'use strict';
const { DataTypes } = require('sequelize');
const sequelize     = require('../../config/db.config');
const { Course }    = require('./courses.mdl');
const Unit          = require('./units.mdl');
const Lesson        = require('./lessons.mdl');

// Polymorphic target — a product is sold against exactly one Course, Unit, or
// Lesson (purchasable_type + purchasable_id), not just courses. See
// utils/purchasable.util.js for the type -> model/checkout-path resolver used
// by every consumer (access checks, admin CRUD, checkout).
//
// constraints: false below because purchasable_id doesn't point at a single
// table — referential integrity across the three possible targets is
// enforced at the application layer only (see
// 20270101000078-generalize-products-purchasable.js).
const mdl_Product = sequelize.define('Product', {
  id:               { type: DataTypes.BIGINT, primaryKey: true, autoIncrement: true },
  purchasable_type: { type: DataTypes.STRING(10), allowNull: false, defaultValue: 'course' },
  purchasable_id:   { type: DataTypes.BIGINT, allowNull: false },
  name:        { type: DataTypes.STRING(200), allowNull: false },
  description: { type: DataTypes.TEXT, allowNull: true },
  price:       { type: DataTypes.DECIMAL(10, 2), allowNull: false },
  currency:    { type: DataTypes.STRING(10), allowNull: false, defaultValue: 'USD' },
  access_days: { type: DataTypes.INTEGER, allowNull: true },
  is_active:   { type: DataTypes.BOOLEAN, allowNull: false, defaultValue: true },
}, {
  tableName:  'products',
  timestamps: true,
  paranoid:   true,
});

// Scoped hasOne per target type — Sequelize automatically adds the matching
// purchasable_type filter to the join, so existing
// `include: [{ model: mdl_Product, as: 'product' }]` call sites on Course
// keep working unchanged.
Course.hasOne(mdl_Product,  { foreignKey: 'purchasable_id', constraints: false, scope: { purchasable_type: 'course' }, as: 'product' });
Unit.hasOne(mdl_Product,    { foreignKey: 'purchasable_id', constraints: false, scope: { purchasable_type: 'unit' },   as: 'product' });
Lesson.hasOne(mdl_Product,  { foreignKey: 'purchasable_id', constraints: false, scope: { purchasable_type: 'lesson' }, as: 'product' });

module.exports = mdl_Product;