import axios from 'axios'

// Create axios instance
const api = axios.create({
  baseURL: import.meta.env.VITE_API_URL || 'http://localhost:5000/api',
  headers: {
    'Content-Type': 'application/json'
  },
  // Disable caching for API requests to ensure we always get fresh data
  adapter: 'xhr', // Use XHR adapter to avoid service worker caching issues
  withCredentials: true // Send cookies with requests
})

// Add request timeout to prevent hanging requests
api.defaults.timeout = 10000 // 10 seconds timeout

// Environment-specific configuration
const isDevelopment = import.meta.env.VITE_NODE_ENV === 'development'
const isProduction = import.meta.env.VITE_NODE_ENV === 'production'

// Debug logging function for development
const logApiCall = (config) => {
  if (isDevelopment) {
    console.log(`🚀 [API] ${config.method?.toUpperCase()} ${config.url}`, {
      data: config.data,
      params: config.params,
      headers: config.headers
    })
  }
}

// Error logging function for development
const logApiError = (error) => {
  if (isDevelopment) {
    console.error(`❌ [API Error] ${error.config?.url || 'Unknown URL'}`, {
      status: error.response?.status,
      statusText: error.response?.statusText,
      data: error.response?.data,
      message: error.message
    })
  }
}

// Request interceptor to add auth token and logging
api.interceptors.request.use(
  (config) => {
    // Add debug logging
    logApiCall(config)
    
    const token = localStorage.getItem('token')
    if (token) {
      config.headers.Authorization = `Bearer ${token}`
    }
    return config
  },
  (error) => {
    logApiError(error)
    return Promise.reject(error)
  }
)

// Add token validation and refresh logic
api.interceptors.request.use(
  async (config) => {
    const token = localStorage.getItem('token')
    if (token) {
      try {
        // Check if token is expired
        const tokenData = JSON.parse(atob(token.split('.')[1]))
        const isExpired = tokenData.exp * 1000 < Date.now()
        
        if (isExpired) {
          // Token is expired, remove it
          localStorage.removeItem('token')
          if (isDevelopment) {
            console.log('🔑 [Token] Token expired, removed from storage')
          }
          
          // If we're not on the login page, redirect there
          if (!window.location.pathname.includes('/login')) {
            window.location.href = '/login'
          }
        } else {
          // Token is valid, add to headers
          config.headers.Authorization = `Bearer ${token}`
        }
      } catch (error) {
        // Invalid token format, remove it
        localStorage.removeItem('token')
        if (isDevelopment) {
          console.log('🔑 [Token] Invalid token format, removed from storage')
        }
        
        // If we're not on the login page, redirect there
        if (!window.location.pathname.includes('/login')) {
          window.location.href = '/login'
        }
      }
    }
    return config
  },
  (error) => {
    logApiError(error)
    return Promise.reject(error)
  }
)

// Response interceptor to handle errors and logging
api.interceptors.response.use(
  (response) => {
    if (isDevelopment) {
      console.log(`✅ [API Response] ${response.config.url}`, {
        status: response.status,
        data: response.data
      })
    }
    return response
  },
  (error) => {
    logApiError(error)
    
    if (error.response?.status === 401) {
      // Only redirect if we're not already on the login page
      if (!window.location.pathname.includes('/login')) {
        localStorage.removeItem('token')
        window.location.href = '/login'
      }
    }
    
    // Add more detailed error handling for different status codes
    if (error.response) {
      // The request was made and the server responded with a status code
      // that falls out of the range of 2xx
      const status = error.response.status
      const data = error.response.data
      
      if (isDevelopment) {
        console.error(`🚨 [API Error ${status}]`, {
          url: error.config.url,
          method: error.config.method,
          data: data,
          headers: error.response.headers
        })
      }
    } else if (error.request) {
      // The request was made but no response was received
      if (isDevelopment) {
        console.error('🚨 [Network Error] No response received:', {
          url: error.config?.url,
          message: error.message
        })
      }
    } else {
      // Something happened in setting up the request that triggered an Error
      if (isDevelopment) {
        console.error('🚨 [Request Error]', error.message)
      }
    }
    
    return Promise.reject(error)
  }
)

export default api