// Mock flight data source.
// In production this would be replaced by an API call (e.g. FlightAware AeroAPI).

const AIRLINES = {
  AA: { name: "American Airlines", iata: "AA" },
  DL: { name: "Delta Air Lines", iata: "DL" },
  UA: { name: "United Airlines", iata: "UA" },
  BA: { name: "British Airways", iata: "BA" },
  LH: { name: "Lufthansa", iata: "LH" },
  AF: { name: "Air France", iata: "AF" },
  JL: { name: "Japan Airlines", iata: "JL" },
  QF: { name: "Qantas", iata: "QF" },
};

const AIRPORTS = {
  JFK: { city: "New York", country: "USA", lat: 40.6413, lon: -73.7781, tz: "America/New_York" },
  LAX: { city: "Los Angeles", country: "USA", lat: 33.9416, lon: -118.4085, tz: "America/Los_Angeles" },
  ORD: { city: "Chicago", country: "USA", lat: 41.9742, lon: -87.9073, tz: "America/Chicago" },
  SFO: { city: "San Francisco", country: "USA", lat: 37.6213, lon: -122.379, tz: "America/Los_Angeles" },
  ATL: { city: "Atlanta", country: "USA", lat: 33.6407, lon: -84.4277, tz: "America/New_York" },
  LHR: { city: "London", country: "UK", lat: 51.47, lon: -0.4543, tz: "Europe/London" },
  CDG: { city: "Paris", country: "France", lat: 49.0097, lon: 2.5479, tz: "Europe/Paris" },
  FRA: { city: "Frankfurt", country: "Germany", lat: 50.0333, lon: 8.5706, tz: "Europe/Berlin" },
  NRT: { city: "Tokyo", country: "Japan", lat: 35.772, lon: 140.3929, tz: "Asia/Tokyo" },
  SYD: { city: "Sydney", country: "Australia", lat: -33.9399, lon: 151.1753, tz: "Australia/Sydney" },
};

// key: `${airlineCode}-${flightNumber}`
const FLIGHTS = {
  "AA-100": { origin: "JFK", destination: "LAX", status: "on-time", depOffset: 45, durationMin: 330 },
  "AA-200": { origin: "LAX", destination: "JFK", status: "delayed", depOffset: 120, durationMin: 345, delayMin: 40 },
  "AA-300": { origin: "ORD", destination: "ATL", status: "on-time", depOffset: 90, durationMin: 110 },
  "DL-123": { origin: "ATL", destination: "SFO", status: "on-time", depOffset: 30, durationMin: 240 },
  "DL-456": { origin: "SFO", destination: "ATL", status: "cancelled", depOffset: 60, durationMin: 250 },
  "UA-789": { origin: "ORD", destination: "LHR", status: "delayed", depOffset: 180, durationMin: 420, delayMin: 25 },
  "UA-101": { origin: "LHR", destination: "ORD", status: "on-time", depOffset: 200, durationMin: 430 },
  "BA-117": { origin: "LHR", destination: "JFK", status: "on-time", depOffset: 15, durationMin: 420 },
  "BA-118": { origin: "JFK", destination: "LHR", status: "on-time", depOffset: 75, durationMin: 435 },
  "LH-400": { origin: "FRA", destination: "JFK", status: "delayed", depOffset: 100, durationMin: 440, delayMin: 55 },
  "LH-401": { origin: "JFK", destination: "FRA", status: "on-time", depOffset: 140, durationMin: 450 },
  "LH-700": { origin: "FRA", destination: "NRT", status: "on-time", depOffset: 220, durationMin: 720 },
  "AF-001": { origin: "CDG", destination: "JFK", status: "on-time", depOffset: 55, durationMin: 430 },
  "JL-003": { origin: "NRT", destination: "LAX", status: "delayed", depOffset: 260, durationMin: 480, delayMin: 35 },
  "QF-010": { origin: "SYD", destination: "LAX", status: "on-time", depOffset: 300, durationMin: 470 },
};

