#!/usr/bin/env python3
"""
BackgroundFX Pro - Basic Python Usage Examples

This script demonstrates the fundamental operations of the BackgroundFX Pro API
including authentication, image processing, and result handling.
"""

import os
import sys
import time
from pathlib import Path
from typing import Optional, Dict, Any

import requests
from PIL import Image
import json

# Configuration
API_BASE_URL = os.getenv("BACKGROUNDFX_API_URL", "https://api.backgroundfx.pro/v1")
API_KEY = os.getenv("BACKGROUNDFX_API_KEY", "your-api-key-here")


class BackgroundFXClient:
    """Simple client for BackgroundFX Pro API."""
    
    def __init__(self, api_key: str, base_url: str = API_BASE_URL):
        """
        Initialize the BackgroundFX client.
        
        Args:
            api_key: Your API key
            base_url: API base URL
        """
        self.api_key = api_key
        self.base_url = base_url.rstrip('/')
        self.session = requests.Session()
        self.session.headers.update({
            'Authorization': f'Bearer {api_key}',
            'User-Agent': 'BackgroundFX-Python-Client/1.0'
        })
    
    def remove_background(
        self,
        image_path: str,
        quality: str = "high",
        model: str = "auto",
        return_mask: bool = False
    ) -> Dict[str, Any]:
        """
        Remove background from an image.
        
        Args:
            image_path: Path to the image file
            quality: Processing quality (low, medium, high, ultra)
            model: Model to use (auto, rembg, u2net, sam2)
            return_mask: Whether to return the mask image
            
        Returns:
            Dictionary with processed image URL and metadata
        """
        # Validate image exists
        if not Path(image_path).exists():
            raise FileNotFoundError(f"Image not found: {image_path}")
        
        # Prepare the request
        url = f"{self.base_url}/process/remove-background"
        
        with open(image_path, 'rb') as f:
            files = {'file': (Path(image_path).name, f, 'image/jpeg')}
            data = {
                'quality': quality,
                'model': model,
                'return_mask': str(return_mask).lower()
            }
            
            # Make the request
            print(f"Processing image: {image_path}")
            response = self.session.post(url, files=files, data=data)
        
        # Handle response
        if response.status_code == 200:
            result = response.json()
            print(f"✓ Background removed successfully!")
            print(f"  Result URL: {result['image']}")
            if return_mask and 'mask' in result:
                print(f"  Mask URL: {result['mask']}")
            return result
        else:
            print(f"✗ Error: {response.status_code} - {response.text}")
            response.raise_for_status()
    
    def replace_background(
        self,
        image_id: str,
        background: str,
        blend_mode: str = "normal"
    ) -> Dict[str, Any]:
        """
        Replace image background with a new one.
        
        Args:
            image_id: ID of the processed image
            background: Background color (hex), gradient, or image URL
            blend_mode: How to blend (normal, multiply, screen, overlay)
            
        Returns:
            Dictionary with result
        """
        url = f"{self.base_url}/process/replace-background"
        
        payload = {
            'image_id': image_id,
            'background': background,
            'blend_mode': blend_mode
        }
        
        response = self.session.post(url, json=payload)
        
        if response.status_code == 200:
            result = response.json()
            print(f"✓ Background replaced successfully!")
            return result
        else:
            response.raise_for_status()
    
    def download_result(self, url: str, output_path: str) -> str:
        """
        Download processed image to local file.
        
        Args:
            url: URL of the processed image
            output_path: Where to save the image
            
        Returns:
            Path to saved file
        """
        response = requests.get(url, stream=True)
        response.raise_for_status()
        
        output_path = Path(output_path)
        output_path.parent.mkdir(parents=True, exist_ok=True)
        
        with open(output_path, 'wb') as f:
            for chunk in response.iter_content(chunk_size=8192):
                f.write(chunk)
        
        print(f"✓ Downloaded to: {output_path}")
        return str(output_path)
    
    def get_usage_stats(self) -> Dict[str, Any]:
        """
        Get API usage statistics.
        
        Returns:
            Usage statistics dictionary
        """
        url = f"{self.base_url}/user/usage"
        response = self.session.get(url)
        
        if response.status_code == 200:
            return response.json()
        else:
            response.raise_for_status()


def example_basic_processing():
    """Example: Basic background removal."""
    print("\n" + "="*60)
    print("EXAMPLE 1: Basic Background Removal")
    print("="*60)
    
    client = BackgroundFXClient(API_KEY)
    
    # Process an image
    result = client.remove_background(
        image_path="sample_images/portrait.jpg",
        quality="high"
    )
    
    # Download the result
    client.download_result(
        result['image'],
        "output/portrait_no_bg.png"
    )
    
    print("\n✓ Basic processing complete!")


def example_with_mask():
    """Example: Get both processed image and mask."""
    print("\n" + "="*60)
    print("EXAMPLE 2: Background Removal with Mask")
    print("="*60)
    
    client = BackgroundFXClient(API_KEY)
    
    # Process with mask
    result = client.remove_background(
        image_path="sample_images/product.jpg",
        quality="ultra",
        model="u2net",
        return_mask=True
    )
    
    # Download both results
    client.download_result(result['image'], "output/product_no_bg.png")
    client.download_result(result['mask'], "output/product_mask.png")
    
    print("\n✓ Processing with mask complete!")


def example_background_replacement():
    """Example: Replace background with color/gradient."""
    print("\n" + "="*60)
    print("EXAMPLE 3: Background Replacement")
    print("="*60)
    
    client = BackgroundFXClient(API_KEY)
    
