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

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

// In-memory views
export const sessions = {};
export const desks = {};

export const queries = {};
export let db = null;

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 sessions (
        id INTEGER PRIMARY KEY,
        desk_id INTEGER,
        lsn INTEGER,
        color INTEGER,
        width 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,
        width INTEGER,
        color INTEGER,
        points BLOB
    );`).run();

    db.query(`CREATE TABLE IF NOT EXISTS events (
        id INTEGER PRIMARY KEY,
        type INTEGER,
        desk_id INTEGER,
        session_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 (session_id) 
            REFERENCES sessions (id) 
             ON DELETE NO ACTION
             ON UPDATE NO ACTION

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

    // INSERT
    queries.insert_desk    = db.query('INSERT INTO desks    (id, title, sn)                                        VALUES ($id, $title, 0) RETURNING id');
    queries.insert_stroke  = db.query('INSERT INTO strokes  (width, color, points)                                 VALUES ($width, $color, $points) RETURNING id');
    queries.insert_session = db.query('INSERT INTO sessions (id, desk_id, lsn)                                     VALUES ($id, $desk_id, 0) RETURNING id');
    queries.insert_event   = db.query('INSERT INTO events   (type, desk_id, session_id, stroke_id, image_id, x, y) VALUES ($type, $desk_id, $session_id, $stroke_id, $image_id, $x, $y) RETURNING id');

    // UPDATE
    queries.update_desk_sn       = db.query('UPDATE desks    SET sn = $sn       WHERE id = $id');
    queries.update_session_lsn   = db.query('UPDATE sessions SET lsn = $lsn     WHERE id = $id');
    queries.update_session_color = db.query('UPDATE sessions SET color = $color WHERE id = $id');
    queries.update_session_width = db.query('UPDATE sessions SET width = $width WHERE id = $id');

    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 sessions').get();

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

    // Init in-memory view: merge strokes into events, set all sessions to closed
    const stored_desks = db.query('SELECT * FROM desks').all();
    const stored_events = db.query('SELECT * FROM events').all();
    const stored_strokes = db.query('SELECT * FROM strokes').all();
    const stored_sessions = db.query('SELECT * FROM sessions').all();

    const stroke_dict = {};

    for (const stroke of stored_strokes) {
        stroke.points = new Float32Array(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) {
            const stroke = stroke_dict[event.stroke_id];
            event.points = stroke.points;
            event.color = stroke.color;
            event.width = stroke.width;
        }

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

    for (const session of stored_sessions) {
        session.state = SESSION.CLOSED;
        session.ws = null;
        session.sync_attempts = 0;
        sessions[session.id] = session;
    }
}