use std::net::SocketAddr;
use std::sync::Arc;
use std::time::Duration;
use tokio::task::JoinHandle;
use logic::{
    message_type, CancelMatchmakeDoneMessage, ClientCapabilitiesMessage, GoHomeMessage,
    KeepAliveServerMessage, LoginFailedMessage, LoginMessage, LoginOkMessage, ServerErrorMessage,
};
use service_rpc::{
    AccountRef, DeviceInfo, HomeRequestKind, LoginOutcome, Session as AuthSession, WireMessage,
};
use titan::{Incoming, LogicLong, MessagingSender, OutboundMessage};
use crate::backend::Backends;
use crate::config::GatewayConfig;
#[derive(Debug, thiserror::Error)]
pub enum RoutingError {
    #[error("transport: {0}")]
    Transport(#[from] titan::MessagingError),
    #[error("backend: {0}")]
    Backend(#[from] service_rpc::RpcError),
    #[error("client sent message type {0} before authenticating")]
    Unauthenticated(u16),
}
type RoutingResult<T> = Result<T, RoutingError>;
pub const BATTLE_TICK_INTERVAL: Duration = Duration::from_millis(50);
pub struct MessageManager {
    peer: SocketAddr,
    config: Arc<GatewayConfig>,
    backends: Arc<Backends>,
    sender: MessagingSender,
    account: Option<AccountRef>,
    battle_ticker: Option<JoinHandle<()>>,
}
impl Drop for MessageManager {
    fn drop(&mut self) {
        self.stop_battle_ticker();
    }
}
impl MessageManager {
    pub fn new(
        peer: SocketAddr,
        config: Arc<GatewayConfig>,
        backends: Arc<Backends>,
        sender: MessagingSender,
    ) -> Self {
        Self {
            peer,
            config,
            backends,
            sender,
            account: None,
            battle_ticker: None,
        }
    }
    pub fn account(&self) -> Option<AccountRef> {
        self.account
    }
    pub async fn receive_message(&mut self, incoming: Incoming) -> RoutingResult<()> {
        let message_type = incoming.message_type();
        if self.account.is_none() && message_type != message_type::LOGIN {
            return Err(RoutingError::Unauthenticated(message_type));
        }
        let Some(message) = incoming.message.as_ref() else {
            return Ok(());
        };
        if !message.direction().accepts_from_client() {
            tracing::warn!(
                peer = %self.peer,
                message = message.name(),
                "client sent a server to client message"
            );
            return Ok(());
        }
        match message_type {
            message_type::LOGIN => {
                let login = incoming.downcast::<LoginMessage>().expect("login message");
                self.handle_login(login).await
            }
            message_type::KEEP_ALIVE => {
                self.sender
                    .send_message(&KeepAliveServerMessage::default())
                    .await?;
                Ok(())
            }
            message_type::CLIENT_CAPABILITIES => {
                let capabilities = incoming
                    .downcast::<ClientCapabilitiesMessage>()
                    .expect("client capabilities message");
                if let Some(account) = self.account {
                    self.backends
                        .game
                        .client_capabilities(account, capabilities.ping_ms)
                        .await?;
                }
                Ok(())
            }
            message_type::GO_HOME => {
                let _ = incoming.downcast::<GoHomeMessage>();
                self.stop_battle_ticker();
                self.push_home(HomeRequestKind::GoHome).await
            }
            message_type::SECTOR_COMMAND => {
                let Some(account) = self.account else {
                    return Ok(());
                };
                if let Err(error) = self
                    .backends
                    .game
                    .sector_command(account, incoming.payload)
                    .await
                {
                    tracing::warn!(peer = %self.peer, %error, "could not deliver the sector command");
                }
                Ok(())
            }
            message_type::SEND_BATTLE_EVENT => {
                let Some(account) = self.account else {
                    return Ok(());
                };
                if let Err(error) = self
                    .backends
                    .game
                    .battle_event(account, incoming.payload)
                    .await
                {
                    tracing::warn!(peer = %self.peer, %error, "could not deliver the battle event");
                }
                Ok(())
            }
            message_type::CANCEL_MATCHMAKE => {
                tracing::info!(peer = %self.peer, "client cancelled matchmaking");
                self.stop_battle_ticker();
                if let Some(account) = self.account {
                    let _ = self.backends.game.cancel_matchmake(account).await;
                }
                self.sender
                    .send_message(&CancelMatchmakeDoneMessage::default())
                    .await?;
                Ok(())
            }
            message_type::HOME_LOGIC_STOPPED => {
                let Some(account) = self.account else {
                    return Ok(());
                };
                match self
                    .backends
                    .game
                    .home_logic_stopped(account, incoming.payload)
                    .await
                {
                    Ok(replies) => {
                        self.push_wire_messages(replies).await?;
                        self.start_battle_ticker();
                    }
                    Err(error) => {
                        tracing::warn!(peer = %self.peer, %error, "could not match the player");
                        self.sender
                            .send_message(&CancelMatchmakeDoneMessage::default())
                            .await?;
                    }
                }
                Ok(())
            }
            message_type::START_MISSION => {
                let Some(account) = self.account else {
                    return Ok(());
                };
                match self
                    .backends
                    .game
                    .start_mission(account, incoming.payload)
                    .await
                {
                    Ok(replies) => {
                        self.push_wire_messages(replies).await?;
                        self.start_battle_ticker();
                    }
                    Err(error) => {
                        tracing::warn!(peer = %self.peer, %error, "could not start the mission");
                        self.sender
                            .send_message(&ServerErrorMessage::new(
                                "this server could not build the battle",
