import json
import sys
import time
import garth
from datetime import datetime

def main():
    try:
        # Load configuration
        with open('config.json') as f:
            config = json.load(f)
        
        garmin_config = config.get('garmin', {})
        username = garmin_config.get('username')
        password = garmin_config.get('password')
        is_china = garmin_config.get('is_china', False)
        session_file = garmin_config.get('session_data_file', 'garmin_session.json')
        
        if not username or not password:
            print("❌ Missing Garmin credentials in config.json")
            return 1
        
        # Set domain based on region
        domain = "garmin.cn" if is_china else "garmin.com"
        garth.configure(domain=domain)
        
        try:
            # Authentication attempt
            start_time = time.time()
            garth.login(username, password)
            end_time = time.time()
            
            print("✅ Authentication successful!")
            print(f"⏱️ Authentication time: {end_time - start_time:.2f} seconds")
            garth.save(session_file)
            return 0
            
        except garth.exc.GarthHTTPError as e:
            end_time = time.time()  # Capture time when error occurred
            # Extract information from the exception message
            error_msg = str(e)
            print(f"\n⚠️  Garth HTTP Error: {error_msg}")
            
            # Check if it's a 429 error by parsing the message
            if "429" in error_msg:
                print("=" * 50)
                print("Rate Limit Exceeded (429)")
                print(f"Response Time: {end_time - start_time:.2f} seconds")
                
                # Try to extract URL from error message
                url_start = error_msg.find("url: ")
                if url_start != -1:
                    url = error_msg[url_start + 5:]
                    print(f"URL: {url}")
                
                # Try to access response headers if available
                if hasattr(e, 'response') and e.response is not None:
                    headers = e.response.headers
                    retry_after = headers.get('Retry-After')
                    reset_timestamp = headers.get('X-RateLimit-Reset')
                    remaining = headers.get('X-RateLimit-Remaining')
                    limit = headers.get('X-RateLimit-Limit')
                    
                    print("\n📊 Rate Limit Headers Found:")
                    if retry_after:
                        print(f"⏳ Retry-After: {retry_after} seconds")
                        wait_time = int(retry_after)
                        reset_time = datetime.utcfromtimestamp(time.time() + wait_time)
                        print(f"⏰ Estimated reset time: {reset_time} UTC")
                    if reset_timestamp:
                        try:
                            reset_time = datetime.utcfromtimestamp(float(reset_timestamp))
                            print(f"⏰ Rate limit resets at: {reset_time} UTC")
                        except ValueError:
                            print(f"⚠️  Invalid reset timestamp: {reset_timestamp}")
                    if remaining:
                        print(f"🔄 Requests remaining: {remaining}")
                    if limit:
                        print(f"📈 Rate limit: {limit} requests per window")
                    if not any([retry_after, reset_timestamp, remaining, limit]):
                        print("ℹ️  No rate limit headers found in response")
                else:
                    print("\n⚠️  Response headers not accessible directly from GarthHTTPError")
                    print("Common rate limit headers to look for:")
                    print("  - Retry-After: Seconds to wait before retrying")
                    print("  - X-RateLimit-Limit: Maximum requests per time window")
                    print("  - X-RateLimit-Remaining: Remaining requests in current window")
                    print("  - X-RateLimit-Reset: Time when rate limit resets")
                    print(f"\nRecommend waiting at least 60 seconds before retrying.")
                
                return 429
                
            # Handle other HTTP errors
            print(f"❌ HTTP Error detected: {error_msg}")
            return 1
            
        except Exception as e:
            print(f"❌ Authentication failed: {str(e)}")
            return 1
            
    except FileNotFoundError:
        print("❌ config.json file not found")
        return 1
    except json.JSONDecodeError:
        print("❌ Error parsing config.json")
        return 1

if __name__ == "__main__":
    sys.exit(main())