import os
import logging
import json
import httpx
from fastapi import FastAPI, Request, HTTPException
from fastapi.responses import StreamingResponse
from fastapi.middleware.cors import CORSMiddleware

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

app = FastAPI()

# Optional: Configure CORS if needed
origins = [
    # Add allowed origins if you implement a frontend later
]

app.add_middleware(
    CORSMiddleware,
    allow_origins=origins,  # Adjust as needed
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Load your API key from the environment (defaults to "change_me")
API_KEY = os.environ.get("API_KEY", "change_me")
logger.debug(f"Loaded API key: {API_KEY}")

# URL of the running Ollama server (adjust as needed)
OLLAMA_SERVER_URL = "http://localhost:11434/api/generate"
logger.debug(f"Ollama server URL: {OLLAMA_SERVER_URL}")


@app.post("/api/generate")
async def generate(request: Request):
    """Endpoint that generates text based on the prompt."""
    try:
        # Parse the incoming request
        body = await request.json()
        model = body.get("model", "hf.co/abanm/Dubs-Q8_0-GGUF:latest")  # Default model
        prompt_text = body.get("prompt", "")

        if not prompt_text:
            logger.error("No prompt provided in the request")
            raise HTTPException(status_code=400, detail="No prompt provided")

        logger.debug(f"Request body: {body}")

        # Validate API key
        auth_header = request.headers.get("Authorization")
        logger.debug(f"Received Authorization header: {auth_header}")

        if not auth_header or not auth_header.startswith("Bearer "):
            logger.error("Missing or invalid Authorization header")
            raise HTTPException(status_code=401, detail="Missing or invalid Authorization header")

        token = auth_header.split(" ")[1]
        if token != API_KEY:
            logger.error(f"Invalid API key provided: {token}")
            raise HTTPException(status_code=401, detail="Invalid API key")

        # Prepare request payload
        payload = {"model": model, "prompt": prompt_text}
        logger.debug(f"Payload prepared for Ollama: {payload}")

        # Stream response from Ollama
        async def stream_response():
            try:
                async with httpx.AsyncClient(timeout=httpx.Timeout(60.0)) as client:
                    async with client.stream(
                        "POST", OLLAMA_SERVER_URL, json=payload, headers={"Content-Type": "application/json"}
                    ) as response:
                        logger.info(f"Response status code from Ollama: {response.status_code}")

                        if response.status_code != 200:
                            logger.error(f"HTTP error: {response.status_code} - {await response.text()}")
                            yield json.dumps({"error": f"HTTP error: {response.status_code}"})
                            return

                        async for chunk in response.aiter_text():
                            logger.debug(f"Chunk received: {chunk}")
                            yield chunk
            except httpx.ReadTimeout:
                logger.error("ReadTimeout while waiting for response chunks")
                yield json.dumps({"error": "Server response timeout. Try again later."})
            except httpx.RequestError as exc:
                logger.error(f"Request error while communicating with Ollama: {str(exc)}")
                yield json.dumps({"error": "Network error occurred while communicating with Ollama"})
            except Exception as exc:
                logger.exception(f"Unexpected error during streaming: {str(exc)}")
                yield json.dumps({"error": "An unexpected error occurred during streaming."})

        return StreamingResponse(stream_response(), media_type="application/json")

    except Exception as e:
        logger.exception(f"Unexpected error: {str(e)}")
        raise HTTPException(status_code=500, detail="An unexpected error occurred")


@app.get("/health")
async def health():
    """Health check endpoint."""
    logger.info("Health check endpoint accessed")
    return {"status": "OK"}


if __name__ == "__main__":
    import uvicorn
    logger.info("Starting FastAPI application")
    uvicorn.run(app, host="0.0.0.0", port=7860)