server/src/chatHandler.ts

import { lucia } from "./auth.js";
import { generateId, Lucia } from "lucia";
import bcrypt from "bcrypt";
import { Database } from "better-sqlite3";
import { getDB } from "./db.js";

var db: Database;
db = getDB();



type MessageType = {
    id: string,
    content: string,
    type: string,
    timestamp: number,
    sender_id: string,
    receiver_id: string,
    status: "sent" | "received" | "seen",
};

type ContactType = {
    id: string,
    name: string,
    chat_data: {
        last_message: MessageType,
        unseen_count: number,
    }
};

export function searchContacts(user_id: string, search_string: string) {
    var contacts = db.prepare(`SELECT id,name FROM users WHERE id LIKE ? AND id!=?`)
        .all("%" + search_string + "%",user_id);


    // console.log(contacts);
    contacts = contacts.map((contact: any) => {
        var last_msg: any = getLastMessage(user_id, contact.id);

        // console.log(user_id, contact.id, last_msg);
        
        var chat_data: any = {};
        if (last_msg.id) {
            chat_data.last_message = last_msg;
            chat_data.unseen_count = getUnseenCount(user_id, contact.id);
        }

        return { ...contact, chat_data }
    })

    return contacts as ContactType[];
}


export function getContact(user_id: string, other_contact_id: string) {
    var contact: any = {};
    var user: any = db.prepare(`SELECT id,name from users
        WHERE id=?
        `).get(other_contact_id);

    contact.id = user.id;
    contact.name = user.name;
    contact.chat_data = {
        last_message: getLastMessage(user_id, other_contact_id),
        unseen_count: getUnseenCount(user_id, other_contact_id),
    }

    return contact as ContactType;
}

export const getMyChats = (user_id: string) => {
    // var contacts = db.prepare("SELECT send_to,send_from FROM messages WHERE send_to=? or send_from=?").all(user_id,user_id);

    var chat_ids: any = db.prepare(`
        SELECT Distinct(sender_id) as id FROM messages WHERE receiver_id=?
        UNION
        SELECT Distinct(receiver_id) as id FROM messages WHERE sender_id=?
        `).all(user_id, user_id);

    // get data of all   
    var contacts: any = [];
    for (var i = 0; i < chat_ids.length; i++) {
        contacts.push(getContact(user_id, chat_ids[i].id));
    }
    return contacts as ContactType[];
};


export function getLastMessage(user_id: string, other_contact_id: string) {
    const msg_stmt = db.prepare(`SELECT id,content,type,MAX(timestamp) as timestamp,sender_id,receiver_id,status 
    FROM messages 
    WHERE sender_id in (?,?) AND receiver_id in (?,?)`)

    const last_message = msg_stmt.get(user_id, other_contact_id, user_id, other_contact_id);
    return last_message as MessageType;
}

export function getUnseenCount(user_id: string, other_contact_id: string) {
    const stmt = db.prepare(`SELECT COUNT(id) as unseen_count FROM messages
        WHERE sender_id=? AND receiver_id=? AND status!='seen'
    `)

    const unseen_count: any = stmt.get(other_contact_id, user_id);
    return unseen_count.unseen_count;
}

export function addMessage({
    content,
    type = "text",
    sender_id,
    receiver_id,
}: {
    content: string,
    type: string,
    sender_id: string,
    receiver_id: string,

}) {

    type = type.toLowerCase();
    const id = generateId(10);
    const stmt = db.prepare(`INSERT INTO messages(id,content,type,sender_id,receiver_id) VALUES(?,?,?,?,?)`);

    stmt.run(
        id,
        content,
        type,
        sender_id,
        receiver_id
    );

    return db.prepare(`SELECT * FROM messages WHERE id=?`).get(id) as MessageType;
}

export function markMessageSeen(user_id: string, msg_id: string) {
    const stmt = db.prepare(`UPDATE messages SET status='seen' WHERE sender_id!=? AND id=?`);
    stmt.run(user_id, msg_id);
}

export function getAllMessages(user_id: string, other_contact_id: string) {
    const stmt = db.prepare(`SELECT * from messages 
    WHERE sender_id in (?,?) AND receiver_id in (?,?)
    ORDER BY messages.timestamp DESC
    `);

    const msgs = stmt.all(user_id, other_contact_id, user_id, other_contact_id);
    return msgs as MessageType[];
}

export function deleteChat(user_id: string, other_contact_id: string) {
    db.prepare(`DELETE FROM message WHERE sender_id in (?,?) AND receiver_id in (?,?) `)
        .run(user_id, other_contact_id, user_id, other_contact_id);
    return true;
}

// console.log(searchContacts("user1","u"))
// console.log(getMyChats("user1"))
// console.log(getMyChats("user2"))
// console.log(getMyChats("user3"))

// console.log(getLastMessage("user1","user1"))
// console.log(getUnseenCount("user1", "user2"))

// // console.log(addMessage({
// //         message: "new_msg",
// //         type: "text",
// //         send_from: "user3",
// //     send_to: "wx6uv",
// // }))

// console.log(getUnseenCount("user1", "wx6uv"))
// // markMessageSeen("user1", "33w87");
// console.log(getAllMessages("user1", "wx6uv"))

// console.log(deleteChat('user2',"sblua"))