/***********************************************************************************************************************************************************************
 * File Name: playback_position.service.js
 * Type of Program: Service
 * Description: Last-known video/audio playback position per (user, lesson, block) — entirely
 *              decoupled from CompletionRequirement, tracked for ANY video/audio block regardless
 *              of whether the lesson has a watch-type completion requirement configured. Powers
 *              "resume where I left off" only; no anti-cheat/wall-clock validation here since
 *              there's nothing being gated — see completion_requirements.service.js for that.
 *
 *   recordPlaybackPosition — last-write-wins upsert (not a ratcheted max — a deliberate rewind
 *                             should resume there, not snap back to a prior high-water mark).
 *   getPlaybackPositions   — { [block_id]: percent } for every block tracked on a lesson.
 *
 * Author: Kenneth Obsequio (@lash0000)
 * Date Created: Jul. 17, 2026
 ***********************************************************************************************************************************************************************/
'use strict';

const MediaPlaybackPosition = require('../models/courses/media_playback_position.mdl');

async function recordPlaybackPosition(userId, { lessonId, blockId, percent }) {
    if (!blockId) return;

    await MediaPlaybackPosition.upsert({
        user_id:   userId,
        lesson_id: lessonId,
        block_id:  blockId,
        percent:   Math.min(100, Math.max(0, Math.round(percent))),
    }, { conflictFields: ['user_id', 'lesson_id', 'block_id'] });
}

async function getPlaybackPositions(userId, lessonId) {
    const rows = await MediaPlaybackPosition.findAll({
        where: { user_id: userId, lesson_id: lessonId },
        attributes: ['block_id', 'percent'],
    });
    return Object.fromEntries(rows.map((r) => [r.block_id, r.percent]));
}

module.exports = { recordPlaybackPosition, getPlaybackPositions };