const { DataTypes } = require("sequelize");
const sequelize = require("../../config/db.config");
const { mdl_UserGroups } = require('../users/user_groups.mdl');

const TaskList = sequelize.define('TaskList', {
    task_list_id: { type: DataTypes.UUID, defaultValue: DataTypes.UUIDV4, primaryKey: true, hidden: true },
    name: { type: DataTypes.STRING, allowNull: false, validate: { notEmpty: true }, filterable: true },
    description: { type: DataTypes.TEXT, allowNull: true, hidden: true, filterable: false },

    // ── Audit trails ────────────────────────────────────────────────────────
    createdBy: { type: DataTypes.INTEGER, allowNull: true, filterable: true },
    updatedBy: { type: DataTypes.INTEGER, allowNull: true, filterable: true },
    deletedBy: { type: DataTypes.INTEGER, allowNull: true, filterable: true },
}, {
    tableName: 'task_lists',
    paranoid: true,
    timestamps: true,
});

// ─── Junction: TaskList ↔ UserGroups ──────────────────────────────────────────
const TaskListGroup = sequelize.define('TaskListGroup', {
    id: { type: DataTypes.UUID, defaultValue: DataTypes.UUIDV4, primaryKey: true },
    task_list_id: { type: DataTypes.UUID, allowNull: false, references: { model: 'task_lists', key: 'task_list_id' }, onDelete: 'CASCADE', },
    group_id: { type: DataTypes.BIGINT, allowNull: false, references: { model: 'user_groups', key: 'group_id' }, onDelete: 'CASCADE', },
    assignedAt: { type: DataTypes.DATE, defaultValue: DataTypes.NOW, allowNull: false, filterable: true },
    assignedBy: { type: DataTypes.BIGINT, allowNull: true, filterable: true },
}, {
    tableName: 'task_list_groups',
    timestamps: false,
    indexes: [
        { unique: true, fields: ['task_list_id', 'group_id'], name: 'uq_task_list_group' },
        { fields: ['task_list_id'], name: 'idx_tlg_task_list_id' },
        { fields: ['group_id'],     name: 'idx_tlg_group_id' },
    ],
});


const Task = sequelize.define('Task', {
    task_id: { type: DataTypes.UUID, defaultValue: DataTypes.UUIDV4, primaryKey: true, hidden: true },
    task_list_id: { type: DataTypes.UUID, allowNull: false, references: { model: 'task_lists', key: 'task_list_id' }, hidden: true, filterable: false },
    name: { type: DataTypes.STRING, allowNull: false, validate: { notEmpty: true }, order: 1, filterable: true },
    description: { type: DataTypes.TEXT, allowNull: true, hidden: true, filterable: false },
    deadline: { type: DataTypes.DATE, allowNull: true, order: 2, filterable: true },
    status: { type: DataTypes.ENUM('pending', 'in_progress', 'completed', 'overdue'), defaultValue: 'pending', allowNull: false, filterable: true },

    // ── Audit trails ────────────────────────────────────────────────────────
    createdBy: { type: DataTypes.INTEGER, allowNull: true, filterable: true },
    updatedBy: { type: DataTypes.INTEGER, allowNull: true, filterable: true },
    deletedBy: { type: DataTypes.INTEGER, allowNull: true, filterable: true },
}, {
    tableName: 'tasks',
    paranoid: true,
    timestamps: true,
});

const TaskRequirement = sequelize.define('TaskRequirement', {
    requirement_id: { type: DataTypes.UUID, defaultValue: DataTypes.UUIDV4, primaryKey: true },
    task_id: { type: DataTypes.UUID, allowNull: false, references: { model: 'tasks', key: 'task_id' } },
    type: { type: DataTypes.ENUM('visit_link', 'upload_file', 'read_course', 'read_unit', 'read_lesson'), allowNull: false, filterable: true },

    // ── visit_link ──────────────────────────────────────────────────────────
    link_url: { type: DataTypes.STRING, allowNull: true, filterable: false },
    link_label: { type: DataTypes.STRING, allowNull: true, filterable: false },

    // ── upload_file ─────────────────────────────────────────────────────────
    allowed_file_types: { type: DataTypes.JSONB, allowNull: true, filterable: false },
    max_file_count: { type: DataTypes.INTEGER, allowNull: true, defaultValue: 1, filterable: false },

    // ── read_course / read_unit / read_lesson ────────────────────────────────
    reference_id: { type: DataTypes.UUID, allowNull: true, comment: 'course_id | unit_id | lesson_id depending on type', filterable: false },
    reference_label: { type: DataTypes.STRING, allowNull: true, comment: 'Cached display name so we do not always join', filterable: false },
    order: { type: DataTypes.INTEGER, defaultValue: 0, filterable: true },

    // ── Audit trails ────────────────────────────────────────────────────────
    createdBy: { type: DataTypes.INTEGER, allowNull: true },
    updatedBy: { type: DataTypes.INTEGER, allowNull: true },
    deletedBy: { type: DataTypes.INTEGER, allowNull: true },
}, {
    tableName: 'task_requirements',
    paranoid: true,
    timestamps: true,
});

TaskList.hasMany(Task, { foreignKey: 'task_list_id', as: 'tasks' });
Task.belongsTo(TaskList, { foreignKey: 'task_list_id', as: 'taskList' });
Task.hasMany(TaskRequirement, { foreignKey: 'task_id', as: 'requirements' });
TaskRequirement.belongsTo(Task, { foreignKey: 'task_id', as: 'task' });

// TaskList ↔ UserGroups  (many-to-many through TaskListGroup)
TaskList.belongsToMany(mdl_UserGroups, { through: TaskListGroup, foreignKey: 'task_list_id', otherKey: 'group_id', as: 'groups', });
mdl_UserGroups.belongsToMany(TaskList, { through: TaskListGroup, foreignKey: 'group_id', otherKey: 'task_list_id', as: 'taskLists', });

module.exports = { Task, TaskList, TaskRequirement, TaskListGroup, mdl_UserGroups };