const {
  getStoreLocation,
  getStoreRegisters,
  getStorePrinters,
  getStorePaymentTerminals,
} = require('../services/siw');
const {
  findMerakiNetwork,
  getMerakiDeviceAvailabilities,
  getMerakiClients,
} = require('../services/meraki');
const { getMDMDevices } = require('../services/mdm');
const { createStore } = require('../models/Store');
const {
  findMatchingClient,
  getClientStatus,
  formatLastSeen,
  buildMerakiClientLink,
} = require('../utils/merakiMatcher');
const { STORE_MODES, MDM_DEVICE_TYPES, filterMdmByType } = require('../constants');
const logger = require('../utils/logger');

function shouldFetchForMode(mode, category) {
  if (mode === STORE_MODES.IOS) {
    return ['mdm', 'meraki', 'merakiClients'].includes(category);
  }
  if (mode === STORE_MODES.POS) {
    return ['siw', 'mdm', 'meraki', 'merakiClients'].includes(category);
  }
  return true; // default fetches most things
}

async function getStoreDetail(storeNumber, mode = STORE_MODES.DEFAULT) {
  logger.info('Starting store analysis', { storeNumber, mode });

  let locationData = null,
    merakiNetwork = null,
    registers = [],
    printers = [],
    paymentTerminals = [],
    merakiClients = [],
    mdmDevices = [];

  try {
    // Phase 1: basic lookups
    [locationData, merakiNetwork] = await Promise.all([
      shouldFetchForMode(mode, 'location') ? getStoreLocation(storeNumber) : Promise.resolve(null),
      shouldFetchForMode(mode, 'meraki') ? findMerakiNetwork(storeNumber) : Promise.resolve(null),
    ]);

    // Phase 2: heavy data, fanned out in parallel
    const dataPromises = [];

    if (shouldFetchForMode(mode, 'siw')) {
      dataPromises.push(
        getStoreRegisters(storeNumber),
        getStorePrinters(storeNumber),
        getStorePaymentTerminals(storeNumber)
      );
    } else {
      dataPromises.push(Promise.resolve([]), Promise.resolve([]), Promise.resolve([]));
    }

    dataPromises.push(
      merakiNetwork && shouldFetchForMode(mode, 'merakiClients')
        ? getMerakiClients(merakiNetwork.id)
        : Promise.resolve([])
    );

    dataPromises.push(
      shouldFetchForMode(mode, 'mdm') ? getMDMDevices(storeNumber) : Promise.resolve([])
    );

    const [reg, prn, pay, clients, mdm] = await Promise.all(dataPromises);
    registers = reg || [];
    printers = prn || [];
    paymentTerminals = pay || [];
    merakiClients = clients || [];
    mdmDevices = mdm || [];

    logger.info('Store data fetched', { mode });
  } catch (err) {
    logger.error('Error fetching store data', { error: err.message });
  }

  let report = '';

  if (mode === STORE_MODES.DEFAULT) {
    report += createStore(locationData, storeNumber).toSummary();
    report += await buildActiveNetworkDevices(merakiNetwork);
    report += buildStoreServers(mdmDevices, merakiClients, merakiNetwork);
  } else if (mode === STORE_MODES.POS) {
    report += buildStoreServers(mdmDevices, merakiClients, merakiNetwork);
    report += buildRegisters(registers, merakiClients, merakiNetwork);
    report += buildMobileRegisters(mdmDevices, merakiClients, merakiNetwork);
    report += buildPrinters(printers, merakiClients, merakiNetwork);
    report += buildPaymentTerminals(paymentTerminals, merakiClients, merakiNetwork);
  } else if (mode === STORE_MODES.IOS) {
    report += buildIOSDevices(mdmDevices, merakiClients, merakiNetwork);
  }

  return report || 'No matching data for this view.';
}

// === Section Builders ===

/**
 * Render a single "device → matched Meraki client" line.
 * `prefixParts` is rendered before the status; `identifiers` is passed
 * straight through to findMatchingClient.
 */
function renderClientLine({ prefixParts, identifiers, merakiClients, merakiNetwork }) {
  const match = findMatchingClient(merakiClients, identifiers);
  const status = getClientStatus(match);
  const lastSeen = formatLastSeen(match?.lastSeen);
  const recentDevice = match?.recentDeviceName ? ` via ${match.recentDeviceName}` : '';
  const connection = match?.recentDeviceConnection ? ` (${match.recentDeviceConnection})` : '';
  const link = match ? ` → [Meraki Client](${buildMerakiClientLink(merakiNetwork, match)})` : '';
  const prefix = prefixParts.filter(Boolean).join(' — ');
  return `${prefix} — ${status} — ${lastSeen}${recentDevice}${connection}${link}\n`;
}

async function buildActiveNetworkDevices(merakiNetwork) {
  if (!merakiNetwork) return '\n⚠️ No matching Meraki network found.\n';

  let out = `**🌐 [${merakiNetwork.name}](${merakiNetwork.url})**\n\n`;

  let activeDevices = [];
  try {
    const availabilities = await getMerakiDeviceAvailabilities(merakiNetwork.id);
    activeDevices = availabilities.filter(d => d.status !== 'dormant');
  } catch (e) {
    logger.error('Device availabilities failed', { error: e.message });
  }

  activeDevices.sort((a, b) => {
    const nameA = (a.name || '').trim().toUpperCase();
    const nameB = (b.name || '').trim().toUpperCase();

