pub mod http;
pub mod ws;

use std::sync::Arc;
use axum::{routing, Router};
use tokio::net::TcpListener;

use crate::bus::{ControlMessage, OutboundDispatcher};
use crate::channels::{ChannelManager, CliChatChannel};
use crate::channels::base::{Channel, ChannelError};
use crate::config::{Config, expand_path, ensure_workspace_dir};
use crate::logging;
use crate::session::SessionManager;

pub struct GatewayState {
    pub config: Config,
    pub workspace_dir: std::path::PathBuf,
    pub session_manager: SessionManager,
    pub channel_manager: ChannelManager,
}

impl GatewayState {
    pub fn new() -> Result<Self, Box<dyn std::error::Error>> {
        let config = Config::load_default()?;

        // Initialize workspace directory: expand path and ensure it exists
        let workspace_path = expand_path(&config.workspace_dir);
        let workspace_path = ensure_workspace_dir(&workspace_path)?;

        // Switch current working directory to workspace
        std::env::set_current_dir(&workspace_path)
            .map_err(|e| format!("Failed to switch to workspace directory {}: {}", workspace_path.display(), e))?;

        tracing::info!("Using workspace directory: {}", workspace_path.display());

        // Get provider config for SessionManager
        let mut provider_config = config.get_provider_config("default")?;
        // Override workspace_dir with the ensured path
        provider_config.workspace_dir = workspace_path.clone();

        // Session TTL from config (default 4 hours)
        let session_ttl_hours = config.gateway.session_ttl_hours.unwrap_or(4);

        let session_manager = SessionManager::new(session_ttl_hours, provider_config.clone())?;

        // Create CLI Chat Channel first (needed for ChannelManager)
        let cli_chat_channel = Arc::new(CliChatChannel::new());
        let channel_manager = ChannelManager::new(cli_chat_channel);

        Ok(Self {
            config,
            workspace_dir: workspace_path,
            session_manager,
            channel_manager,
        })
    }

    /// Get a reference to the MessageBus
    pub fn bus(&self) -> Arc<crate::bus::MessageBus> {
        self.channel_manager.bus()
    }

    /// Get CLI chat channel for WebSocket handling
    pub fn cli_chat_channel(&self) -> Arc<CliChatChannel> {
        self.channel_manager.cli_chat_channel()
    }

    /// Start the message processing loops
    pub async fn start_message_processing(&self) {
        let bus = self.bus();
        let bus_for_outbound = bus.clone();
        let session_manager = self.session_manager.clone();

        // Start CLI Chat Channel (it's already registered in ChannelManager)
        let cli_chat_channel = self.cli_chat_channel();
        if let Err(e) = cli_chat_channel.start(bus.clone()).await {
            tracing::error!(error = %e, "Failed to start CLI chat channel");
        }

        // Spawn unified message processor
        // This handles both inbound AI messages and control messages in one loop
        tokio::spawn(async move {
            tracing::info!("Message processor started");

            loop {
                tokio::select! {
                    // Inbound: AI message flow
                    inbound = bus.consume_inbound() => {
                        match session_manager.handle_message(
                            &inbound.channel,
                            &inbound.sender_id,
                            &inbound.chat_id,
                            inbound.dialog_id.as_deref(),
                            &inbound.content,
                            inbound.media,
                        ).await {
                            Ok(crate::session::session::HandleResult::AgentResponse(content)) => {
                                let outbound = crate::bus::OutboundMessage {
                                    channel: inbound.channel.clone(),
                                    chat_id: inbound.chat_id.clone(),
                                    content,
                                    reply_to: None,
                                    media: vec![],
                                    metadata: inbound.forwarded_metadata,
                                };
                                if let Err(e) = bus.publish_outbound(outbound).await {
                                    tracing::error!(error = %e, "Failed to publish outbound");
                                }
                            }
                            Ok(crate::session::session::HandleResult::CommandOutput(content)) => {
                                let outbound = crate::bus::OutboundMessage {
                                    channel: inbound.channel.clone(),
                                    chat_id: inbound.chat_id.clone(),
                                    content,
                                    reply_to: None,
                                    media: vec![],
                                    metadata: inbound.forwarded_metadata,
                                };
                                if let Err(e) = bus.publish_outbound(outbound).await {
                                    tracing::error!(error = %e, "Failed to publish outbound");
                                }
                            }
                            Err(e) => {
                                tracing::error!(error = %e, "Failed to handle message");
                            }
                        }
                    }

                    // Control: session management operations
                    msg = bus.consume_control() => {
                        Self::handle_control_message(&session_manager, msg).await;
                    }
                }
            }
        });

        // Spawn outbound dispatcher
        let dispatcher = OutboundDispatcher::new(bus_for_outbound, self.channel_manager.clone());

        tokio::spawn(async move {
            tracing::info!("Outbound dispatcher started");
            dispatcher.run().await;
        });
    }

