'use strict';
const mdl_Product    = require('../../models/courses/products.mdl');
const mdl_Category   = require('../../models/courses/categories.mdl');
const { Course, CourseProductCategory: mdl_CourseProductCategory } = require('../../models/courses/courses.mdl');
const R                        = require('../../utils/response.util');
const logActivity              = require('../../utils/logActivity.util');

// ─── PRODUCT (per course) ─────────────────────────────────────────────────────

exports.getCourseProduct = async (req, res) => {
  try {
    const product = await mdl_Product.findOne({ where: { course_id: req.params.courseId }, paranoid: false });
    return R.success(res, 'Product retrieved.', product ?? null);
  } catch (err) {
    console.error('[ADMIN][PRODUCTS][GET]', err);
    return R.error(res, 'Could not retrieve product.', 500);
  }
};

exports.upsertCourseProduct = async (req, res) => {
  try {
    const { courseId } = req.params;
    const { name, description, price, currency, access_days, is_active } = req.body;
    if (!name || price == null) return R.error(res, 'name and price are required.', 400);

    const existing = await mdl_Product.findOne({ where: { course_id: courseId }, paranoid: false });

    if (existing) {
      if (existing.deletedAt) await existing.restore();
      await existing.update({ name, description: description ?? null, price, currency: currency ?? 'USD', access_days: access_days ?? null, is_active: is_active ?? true });
      logActivity(req.user?.user_id, 'upsert_course_product', { entityType: 'product', details: { course_id: courseId, name } });
      return R.success(res, 'Product updated.', existing);
    }

    const product = await mdl_Product.create({ course_id: courseId, name, description: description ?? null, price, currency: currency ?? 'USD', access_days: access_days ?? null, is_active: is_active ?? true });
    logActivity(req.user?.user_id, 'upsert_course_product', { entityType: 'product', entityId: product.product_id, details: { course_id: courseId, name } });
    return R.success(res, 'Product created.', product, 201);
  } catch (err) {
    console.error('[ADMIN][PRODUCTS][UPSERT]', err);
    return R.error(res, 'Could not save product.', 500);
  }
};

exports.removeCourseProduct = async (req, res) => {
  try {
    const product = await mdl_Product.findOne({ where: { course_id: req.params.courseId } });
    if (!product) return R.error(res, 'Product not found.', 404);
    await product.destroy();
    logActivity(req.user?.user_id, 'remove_course_product', { entityType: 'product', details: { course_id: req.params.courseId } });
    return R.success(res, 'Product removed.');
  } catch (err) {
    console.error('[ADMIN][PRODUCTS][REMOVE]', err);
    return R.error(res, 'Could not remove product.', 500);
  }
};

// ─── CATEGORIES (per course) ──────────────────────────────────────────────────

exports.getCourseCategories = async (req, res) => {
  try {
    const course = await Course.findByPk(req.params.courseId, {
      include: [{ model: mdl_Category, as: 'categories', through: { attributes: [] } }],
    });
    if (!course) return R.error(res, 'Course not found.', 404);
    return R.success(res, 'Course categories retrieved.', course.categories ?? []);
  } catch (err) {
    console.error('[ADMIN][PRODUCTS][GET CATEGORIES]', err);
    return R.error(res, 'Could not retrieve course categories.', 500);
  }
};

exports.syncCourseCategories = async (req, res) => {
  try {
    const { courseId } = req.params;
    const { category_ids = [] } = req.body;

    await mdl_CourseProductCategory.destroy({ where: { course_id: courseId } });

    if (category_ids.length > 0) {
      await mdl_CourseProductCategory.bulkCreate(
        category_ids.map((id) => ({ course_id: courseId, category_id: id }))
      );
    }

    logActivity(req.user?.user_id, 'sync_course_categories', { entityType: 'product', details: { course_id: courseId, category_ids, count: category_ids.length } });
    return R.success(res, 'Course categories updated.');
  } catch (err) {
    console.error('[ADMIN][PRODUCTS][SYNC CATEGORIES]', err);
    return R.error(res, 'Could not sync course categories.', 500);
  }
};