// Single client for the Car Control API Server. The web app never talks to
// PocketBase directly — only to these endpoints (proxied to the API Server in
// dev via vite.config.js).

// Default API base: the Vite env override, else the same-origin "/api" (proxied
// to the API Server in dev). A user can override this at runtime via the login
// screen's "Server settings" — stored in localStorage and used for every call.
export const DEFAULT_API_BASE = import.meta.env.VITE_API_BASE || "/api";
const SERVER_KEY = "cc_server_url";

// Resolved fresh on each request so changing it takes effect without a reload.
function apiBase() {
  return localStorage.getItem(SERVER_KEY) || DEFAULT_API_BASE;
}

export function getServerUrl() {
  return localStorage.getItem(SERVER_KEY) || "";
}

// Persist a custom API base URL (trailing slashes trimmed). Empty/blank clears
// the override, falling back to the default.
export function setServerUrl(url) {
  const trimmed = (url || "").trim().replace(/\/+$/, "");
  if (trimmed) localStorage.setItem(SERVER_KEY, trimmed);
  else localStorage.removeItem(SERVER_KEY);
}

export const TOKEN_KEY = "cc_token";
export const USER_KEY = "cc_user";

function authHeader() {
  const t = localStorage.getItem(TOKEN_KEY);
  return t ? { Authorization: "Bearer " + t } : {};
}

async function handleResponse(res, path) {
  // An expired/invalid token on any non-login call ends the session.
  if (res.status === 401 && path !== "/auth/login") {
    localStorage.removeItem(TOKEN_KEY);
    localStorage.removeItem(USER_KEY);
    if (location.pathname !== "/login") location.href = "/login";
    throw new Error("Session expired — please log in again.");
  }

  if (res.status === 204) return null;
  const text = await res.text();
  const data = text ? JSON.parse(text) : null;
  if (!res.ok) throw new Error(errorMessage(data, res.statusText));
  return data;
}

// Digs a human-readable message out of the error shapes in play: this server's
// {error}, and PocketBase's {message, data:{field:{message}}} — which the user
// and organization endpoints relay verbatim, so a duplicate email arrives as a
// per-field error rather than a flat string.
function errorMessage(data, fallback) {
  if (!data || typeof data !== "object") return fallback;
  if (data.error) return data.error;
  const fieldErrors = Object.entries(data.data || {})
    .map(([field, e]) => `${field}: ${e?.message || e}`)
    .filter(Boolean);
  if (fieldErrors.length) return fieldErrors.join("; ");
  return data.message || fallback;
}

async function request(path, options = {}) {
  const res = await fetch(apiBase() + path, {
    headers: { "Content-Type": "application/json", ...authHeader(), ...(options.headers || {}) },
    ...options,
  });
  return handleResponse(res, path);
}

// Like request(), but for multipart/form-data bodies (file uploads) — the
// browser sets its own Content-Type (with boundary), so we must not.
async function requestForm(path, options = {}) {
  const res = await fetch(apiBase() + path, { headers: { ...authHeader() }, ...options });
  return handleResponse(res, path);
}

// Fetches a binary response (image, export file) as a Blob, since it needs the
// Authorization header — a plain <img src> or <a href> can't attach one.
async function requestBlob(path) {
  const res = await fetch(apiBase() + path, { headers: authHeader() });
  if (res.status === 401) return handleResponse(res, path);
  if (!res.ok) throw new Error("Request failed: " + res.statusText);
  const filename = (res.headers.get("Content-Disposition") || "").match(/filename="([^"]+)"/)?.[1];
  return { blob: await res.blob(), filename };
}

// Attachments. Every record that can carry a file — documents, service records,
// workshop visits, refills, catalog parts — exposes the same three endpoints
// under its own path, so they are built from one place rather than spelled out
// five times.
//
// The file is proxied by the API (PocketBase's files aren't public), so it needs
// the auth header — hence a multipart POST and a Blob fetch rather than a plain
// <a href>. Uploading addresses a record that must already exist; see
// applyAttachment in lib/attachment.js for the order the forms use.
const attachment = (path) => ({
  upload: (id, file) => {
    const form = new FormData();
    form.append("file", file);
    return requestForm(`${path}/${id}/file`, { method: "POST", body: form });
  },
  download: (id) => requestBlob(`${path}/${id}/file`),
  remove: (id) => request(`${path}/${id}/file`, { method: "DELETE" }),
});

export const api = {
  // Auth
  login: (email, password) =>
    request("/auth/login", { method: "POST", body: JSON.stringify({ email, password }) }),
  me: () => request("/auth/me"),

  // Cars
  listCars: () => request("/cars"),
  getCar: (id) => request(`/cars/${id}`),
  createCar: (body) => request("/cars", { method: "POST", body: JSON.stringify(body) }),
  updateCar: (id, body) => request(`/cars/${id}`, { method: "PATCH", body: JSON.stringify(body) }),
  deleteCar: (id) => request(`/cars/${id}`, { method: "DELETE" }),

  // Sharing (owner-only). A share grants another user read or write access.
  listCarShares: (carId) => request(`/cars/${carId}/shares`),
  addCarShare: (carId, email, permission) =>
    request(`/cars/${carId}/shares`, { method: "POST", body: JSON.stringify({ email, permission }) }),
  removeCarShare: (carId, userId) =>
    request(`/cars/${carId}/shares/${userId}`, { method: "DELETE" }),

