//! Module WebSocket pour le chat server
//!
//! Ce module contient:
//! - Les types de messages WebSocket (IncomingMessage, OutgoingMessage)
//! - Le gestionnaire de connexions (WebSocketManager)
//! - Le handler Axum (handler.rs)
//! - Le système de broadcast (broadcast.rs)

pub mod broadcast;
pub mod handler;

use crate::error::Result;
use axum::extract::ws::{Message, WebSocket};
use futures_util::{stream::SplitSink, SinkExt};
use serde::{Deserialize, Serialize};
use std::collections::HashSet;
use std::sync::Arc;
use tokio::sync::RwLock;
use uuid::Uuid;

/// Message WebSocket entrant
#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(tag = "type")]
pub enum IncomingMessage {
    /// Envoi d'un message de chat
    SendMessage {
        conversation_id: Uuid,
        content: String,
        parent_message_id: Option<Uuid>,
    },
    /// Rejoindre une conversation
    JoinConversation { conversation_id: Uuid },
    /// Quitter une conversation
    LeaveConversation { conversation_id: Uuid },
    /// Marquer des messages comme lus
    MarkAsRead {
        conversation_id: Uuid,
        message_id: Uuid,
    },
    /// Indicateur de frappe (typing indicator)
    Typing {
        conversation_id: Uuid,
        is_typing: bool,
    },
    /// Marquer un message comme délivré (reçu par le client)
    Delivered {
        conversation_id: Uuid,
        message_id: Uuid,
    },
    /// Éditer un message
    EditMessage {
        message_id: Uuid,
        conversation_id: Uuid,
        new_content: String,
    },
    /// Supprimer un message
    DeleteMessage {
        message_id: Uuid,
        conversation_id: Uuid,
    },
    /// Récupérer l'historique avec pagination
    FetchHistory {
        conversation_id: Uuid,
        before: Option<chrono::DateTime<chrono::Utc>>,
        after: Option<chrono::DateTime<chrono::Utc>>,
        limit: Option<usize>,
    },
    /// Rechercher des messages
    SearchMessages {
        conversation_id: Uuid,
        query: String,
        limit: Option<usize>,
        offset: Option<usize>,
    },
    /// Synchroniser les messages depuis un timestamp (offline sync)
    SyncMessages {
        conversation_id: Uuid,
        since: chrono::DateTime<chrono::Utc>,
    },
    /// Ping de connexion
    Ping,
}

/// Message WebSocket sortant
#[derive(Debug, Clone, Serialize)]
#[serde(tag = "type")]
pub enum OutgoingMessage {
    /// Nouveau message reçu
    NewMessage {
        conversation_id: Uuid,
        message_id: Uuid,
        sender_id: Uuid,
        content: String,
        created_at: chrono::DateTime<chrono::Utc>,
    },
    /// Message marqué comme lu
    MessageRead {
        message_id: Uuid,
        user_id: Uuid,
        conversation_id: Uuid,
        read_at: chrono::DateTime<chrono::Utc>,
    },
    /// Message délivré (reçu par le client)
    MessageDelivered {
        message_id: Uuid,
        user_id: Uuid,
        conversation_id: Uuid,
        delivered_at: chrono::DateTime<chrono::Utc>,
    },
    /// Indicateur de frappe (typing indicator)
    UserTyping {
        conversation_id: Uuid,
        user_id: Uuid,
        is_typing: bool,
    },
    /// Message édité
    MessageEdited {
        message_id: Uuid,
        conversation_id: Uuid,
        editor_id: Uuid,
        edited_at: chrono::DateTime<chrono::Utc>,
        new_content: String,
    },
    /// Message supprimé
    MessageDeleted {
        message_id: Uuid,
        conversation_id: Uuid,
        deleter_id: Uuid,
        deleted_at: chrono::DateTime<chrono::Utc>,
    },
    /// Chunk d'historique (pagination)
    HistoryChunk {
        conversation_id: Uuid,
        messages: Vec<crate::models::message::Message>,
        has_more_before: bool,
        has_more_after: bool,
    },
    /// Résultats de recherche
    SearchResults {
        conversation_id: Uuid,
        messages: Vec<crate::models::message::Message>,
        query: String,
        total: i64,
    },
    /// Chunk de synchronisation (offline sync)
    SyncChunk {
        conversation_id: Uuid,
        messages: Vec<crate::models::message::Message>,
        last_sync: chrono::DateTime<chrono::Utc>,
    },
    /// Confirmation d'action
    ActionConfirmed { action: String, success: bool },
    /// Erreur
    Error { message: String },
    /// Pong de connexion
    Pong,
}

/// Client WebSocket connecté
pub struct WebSocketClient {
    pub id: Uuid,
    pub user_id: String,
    pub stream: Arc<RwLock<SplitSink<WebSocket, Message>>>,
    pub conversations: Arc<RwLock<HashSet<Uuid>>>,
}

impl WebSocketClient {
    pub fn new(id: Uuid, user_id: String, stream: SplitSink<WebSocket, Message>) -> Self {
        Self {
            id,
            user_id,
            stream: Arc::new(RwLock::new(stream)),
            conversations: Arc::new(RwLock::new(HashSet::new())),
        }
    }

    /// Envoie un message au client
    pub async fn send_message(&self, message: OutgoingMessage) -> Result<()> {
        let json = serde_json::to_string(&message)
            .map_err(|e| crate::error::ChatError::serialization_error("OutgoingMessage", "", e))?;

        let mut stream = self.stream.write().await;
        stream.send(Message::Text(json.into())).await.map_err(|e| {
            crate::error::ChatError::internal_error(format!("WebSocket send error: {}", e))
        })?;

        Ok(())
    }

    /// Ajoute une conversation à la liste du client
    pub async fn add_conversation(&self, conversation_id: Uuid) {
        let mut conversations = self.conversations.write().await;
        conversations.insert(conversation_id);
    }

    /// Supprime une conversation de la liste du client
    pub async fn remove_conversation(&self, conversation_id: Uuid) {
        let mut conversations = self.conversations.write().await;
        conversations.remove(&conversation_id);
    }
}

/// Gestionnaire de connexions WebSocket
pub struct WebSocketManager {
    clients: Arc<RwLock<Vec<Arc<WebSocketClient>>>>,
}

impl WebSocketManager {
    pub fn new() -> Self {
        Self {
            clients: Arc::new(RwLock::new(Vec::new())),
        }
    }

    /// Ajoute un nouveau client
    pub async fn add_client(&self, client: Arc<WebSocketClient>) {
        let mut clients = self.clients.write().await;
        clients.push(client);
    }

    /// Supprime un client
    pub async fn remove_client(&self, client_id: Uuid) {
        let mut clients = self.clients.write().await;
        clients.retain(|c| c.id != client_id);
    }

    /// Diffuse un message à tous les clients d'une conversation
    pub async fn broadcast_to_conversation(
        &self,
        conversation_id: Uuid,
        message: OutgoingMessage,
    ) -> Result<()> {
        let clients = self.clients.read().await;

        for client in clients.iter() {
            let conversations = client.conversations.read().await;
            if conversations.contains(&conversation_id) {
                // Ignore send errors during broadcast to avoid stopping
                let _ = client.send_message(message.clone()).await;
            }
        }

        Ok(())
    }

    /// Récupère un client par son ID
    pub async fn get_client(&self, client_id: Uuid) -> Option<Arc<WebSocketClient>> {
        let clients = self.clients.read().await;
        clients.iter().find(|c| c.id == client_id).cloned()
    }
}