from fastapi import FastAPI, HTTPException
from fastapi.middleware.cors import CORSMiddleware
import base64
import os

app = FastAPI()

# Middleware to handle CORS (optional, but useful if Testing4 calls this API)
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],  # Adjust as needed for security
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Load LoRA weights globally
lora_weights = None

@app.on_event("startup")
async def startup_event():
    global lora_weights
    lora_path = "./lora_file.pth"
    if os.path.exists(lora_path):
        with open(lora_path, "rb") as f:
            # Base64 encode the LoRA weights for easy JSON transmission
            lora_weights = base64.b64encode(f.read()).decode("utf-8")
            print("LoRA weights loaded and preprocessed successfully.")
    else:
        print("LoRA file not found during startup.")
        raise HTTPException(status_code=500, detail="LoRA file not found.")

@app.post("/modify-prompt")
async def modify_prompt(prompt: str):
    global lora_weights
    if lora_weights is None:
        raise HTTPException(status_code=500, detail="LoRA weights not loaded.")
    # Combine prompt with preprocessed LoRA data
    extended_prompt = {
        "prompt": prompt,
        "lora": lora_weights
    }
    return extended_prompt