// --- i18n ---

const I18N = {
  en: {
    title: "Flight Lookup",
    subtitle: "Enter an airline and flight number to see its route.",
    airline: "Airline",
    airlinePlaceholder: "e.g. American, BA, Lufthansa…",
    flightNumber: "Flight number",
    flightNumberPlaceholder: "e.g. 100",
    lookup: "Look up flight",
    onTime: "On time",
    delayed: "Delayed",
    cancelled: "Cancelled",
    departs: "Departs",
    arrives: "Arrives",
    copyLink: "Copy link",
    copied: "Copied!",
    recentLookups: "Recent lookups",
    noFlightFound: "No flight found for {flight}. Try e.g. AA 100 or BA 117.",
    multipleAirlines: 'Multiple airlines match "{query}". Please select one from the list.',
    noAirlineFound: 'No airline found matching "{query}".',
    enterFlightNumber: "Please enter a flight number.",
    searching: "Searching…",
    networkError: "Network error. Please try again.",
    themeToggle: "Toggle theme",
    language: "Language",
    live: "LIVE",
    mock: "SAMPLE",
    airborne: "Airborne",
    onGround: "On ground",
    altitude: "Altitude",
    speed: "Speed",
    heading: "Heading",
    vertRate: "Vert. rate",
    position: "Position",
    lastSeen: "Last seen",
  },
  fr: {
    title: "Recherche de vol",
    subtitle: "Saisissez une compagnie et un numéro de vol pour voir son itinéraire.",
    airline: "Compagnie",
    airlinePlaceholder: "ex. American, BA, Lufthansa…",
    flightNumber: "Numéro de vol",
    flightNumberPlaceholder: "ex. 100",
    lookup: "Rechercher le vol",
    onTime: "À l'heure",
    delayed: "Retardé",
    cancelled: "Annulé",
    departs: "Départ",
    arrives: "Arrivée",
    copyLink: "Copier le lien",
    copied: "Copié !",
    recentLookups: "Recherches récentes",
    noFlightFound: "Aucun vol trouvé pour {flight}. Essayez p. ex. AA 100 ou BA 117.",
    multipleAirlines: 'Plusieurs compagnies correspondent à « {query} ». Veuillez en sélectionner une.',
    noAirlineFound: 'Aucune compagnie trouvée pour « {query} ».',
    enterFlightNumber: "Veuillez saisir un numéro de vol.",
    searching: "Recherche…",
    networkError: "Erreur réseau. Veuillez réessayer.",
    themeToggle: "Changer de thème",
    language: "Langue",
    live: "EN DIRECT",
    mock: "EXEMPLE",
    airborne: "En vol",
    onGround: "Au sol",
    altitude: "Altitude",
    speed: "Vitesse",
    heading: "Cap",
    vertRate: "Vitesse vert.",
    position: "Position",
    lastSeen: "Vu il y a",
  },
  de: {
    title: "Flugsuche",
    subtitle: "Geben Sie eine Airline und eine Flugnummer ein, um die Route zu sehen.",
    airline: "Airline",
    airlinePlaceholder: "z. B. American, BA, Lufthansa…",
    flightNumber: "Flugnummer",
    flightNumberPlaceholder: "z. B. 100",
    lookup: "Flug suchen",
    onTime: "Pünktlich",
    delayed: "Verspätet",
    cancelled: "Storniert",
    departs: "Abflug",
    arrives: "Ankunft",
    copyLink: "Link kopieren",
    copied: "Kopiert!",
    recentLookups: "Letzte Suchen",
    noFlightFound: "Kein Flug für {flight} gefunden. Z. B. AA 100 oder BA 117.",
    multipleAirlines: 'Mehrere Airlines passen auf „{query}". Bitte eine auswählen.',
    noAirlineFound: 'Keine Airline gefunden für „{query}"',
    enterFlightNumber: "Bitte geben Sie eine Flugnummer ein.",
    searching: "Suche…",
    networkError: "Netzwerkfehler. Bitte erneut versuchen.",
    themeToggle: "Theme wechseln",
    language: "Sprache",
    live: "LIVE",
    mock: "BEISPIEL",
    airborne: "In der Luft",
    onGround: "Am Boden",
    altitude: "Höhe",
    speed: "Geschwindigkeit",
    heading: "Richtung",
    vertRate: "Vertikalrate",
    position: "Position",
    lastSeen: "Zuletzt gesehen",
  },
  ja: {
    title: "フライト検索",
    subtitle: "航空会社とフライト番号を入力してルートを確認します。",
    airline: "航空会社",
    airlinePlaceholder: "例: American, BA, Lufthansa…",
    flightNumber: "フライト番号",
    flightNumberPlaceholder: "例: 100",
    lookup: "フライトを検索",
    onTime: "定時",
    delayed: "遅延",
    cancelled: "欠航",
    departs: "出発",
    arrives: "到着",
    copyLink: "リンクをコピー",
    copied: "コピーしました！",
    recentLookups: "最近の検索",
    noFlightFound: "{flight} のフライトが見つかりません。例: AA 100 や BA 117。",
    multipleAirlines: '「{query}」に複数の航空会社があります。一覧から選択してください。',
    noAirlineFound: '「{query}」に一致する航空会社が見つかりません。',
    enterFlightNumber: "フライト番号を入力してください。",
    searching: "検索中…",
    networkError: "ネットワークエラー。もう一度お試しください。",
    themeToggle: "テーマ切替",
    language: "言語",
    live: "ライブ",
    mock: "サンプル",
    airborne: "飛行中",
    onGround: "地上",
    altitude: "高度",
    speed: "速度",
    heading: "針路",
    vertRate: "垂直速度",
    position: "位置",
    lastSeen: "最終確認",
  },
};

