use crate::{config::Host, wol};

use std::{collections::HashMap, str::FromStr, time::Duration};

use tracing::{error, info};

use async_trait::async_trait;
use matrix_sdk::{
    self,
    identifiers::RoomId,
    events::{
        room::{
            member::MemberEventContent,
            message::{MessageEvent, MessageEventContent, TextMessageEventContent, NoticeMessageEventContent},
        },
        stripped::StrippedStateEvent,
    },
    Client, EventEmitter, SyncRoom,
};

use lazy_static::lazy_static;
use regex::Regex;

pub(crate) struct WakeOnLanBot {
    pub(crate) client: Client,
    pub(crate) hosts: HashMap<String, Host>,
}

impl WakeOnLanBot {
    pub fn new(client: Client, hosts: HashMap<String, Host>) -> Self {
        Self { client, hosts }
    }
}

#[async_trait]
impl EventEmitter for WakeOnLanBot {
    async fn on_stripped_state_member(
        &self,
        room: SyncRoom,
        _room_member: &StrippedStateEvent<MemberEventContent>,
        _: Option<MemberEventContent>,
    ) {
        match room {
            SyncRoom::Invited(room) => {
                let room = room.read().await;
                info!("Autojoining room {}", room.room_id);
                let mut delay = 2;

                while let Err(err) = self.client.join_room_by_id(&room.room_id).await {
                    // retry autojoin due to synapse sending invites, before the
                    // invited user can join for more information see
                    // https://github.com/matrix-org/synapse/issues/4345
                    info!(
                        "Failed to join room {} ({:?}), retrying in {}s",
                        room.room_id, err, delay
                    );

                    tokio::time::delay_for(Duration::from_secs(delay)).await;
                    delay *= 2;

                    if delay > 3600 {
                        error!("Can't join room {} ({:?})", room.room_id, err);
                        break;
                    }
                }
                info!("Successfully joined room {}", room.room_id);
            }
            _ => {}
        }
    }
    async fn on_room_message(&self, room: SyncRoom, event: &MessageEvent) {
        match room {
            SyncRoom::Joined(room) => {
                let msg_body = if let MessageEvent {
                    content:
                        MessageEventContent::Text(TextMessageEventContent { body: msg_body, .. }),
                    ..
                } = event
                {
                    msg_body.clone()
                } else {
                    String::new()
                };

                if let Ok(command) = Command::from_str(&msg_body) {
                    handle_command(command, &self.client, &self.hosts, event, &room.read().await.room_id.clone()).await;
                } else {
                    //TODO: give help text
                }
            }
            _ => {}
        }
    }
}

async fn handle_command(command: Command, client: &Client, hosts: &HashMap<String, Host>, event: &MessageEvent, room: &RoomId) {
    match command {
        Command::Wake { host } => {
            if let Some(host_conf) = hosts.get(&host) {
                if host_conf.users.contains(&event.sender.to_string()) {
                    info!("Waking host {}", host);
                    match wol::wake(host_conf.mac_addr) {
                        Ok(()) => {
                            info!("Magic packet sent to {} successfully", host);
                            send_message(client, &format!("Successfully send magic packet to {}", host), room).await;
                        }
                        Err(e) => {
                            error!("Couldn't send magic packet to {}, error: {}", host, e);
                            send_message(client, &format!("Failed to send magic packet to {}", host), room).await;
                        }
                    }
                } else {
                    send_message(client, &format!("No permission to wake up {}!", host), room).await;
                }
            } else {
                send_message(client, &format!("Host {} not found!", host), room).await;
            }
        }
    }
}

async fn send_message(client: &Client, message: &str, room: &RoomId) {
    client.room_send(room, MessageEventContent::Notice(NoticeMessageEventContent {
        body: message.to_owned(),
        format: None,
        formatted_body: None,
        relates_to: None,
    }), None).await.unwrap(); //TODO error handling here
}

enum Command {
    Wake { host: String },
}

impl FromStr for Command {
    type Err = &'static str;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        lazy_static! {
            static ref RE_WAKE: Regex = Regex::new("!wake (?P<host>.*)").unwrap();
        }

        if let Some(captures) = RE_WAKE.captures(s) {
            return Ok(Self::Wake {
                host: captures["host"].to_string(),
            });
        } else {
            return Err("Invalid command");
        }
    }
}