const mongoose = require('mongoose');
const CourseModel = require('../models/CourseModel');
const AcademyModel = require('../models/AcademyModel');
const ProjectModel = require('../models/ProjectModel');
const AdvertisingModel = require('../models/AdvertisingModel');
const ShopModel = require('../models/ShopModel');
const ShopProductListingModel = require('../models/ShopProductListingModel');
const BookingConfigModel = require('../models/BookingConfigModel');
const {
  PUBLIC_COURSE_STATUSES,
  PUBLIC_BILLBOARD_STATUSES,
  PUBLIC_PROJECT_STATUSES,
} = require('./moderationStatus');

function sameId(a, b) {
  if (a == null || b == null) return false;
  const sa = typeof a === 'object' && a._id != null ? String(a._id) : String(a);
  const sb = typeof b === 'object' && b._id != null ? String(b._id) : String(b);
  return sa === sb;
}

// اعتبارسنجی مشترک «آیتم قابل‌لینک‌شدن»
// options.requirePublic (پیش‌فرض true): برای لینک داخل پست/استوری وضعیت عمومی لازم است.
// برای صفحه «اشتراک‌گذاری لینک» فقط مالکیت کافی است (requirePublic: false).
async function resolveLinkedEntity(kind, id, userId, options = {}) {
  const requirePublic = options.requirePublic !== false;
  if (!id || !mongoose.Types.ObjectId.isValid(id)) return null;

  switch (kind) {
    case 'pkg': {
      const course = await CourseModel.findById(id)
        .select('_id user_id academyId status')
        .lean();
      if (!course) return null;
      if (requirePublic && !PUBLIC_COURSE_STATUSES.includes(course.status)) return null;

      // مالکیت: user_id مستقیم روی دوره، یا مالک آکادمیِ دوره
      if (sameId(course.user_id, userId)) return String(course._id);
      if (course.academyId) {
        const academy = await AcademyModel.findById(course.academyId).select('userId').lean();
        if (academy && sameId(academy.userId, userId)) return String(course._id);
      }
      return null;
    }
    case 'project': {
      const project = await ProjectModel.findById(id)
        .select('_id creator_id status')
        .lean();
      if (!project) return null;
      if (requirePublic && !PUBLIC_PROJECT_STATUSES.includes(project.status)) return null;
      if (sameId(project.creator_id, userId)) return String(project._id);
      return null;
    }
    case 'billboard': {
      const ad = await AdvertisingModel.findById(id)
        .select('_id creator_id status')
        .lean();
      if (!ad) return null;
      if (requirePublic && !PUBLIC_BILLBOARD_STATUSES.includes(ad.status)) return null;
      if (sameId(ad.creator_id, userId)) return String(ad._id);
      return null;
    }
    case 'shop': {
      const shop = await ShopModel.findById(id).select('_id owner status').lean();
      if (!shop) return null;
      if (requirePublic && !['active', 'pending_review'].includes(shop.status)) return null;
      if (sameId(shop.owner, userId)) return String(shop._id);
      return null;
    }
    case 'shopproduct': {
      const listing = await ShopProductListingModel.findById(id)
        .select('_id shop status')
        .lean();
      if (!listing) return null;
      if (requirePublic && !['active', 'pending_shop_approval'].includes(listing.status)) {
        return null;
      }
      const shop = await ShopModel.findById(listing.shop).select('_id owner').lean();
      if (shop && sameId(shop.owner, userId)) return String(listing._id);
      return null;
    }
    case 'booking': {
      // ref_id برای رزرو = userId مالک کانفیگ (نه _id خودِ BookingConfig)
      if (!sameId(id, userId)) return null;
      const query = requirePublic
        ? { owner: userId, status: 'active' }
        : { owner: userId };
      const config = await BookingConfigModel.findOne(query).select('_id').lean();
      return config ? String(userId) : null;
    }
    default:
      return null;
  }
}

module.exports = { resolveLinkedEntity };