app/backend/main.py

"""
FastAPI backend for LionGuard moderation
"""

from fastapi import FastAPI, HTTPException
from fastapi.staticfiles import StaticFiles
from fastapi.responses import FileResponse
from fastapi.middleware.cors import CORSMiddleware
import os
from typing import List

from models import (
    ModerateRequest,
    ModerateResponse,
    FeedbackRequest,
    FeedbackResponse,
    ChatRequest,
    ChatResponse,
    CategoryScore,
    ChatHistories,
)
from services import (
    analyze_text,
    submit_feedback,
    process_chat_message,
)

app = FastAPI(
    title="LionGuard API",
    description="Multilingual moderation and guardrail comparison",
    version="2.0.0"
)

# Enable CORS for development
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Get the path to frontend directory
FRONTEND_DIR = os.path.join(os.path.dirname(__file__), "../frontend")


@app.post("/moderate", response_model=ModerateResponse)
async def moderate_text(request: ModerateRequest):
    """
    Analyze text for moderation risks using LionGuard models
    """
    try:
        result = analyze_text(request.text, request.model)
        return ModerateResponse(**result)
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Error analyzing text: {str(e)}")


@app.post("/send_feedback", response_model=FeedbackResponse)
async def send_feedback(request: FeedbackRequest):
    """
    Submit user feedback on moderation result
    """
    try:
        result = submit_feedback(request.text_id, request.agree)
        return FeedbackResponse(**result)
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Error submitting feedback: {str(e)}")


@app.post("/chat", response_model=ChatResponse)
async def chat_comparison(request: ChatRequest):
    """
    Compare guardrails across three approaches:
    - No moderation
    - OpenAI moderation
    - LionGuard moderation
    """
    try:
        # Convert request histories to list of dicts
        history_no_mod = [msg.dict() for msg in request.histories.no_moderation]
        history_openai = [msg.dict() for msg in request.histories.openai_moderation]
        history_lg = [msg.dict() for msg in request.histories.lionguard]
        
        # Process message
        updated_no_mod, updated_openai, updated_lg, lg_score = await process_chat_message(
            request.message,
            request.model,
            history_no_mod,
            history_openai,
            history_lg
        )
        
        # Convert back to response format
        return ChatResponse(
            histories=ChatHistories(
                no_moderation=updated_no_mod,
                openai_moderation=updated_openai,
                lionguard=updated_lg
            ),
            lionguard_score=lg_score
        )
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Error processing chat: {str(e)}")


# Serve static frontend files
app.mount("/static", StaticFiles(directory=FRONTEND_DIR), name="static")


@app.get("/")
async def serve_frontend():
    """
    Serve the main HTML page
    """
    index_path = os.path.join(FRONTEND_DIR, "index.html")
    if os.path.exists(index_path):
        return FileResponse(index_path)
    raise HTTPException(status_code=404, detail="Frontend not found")


@app.get("/health")
async def health_check():
    """
    Health check endpoint
    """
    return {"status": "healthy", "service": "lionguard-api"}


if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=8000)