import axios, { AxiosInstance, AxiosRequestConfig, AxiosResponse } from 'axios'

export interface ApiResponse<T> {
  data: T
  meta?: {
    pagination?: {
      page: number
      page_size: number
      total: number
      total_pages: number
    }
  }
}

export interface ApiError {
  error: {
    code: string
    message: string
    details?: unknown
    request_id?: string
  }
}

class ApiClient {
  private client: AxiosInstance

  constructor(baseURL: string = process.env.NEXT_PUBLIC_API_URL || 'http://localhost:8080') {
    this.client = axios.create({
      baseURL,
      timeout: 30000,
      headers: {
        'Content-Type': 'application/json',
      },
    })

    // Request interceptor
    this.client.interceptors.request.use(
      (config) => {
        // Add API key if available
        const apiKey = this.getApiKey()
        if (apiKey) {
          config.headers['X-API-Key'] = apiKey
        }
        return config
      },
      (error) => Promise.reject(error)
    )

    // Response interceptor
    this.client.interceptors.response.use(
      (response) => response,
      (error) => {
        // Handle errors
        if (error.response) {
          const apiError: ApiError = error.response.data
          return Promise.reject(apiError)
        }
        return Promise.reject(error)
      }
    )
  }

  private getApiKey(): string | null {
    if (typeof window !== 'undefined') {
      return localStorage.getItem('api_key')
    }
    return null
  }

  async get<T>(url: string, config?: AxiosRequestConfig): Promise<ApiResponse<T>> {
    const response: AxiosResponse<ApiResponse<T>> = await this.client.get(url, config)
    return response.data
  }

  async post<T>(url: string, data?: unknown, config?: AxiosRequestConfig): Promise<ApiResponse<T>> {
    const response: AxiosResponse<ApiResponse<T>> = await this.client.post(url, data, config)
    return response.data
  }

  async put<T>(url: string, data?: unknown, config?: AxiosRequestConfig): Promise<ApiResponse<T>> {
    const response: AxiosResponse<ApiResponse<T>> = await this.client.put(url, data, config)
    return response.data
  }

  async delete<T>(url: string, config?: AxiosRequestConfig): Promise<ApiResponse<T>> {
    const response: AxiosResponse<ApiResponse<T>> = await this.client.delete(url, config)
    return response.data
  }
}

export const apiClient = new ApiClient()