const SUPPORTED_LANGS = ["en", "fr", "de", "ja"];

let currentLang = "en";

function t(key, params) {
  const dict = I18N[currentLang] || I18N.en;
  let str = dict[key] || I18N.en[key] || key;
  if (params) {
    for (const [k, v] of Object.entries(params)) {
      str = str.replace(`{${k}}`, v);
    }
  }
  return str;
}

function setLang(lang) {
  if (!SUPPORTED_LANGS.includes(lang)) lang = "en";
  currentLang = lang;
  document.documentElement.lang = lang;
  applyTranslations();
}

function applyTranslations() {
  document.title = t("title");
  document.querySelector("h1").textContent = t("title");
  document.querySelector(".subtitle").textContent = t("subtitle");
  document.querySelector('[for="airline"]').textContent = t("airline");
  airlineInput.placeholder = t("airlinePlaceholder");
  document.querySelector('[for="flight-number"]').textContent = t("flightNumber");
  flightInput.placeholder = t("flightNumberPlaceholder");
  document.querySelector('button[type="submit"]').textContent = t("lookup");
  const histHeading = document.querySelector("#history-section h2");
  if (histHeading) histHeading.textContent = t("recentLookups");
  const themeBtn = document.querySelector("#theme-toggle");
  if (themeBtn) themeBtn.title = t("themeToggle");
  const langLabel = document.querySelector('[for="lang"]');
  if (langLabel) langLabel.textContent = t("language");
  // Re-render result if visible
  if (lastFlight && !resultBox.classList.contains("hidden")) {
    renderResult(lastFlight);
  }
}

// --- Lookup (async to simulate network) ---

// Look up a flight. Tries the live OpenSky proxy first; if the flight has
// no live position (or the proxy is unavailable), falls back to the mock
// dataset so the UI always has something to show.
async function lookupFlight(airlineCode, flightNumber) {
  // 1) Try live data via the Node proxy
  try {
    const r = await fetch(
      `/api/lookup?code=${encodeURIComponent(airlineCode)}&num=${encodeURIComponent(flightNumber)}`
    );
    if (r.ok) {
      const live = await r.json();
      if (live.live) {
        // Enrich with airline name + airport info when we can
        const airlineName = AIRLINES[airlineCode] ? AIRLINES[airlineCode].name : airlineCode;
        return { ...live, airline: airlineName, live: true };
      }
      // live === false → not airborne or OpenSky error. Fall through to mock.
    }
  } catch (e) {
    // Proxy unreachable (e.g. opened via file://) — fall through to mock.
  }

  // 2) Fallback: mock dataset
  const key = `${airlineCode}-${flightNumber}`;
  const flight = FLIGHTS[key];
  if (!flight) return null;
  const now = Date.now();
  const depEpoch = now + flight.depOffset * 60000;
  const arrEpoch = depEpoch + flight.durationMin * 60000;
  return {
    airline: AIRLINES[airlineCode].name,
    airlineCode,
    flightNumber,
    status: flight.status,
    delayMin: flight.delayMin || 0,
    origin: { code: flight.origin, ...AIRPORTS[flight.origin] },
    destination: { code: flight.destination, ...AIRPORTS[flight.destination] },
    depTime: depEpoch,
    arrTime: arrEpoch,
    live: false,
  };
}

// Fuzzy airline search
function searchAirlines(query) {
  const q = query.trim().toLowerCase();
  if (!q) return Object.entries(AIRLINES).map(([code, a]) => ({ code, name: a.name }));

  const scored = Object.entries(AIRLINES).map(([code, a]) => {
    const name = a.name.toLowerCase();
    let score = 0;
    if (code.toLowerCase() === q) score = 100;
    else if (code.toLowerCase().startsWith(q)) score = 80;
    else if (name.startsWith(q)) score = 70;
    else if (name.includes(q)) score = 50;
    else {
      let idx = 0;
      for (const ch of name) {
        if (ch === q[idx]) idx++;
        if (idx === q.length) break;
      }
      if (idx === q.length) score = 30;
    }
    return { code, name: a.name, score };
  }).filter((a) => a.score > 0);

  scored.sort((a, b) => b.score - a.score || a.name.localeCompare(b.name));
  return scored.map(({ code, name }) => ({ code, name }));
}

function encodeFlight(airlineCode, flightNumber) {
  return `?f=${encodeURIComponent(airlineCode)}${encodeURIComponent(flightNumber)}`;
}

function decodeFlight(url) {
  const params = new URLSearchParams(url.search);
  const f = params.get("f");
  if (!f) return null;
  const match = f.match(/^([A-Z]{2,3})(\d+)$/i);
  if (!match) return null;
  return { airline: match[1].toUpperCase(), number: match[2] };
}