use axum::http::StatusCode;
use axum::{Extension, Json};
use axum::extract::Path;
use diesel::{Connection, PgConnection};
use serde::Deserialize;
use skillratings::weng_lin::WengLinConfig;
use teloxide::Bot;
use teloxide::requests::Requester;
use teloxide::types::{ChatId, MessageId, ParseMode, ThreadId};
use crate::config;
use crate::database::model::{Match, MatchI, Outcome, Player, WengLinRating};

#[derive(Debug, Clone, Deserialize)]
pub struct MatchII {
	name: Option<String>,
	player_a: i32,
	player_b: i32,
	outcome: Outcome,
}

#[axum::debug_handler]
pub async fn get_all()
	-> Result<Json<Vec<Match>>, StatusCode>
{
	let mut conn = PgConnection::establish(config::DATABASE_URL())
		.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
	
	let matches = Match::all(&mut conn)
		.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
	
	Ok(Json(matches))
}

#[axum::debug_handler]
pub async fn get_played_by_id(
	Path(player_id): Path<i32>,
)
	-> Result<Json<Vec<Match>>, StatusCode>
{
	let mut conn = PgConnection::establish(config::DATABASE_URL())
		.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
	
	let matches = Match::played_by(&mut conn, player_id)
		.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
	
	Ok(Json(matches))
}

fn player_to_text(player: &Player, before: &WengLinRating, after: &WengLinRating) -> String {
	let name = &player.username;
	let competitive = &player.competitive;
	let telegram_id = &player.telegram_id.clone().map(|t| t.0);
	
	match competitive {
		false => {
			match telegram_id {
				None =>
					format!(r#"<b>{name}</b>"#),
				Some(telegram_id) =>
					format!(r#"<b><a href="tg://user?id={telegram_id}">{name}</a></b>"#),
			}
		},
		true => {
			let before = before.human_score();
			let after = after.human_score();
			let change = after - before;
			
			match telegram_id {
				None =>
					format!(r#"<b>{name}</b> ({change:+} ★)"#),
				Some(telegram_id) =>
					format!(r#"<b><a href="tg://user?id={telegram_id}">{name}</a></b> ({change:+} ★)"#),
			}
		},
	}
}

fn match_to_text(r#match: &Match, player_a: &Player, player_b: &Player) -> String {
	let player_a = player_to_text(player_a, &r#match.player_a_wenglin_before, &r#match.player_a_wenglin_after);
	let player_b = player_to_text(player_b, &r#match.player_b_wenglin_before, &r#match.player_b_wenglin_after);
	
	match r#match.outcome {
		Outcome::AWins => match &r#match.name {
			Some(name) => format!("🔵 {player_a} ha trionfato su {player_b} in <b>{name}</b>!"),
			None => format!("🔵 {player_a} ha trionfato su {player_b}!"),
		},
		Outcome::BWins => match &r#match.name {
			Some(name) => format!("🟠 {player_a} è stato sconfitto da {player_b} in <b>{name}</b>!"),
			None => format!("🟠 {player_a} è stato sconfitto da {player_b}!"),
		},
		Outcome::Tie => match &r#match.name {
			Some(name) => format!("⚪️ {player_a} e {player_b} hanno pareggiato in <b>{name}</b>!"),
			None => format!("⚪️ {player_a} e {player_b} hanno pareggiato!"),
		},
	}
}

pub async fn post_match(
	Extension(bot): Extension<Bot>,
	Json(matchii): Json<MatchII>,
)
	-> Result<Json<Match>, StatusCode>
{
	log::debug!("New MatchII just dropped: {matchii:#?}");
	let name = matchii.name;
	let outcome = matchii.outcome;
	
	log::trace!("Establishing database connection...");
	let mut conn = PgConnection::establish(config::DATABASE_URL())
		.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
	
	log::trace!("Finding player A's info...");
	let player_a = Player::get_by_id(&mut conn, matchii.player_a)
		.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?
		.ok_or_else(|| StatusCode::NOT_FOUND)?;
	let player_a_id = player_a.id;
	let player_a_wenglin_before = player_a.wenglin.clone();
	
	log::trace!("Finding player B's info...");
	let player_b = Player::get_by_id(&mut conn, matchii.player_b)
		.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?
		.ok_or_else(|| StatusCode::NOT_FOUND)?;
	let player_b_id = player_b.id;
	let player_b_wenglin_before = player_b.wenglin.clone();
	
	log::trace!("Calculating rating changes...");
	let (player_a_wenglin_after, player_b_wenglin_after) = skillratings::weng_lin::weng_lin(
		&player_a_wenglin_before.0,
		&player_b_wenglin_before.0,
		&outcome.into(),
		&WengLinConfig::default(),
	);
	let player_a_wenglin_after = WengLinRating(player_a_wenglin_after);
	log::trace!("A's new rating is: {player_a_wenglin_after:?}");
	let player_b_wenglin_after = WengLinRating(player_b_wenglin_after);
	log::trace!("B's new rating is: {player_b_wenglin_after:?}");
	
	log::trace!("Starting database transaction...");
	let (r#match, player_a, player_b) = conn.transaction(|tx| {
		log::trace!("Updating A's rating...");
		let player_a = player_a.update_wenglin(tx, &player_a_wenglin_after)
			.map_err(|_| diesel::result::Error::RollbackTransaction)?;
		log::trace!("Updating B's rating...");
		let player_b = player_b.update_wenglin(tx, &player_b_wenglin_after)
			.map_err(|_| diesel::result::Error::RollbackTransaction)?;
		
		log::trace!("Inserting match...");
		let matchi = MatchI {
			name,
			player_a_id,
			player_a_wenglin_before,
			player_a_wenglin_after,
			player_b_id,
			player_b_wenglin_before,
			player_b_wenglin_after,
			outcome,
		};
		let r#match = matchi.insert(tx)
			.map_err(|_| diesel::result::Error::RollbackTransaction)?;
		
		Ok::<(Match, Player, Player), anyhow::Error>((r#match, player_a, player_b))
	})
		.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
	
	log::trace!("Preparing send message future...");
	
	let chat = config::TELEGRAM_NOTIFICATION_CHAT_ID();
	let chat = ChatId(*chat);
	let mut send_message_future = bot.send_message(chat, match_to_text(&r#match, &player_a, &player_b));
	
	send_message_future.parse_mode = Some(ParseMode::Html);
	
	let topic = config::TELEGRAM_NOTIFICATION_TOPIC_ID();
	if let Some(topic) = topic {
		let topic = MessageId(*topic);
		let topic = ThreadId(topic);
		send_message_future.message_thread_id = Some(topic);
	}
	
	log::trace!("Sending message...");
	let _message = send_message_future.await
		.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
	
	Ok(Json(r#match))
}