    if (nameA.includes('SWR') || /SW.*R\d?$/.test(nameA)) return -1;
    if (nameB.includes('SWR') || /SW.*R\d?$/.test(nameB)) return 1;

    if (nameA.includes('SWF') || /SW.*F\d/.test(nameA)) return -1;
    if (nameB.includes('SWF') || /SW.*F\d/.test(nameB)) return 1;

    return nameA.localeCompare(nameB);
  });

  out += `**🛠️ Active Network Devices (${activeDevices.length})**\n`;

  activeDevices.forEach(dev => {
    const statusEmoji = dev.status === 'online' ? '✅' : '⚠️';
    const deviceName = (dev.name || dev.serial || 'Unknown').trim();

    out += `**${deviceName}** — ${statusEmoji} ${dev.status}`;

    if (dev.serial && merakiNetwork.url) {
      const urlParts = merakiNetwork.url.split('/n/');
      const networkCode = urlParts[1] ? urlParts[1].split('/')[0] : merakiNetwork.id;
      let link = `${urlParts[0]}/n/${networkCode}`;

      if (dev.productType === 'switch') link += `/manage/switches/${dev.serial}/summary`;
      else if (dev.productType === 'wireless')
        link += `/manage/access_points/${dev.serial}/summary`;
      else link += `/manage/${dev.serial}/summary`;

      out += ` → [Dashboard](${link})`;
    }
    out += `\n`;
  });

  return out;
}

function buildMdmSection({
  devices,
  marker,
  title,
  fallbackName,
  merakiClients,
  merakiNetwork,
  formatPrefix,
}) {
  const filtered = filterMdmByType(devices, marker);
  if (filtered.length === 0) return '';

  let out = `\n**${title} (${filtered.length})**\n`;

  filtered.forEach(dev => {
    const name = dev.UserName || dev.DeviceFriendlyName || fallbackName;
    out += renderClientLine({
      prefixParts: formatPrefix ? formatPrefix(name, dev) : [`**${name}**`],
      identifiers: {
        UserName: dev.UserName,
        DeviceFriendlyName: dev.DeviceFriendlyName,
        name,
      },
      merakiClients,
      merakiNetwork,
    });
  });

  return out;
}

function buildStoreServers(mdmDevices, merakiClients, merakiNetwork) {
  return buildMdmSection({
    devices: mdmDevices,
    marker: MDM_DEVICE_TYPES.SERVER,
    title: '🖥️ Store Servers',
    fallbackName: 'Unknown Server',
    merakiClients,
    merakiNetwork,
  });
}

function buildMobileRegisters(mdmDevices, merakiClients, merakiNetwork) {
  return buildMdmSection({
    devices: mdmDevices,
    marker: MDM_DEVICE_TYPES.MOBILE_REGISTER,
    title: '📱 Mobile Registers',
    fallbackName: 'Unknown Mobile Register',
    merakiClients,
    merakiNetwork,
  });
}

function buildIOSDevices(mdmDevices, merakiClients, merakiNetwork) {
  return buildMdmSection({
    devices: mdmDevices,
    marker: MDM_DEVICE_TYPES.IPHONE,
    title: '📱 Store iPhones',
    fallbackName: 'Unknown iPhone',
    merakiClients,
    merakiNetwork,
  });
}

function buildRegisters(registers, merakiClients, merakiNetwork) {
  if (!registers || registers.length === 0) return '';

  let out = `\n**🖥️ Store Registers (${registers.length})**\n`;

  registers.forEach(reg => {
    const regNum = reg.register_number ? `Register ${reg.register_number}` : 'Register';
    const brand = reg.brand_display_name || 'Unknown';
    const type = reg.register_type_name || 'Unknown';
    const name = (reg.register_display_name || reg.printer_name || 'Unknown').trim();

    out += renderClientLine({
      prefixParts: [`**${regNum}**`, brand, type],
      identifiers: { name, register_display_name: name },
      merakiClients,
      merakiNetwork,
    });
  });

  return out;
}

function buildPrinters(printers, merakiClients, merakiNetwork) {
  const filtered = (printers || []).filter(
    p => (p.connection_type_name || '').toLowerCase() !== 'usb'
  );
  if (filtered.length === 0) return '';

  let out = `\n**🖨️ Store Printers (${filtered.length})**\n`;

  filtered.forEach(printer => {
    const name = (printer.printer_name || 'Unknown').trim();
    const model = printer.printer_model_name || 'N/A';
    out += renderClientLine({
      prefixParts: [`**${name}**`, model],
      identifiers: { name, printer_name: name },
      merakiClients,
      merakiNetwork,
    });
  });

  return out;
}

function buildPaymentTerminals(paymentTerminals, merakiClients, merakiNetwork) {
  if (!paymentTerminals || paymentTerminals.length === 0) return '';

  let out = `\n**💳 Payment Terminals (${paymentTerminals.length})**\n`;

  paymentTerminals.forEach(term => {
    const deviceName = term.device_name || 'Unknown Terminal';
    const adyenName = term.adyen_device_name || 'N/A';
    const model = term.device_model_name || 'N/A';
    const type = term.device_type_name || 'N/A';
    out += renderClientLine({
      prefixParts: [`**${deviceName}**`, adyenName, model, type],
      identifiers: { deviceName, adyenName, ip_address: term.ip_address },
      merakiClients,
      merakiNetwork,
    });
  });

  return out;
}

module.exports = { getStoreDetail };