    # First, remove background
    result = client.remove_background(
        image_path="sample_images/person.jpg",
        quality="high"
    )
    
    image_id = result['id']
    
    # Replace with solid color
    color_result = client.replace_background(
        image_id=image_id,
        background="#3498db"  # Blue background
    )
    client.download_result(color_result['image'], "output/person_blue_bg.png")
    
    # Replace with gradient
    gradient_result = client.replace_background(
        image_id=image_id,
        background="linear-gradient(45deg, #667eea, #764ba2)"
    )
    client.download_result(gradient_result['image'], "output/person_gradient_bg.png")
    
    print("\n✓ Background replacement complete!")


def example_batch_processing():
    """Example: Process multiple images."""
    print("\n" + "="*60)
    print("EXAMPLE 4: Batch Processing")
    print("="*60)
    
    client = BackgroundFXClient(API_KEY)
    
    # List of images to process
    images = [
        "sample_images/product1.jpg",
        "sample_images/product2.jpg",
        "sample_images/product3.jpg"
    ]
    
    results = []
    for image_path in images:
        try:
            print(f"\nProcessing: {image_path}")
            result = client.remove_background(
                image_path=image_path,
                quality="medium"  # Lower quality for batch
            )
            results.append(result)
            
            # Download result
            output_name = Path(image_path).stem + "_no_bg.png"
            client.download_result(
                result['image'],
                f"output/batch/{output_name}"
            )
            
        except Exception as e:
            print(f"✗ Failed to process {image_path}: {e}")
    
    print(f"\n✓ Batch processing complete! Processed {len(results)}/{len(images)} images")


def example_quality_comparison():
    """Example: Compare different quality settings."""
    print("\n" + "="*60)
    print("EXAMPLE 5: Quality Comparison")
    print("="*60)
    
    client = BackgroundFXClient(API_KEY)
    
    image_path = "sample_images/detailed.jpg"
    qualities = ["low", "medium", "high", "ultra"]
    
    for quality in qualities:
        print(f"\nProcessing with {quality} quality...")
        start_time = time.time()
        
        result = client.remove_background(
            image_path=image_path,
            quality=quality
        )
        
        processing_time = time.time() - start_time
        
        # Download result
        client.download_result(
            result['image'],
            f"output/comparison/detailed_{quality}.png"
        )
        
        # Print stats
        print(f"  Processing time: {processing_time:.2f}s")
        print(f"  File size: {result['metadata']['size'] / 1024:.1f} KB")
        print(f"  Resolution: {result['metadata']['width']}x{result['metadata']['height']}")
    
    print("\n✓ Quality comparison complete!")


def example_error_handling():
    """Example: Proper error handling."""
    print("\n" + "="*60)
    print("EXAMPLE 6: Error Handling")
    print("="*60)
    
    client = BackgroundFXClient(API_KEY)
    
    # Test various error scenarios
    test_cases = [
        ("non_existent.jpg", "File not found"),
        ("sample_images/corrupted.jpg", "Invalid image"),
        ("sample_images/huge_file.jpg", "File too large")
    ]
    
    for image_path, expected_error in test_cases:
        try:
            print(f"\nTesting: {expected_error}")
            result = client.remove_background(image_path)
            print(f"✓ Unexpectedly succeeded")
        except FileNotFoundError as e:
            print(f"✓ Caught FileNotFoundError: {e}")
        except requests.HTTPError as e:
            print(f"✓ Caught HTTPError: {e.response.status_code}")
        except Exception as e:
            print(f"✓ Caught Exception: {type(e).__name__}: {e}")
    
    print("\n✓ Error handling examples complete!")


def example_check_usage():
    """Example: Check API usage and limits."""
    print("\n" + "="*60)
    print("EXAMPLE 7: Check API Usage")
    print("="*60)
    
    client = BackgroundFXClient(API_KEY)
    
    try:
        usage = client.get_usage_stats()
        
        print("\nYour API Usage:")
        print(f"  Images processed: {usage['images_processed']}")
        print(f"  Videos processed: {usage['videos_processed']}")
        print(f"  Storage used: {usage['storage_used_mb']:.1f} MB")
        print(f"  API calls today: {usage['api_calls']}")
        
        print(f"\nPlan Limits:")
        limits = usage['plan_limits']
        print(f"  Images per month: {limits['images_per_month']}")
        print(f"  Storage: {limits['storage_gb']} GB")
        print(f"  API calls per hour: {limits['api_calls_per_hour']}")
        
    except Exception as e:
        print(f"✗ Failed to get usage stats: {e}")


def main():
    """Run all examples."""
    print("\n" + "#"*60)
    print("# BackgroundFX Pro - Python Examples")
    print("#"*60)
    
    # Check API key
    if API_KEY == "your-api-key-here":
        print("\n⚠️  Please set your API key in the BACKGROUNDFX_API_KEY environment variable")
        print("   or update the API_KEY variable in this script.")
        sys.exit(1)
    
    # Create output directories
    Path("output/batch").mkdir(parents=True, exist_ok=True)
    Path("output/comparison").mkdir(parents=True, exist_ok=True)
    Path("sample_images").mkdir(parents=True, exist_ok=True)
    
    # Run examples
    examples = [
        example_basic_processing,
        example_with_mask,
        example_background_replacement,
        example_batch_processing,
        example_quality_comparison,
        example_error_handling,
        example_check_usage
    ]
    
    for example in examples:
        try:
            example()
        except Exception as e:
            print(f"\n✗ Example failed: {e}")
            print("  Continuing with next example...")
    
    print("\n" + "#"*60)
    print("# All examples complete!")
    print("#"*60)


if __name__ == "__main__":
    main()