/**
 * Load pharmacy rows from a public open-data URL (JSON array, GeoJSON, or similar).
 * No default URL — pass the dataset URL from the client (regional open-data portals).
 */

function rowsFromGeoJson(json) {
  if (!json || json.type !== 'FeatureCollection' || !Array.isArray(json.features)) {
    return [];
  }
  return json.features
    .map((f) => {
      const p = f.properties || {};
      const name = p.name || p.nombre || p.denominacion || p.title;
      const address =
        p.address ||
        p.direccion ||
        p.domicilio ||
        [p.calle, p.municipio, p.codigo_postal].filter(Boolean).join(', ');
      let lat;
      let lon;
      if (f.geometry?.type === 'Point' && Array.isArray(f.geometry.coordinates)) {
        lon = f.geometry.coordinates[0];
        lat = f.geometry.coordinates[1];
      }
      return {
        name: name ? String(name).trim() : null,
        address: address ? String(address).trim() : null,
        phone: p.phone || p.telefono || p.tel || null,
        latitude: lat != null ? Number(lat) : null,
        longitude: lon != null ? Number(lon) : null,
      };
    })
    .filter((r) => r.name && r.address);
}

function rowsFromJsonArray(json) {
  if (!Array.isArray(json)) return [];
  return json
    .map((row) => {
      if (!row || typeof row !== 'object') return null;
      const name = row.name || row.nombre || row.farmacia;
      const address =
        row.address ||
        row.direccion ||
        row.domicilio ||
        row.full_address;
      return {
        name: name ? String(name).trim() : null,
        address: address ? String(address).trim() : null,
        phone: row.phone || row.telefono || null,
        latitude:
          row.latitude != null
            ? Number(row.latitude)
            : row.lat != null
              ? Number(row.lat)
              : null,
        longitude:
          row.longitude != null
            ? Number(row.longitude)
            : row.lon != null
              ? Number(row.lon)
              : row.lng != null
                ? Number(row.lng)
                : null,
      };
    })
    .filter((r) => r && r.name && r.address);
}

/**
 * @param {string} openDataUrl - HTTPS URL returning JSON
 * @returns {Promise<Array<{name,address,phone,latitude,longitude}>>}
 */
export async function fetchPharmaciesFromOpenDataUrl(openDataUrl) {
  if (!openDataUrl || typeof openDataUrl !== 'string' || !openDataUrl.trim()) {
    throw new Error('openData source requires a non-empty openDataUrl');
  }
  const u = openDataUrl.trim();
  if (!/^https?:\/\//i.test(u)) {
    throw new Error('openDataUrl must be an http(s) URL');
  }

  const res = await fetch(u, {
    headers: {
      Accept: 'application/json',
      'User-Agent': 'FarmaFinder/1.0 (open-data pharmacy import)',
    },
  });
  const text = await res.text();
  if (!res.ok) {
    throw new Error(`Open data HTTP ${res.status}: ${text.slice(0, 120)}`);
  }
  let json;
  try {
    json = text ? JSON.parse(text) : null;
  } catch {
    throw new Error('Open data response is not JSON');
  }

  if (json && json.type === 'FeatureCollection') {
    return rowsFromGeoJson(json);
  }
  if (Array.isArray(json)) {
    return rowsFromJsonArray(json);
  }
  if (json && Array.isArray(json.data)) {
    return rowsFromJsonArray(json.data);
  }
  if (json && Array.isArray(json.records)) {
    return rowsFromJsonArray(json.records);
  }

  throw new Error(
    'Unsupported open-data JSON shape (expected FeatureCollection, array, or { data: [] })'
  );
}