    /// Handle control messages (session management operations)
    async fn handle_control_message(
        session_manager: &SessionManager,
        msg: ControlMessage,
    ) {
        use crate::session::{SessionCommand::*, SessionEvent};

        let reply_tx = msg.reply_tx;
        let result: Result<SessionEvent, ChannelError> = match msg.op {
            CreateDialog { channel, chat_id, title } => {
                session_manager.create_dialog(&channel, &chat_id, title.as_deref()).await
                    .map(|(session_id, title)| SessionEvent::DialogCreated { session_id, title })
                    .map_err(|e| ChannelError::Other(e.to_string()))
            }
            ListDialogs { channel, chat_id, include_archived } => {
                session_manager.list_dialogs(&channel, &chat_id, include_archived).await
                    .map(|(dialogs, current_dialog_id)| SessionEvent::DialogList { dialogs, current_dialog_id })
                    .map_err(|e| ChannelError::Other(e.to_string()))
            }
            GetCurrentDialog { channel, chat_id } => {
                session_manager.get_current_dialog(&channel, &chat_id).await
                    .map(|session_id| SessionEvent::CurrentDialog { session_id })
                    .map_err(|e| ChannelError::Other(e.to_string()))
            }
            SwitchDialog { channel, chat_id, dialog_id } => {
                session_manager.switch_dialog(&channel, &chat_id, &dialog_id).await
                    .map(|session_id| SessionEvent::DialogSwitched { session_id })
                    .map_err(|e| ChannelError::Other(e.to_string()))
            }
            RenameDialog { session_id, title } => {
                session_manager.rename_dialog(&session_id, &title)
                    .map(|()| SessionEvent::DialogRenamed { session_id, title })
                    .map_err(|e| ChannelError::Other(e.to_string()))
            }
            ArchiveDialog { session_id } => {
                session_manager.archive_dialog(&session_id)
                    .map(|()| SessionEvent::DialogArchived { session_id })
                    .map_err(|e| ChannelError::Other(e.to_string()))
            }
            DeleteDialog { session_id } => {
                session_manager.delete_dialog(&session_id)
                    .map(|()| SessionEvent::DialogDeleted { session_id })
                    .map_err(|e| ChannelError::Other(e.to_string()))
            }
            ClearHistory { session_id } => {
                session_manager.clear_dialog_history(&session_id)
                    .map(|()| SessionEvent::HistoryCleared { session_id })
                    .map_err(|e| ChannelError::Other(e.to_string()))
            }
            GetSlashCommands { channel: _, chat_id: _ } => {
                let commands = session_manager.get_slash_commands().to_vec();
                Ok(SessionEvent::SlashCommandsList { commands })
            }
            ExecuteSlashCommand { command, args, channel, chat_id, current_session_id } => {
                session_manager.execute_slash_command(&command, args.as_deref(), &channel, &chat_id, current_session_id.as_ref())
                    .await
                    .map(|(new_id, msg)| SessionEvent::SlashCommandExecuted { new_session_id: new_id, message: msg })
                    .map_err(|e| ChannelError::Other(e.to_string()))
            }
        };

        let _ = reply_tx.send(result).await;
    }
}

pub async fn run(host: Option<String>, port: Option<u16>) -> Result<(), Box<dyn std::error::Error>> {
    // Initialize logging
    logging::init_logging();
    tracing::info!("Starting PicoBot Gateway");

    let state = Arc::new(GatewayState::new()?);

    // Initialize and start channels with workspace directory
    state.channel_manager.init(
        &state.config,
        state.workspace_dir.clone(),
    ).await?;
    state.channel_manager.start_all().await?;

    // Start message processing (inbound processor + control processor + outbound dispatcher)
    state.start_message_processing().await;

    // CLI args override config file values
    let bind_host = host.unwrap_or_else(|| state.config.gateway.host.clone());
    let bind_port = port.unwrap_or(state.config.gateway.port);

    let app = Router::new()
        .route("/health", routing::get(http::health))
        .route("/ws", routing::get(ws::ws_handler))
        .with_state(state.clone());

    let addr = format!("{}:{}", bind_host, bind_port);
    let listener = TcpListener::bind(&addr).await?;
    tracing::info!(address = %addr, "Gateway listening");

    // Graceful shutdown using oneshot channel
    let (shutdown_tx, shutdown_rx) = tokio::sync::oneshot::channel::<()>();
    let channel_manager = state.channel_manager.clone();

    // Spawn ctrl_c handler
    tokio::spawn(async move {
        tokio::signal::ctrl_c().await.ok();
        tracing::info!("Shutdown signal received");
        let _ = channel_manager.stop_all().await;
        let _ = shutdown_tx.send(());
    });

    // Serve with graceful shutdown
    axum::serve(listener, app)
        .with_graceful_shutdown(async {
            shutdown_rx.await.ok();
        })
        .await?;

    Ok(())
}