app.py

import logging
from fastapi import FastAPI, UploadFile, File, HTTPException, Form
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import FileResponse
import requests
import base64
import os
import time
import jwt
from pathlib import Path
from typing import List
import io

# Configure logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

# Initialize FastAPI app
app = FastAPI(title="Kling AI Multi-Image Generator API")

# Enable CORS for the frontend
app.add_middleware(
    CORSMiddleware,
    allow_origins=["https://hivili.web.app"],  # Allow your frontend
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# ===== API CONFIGURATION =====
ACCESS_KEY_ID = os.getenv("ACCESS_KEY_ID", "AFyHfnQATghFdCMyAG3gRPbNY4TNKFGB")
ACCESS_KEY_SECRET = os.getenv("ACCESS_KEY_SECRET", "TTepeLyBterLNM3brYPGmdndBnnyKJBA")
API_BASE_URL = "https://api-singapore.klingai.com"
CREATE_TASK_ENDPOINT = f"{API_BASE_URL}/v1/images/multi-image2image"

# ===== AUTHENTICATION =====
def generate_jwt_token():
    """Generate JWT token for API authentication"""
    payload = {
        "iss": ACCESS_KEY_ID,
        "exp": int(time.time()) + 1800,  # 30 minutes expiration
        "nbf": int(time.time()) - 5      # Not before 5 seconds ago
    }
    return jwt.encode(payload, ACCESS_KEY_SECRET, algorithm="HS256")

# ===== IMAGE PROCESSING =====
def prepare_image_base64(image_content: bytes):
    """Convert image bytes to base64 without prefix"""
    try:
        return base64.b64encode(image_content).decode('utf-8')
    except Exception as e:
        logger.error(f"Image processing failed: {str(e)}")
        raise HTTPException(status_code=500, detail=f"Image processing failed: {str(e)}")

def validate_image(image_content: bytes):
    """Validate image meets API requirements"""
    try:
        size_mb = len(image_content) / (1024 * 1024)
        if size_mb > 10:
            raise HTTPException(status_code=400, detail="Image too large (max 10MB)")
        return True, ""
    except Exception as e:
        raise HTTPException(status_code=400, detail=f"Image validation error: {str(e)}")

# ===== API FUNCTIONS =====
def create_multi_image_task(subject_images: List[bytes], prompt: str):
    """Create multi-image generation task"""
    headers = {
        "Authorization": f"Bearer {generate_jwt_token()}",
        "Content-Type": "application/json"
    }
    
    subject_image_list = []
    for img_content in subject_images:
        if img_content:
            base64_img = prepare_image_base64(img_content)
            if base64_img:
                subject_image_list.append({"subject_image": base64_img})
    
    if len(subject_image_list) < 2:
        raise HTTPException(status_code=400, detail="At least 2 subject images required")
    
    payload = {
        "model_name": "kling-v2",
        "prompt": prompt,
        "subject_image_list": subject_image_list,
        "n": 1,
        "aspect_ratio": "1:1"
    }
    
    try:
        response = requests.post(CREATE_TASK_ENDPOINT, json=payload, headers=headers)
        response.raise_for_status()
        return response.json()
    except requests.exceptions.RequestException as e:
        logger.error(f"API request failed: {str(e)}")
        if hasattr(e, 'response') and e.response:
            logger.error(f"API response: {e.response.text}")
        raise HTTPException(status_code=500, detail=f"API Error: {str(e)}")

def check_task_status(task_id: str):
    """Check task completion status"""
    headers = {"Authorization": f"Bearer {generate_jwt_token()}"}
    status_url = f"{API_BASE_URL}/v1/images/multi-image2image/{task_id}"
    
    try:
        response = requests.get(status_url, headers=headers)
        response.raise_for_status()
        return response.json()
    except requests.exceptions.RequestException as e:
        raise HTTPException(status_code=500, detail=f"Status check failed: {str(e)}")

# ===== MAIN PROCESSING =====
async def generate_image(subject_images: List[bytes], prompt: str):
    """Handle complete image generation workflow"""
    for img_content in subject_images:
        if img_content:
            validate_image(img_content)
    
    task_response = create_multi_image_task(subject_images, prompt)
    if task_response.get("code") != 0:
        raise HTTPException(status_code=500, detail=f"API error: {task_response.get('message', 'Unknown error')}")
    
    task_id = task_response["data"]["task_id"]
    logger.info(f"Task created: {task_id}")
    
    for _ in range(60):
        task_data = check_task_status(task_id)
        status = task_data["data"]["task_status"]
        
        if status == "succeed":
            image_url = task_data["data"]["task_result"]["images"][0]["url"]
            try:
                response = requests.get(image_url)
                response.raise_for_status()
                output_dir = Path("/tmp")
                output_dir.mkdir(exist_ok=True)
                output_path = output_dir / f"kling_output_{task_id}.png"
                with open(output_path, "wb") as f:
                    f.write(response.content)
                return output_path
            except Exception as e:
                raise HTTPException(status_code=500, detail=f"Failed to download result: {str(e)}")
                
        elif status in ("failed", "canceled"):
            error_msg = task_data["data"].get("task_status_msg", "Unknown error")
            raise HTTPException(status_code=500, detail=f"Task failed: {error_msg}")
            
        time.sleep(10)
    
    raise HTTPException(status_code=500, detail="Task timed out after 10 minutes")

# ===== API ENDPOINTS =====
@app.post("/generate")
async def generate_image_endpoint(
    prompt: str = Form(...),
    images: List[UploadFile] = File(...)
):
    """Endpoint to generate an image from multiple input images and a prompt"""
    try:
        if len(images) < 2:
            raise HTTPException(status_code=400, detail="At least 2 images are required")
        if len(images) > 4:
            raise HTTPException(status_code=400, detail="Maximum 4 images allowed")

        image_contents = [await image.read() for image in images]
        output_path = await generate_image(image_contents, prompt)

        return FileResponse(
            path=output_path,
            media_type="image/png",
            filename=f"kling_output_{Path(output_path).stem}.png"
        )
    except Exception as e:
        logger.error(f"Error in /generate: {str(e)}")
        raise HTTPException(status_code=500, detail=str(e))

@app.get("/")
async def index():
    return {"status": "Kling AI Multi-Image Generator API is running"}

if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=7860)