/**
 * API Client Component
 * 
 * Frontend helper for making authenticated requests to the backend.
 * Uses PocketBase token from auth session.
 */

// Header constants (inline to avoid cross-component dependency)
const HEADERS = {
  AUTH: 'Authorization',
  CONTENT_TYPE: 'Content-Type',
} as const;

const CONTENT_TYPES = {
  JSON: 'application/json',
} as const;

function authHeader(token: string): string {
  return `Bearer ${token}`;
}

export interface ApiResponse<T = unknown> {
  ok: boolean;
  status: number;
  data?: T;
  error?: string;
}

export interface ApiClientConfig {
  baseUrl: string;
  getToken: () => string | null;
}

/**
 * Create an API client instance
 */
export function createApiClient(config: ApiClientConfig) {
  const { baseUrl, getToken } = config;

  async function request<T>(
    method: string,
    path: string,
    body?: unknown
  ): Promise<ApiResponse<T>> {
    const token = getToken();
    
    const headers: Record<string, string> = {
      [HEADERS.CONTENT_TYPE]: CONTENT_TYPES.JSON,
    };

    if (token) {
      headers[HEADERS.AUTH] = authHeader(token);
    }

    try {
      const response = await fetch(`${baseUrl}${path}`, {
        method,
        headers,
        body: body ? JSON.stringify(body) : undefined,
      });

      const data = response.headers.get('content-type')?.includes('application/json')
        ? await response.json()
        : await response.text();

      if (!response.ok) {
        return {
          ok: false,
          status: response.status,
          error: typeof data === 'string' ? data : data.message || 'Request failed',
        };
      }

      return {
        ok: true,
        status: response.status,
        data: data as T,
      };
    } catch (err) {
      return {
        ok: false,
        status: 0,
        error: err instanceof Error ? err.message : 'Network error',
      };
    }
  }

  return {
    get: <T>(path: string) => request<T>('GET', path),
    post: <T>(path: string, body?: unknown) => request<T>('POST', path, body),
    put: <T>(path: string, body?: unknown) => request<T>('PUT', path, body),
    patch: <T>(path: string, body?: unknown) => request<T>('PATCH', path, body),
    delete: <T>(path: string) => request<T>('DELETE', path),
  };
}

export type ApiClient = ReturnType<typeof createApiClient>;