                            ))
                            .await?;
                    }
                }
                Ok(())
            }
            message_type::END_CLIENT_TURN => {
                if let Some(account) = self.account {
                    let replies = self
                        .backends
                        .game
                        .end_client_turn(account, incoming.payload)
                        .await?;
                    self.push_wire_messages(replies).await?;
                }
                Ok(())
            }
            _ => {
                tracing::debug!(
                    peer = %self.peer,
                    message = message.name(),
                    "no gateway route for this message"
                );
                Ok(())
            }
        }
    }
    pub async fn on_disconnect(&self) {
        if let Some(account) = self.account {
            if let Err(error) = self.backends.game.disconnect(account).await {
                tracing::debug!(peer = %self.peer, %error, "disconnect notification failed");
            }
        }
    }
    async fn handle_login(&mut self, login: &LoginMessage) -> RoutingResult<()> {
        let account = AccountRef::new(login.account_id.high, login.account_id.low);
        let device = DeviceInfo {
            udid: login.udid.clone(),
            open_udid: login.open_udid.clone(),
            device: login.device.clone(),
            os_version: login.os_version.clone(),
            android: login.android,
            preferred_language: login.preferred_device_language.clone(),
            client_major_version: login.client_major_version,
            client_minor_version: login.client_minor_version,
            client_build: login.client_build,
            resource_sha: login.resource_sha.clone(),
        };
        tracing::info!(
            peer = %self.peer,
            %account,
            version = format!(
                "{}.{}.{}",
                login.client_major_version, login.client_minor_version, login.client_build
            ),
            device = login.device.as_deref().unwrap_or("unknown"),
            "login attempt"
        );
        match self
            .backends
            .auth
            .login(account, login.pass_token.clone(), device)
            .await?
        {
            LoginOutcome::Rejected {
                error_code,
                message,
            } => {
                tracing::info!(
                    peer = %self.peer,
                    error_code,
                    reason = message.as_deref().unwrap_or("unspecified"),
                    "login rejected"
                );
                self.sender
                    .send_message(&LoginFailedMessage {
                        error_code,
                        fingerprint_json: None,
                        redirect_domain: None,
                        content_url: None,
                        remaining_seconds: 0,
                    })
                    .await?;
                Ok(())
            }
            LoginOutcome::Accepted(session) => {
                self.account = Some(session.account);
                self.sender.send_message(&self.login_ok(&session)).await?;
                self.push_home(HomeRequestKind::Login).await
            }
        }
    }
    fn login_ok(&self, session: &AuthSession) -> LoginOkMessage {
        let account = LogicLong::new(session.account.high, session.account.low);
        LoginOkMessage {
            account_id: account,
            home_id: account,
            pass_token: Some(session.pass_token.clone()),
            facebook_id: None,
            gamecenter_id: None,
            server_major_version: self.config.server_major_version,
            server_minor_version: self.config.server_minor_version,
            server_build: self.config.server_build,
            content_version: self.config.content_version,
            server_environment: Some(self.config.server_environment.clone()),
            session_count: session.session_count,
            play_time_seconds: session.play_time_seconds,
            days_since_started_playing: session.days_since_started_playing,
            facebook_app_id: self.config.facebook_app_id.clone(),
            server_time: Some(session.server_time.clone()),
            account_created_date: Some(session.account_created_date.clone()),
            startup_cooldown_seconds: self.config.startup_cooldown_seconds,
        }
    }
    async fn push_home(&self, kind: HomeRequestKind) -> RoutingResult<()> {
        let Some(account) = self.account else {
            return Ok(());
        };
        let messages = self.backends.game.load_home(account, kind).await?;
        self.push_wire_messages(messages).await
    }
    fn start_battle_ticker(&mut self) {
        let Some(account) = self.account else {
            return;
        };
        self.stop_battle_ticker();
        let backends = Arc::clone(&self.backends);
        let sender = self.sender.clone();
        let peer = self.peer;
        self.battle_ticker = Some(tokio::spawn(async move {
            let mut ticker = tokio::time::interval(BATTLE_TICK_INTERVAL);
            ticker.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Skip);
            loop {
                ticker.tick().await;
                if sender.is_closed() {
                    return;
                }
                match backends.game.battle_tick(account).await {
                    Ok(messages) => {
                        for message in messages {
                            let outbound = OutboundMessage::raw(
                                message.message_type,
                                message.message_version,
                                message.payload,
                            );
                            if sender.send(outbound).await.is_err() {
                                return;
                            }
                        }
                    }
                    Err(error) => {
                        tracing::warn!(%peer, %error, "the battle tick failed, stopping the ticker");
                        return;
                    }
                }
            }
        }));
    }
    fn stop_battle_ticker(&mut self) {
        if let Some(handle) = self.battle_ticker.take() {
            handle.abort();
        }
    }
    async fn push_wire_messages(&self, messages: Vec<WireMessage>) -> RoutingResult<()> {
        for message in messages {
            self.sender
                .send(OutboundMessage::raw(
                    message.message_type,
                    message.message_version,
                    message.payload,
                ))
                .await?;
        }
        Ok(())
    }
}