const mongoose = require('mongoose');
const ParticipantList = require('../models/ParticipantList');
const Participant = require('../models/Participant');

function normalizeEmail(email) {
  return email != null ? String(email).trim().toLowerCase() : '';
}

function parseAccommodationValue(v) {
  if (v === true) return true;
  if (v === false) return false;
  const s = v == null ? '' : String(v).trim().toLowerCase();
  if (!s) return false;
  return ['yes', 'true', '1', 'y'].includes(s);
}

function buildGateStatus({ hasParticipant, accommodationAssigned }) {
  if (!hasParticipant) return 'NO_PARTICIPANT_ID_PRESENT';
  if (!accommodationAssigned) return 'ACCOMMODATION_NOT_ASSIGNED';
  return 'ACCEPTED';
}

function resolveSubmittedValue({ form, dataObj, candidateKeys }) {
  const entries = Array.isArray(candidateKeys) ? candidateKeys : [candidateKeys];
  const source = dataObj && typeof dataObj === 'object' ? dataObj : {};
  const fields = Array.isArray(form?.fields) ? form.fields : [];

  for (const key of entries) {
    if (source[key] !== undefined && source[key] !== null && String(source[key]).trim() !== '') {
      return source[key];
    }
  }

  const fieldMap = new Map();
  for (const field of fields) {
    if (!field?.mapsTo) continue;
    fieldMap.set(String(field.mapsTo).toLowerCase(), field);
  }

  for (const key of entries) {
    const field = fieldMap.get(String(key).toLowerCase());
    if (!field) continue;
    const fieldKey = field.name || field.label;
    const value = fieldKey ? source[fieldKey] : undefined;
    if (value !== undefined && value !== null && String(value).trim() !== '') {
      return value;
    }
  }

  return undefined;
}

async function resolveEventFromForm(form) {
  const directId = form?.event;
  if (!directId) return null;
  if (typeof directId === 'object' && directId._id) return String(directId._id);
  if (mongoose.Types.ObjectId.isValid(String(directId))) return String(directId);
  return null;
}

async function getParticipantListForEvent({ eventId, tenantOrganizationId }) {
  if (!eventId || !tenantOrganizationId) return null;
  return ParticipantList.findOne({
    tenantOrganization: tenantOrganizationId,
    event: eventId,
  }).lean();
}

async function isEmailInParticipantList({ list, tenantOrganizationId, email }) {
  if (!list) return false;
  const emailNorm = normalizeEmail(email);
  if (!emailNorm) return false;

  if (list.type === 'fixed' && Array.isArray(list.participantIds) && list.participantIds.length) {
    const p = await Participant.findOne({
      tenantOrganization: tenantOrganizationId,
      email: emailNorm,
      _id: { $in: list.participantIds },
    }).select('_id').lean();
    return !!p;
  }

  return false;
}

function collectUserEnteredFields({ dataObj }) {
  return dataObj && typeof dataObj === 'object' ? dataObj : {};
}

module.exports = {
  normalizeEmail,
  parseAccommodationValue,
  buildGateStatus,
  resolveSubmittedValue,
  resolveEventFromForm,
  getParticipantListForEvent,
  isEmailInParticipantList,
  collectUserEnteredFields,
};