import Series from '../models/series.js'
import { connectDB } from './mongoose.js'

/**
 * Load a series by ObjectId, string id, or slug for public endpoints.
 * Series has three identifier fields (`_id`, `id`, `slug`); this helper
 * builds the same conditional `$or` query the call sites would otherwise
 * inline. No isVisible gate today (parity with existing call-site behavior).
 *
 * @param {Object} reqEvent - h3 event (reserved for future auth/cookie access)
 * @param {String} identifier - ObjectId string, string id, or slug
 * @param {Object} [options]
 * @param {Boolean} [options.lean] - apply .lean() to the query
 * @param {String} [options.select] - apply .select() to the query
 * @param {Boolean} [options.allowMissing] - return null instead of throwing 404 on miss
 * @returns {Promise<Object|null>} the series document, or null if allowMissing and not found
 */
export async function loadPublicSeries(reqEvent, identifier, options = {}) {
  if (!identifier) {
    throw createError({
      statusCode: 400,
      statusMessage: 'Series identifier is required'
    })
  }

  await connectDB()

  const { lean = false, select = null, allowMissing = false } = options

  const isObjectId = /^[0-9a-fA-F]{24}$/.test(identifier)
  const seriesQuery = isObjectId
    ? { $or: [{ _id: identifier }, { id: identifier }, { slug: identifier }] }
    : { $or: [{ id: identifier }, { slug: identifier }] }

  let query = Series.findOne(seriesQuery)
  if (select) query = query.select(select)
  if (lean) query = query.lean()

  const series = await query

  if (!series) {
    if (allowMissing) return null
    throw createError({ statusCode: 404, statusMessage: 'Series not found' })
  }

  return series
}