/***********************************************************************************************************************************************************************
 * File Name: task_progress.mdl.js
 * Type of Program: Model
 * Description: Sequelize models for tracking user progress on task requirements.
 *
 *   TaskLinkVisit  — tracks when a user visits a visit_link requirement.
 *                    UPSERT key: (requirement_id, user_id)
 *                    Revisiting updates visited_at.
 *
 *   TaskProgress   — tracks completion of read_course / read_unit / read_lesson.
 *                    UPSERT key: (requirement_id, user_id, reference_id)
 *                    Lessons: completed flipped directly by client.
 *                    Units/Courses: completed derived from child completion.
 *
 * Author: Kenneth Obsequio (@lash0000)
 * Date Created: Jun. 13, 2026
 ***********************************************************************************************************************************************************************/
const { DataTypes } = require('sequelize');
const sequelize = require('../../config/db.config');
const mdl_Users = require('../users/users.mdl');
const { Task, TaskRequirement } = require('./task.mdl');

// ─── TaskLinkVisit ─────────────────────────────────────────────────────────────
const TaskLinkVisit = sequelize.define('TaskLinkVisit', {
    visit_id: {
        type: DataTypes.UUID,
        defaultValue: DataTypes.UUIDV4,
        primaryKey: true,
    },
    task_id: {
        type: DataTypes.UUID,
        allowNull: false,
        references: { model: 'tasks', key: 'task_id' },
        onDelete: 'CASCADE',
    },
    requirement_id: {
        type: DataTypes.UUID,
        allowNull: false,
        references: { model: 'task_requirements', key: 'requirement_id' },
        onDelete: 'CASCADE',
    },
    user_id: {
        type: DataTypes.BIGINT,
        allowNull: false,
        references: { model: 'users', key: 'user_id' },
        onDelete: 'CASCADE',
    },
    visited_at: {
        type: DataTypes.DATE,
        defaultValue: DataTypes.NOW,
        allowNull: false,
        comment: 'Updated on every revisit via UPSERT.',
    },

    // ── Audit trails ────────────────────────────────────────────────────────
    createdBy: { type: DataTypes.BIGINT, allowNull: true },
    updatedBy: { type: DataTypes.BIGINT, allowNull: true },
}, {
    tableName: 'task_link_visits',
    timestamps: true,
    paranoid: false,    // visits are never soft-deleted
    indexes: [
        {
            unique: true,
            fields: ['requirement_id', 'user_id'],
            name: 'uq_tlv_requirement_user',
        },
        { fields: ['task_id'],        name: 'idx_tlv_task_id' },
        { fields: ['user_id'],        name: 'idx_tlv_user_id' },
        { fields: ['requirement_id'], name: 'idx_tlv_requirement_id' },
    ],
});

// ─── TaskProgress ──────────────────────────────────────────────────────────────
const TaskProgress = sequelize.define('TaskProgress', {
    progress_id: {
        type: DataTypes.UUID,
        defaultValue: DataTypes.UUIDV4,
        primaryKey: true,
    },
    task_id: {
        type: DataTypes.UUID,
        allowNull: false,
        references: { model: 'tasks', key: 'task_id' },
        onDelete: 'CASCADE',
    },
    requirement_id: {
        type: DataTypes.UUID,
        allowNull: false,
        references: { model: 'task_requirements', key: 'requirement_id' },
        onDelete: 'CASCADE',
    },
    user_id: {
        type: DataTypes.BIGINT,
        allowNull: false,
        references: { model: 'users', key: 'user_id' },
        onDelete: 'CASCADE',
    },
    reference_id: {
        type: DataTypes.UUID,
        allowNull: false,
        comment: 'course_id | unit_id | lesson_id | quiz_id depending on type.',
    },
    type: {
        type: DataTypes.ENUM('read_course', 'read_unit', 'read_lesson', 'pass_quiz'),
        allowNull: false,
    },
    completed: {
        type: DataTypes.BOOLEAN,
        defaultValue: false,
        allowNull: false,
    },
    completed_at: {
        type: DataTypes.DATE,
        allowNull: true,
        comment: 'Set when completed flips true. Cleared when it reverts to false.',
    },

    // ── Audit trails ────────────────────────────────────────────────────────
    createdBy: { type: DataTypes.BIGINT, allowNull: true },
    updatedBy: { type: DataTypes.BIGINT, allowNull: true },
}, {
    tableName: 'task_progress',
    timestamps: true,
    paranoid: false,    // progress rows are never soft-deleted
    indexes: [
        {
            unique: true,
            fields: ['requirement_id', 'user_id', 'reference_id'],
            name: 'uq_tp_requirement_user_reference',
        },
        { fields: ['task_id'],        name: 'idx_tp_task_id' },
        { fields: ['user_id'],        name: 'idx_tp_user_id' },
        { fields: ['requirement_id'], name: 'idx_tp_requirement_id' },
        { fields: ['type'],           name: 'idx_tp_type' },
    ],
});

// ─── Associations ──────────────────────────────────────────────────────────────
Task.hasMany(TaskLinkVisit,              { foreignKey: 'task_id',       as: 'linkVisits' });
TaskLinkVisit.belongsTo(Task,            { foreignKey: 'task_id',       as: 'task' });

TaskRequirement.hasMany(TaskLinkVisit,   { foreignKey: 'requirement_id', as: 'visits' });
TaskLinkVisit.belongsTo(TaskRequirement, { foreignKey: 'requirement_id', as: 'requirement' });

mdl_Users.hasMany(TaskLinkVisit,         { foreignKey: 'user_id',       as: 'linkVisits' });
TaskLinkVisit.belongsTo(mdl_Users,       { foreignKey: 'user_id',       as: 'user' });

Task.hasMany(TaskProgress,               { foreignKey: 'task_id',       as: 'progress' });
TaskProgress.belongsTo(Task,             { foreignKey: 'task_id',       as: 'task' });

TaskRequirement.hasMany(TaskProgress,    { foreignKey: 'requirement_id', as: 'progress' });
TaskProgress.belongsTo(TaskRequirement,  { foreignKey: 'requirement_id', as: 'requirement' });

mdl_Users.hasMany(TaskProgress,          { foreignKey: 'user_id',       as: 'taskProgress' });
TaskProgress.belongsTo(mdl_Users,        { foreignKey: 'user_id',       as: 'user' });

module.exports = { TaskLinkVisit, TaskProgress };