const axios = require('axios');

const BASE_URL = 'https://foodsharing.de';

const client = axios.create({
  baseURL: BASE_URL,
  timeout: 20000,
  headers: {
    'User-Agent': 'pickup-config/1.0 (+https://foodsharing.de)',
    Accept: 'application/json, text/plain, */*'
  }
});

function extractCsrfToken(cookies = []) {
  if (!Array.isArray(cookies)) {
    return null;
  }
  const tokenCookie = cookies.find((cookie) => cookie.startsWith('CSRF_TOKEN='));
  if (!tokenCookie) {
    return null;
  }
  return tokenCookie.split(';')[0].split('=')[1];
}

function serializeCookies(cookies = []) {
  if (!Array.isArray(cookies)) {
    return '';
  }
  return cookies.map((c) => c.split(';')[0]).join('; ');
}

function buildHeaders(cookieHeader, csrfToken) {
  const headers = {};
  if (cookieHeader) {
    headers.cookie = cookieHeader;
  }
  if (csrfToken) {
    headers['x-csrf-token'] = csrfToken;
  }
  return headers;
}

async function getCurrentUserDetails(cookieHeader) {
  const response = await client.get('/api/user/current/details', {
    headers: buildHeaders(cookieHeader)
  });
  return response.data;
}

async function login(email, password) {
  const payload = {
    email,
    password,
    remember_me: true
  };

  const headers = {
    'sec-ch-ua': '"Chromium";v="128", "Not;A=Brand";v="24", "Google Chrome";v="128"',
    Referer: BASE_URL,
    DNT: '1',
    'sec-ch-ua-mobile': '?0',
    'sec-ch-ua-platform': '"Linux"',
    'Content-Type': 'application/json; charset=utf-8'
  };

  const response = await client.post('/api/user/login', payload, { headers });
  const cookies = response.headers['set-cookie'] || [];
  const csrfToken = extractCsrfToken(cookies);
  const cookieHeader = serializeCookies(cookies);
  const details = await getCurrentUserDetails(cookieHeader);
  if (!details?.id) {
    throw new Error('Profil-ID konnte nicht ermittelt werden.');
  }

  const nameParts = [];
  if (details.firstname) {
    nameParts.push(details.firstname);
  }
  if (details.lastname) {
    nameParts.push(details.lastname);
  }

  return {
    csrfToken,
    cookieHeader,
    profile: {
      id: String(details.id),
      name: nameParts.length > 0 ? nameParts.join(' ') : details.email || email,
      email: details.email || email
    }
  };
}

async function checkSession(cookieHeader, profileId) {
  if (!cookieHeader) {
    return false;
  }

  try {
    await client.get(`/api/wall/foodsaver/${profileId}?limit=1`, {
      headers: buildHeaders(cookieHeader)
    });
    return true;
  } catch {
    return false;
  }
}

async function fetchProfile(cookieHeader) {
  try {
    return await getCurrentUserDetails(cookieHeader);
  } catch (error) {
    console.warn('Profil konnte nicht geladen werden:', error.message);
    return null;
  }
}

function wait(ms = 0) {
  return new Promise((resolve) => setTimeout(resolve, ms));
}

async function fetchStores(cookieHeader, profileId, options = {}) {
  if (!profileId) {
    return [];
  }
  const delayBetweenRequestsMs = Number.isFinite(options.delayBetweenRequestsMs)
    ? Math.max(0, options.delayBetweenRequestsMs)
    : 0;
  const onStoreCheck =
    typeof options.onStoreCheck === 'function'
      ? options.onStoreCheck
      : null;
  try {
    const response = await client.get(`/api/user/${profileId}/stores`, {
      headers: buildHeaders(cookieHeader),
      params: { activeStores: 1 }
    });
    const stores = Array.isArray(response.data) ? response.data : [];
    const normalized = stores.map((store) => ({
      id: String(store.id),
      name: store.name || `Store ${store.id}`,
      pickupStatus: store.pickupStatus,
      membershipStatus: store.membershipStatus,
      isManaging: !!store.isManaging,
      city: store.city || '',
      street: store.street || '',
      zip: store.zip || ''
    }));

    return annotateStoresWithPickupSlots(normalized, cookieHeader, delayBetweenRequestsMs, onStoreCheck);
  } catch (error) {
    console.warn('Stores konnten nicht geladen werden:', error.message);
    return [];
  }
}

async function annotateStoresWithPickupSlots(stores, cookieHeader, delayBetweenRequestsMs = 0, onStoreCheck) {
  if (!Array.isArray(stores) || stores.length === 0) {
    return [];
  }

  const delayMs = Number.isFinite(delayBetweenRequestsMs) ? Math.max(0, delayBetweenRequestsMs) : 0;
  const annotated = [];

  for (let index = 0; index < stores.length; index += 1) {
    const store = stores[index];
    if (onStoreCheck) {
      try {
        onStoreCheck(store, index + 1, stores.length);
      } catch (callbackError) {
        console.warn('Store-Progress-Callback fehlgeschlagen:', callbackError);
      }
    }
    if (delayMs > 0 && index > 0) {
      await wait(delayMs);
    }
    let hasPickupSlots = null;
    try {
      const pickups = await fetchPickups(store.id, cookieHeader);
      hasPickupSlots = Array.isArray(pickups) && pickups.length > 0;
    } catch (error) {
      const status = error?.response?.status;
      if (status === 403) {
        hasPickupSlots = false;
        console.warn(`Pickups für Store ${store.id} nicht erlaubt (403) – wird als ohne Slots behandelt.`);
      } else {
        console.warn(`Pickups für Store ${store.id} konnten nicht geprüft werden:`, error.message);
      }
    }
    annotated.push({ ...store, hasPickupSlots });
  }

  return annotated;
}

async function fetchPickups(storeId, cookieHeader) {
  const response = await client.get(`/api/stores/${storeId}/pickups`, {
    headers: buildHeaders(cookieHeader)
  });
  return response.data?.pickups || [];
}

async function pickupRuleCheck(storeId, utcDate, profileId, session) {
  const response = await client.get(`/api/stores/${storeId}/pickupRuleCheck/${utcDate}/${profileId}`, {
    headers: buildHeaders(session.cookieHeader, session.csrfToken)
  });
  return response.data?.result === true;
}

async function bookSlot(storeId, utcDate, profileId, session) {
  await client.post(
    `/api/stores/${storeId}/pickups/${utcDate}/${profileId}`,
    {},
    {
      headers: buildHeaders(session.cookieHeader, session.csrfToken)
    }
  );
}

module.exports = {
  login,
  checkSession,
  fetchProfile,
  fetchStores,
  fetchPickups,
  pickupRuleCheck,
  bookSlot
};