// Lightweight client that talks to your PHP proxy via fetch.
// Returns Airport/Flight objects with helpful methods.

export class Airport {
  constructor(dto) {
    Object.assign(this, dto);
  }
  get display() {
    const code = this.iata || this.icao || '';
    return `${code} – ${this.name}${this.city ? ' (' + this.city + ')' : ''}`;
  }
}

export class Flight {
  constructor(dto) {
    Object.assign(this, dto);
  }
  summary() {
    const s = [];
    if (this.departureAirport?.iata) s.push(this.departureAirport.iata);
    if (this.arrivalAirport?.iata) s.push(this.arrivalAirport.iata);
    const route = s.length ? s.join(' → ') : 'Flight';
    const co2 = this.emissions?.co2_total ?? this.co2 ?? null;
    return co2 != null ? `${route}: ${co2} kg CO₂e` : route;
  }
}

export class Calco2latoClient {
  /**
   * @param {string} proxyUrl e.g. "/api-proxy.php"
   * @param {object} [options]
   * @param {number} [options.timeoutMs=10000]
   */
  constructor(proxyUrl, { timeoutMs = 10000 } = {}) {
    this.proxyUrl = proxyUrl;
    this.timeoutMs = timeoutMs;
  }

  async _fetchJSON(payloadOrQuery) {
    const { method = 'GET', query = null, body = null } = payloadOrQuery;
    const url = new URL(this.proxyUrl, window.location.origin);
    if (query) {
      for (const [k, v] of Object.entries(query)) {
        if (v !== undefined && v !== null) url.searchParams.set(k, String(v));
      }
    }

    const ctrl = new AbortController();
    const t = setTimeout(() => ctrl.abort(), this.timeoutMs);

    try {
      const res = await fetch(url.toString(), {
        method,
        headers: body ? { 'Content-Type': 'application/json' } : undefined,
        body: body ? JSON.stringify(body) : undefined,
        credentials: 'include',
        signal: ctrl.signal,
      });
      const data = await res.json().catch(() => ({}));
      if (!res.ok) {
        throw new Error(data?.error || `HTTP ${res.status}`);
      }
      return data;
    } finally {
      clearTimeout(t);
    }
  }

  // ---------- Airports ----------

  /**
   * @param {string} q
   * @param {number} [limit=20]
   * @param {number} [offset=1]
   * @returns {Promise<Airport[]>}
   */
  async searchAirports(q, limit = 20, offset = 1) {
    const data = await this._fetchJSON({
      method: 'GET',
      query: { endpoint: 'airports.search', iata: q, per_page: limit, page: offset }
    });
	  const items = Array.isArray(data?.results) ? data.results : (Array.isArray(data) ? data : []);
    return items.map(a => new Airport(a));
  }

  // ---------- Flights ----------

  /**
   * @param {object} params e.g. { origin: "FRA", destination: "LHR", date: "2025-09-20", pax: 1, cabin: "economy" }
   * @returns {Promise<Flight>}
   */
  async estimateFlight(params) {
    const data = await this._fetchJSON({
      method: 'POST',
      body: { endpoint: 'flights.estimate', params }
    });
    return new Flight(data.flights[0]);
  }
}