use axum::{
    extract::{
        FromRequest,FromRequestParts, State,
    
    }, http::StatusCode, response::{sse::KeepAlive, IntoResponse},
    
};
//use axum::extract::ws::Message;
use chrono::NaiveDateTime;
use rusqlite::params;
use serde::Serialize;
use serde_json::json;

use crate::chat::extractor::{
AddUserConversationPayload, CreateConversationPayload, GetMessagesPayload, SendMessagePayload
};
use crate::utils::db_pool::{AppState};
use crate::utils::auth::AuthClaims;



pub async fn create_conversation(
    State(state): State<AppState>,
    AuthClaims {user_id, hotel_id}: AuthClaims,
    CreateConversationPayload(payload): CreateConversationPayload
) -> impl IntoResponse {

    let pool = state.hotel_pools.get_pool(hotel_id);

    let conn = match pool.get(){
        Ok(conn) => conn,
        Err(err) => return (StatusCode::INTERNAL_SERVER_ERROR, format!("Pool error"))
    };

    let result = conn.execute(
    "INSERT INTO conversation (creator_id, title) VALUES (?1, ?2)",
    params![&user_id, &payload.title],
);

    match result {
        Ok(rows) if rows > 0 => (StatusCode::OK, format!("Created conversation {}", payload.title)),
        Ok(_) => (StatusCode::NOT_FOUND, "not able to create the conversation".to_string() ),
        Err(err) => (StatusCode::INTERNAL_SERVER_ERROR, format!("Error when creating the conversation : {err}")),
    
    }
}

pub async fn add_user_to_conv(
    State(state): State<AppState>,
    AuthClaims {user_id, hotel_id}: AuthClaims,
    AddUserConversationPayload(payload):AddUserConversationPayload
) -> impl IntoResponse {

    let pool = state.hotel_pools.get_pool(hotel_id);

    let conn = match pool.get(){
        Ok(conn) => conn,
        Err(err) => return (StatusCode::INTERNAL_SERVER_ERROR, format!("Pool error"))
    };

    let mut statement = match conn.prepare(
        "SELECT 1 FROM conversation WHERE creator_id = ?1 AND id = ?2" ,
    ){
        Ok(statement) => statement,
        Err(_) => return (StatusCode::INTERNAL_SERVER_ERROR, "prepare failed".to_string())
    };

    match statement.exists(params![user_id, payload.conv_id]) {
        Ok(true) => {
            //user is creator
        }
        Ok(false) => {
            //user is not the creator
            return (StatusCode::FORBIDDEN, "Not the creato of the conversation".to_string())
        }
        Err(_) => {
            return(StatusCode::INTERNAL_SERVER_ERROR, "Query failed".to_string())
        }

    }

    for target_id in &payload.users {
        let rows_inserted = match conn.execute(
            "INSERT INTO conversation_participants (conversation_id, user_id) VALUES (?1, ?2)",
            params![payload.conv_id, target_id],
        ) {
            Ok(n) => n,
            Err(err) => {
                return (StatusCode::INTERNAL_SERVER_ERROR, format!("Err adding user {}: {}", target_id, err));
            }
        };

        if rows_inserted == 0 {
            return (StatusCode::NOT_FOUND, format!("Could not add user {}", target_id));
        }
    }

    return (StatusCode::OK, "ok".to_string());    

}

pub async fn send_message(
    State(state): State<AppState>,
    AuthClaims {user_id, hotel_id}: AuthClaims,
    SendMessagePayload(payload):SendMessagePayload
) -> impl IntoResponse {

    let pool = state.hotel_pools.get_pool(hotel_id);

    let conn = match pool.get(){
        Ok(conn) => conn,
        Err(err) => return (StatusCode::INTERNAL_SERVER_ERROR, format!("Pool error"))
    };

    let mut statement = match conn.prepare(
        "SELECT 1 FROM conversation_participants WHERE user_id = ?1 AND conversation_id = ?2" ,
    ){
        Ok(statement) => statement,
        Err(_) => return (StatusCode::INTERNAL_SERVER_ERROR, "prepare failed".to_string())
    };

    match statement.exists(params![user_id, payload.conv_id]) {
    Ok(true) => {
        // user is part of the conversation — continue
    }
    Ok(false) => {
        // early exit: not part of the conversation
        return (StatusCode::FORBIDDEN, "Not part of the conversation".to_string());
    }
    Err(_) => {
        // query failed
        return (StatusCode::INTERNAL_SERVER_ERROR, "Query failed".to_string());
    }
}

    let result = conn.execute(
    "INSERT INTO message (sender_id, content, conversation_id) VALUES (?1, ?2, ?3)",
    params![&user_id, &payload.message, &payload.conv_id],
    );

