main.py

from fastapi import FastAPI, HTTPException, BackgroundTasks, Depends
from pydantic import BaseModel
from fastapi.concurrency import run_in_threadpool
from fastapi.middleware.cors import CORSMiddleware
import uuid
import tempfile
from concurrent.futures import ThreadPoolExecutor
from pymongo import MongoClient
from urllib.parse import quote_plus
from langchain_groq import ChatGroq
from aura_sr import AuraSR
from io import BytesIO
from PIL import Image
import requests
import os
import os

# Set the Hugging Face cache directory to a writable location
os.environ['HF_HOME'] = '/tmp/huggingface_cache'

app = FastAPI()

# Middleware for CORS
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_methods=["*"],
    allow_headers=["*"],
)

# Globals
executor = ThreadPoolExecutor(max_workers=10)
llm = None
upscale_model = None
client = MongoClient(f"mongodb+srv://hammad:{quote_plus('momimaad@123')}@cluster0.2a9yu.mongodb.net/")
db = client["Flux"]
collection = db["chat_histories"]
chat_sessions = {}

# Use a temporary directory for storing images
image_storage_dir = tempfile.mkdtemp()
print(f"Temporary directory for images: {image_storage_dir}")

# Dictionary to store images temporarily
image_store = {}

@app.on_event("startup")
async def startup():
    global llm, upscale_model
    llm = ChatGroq(
        model="llama-3.3-70b-versatile",
        temperature=0.7,
        max_tokens=1024,
        api_key="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",
    )
    upscale_model = AuraSR.from_pretrained("fal/AuraSR-v2")

@app.on_event("shutdown")
def shutdown():
    client.close()
    executor.shutdown()

# Pydantic models
class ImageRequest(BaseModel):
    subject: str
    style: str
    color_theme: str
    elements: str
    color_mode: str
    lighting_conditions: str
    framing_style: str
    material_details: str
    text: str
    background_details: str
    user_prompt: str
    chat_id: str

# Helper Functions
def generate_chat_id():
    chat_id = str(uuid.uuid4())
    chat_sessions[chat_id] = collection
    return chat_id

def get_chat_history(chat_id):
    messages = collection.find({"session_id": chat_id})
    return "\n".join(
        f"User: {msg['content']}" if msg['role'] == "user" else f"AI: {msg['content']}"
        for msg in messages
    )

def save_image_locally(image, filename):
    filepath = os.path.join(image_storage_dir, filename)
    image.save(filepath, format="PNG")
    return filepath

# Endpoints
@app.post("/new-chat", response_model=dict)
async def new_chat():
    chat_id = generate_chat_id()
    return {"chat_id": chat_id}

@app.post("/generate-image", response_model=dict)
async def generate_image(request: ImageRequest):
    def process_request():
        chat_history = get_chat_history(request.chat_id)
        prompt = f"""
        You are a professional assistant responsible for crafting a clear and visually compelling prompt for an image generation model. Your task is to generate a high-quality prompt for creating both the **main subject** and the **background** of the image.

        Image Specifications:
        - **Subject**: Focus on **{request.subject}**, highlighting its defining features, expressions, and textures.
        - **Style**: Emphasize the **{request.style}**, capturing its key characteristics.
        - **Background**: Create a background with **{request.background_details}** that complements and enhances the subject. Ensure it aligns with the color theme and overall composition.
        - **Camera and Lighting**:
          - Lighting: Apply **{request.lighting_conditions}**, emphasizing depth, highlights, and shadows to accentuate the subject and harmonize the background.
        - **Framing**: Use a **{request.framing_style}** to enhance the composition around both the subject and the background.
        - **Materials**: Highlight textures like **{request.material_details}**, with realistic details and natural imperfections on the subject and background.
        - **Key Elements**: Include **{request.elements}** to enrich the subject’s details and add cohesive elements to the background.
        - **Color Theme**: Follow the **{request.color_theme}** to set the mood and tone for the entire scene.
        - Negative Prompt: Avoid grainy, blurry, or deformed outputs.
        - **Text to Include in Image**: Clearly display the text **"{request.text}"** as part of the composition (e.g., on a card, badge, or banner) attached to the subject in a realistic and contextually appropriate way.
        - Write the prompt only in the output. Do not include anything else except the prompt. Do not write Generated Image Prompt: in the output.

        Chat History:
        {chat_history}

        User Prompt:
        {request.user_prompt}

        Generated Image Prompt:
        """
        refined_prompt = llm.invoke(prompt).content.strip()
        collection.insert_one({"session_id": request.chat_id, "role": "user", "content": request.user_prompt})
        collection.insert_one({"session_id": request.chat_id, "role": "ai", "content": refined_prompt})

        # Simulate image generation
        response = requests.post(
            "https://api.bfl.ml/v1/flux-pro-1.1",
            json={"prompt": refined_prompt}
        ).json()
        image_url = response["result"]["sample"]

        # Download and save the image locally
        image_response = requests.get(image_url)
        img = Image.open(BytesIO(image_response.content))
        filename = f"generated_{uuid.uuid4()}.png"
        filepath = save_image_locally(img, filename)
        return filepath

    # Run the request processing in a thread
    future = executor.submit(process_request)
    filepath = await run_in_threadpool(future.result)  # Wait for the task to complete

    # Load the image to return as a response
    with open(filepath, "rb") as f:
        image_data = f.read()

    # Convert the file path into a downloadable format
    file_url = f"/images/{os.path.basename(filepath)}"

    # Return the response
    return {
        "status": "Image generated successfully",
        "file_path": filepath,
        "file_url": file_url,
        "image": image_data,
    }

@app.post("/upscale-image", response_model=dict)
async def upscale_image(image_url: str, background_tasks: BackgroundTasks):
    def process_image():
        response = requests.get(image_url)
        img = Image.open(BytesIO(response.content))
        upscaled_image = upscale_model.upscale_4x_overlapped(img)
        filename = f"upscaled_{uuid.uuid4()}.png"
        filepath = save_image_locally(upscaled_image, filename)
        return filepath

    task = executor.submit(process_image)
    background_tasks.add_task(task)
    return {"status": "Processing"}


@app.get("/")
async def root():
    return {"message": "API is up and running!"}