCommand::Char(_) => once(first_word).chain(words).collect(),
                                    };

                                    plugin.handle_command(&logger, &system, &message, *command, args).await;
                                    continue 'member_event;
                                } else {
                                    logger.log_line(None, format!("Unknown command: {first_word}")).await;
                                }
                        }
                    }

                    // Handle as message
                    let mut message_response = Response::Noop { delete_source: false };
                    for plugin in &all_plugins {
                        plugin.handle_message(&logger, &system, &message, &mut message_response).await;
                    }

                    match message_response.clone() {
                        Response::Noop { delete_source } => {
                            if delete_source {
                                let client = system.members.iter().find(|m| m.discord_token == seen_by).map(|m| m.client.clone())
                                    .expect("No such client");

                                let _ = client.lock().await.delete_message(message.channel_id, message.id)
                                    .await;
                            }
                        },
                        Response::Proxy { member, content } => {
                            if let Ok(new_message) = util::duplicate_message(&member.client, &message, content.as_str()).await {
                                if let Err(err) = {member.client.lock().await.delete_message(message.channel_id, message.id).await.map(|_| ()).map_err(|err| err.to_string()).clone() } {
                                    logger.log_err(Some(member.discord_token), format!("Could not proxy message: {err}")).await;
                                    {let _ = member.client.lock().await.delete_message(new_message.channel_id, new_message.id).await;}
                                } else {
                                    system.cache_most_recent_message(new_message.channel_id, new_message.clone(), member.clone()).await;
                                }

                                for plugin in &all_plugins {
                                    plugin.post_response(&logger, &system, &new_message, message.channel_id, &message_response).await;
                                }
                            }
                        },
                    }
                },
            }
        }
    }
}