    match result {
        Ok(rows) if rows > 0 => {
            // --- send to conversation participants ---
            let mut stmt_participants = conn
                .prepare("SELECT user_id FROM conversation_participants WHERE conversation_id = ?1")
                .expect("prepare participants failed");

            let participant_ids: Vec<i32> = stmt_participants
                .query_map(params![payload.conv_id], |row| row.get(0))
                .expect("query_map failed")
                .filter_map(Result::ok)
                .collect();

            if let Some(hotel_users) = state.ws_map.get(&hotel_id) {
                let update_msg = serde_json::json!({
                    "conv_id": payload.conv_id,
                    "sender": user_id,
                    "content": payload.message,
                })
                .to_string();

                for uid in &participant_ids {
                    if let Some(sender) = hotel_users.get(&uid) {
                        let _ = sender.send(axum::extract::ws::Message::Text(update_msg.clone().into()));
                    }
                }
            }

            (StatusCode::OK, format!("sent message: {}, to users:{:?}", payload.message, participant_ids))
        }
        Ok(_) => (StatusCode::NOT_FOUND, "Conversation not found".to_string()),
        Err(err) => (StatusCode::INTERNAL_SERVER_ERROR, format!("Error from DB: {err}")),
    }

}


#[derive(Debug, Serialize)]
struct Message {
    id: i32,
    sender_id: i32,
    content: String,
    sent_at: String,
}


pub async fn get_message(
    State(state): State<AppState>,
    AuthClaims {user_id, hotel_id}: AuthClaims,
    GetMessagesPayload(payload):GetMessagesPayload
) -> Result<impl IntoResponse, (StatusCode, String)> {

    let pool = state.hotel_pools.get_pool(hotel_id);

    let conn = pool.get()
        .map_err(|_| (StatusCode::INTERNAL_SERVER_ERROR, "Pool error".to_string()))?;

    let from_time = match payload.timestamp.as_deref() {
        Some("0") | None => "1970-01-01 00:00:00", // default to epoch
        Some(ts) => ts,
    };

    let mut stmt = conn.prepare(
        "SELECT id, sender_id, content, sent_at
         FROM message
         WHERE conversation_id = ?1
           AND sent_at > ?2
         ORDER BY sent_at DESC
         LIMIT 50"
    ).map_err(|_| (StatusCode::INTERNAL_SERVER_ERROR, "Prepare failed".to_string()))?;

   
    let messages = stmt.query_map(
        params![payload.conv_id, from_time],
        |row| {
            Ok(Message {
                id: row.get(0)?,
                sender_id: row.get(1)?,
                content: row.get(2)?,
                sent_at: row.get(3)?,
            })
        }
    )
    .map_err(|_| (StatusCode::INTERNAL_SERVER_ERROR, "Query failed".to_string()))?
    .collect::<Result<Vec<_>, _>>()
    .map_err(|_| (StatusCode::INTERNAL_SERVER_ERROR, "Collect failed".to_string()))?;

    let response = serde_json::to_string(&messages)
        .map_err(|_| (StatusCode::INTERNAL_SERVER_ERROR, "Serialisation failed"));

    Ok((StatusCode::OK, response ))

}


#[derive(Serialize)]
struct User {
    id: i32,
    username: String,
    display_name: String,
}


pub async fn get_hotel_users(
    State(state): State<AppState>,
    AuthClaims { hotel_id, .. }: AuthClaims,
) -> impl IntoResponse {
    let conn = match state.logs_pool.get() {
        Ok(c) => c,
        Err(_) => return (StatusCode::INTERNAL_SERVER_ERROR, "DB connection error".to_string()),
    };

    let mut stmt = match conn.prepare(
        "SELECT id, username, displayname FROM users WHERE hotel_id = ?1",
    ) {
        Ok(s) => s,
        Err(e) => return (StatusCode::INTERNAL_SERVER_ERROR, format!("Prepare failed: {}", e)),
    };

    let users_iter = match stmt.query_map(params![hotel_id], |row| {
        Ok(User {
            id: row.get(0)?,
            username: row.get(1)?,
            display_name: row.get(2)?,
        })
    }) {
        Ok(iter) => iter,
        Err(e) => return (StatusCode::INTERNAL_SERVER_ERROR, format!("Query failed: {}", e)),
    };

    let users: Vec<User> = match users_iter.collect::<Result<Vec<_>, _>>() {
        Ok(u) => u,
        Err(e) => return (StatusCode::INTERNAL_SERVER_ERROR, format!("Collect failed: {}", e)),
    };

    match serde_json::to_string(&users) {
        Ok(json) => (StatusCode::OK, json),
        Err(e) => (StatusCode::INTERNAL_SERVER_ERROR, format!("Serialization failed: {}", e)),
    }
}