import os
import requests
import time
from typing import Dict, Any, Optional
from .exceptions import WBAPIError, WBAuthError, WBRateLimitError, WBBadRequestError

class WBClient:
    """Base client for interacting with Wildberries API."""
    
    # WB domains
    CONTENT_API = "https://content-api.wildberries.ru"
    MARKETPLACE_API = "https://marketplace-api.wildberries.ru"
    PRICES_API = "https://discounts-prices-api.wildberries.ru"
    STATISTICS_API = "https://statistics-api.wildberries.ru"
    
    def __init__(self, api_token: Optional[str] = None):
        # Fetch from env if not provided
        self.api_token = api_token or os.getenv('WB_API_TOKEN')
        
        if not self.api_token:
            raise ValueError("WB_API_TOKEN must be provided")
            
        self.session = requests.Session()
        self.session.headers.update({
            "Authorization": self.api_token,
            "Content-Type": "application/json"
        })

    def request(self, method: str, base_url: str, path: str, data: Optional[Dict[str, Any]] = None, params: Optional[Dict[str, Any]] = None, retries: int = 3) -> Dict[str, Any]:
        """Perform HTTP request to WB API with automatic retries."""
        url = f"{base_url}{path}"
        
        for attempt in range(retries):
            try:
                response = self.session.request(method, url, json=data, params=params)
                
                if response.status_code == 429:
                    if attempt < retries - 1:
                        time.sleep(2 ** attempt)  # Exponential backoff
                        continue
                    raise WBRateLimitError("Rate limit exceeded")

                if response.status_code in (401, 403):
                    raise WBAuthError(f"Authentication failed: {response.text}")
                    
                if response.status_code == 400:
                    raise WBBadRequestError(f"Bad Request: {response.text}")
                    
                response.raise_for_status()
                
                if response.content:
                    return response.json()
                return {}

            except requests.exceptions.RequestException as e:
                if attempt < retries - 1:
                    time.sleep(2 ** attempt)
                    continue
                raise WBAPIError(f"Request failed: {str(e)}")
                
        raise WBAPIError("Request failed after max retries")

    def post(self, base_url: str, path: str, data: Optional[Dict[str, Any]] = None) -> Dict[str, Any]:
        return self.request("POST", base_url, path, data=data)

    def get(self, base_url: str, path: str, params: Optional[Dict[str, Any]] = None) -> Dict[str, Any]:
        return self.request("GET", base_url, path, params=params)