  // Service records
  listCarServices: (carId) => request(`/cars/${carId}/service-records`),
  createService: (body) =>
    request("/service-records", { method: "POST", body: JSON.stringify(body) }),
  updateService: (id, body) =>
    request(`/service-records/${id}`, { method: "PATCH", body: JSON.stringify(body) }),
  deleteService: (id) => request(`/service-records/${id}`, { method: "DELETE" }),

  // Parts
  listCarParts: (carId) => request(`/cars/${carId}/parts`),
  createPart: (body) => request("/parts", { method: "POST", body: JSON.stringify(body) }),
  updatePart: (id, body) =>
    request(`/parts/${id}`, { method: "PATCH", body: JSON.stringify(body) }),
  deletePart: (id) => request(`/parts/${id}`, { method: "DELETE" }),

  // Fuel. Consumption figures on each entry, and the rollup from fuel-stats, are
  // derived server-side from the full history — nothing here is stored.
  listCarFuel: (carId) => request(`/cars/${carId}/fuel-entries`),
  getCarFuelStats: (carId) => request(`/cars/${carId}/fuel-stats`),
  createFuel: (body) => request("/fuel-entries", { method: "POST", body: JSON.stringify(body) }),
  updateFuel: (id, body) =>
    request(`/fuel-entries/${id}`, { method: "PATCH", body: JSON.stringify(body) }),
  deleteFuel: (id) => request(`/fuel-entries/${id}`, { method: "DELETE" }),

  // Maintenance log — workshop visits and repairs (not the service schedule).
  listCarMaintenance: (carId) => request(`/cars/${carId}/maintenance`),
  createMaintenance: (body) => request("/maintenance", { method: "POST", body: JSON.stringify(body) }),
  updateMaintenance: (id, body) =>
    request(`/maintenance/${id}`, { method: "PATCH", body: JSON.stringify(body) }),
  deleteMaintenance: (id) => request(`/maintenance/${id}`, { method: "DELETE" }),

  // Documents — insurance, pollution certificates, … with renewal dates.
  listCarDocuments: (carId) => request(`/cars/${carId}/documents`),
  createDocument: (body) => request("/car-documents", { method: "POST", body: JSON.stringify(body) }),
  updateDocument: (id, body) =>
    request(`/car-documents/${id}`, { method: "PATCH", body: JSON.stringify(body) }),
  deleteDocument: (id) => request(`/car-documents/${id}`, { method: "DELETE" }),

  // Attachments, one per record. Keyed by the same names CarDetail uses for its
  // tabs so a table row can reach for the right one generically.
  files: {
    documents: attachment("/car-documents"),
    services: attachment("/service-records"),
    maintenance: attachment("/maintenance"),
    fuel: attachment("/fuel-entries"),
    parts: attachment("/parts"),
  },

  // Reminders. The list mixes stored reminders with read-only ones derived from
  // documents and service records (flagged `auto`; their ids start with "auto:").
  listCarReminders: (carId) => request(`/cars/${carId}/reminders`),
  createReminder: (body) => request("/reminders", { method: "POST", body: JSON.stringify(body) }),
  updateReminder: (id, body) =>
    request(`/reminders/${id}`, { method: "PATCH", body: JSON.stringify(body) }),
  deleteReminder: (id) => request(`/reminders/${id}`, { method: "DELETE" }),
  completeReminder: (id) => request(`/reminders/${id}/complete`, { method: "POST" }),

  // Admin — user management (admin or superadmin). Admins are scoped by the
  // server to their own organization; superadmins see everyone.
  listUsers: () => request("/users").then((r) => r.users),
  createUser: (body) =>
    request("/users", { method: "POST", body: JSON.stringify(body) }).then((r) => r.user),
  updateUser: (id, body) =>
    request(`/users/${id}`, { method: "PATCH", body: JSON.stringify(body) }).then((r) => r.user),
  // Password resets are a field on the user PATCH now, not a separate endpoint.
  setUserPassword: (id, password) =>
    request(`/users/${id}`, { method: "PATCH", body: JSON.stringify({ password }) }).then((r) => r.user),
  deleteUser: (id) => request(`/users/${id}`, { method: "DELETE" }),

  // Settings — account/profile/appearance
  getMe: () => request("/me"),
  updateMe: (body) => request("/me", { method: "PATCH", body: JSON.stringify(body) }),
  changePassword: (oldPassword, newPassword) =>
    request("/me/password", { method: "POST", body: JSON.stringify({ oldPassword, newPassword }) }),
  requestVerification: () => request("/me/verify/request", { method: "POST" }),
  uploadAvatar: (file) => {
    const form = new FormData();
    form.append("avatar", file);
    return requestForm("/me/avatar", { method: "POST", body: form });
  },
  deleteAvatar: () => request("/me/avatar", { method: "DELETE" }),
  getAvatarBlob: () => requestBlob("/me/avatar"),

  // Settings — advanced / danger zone
  exportData: () => requestBlob("/me/export"),
  importData: (payload) => request("/me/import", { method: "POST", body: JSON.stringify(payload) }),
  requestAccountDeletion: (confirmEmail) =>
    request("/me/delete", { method: "POST", body: JSON.stringify({ confirmEmail }) }),
  cancelAccountDeletion: () => request("/me/delete/cancel", { method: "POST" }),
  finalizeAccountDeletion: () => request("/me", { method: "DELETE" }),
};