const { DataTypes } = require("sequelize");
const sequelize     = require("../../config/db.config");
const mdl_Users     = require("../users/users.mdl");
const Unit          = require("./units.mdl");

const Lesson = sequelize.define("Lesson", {
  lesson_id:   { type: DataTypes.BIGINT, primaryKey: true, autoIncrement: true },
  uuid:        { type: DataTypes.UUID, defaultValue: DataTypes.UUIDV4, allowNull: false, unique: true },
  unit_id:     { type: DataTypes.BIGINT, allowNull: false },
  title:       { type: DataTypes.STRING(255), allowNull: false, label: "Title" },
  description: { type: DataTypes.TEXT,        allowNull: true,  label: "Description" },
  order_index: { type: DataTypes.INTEGER,     allowNull: false, defaultValue: 0, label: "Order" },
  createdBy:   { type: DataTypes.BIGINT, allowNull: true, label: "Created By" },
  updatedBy:   { type: DataTypes.BIGINT, allowNull: true, label: "Updated By" },
  deletedBy:   { type: DataTypes.BIGINT, allowNull: true, label: "Deleted By" },
}, {
  tableName:  "lessons",
  timestamps: true,
  paranoid:   true,
  indexes: [
    { fields: ["uuid"] },
    { fields: ["unit_id"] },
    { fields: ["order_index"] },
    { fields: ["deletedAt"] },
  ],
});

Lesson.belongsTo(Unit,      { as: "unit",    foreignKey: "unit_id" });
Lesson.belongsTo(mdl_Users, { as: "creator", foreignKey: "createdBy" });
Lesson.belongsTo(mdl_Users, { as: "updater", foreignKey: "updatedBy" });
Unit.hasMany(Lesson, { as: "lessons", foreignKey: "unit_id" });

module.exports = Lesson;