import * as config from './config';
import * as sqlite from 'bun:sqlite';

import { EVENT, SESSION } from './enums';

export const sessions = {};
export const desks = {};

let db = null;
const queries = {};

export function startup() {
    const path = `${config.DATADIR}/db.sqlite`;
    
    db = new sqlite.Database(path, { create: true });

    db.query(`CREATE TABLE IF NOT EXISTS desks (
        id INTEGER PRIMARY KEY,
        sn INTEGER,
        title TEXT
    );`).run();

    db.query(`CREATE TABLE IF NOT EXISTS users (
        id INTEGER PRIMARY KEY,
        login TEXT
    );`).run();

    db.query(`CREATE TABLE IF NOT EXISTS sessions (
        id INTEGER PRIMARY KEY,
        user_id INTEGER,
        desk_id INTEGER,
        lsn INTEGER,

        FOREIGN KEY (user_id) 
            REFERENCES users (id) 
             ON DELETE CASCADE 
             ON UPDATE NO ACTION,

        FOREIGN KEY (desk_id) 
            REFERENCES desks (id) 
             ON DELETE CASCADE 
             ON UPDATE NO ACTION
    );`).run();

    db.query(`CREATE TABLE IF NOT EXISTS images (
        id INTEGER PRIMARY KEY,
        desk_id INTEGER,

        FOREIGN KEY (desk_id) 
            REFERENCES desks (id) 
             ON DELETE CASCADE 
             ON UPDATE NO ACTION
    );`).run();

    db.query(`CREATE TABLE IF NOT EXISTS strokes (
        id INTEGER PRIMARY KEY,
        desk_id INTEGER,
        points BLOB,

        FOREIGN KEY (desk_id) 
            REFERENCES desks (id) 
             ON DELETE CASCADE 
             ON UPDATE NO ACTION
    );`).run();

    db.query(`CREATE TABLE IF NOT EXISTS events (
        id INTEGER PRIMARY KEY,
        type INTEGER,
        desk_id INTEGER,
        user_id INTEGER,
        stroke_id INTEGER,
        image_id INTEGER,
        x INTEGER,
        y INTEGER,

        FOREIGN KEY (desk_id) 
            REFERENCES desks (id) 
             ON DELETE CASCADE 
             ON UPDATE NO ACTION

        FOREIGN KEY (user_id) 
            REFERENCES users (id) 
             ON DELETE CASCADE 
             ON UPDATE NO ACTION

        FOREIGN KEY (stroke_id) 
            REFERENCES strokes (id) 
             ON DELETE CASCADE 
             ON UPDATE NO ACTION

        FOREIGN KEY (image_id) 
            REFERENCES images (id) 
             ON DELETE CASCADE 
             ON UPDATE NO ACTION
    );`).run();

    db.query(`CREATE INDEX IF NOT EXISTS idx_events_desk_id 
        ON events (desk_id);
    `).run();

    db.query(`CREATE INDEX IF NOT EXISTS idx_strokes_desk_id 
        ON strokes (desk_id);
    `).run();

    const res1 = db.query('SELECT COUNT(id) as count FROM desks').get();
    const res2 = db.query('SELECT COUNT(id) as count FROM events').get();
    const res3 = db.query('SELECT COUNT(id) as count FROM strokes').get();
    const res4 = db.query('SELECT COUNT(id) as count FROM users').get();
    const res5 = db.query('SELECT COUNT(id) as count FROM sessions').get();
    const res6 = db.query('SELECT COUNT(id) as count FROM images').get();

    queries.desks = db.query('SELECT id, sn FROM desks');
    queries.events = db.query('SELECT * FROM events');
    queries.sessions = db.query('SELECT id, lsn, user_id, desk_id FROM sessions');
    queries.strokes = db.query('SELECT id, points FROM strokes');
    queries.empty_desk = db.query('INSERT INTO desks (id, title, sn) VALUES (?1, ?2, 0)');
    queries.desk_strokes = db.query('SELECT id, points FROM strokes WHERE desk_id = ?1');
    queries.put_desk_stroke = db.query('INSERT INTO strokes (id, desk_id, points) VALUES (?1, ?2, ?3)');
    queries.clear_desk_events = db.query('DELETE FROM events WHERE desk_id = ?1');
    queries.set_desk_sn = db.query('UPDATE desks SET sn = ?1 WHERE id = ?2');
    queries.save_session_lsn = db.query('UPDATE sessions SET lsn = ?1 WHERE id = ?2');
    queries.create_session = db.query('INSERT INTO sessions (id, lsn, user_id, desk_id) VALUES (?1, 0, ?2, ?3)');
    queries.create_user = db.query('INSERT INTO users (id, login) VALUES (?1, ?2)');
    queries.put_event = db.query('INSERT INTO events (type, desk_id, user_id, stroke_id, image_id, x, y) VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7)');
    queries.put_image = db.query('INSERT INTO images (id, desk_id) VALUES (?1, ?2)');

    console.log(`Storing data in ${path}`);
    console.log(`Entity count at startup:
        ${res1.count} desks
        ${res2.count} events
        ${res3.count} strokes
        ${res4.count} users
        ${res5.count} sessions
        ${res6.count} images`
    );

    const stored_desks = get_desks();
    const stored_events = get_events();
    const stored_strokes = get_strokes();
    const stored_sessions = get_sessions();

    const stroke_dict = {};

    for (const stroke of stored_strokes) {
        stroke.points = new Uint16Array(stroke.points.buffer);
        stroke_dict[stroke.id] = stroke;
    }

    for (const desk of stored_desks) {
        desks[desk.id] = desk;
        desks[desk.id].events = [];
    }
    
    for (const event of stored_events) {
        if (event.type === EVENT.STROKE) {
            event.points = stroke_dict[event.stroke_id].points;
        }


        desks[event.desk_id].events.push(event);
    }

    for (const session of stored_sessions) {
        session.state = SESSION.CLOSED;
        session.ws = null;
        sessions[session.id] = session;
    }
}

export function get_strokes() {
    return queries.strokes.all();
}

export function get_sessions() {
    return queries.sessions.all();
}

export function get_desks() {
    return queries.desks.all();
}

export function get_events() {
    return queries.events.all();
}

export function get_desk_strokes(desk_id) {
    return queries.desk_strokes.all(desk_id);
}

export function put_event(event) {
    return queries.put_event.get(event.type, event.desk_id || 0, event.user_id || 0, event.stroke_id || 0, event.image_id || 0, event.x || 0, event.y || 0);
}

export function put_stroke(stroke_id, desk_id, points) {
    return queries.put_desk_stroke.get(stroke_id, desk_id, new Uint8Array(points.buffer, points.byteOffset, points.byteLength));
}

export function clear_events(desk_id) {
    return queries.clear_desk_events.get(desk_id);
}

export function create_desk(desk_id, title = 'untitled') {
    return queries.empty_desk.get(desk_id, title);
}

export function save_desk_sn(desk_id, sn) {
    return queries.set_desk_sn.get(sn, desk_id);
}

export function create_session(session) {
    return queries.create_session.get(session.id, session.user_id, session.desk_id);
}

export function create_user(user) {
    return queries.create_user.get(user.id, user.login);
}

export function save_session_lsn(session_id, lsn) {
    return queries.save_session_lsn.get(lsn, session_id);
}

export function put_image(image_id, desk_id) {
    return queries.put_image.get(image_id, desk_id);
}