/***********************************************************************************************************************************************************************
 * File Name: media_playback_position.mdl.js
 * Type of Program: Model
 * Description: Per-user "where did I last leave off" position for a video/audio 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-on-reopen only; carries no completion/anti-cheat semantics (that's
 *              CompletionRequirementProgress's job, see completion_requirement_progress.mdl.js).
 *
 *   MediaPlaybackPosition — UPSERT key: (user_id, lesson_id, block_id). Last-write-wins, not a
 *                            ratcheted max — a deliberate rewind-and-stop should resume there, not
 *                            snap back to a previously-reached high-water mark.
 *
 * Author: Kenneth Obsequio (@lash0000)
 * Date Created: Jul. 17, 2026
 ***********************************************************************************************************************************************************************/
const { DataTypes } = require('sequelize');
const sequelize = require('../../config/db.config');

const MediaPlaybackPosition = sequelize.define('MediaPlaybackPosition', {
    position_id: {
        type: DataTypes.UUID,
        defaultValue: DataTypes.UUIDV4,
        primaryKey: true,
    },
    user_id: {
        type: DataTypes.BIGINT,
        allowNull: false,
        references: { model: 'users', key: 'user_id' },
        onDelete: 'CASCADE',
    },
    lesson_id: {
        type: DataTypes.BIGINT,
        allowNull: false,
        references: { model: 'lessons', key: 'lesson_id' },
        onDelete: 'CASCADE',
    },
    block_id: {
        type: DataTypes.STRING,
        allowNull: false,
        comment: 'The block\'s own id within LessonPage.blocks JSONB — no DB-level FK, blocks are not their own table.',
    },
    percent: {
        type: DataTypes.INTEGER,
        allowNull: false,
        comment: 'Last-known % position, 0-100. Last-write-wins — not a ratcheted max.',
    },
}, {
    tableName: 'media_playback_positions',
    timestamps: true,
    paranoid: false, // position rows are never soft-deleted, matches CompletionRequirementProgress
    indexes: [
        {
            unique: true,
            fields: ['user_id', 'lesson_id', 'block_id'],
            name: 'uq_mpp_user_lesson_block',
        },
        { fields: ['user_id', 'lesson_id'], name: 'idx_mpp_user_lesson' },
    ],
});

module.exports = MediaPlaybackPosition;