/**
 * Thin REST client for the local backend.
 * The page never talks to the robot directly - only to this origin.
 */

class ApiError extends Error {
  constructor(message, code, status) {
    super(message);
    this.name = 'ApiError';
    this.code = code || 'error';
    this.status = status || 0;
  }
}

async function request(path, options = {}) {
  let response;
  try {
    response = await fetch(path, {
      headers: { 'Content-Type': 'application/json' },
      ...options,
    });
  } catch (err) {
    // The backend itself is unreachable - a different failure from "robot offline".
    throw new ApiError(
      'Cannot reach the local server. Is backend/main.py still running?',
      'backend_down',
      0,
    );
  }

  let body = null;
  const text = await response.text();
  if (text) {
    try { body = JSON.parse(text); } catch { body = { error: text }; }
  }

  if (!response.ok) {
    const message =
      (body && (body.error || body.detail)) ||
      `Request failed (HTTP ${response.status})`;
    throw new ApiError(
      typeof message === 'string' ? message : JSON.stringify(message),
      (body && body.errorCode) || 'http_error',
      response.status,
    );
  }
  return body;
}

export const api = {
  status:        ()      => request('/api/robot/status'),
  config:        ()      => request('/api/config'),
  diagnostics:   ()      => request('/api/robot/diagnostics'),
  reloadConfig:  ()      => request('/api/config/reload', { method: 'POST' }),
  reconnect:     ()      => request('/api/robot/reconnect', { method: 'POST' }),
  speak:         (text)  => request('/api/robot/speak', {
                              method: 'POST',
                              body: JSON.stringify({ text }),
                            }),
  stop:          ()      => request('/api/robot/stop', { method: 'POST' }),
  history:       ()      => request('/api/speech/history'),
  clearHistory:  ()      => request('/api/speech/history', { method: 'DELETE' }),
  audio:         ()      => request('/api/audio'),
  audioUrl:      (id)    => `/api/audio/${id}/file`,
  deleteAudio:   (id)    => request(`/api/audio/${id}`, { method: 'DELETE' }),
  clearAudio:    ()      => request('/api/audio', { method: 'DELETE' }),
};

export { ApiError };