function resolveServiceUrl(explicitEnv, fallbackPort, suffix = "") {
  const explicit = String(explicitEnv || "").trim();
  if (explicit) {
    return explicit.replace(/\/$/, "") + suffix;
  }

  if (typeof window !== "undefined") {
    const { protocol, hostname } = window.location;
    return `${protocol}//${hostname}:${fallbackPort}${suffix}`;
  }

  return `http://localhost:${fallbackPort}${suffix}`;
}

const API_URL = resolveServiceUrl(import.meta.env.VITE_API_URL, import.meta.env.VITE_API_PORT || "18080", "/api");
const COLLECTOR_URL = resolveServiceUrl(import.meta.env.VITE_COLLECTOR_URL, import.meta.env.VITE_COLLECTOR_PORT || "18110");

async function request(baseUrl, path, options = {}) {
  const headers = {
    ...(options.token ? { Authorization: `Bearer ${options.token}` } : {}),
    ...options.headers,
  };

  const isJsonBody = options.body !== undefined && !(options.body instanceof FormData);
  if (isJsonBody) {
    headers["Content-Type"] = "application/json";
  }

  const response = await fetch(baseUrl + path, {
    headers,
    method: options.method || "GET",
    cache: options.cache || "no-store",
    body: options.body === undefined ? undefined : isJsonBody ? JSON.stringify(options.body) : options.body,
  });

  if (response.status === 204) {
    return null;
  }

  const data = await response.json().catch(() => ({}));

  if (!response.ok) {
    throw new Error(data.error || "Anfrage fehlgeschlagen.");
  }

  return data;
}

const apiRequest = (path, options) => request(API_URL, path, options);
const collectorRequest = (path, options) => request(COLLECTOR_URL, path, options);

export const api = {
  login: (body) => apiRequest("/auth/login", { method: "POST", body }),
  me: (token) => apiRequest("/auth/me", { token }),
  changePassword: (token, body) => apiRequest("/auth/change-password", { method: "POST", token, body }),
  health: () => apiRequest("/health"),
  getIsps: (token) => apiRequest("/isps", { token }),
  getAliases: (token, isp) => apiRequest(`/isps/${isp}/aliases`, { token }),
  saveAliases: (token, isp, body) => apiRequest(`/isps/${isp}/aliases`, { method: "PUT", token, body }),
  getUnits: (token) => apiRequest("/units", { token }),
  createUnit: (token, body) => apiRequest("/units", { method: "POST", token, body }),
  updateUnit: (token, symbol, body) => apiRequest(`/units/${encodeURIComponent(symbol)}`, { method: "PATCH", token, body }),
  createTrendTable: (token, body) => apiRequest("/trend-tables", { method: "POST", token, body }),
  normalizeAliasMetadata: (token, body) => apiRequest("/admin/normalize-alias-metadata", { method: "POST", token, body }),
  importSql: (token, body) => apiRequest("/admin/import-sql", { method: "POST", token, body }),
  getUsers: (token) => apiRequest("/users", { token }),
  createUser: (token, body) => apiRequest("/users", { method: "POST", token, body }),
  updateUser: (token, id, body) => apiRequest(`/users/${id}`, { method: "PATCH", token, body }),
  getRoles: (token) => apiRequest("/roles", { token }),
  createRole: (token, body) => apiRequest("/roles", { method: "POST", token, body }),
  updateRole: (token, name, body) => apiRequest(`/roles/${encodeURIComponent(name)}`, { method: "PATCH", token, body }),
  getSelections: (token) => apiRequest("/selections", { token }),
  createSelection: (token, body) => apiRequest("/selections", { method: "POST", token, body }),
  updateSelection: (token, id, body) => apiRequest(`/selections/${id}`, { method: "PUT", token, body }),
  deleteSelection: (token, id) => apiRequest(`/selections/${id}`, { method: "DELETE", token }),
  queryTrends: (token, body) => apiRequest("/trends/query", { method: "POST", token, body }),
  latestValues: (token, body) => apiRequest("/points/latest", { method: "POST", token, body }),
  getDashboard: (token) => apiRequest("/dashboard", { token }),
  saveDashboard: (token, body) => apiRequest("/dashboard", { method: "PUT", token, body }),
  loadDashboardData: (token, body) => apiRequest("/dashboard/data", { method: "POST", token, body }),
  getPreferences: (token) => apiRequest("/preferences", { token }),
  savePreferences: (token, body) => apiRequest("/preferences", { method: "PUT", token, body }),
  getIntegrations: (token) => apiRequest("/integrations", { token }),
  saveIntegrations: (token, body) => apiRequest("/integrations", { method: "PUT", token, body }),
  getRunnerJobs: (token) => apiRequest("/runner/jobs", { token }),
  createRunnerJob: (token, body) => apiRequest("/runner/jobs", { method: "POST", token, body }),
  updateRunnerJob: (token, id, body) => apiRequest(`/runner/jobs/${encodeURIComponent(id)}`, { method: "PATCH", token, body }),
  testRunnerJob: (token, id) => apiRequest(`/runner/jobs/${encodeURIComponent(id)}/test`, { method: "POST", token }),
  deleteRunnerJob: (token, id) => apiRequest(`/runner/jobs/${encodeURIComponent(id)}`, { method: "DELETE", token }),
  getCollectorCapabilities: () => collectorRequest("/capabilities"),
  getCollectorSources: () => collectorRequest("/sources"),
  getCollectorDatapoints: (sourceId = "") => collectorRequest(sourceId ? `/datapoints?sourceId=${encodeURIComponent(sourceId)}` : "/datapoints"),
  createCollectorSource: (body) => collectorRequest("/sources", { method: "POST", body }),
  updateCollectorSource: (id, body) => collectorRequest(`/sources/${id}`, { method: "PUT", body }),
  deleteCollectorSource: (id) => collectorRequest(`/sources/${id}`, { method: "DELETE" }),
  createCollectorDatapoint: (body) => collectorRequest("/datapoints/manual", { method: "POST", body }),
  updateCollectorDatapoint: (id, body) => collectorRequest(`/datapoints/${encodeURIComponent(id)}`, { method: "PATCH", body }),
  readCollectorDatapoint: (id) => collectorRequest(`/datapoints/${encodeURIComponent(id)}/read`, { method: "POST" }),
  getCollectorDebug: () => collectorRequest("/debug"),
  importModbusCsv: (body) => collectorRequest("/imports/modbus-csv", { method: "POST", body }),
  importKnxXml: (body) => collectorRequest("/imports/knx-xml", { method: "POST", body }),
  scanOpcua: (body) => collectorRequest("/scan/opcua", { method: "POST", body }),
  scanBacnet: (body) => collectorRequest("/scan/bacnet", { method: "POST", body }),
  scanIpsymcon: (body) => collectorRequest("/scan/ipsymcon", { method: "POST", body }),
};