export class ApiError extends Error {
  statusCode: number;
  details?: unknown;

  constructor(
    message: string,
    statusCode: number,
    details?: unknown
  ) {
    super(message);
    this.name = 'ApiError';
    this.statusCode = statusCode;
    this.details = details;
  }
}

interface ErrorResponseBody {
  error?: string;
  details?: unknown;
}

import { getApiBaseUrl } from './config';

export class ApiClient {
  private baseUrl: string;

  constructor(baseUrl: string = getApiBaseUrl()) {
    this.baseUrl = baseUrl;
  }

  getBaseURL(): string {
    return this.baseUrl;
  }

  private async request<T>(
    endpoint: string,
    options?: RequestInit
  ): Promise<T> {
    const url = `${this.baseUrl}${endpoint}`;

    try {
      const response = await fetch(url, {
        ...options,
        headers: {
          'Content-Type': 'application/json',
          ...options?.headers,
        },
      });

      if (!response.ok) {
        const errorData: ErrorResponseBody = await response.json().catch(() => ({}));
        throw new ApiError(
          errorData.error || `HTTP ${response.status}: ${response.statusText}`,
          response.status,
          errorData
        );
      }

      // Handle 204 No Content — intentional no-data for void operations
      if (response.status === 204) {
        return undefined as unknown as T;
      }

      return response.json();
    } catch (error) {
      if (error instanceof ApiError) {
        throw error;
      }
      throw new ApiError(
        error instanceof Error ? error.message : 'Network error',
        0
      );
    }
  }

  async get<T>(endpoint: string): Promise<T> {
    return this.request<T>(endpoint, { method: 'GET' });
  }

  async post<T>(endpoint: string, data?: unknown): Promise<T> {
    return this.request<T>(endpoint, {
      method: 'POST',
      body: data ? JSON.stringify(data) : undefined,
    });
  }

  async put<T>(endpoint: string, data?: unknown): Promise<T> {
    return this.request<T>(endpoint, {
      method: 'PUT',
      body: data ? JSON.stringify(data) : undefined,
    });
  }

  async patch<T>(endpoint: string, data?: unknown): Promise<T> {
    return this.request<T>(endpoint, {
      method: 'PATCH',
      body: data ? JSON.stringify(data) : undefined,
    });
  }

  async delete<T>(endpoint: string): Promise<T> {
    return this.request<T>(endpoint, { method: 'DELETE' });
  }

  async getText(endpoint: string): Promise<string> {
    const url = `${this.baseUrl}${endpoint}`;
    const response = await fetch(url);

    if (!response.ok) {
      const errorData = await response.json().catch(() => ({}));
      throw new ApiError(
        errorData.error || `HTTP ${response.status}: ${response.statusText}`,
        response.status,
        errorData
      );
    }

    return response.text();
  }

  async putText(endpoint: string, text: string): Promise<{ message?: string; [key: string]: unknown }> {
    const url = `${this.baseUrl}${endpoint}`;
    const response = await fetch(url, {
      method: 'PUT',
      headers: { 'Content-Type': 'text/plain' },
      body: text,
    });

    if (!response.ok) {
      const errorData = await response.json().catch(() => ({}));
      throw new ApiError(
        errorData.error || `HTTP ${response.status}: ${response.statusText}`,
        response.status,
        errorData
      );
    }

    return response.json();
  }
}

export const apiClient = new ApiClient();