from fastapi import FastAPI, File, UploadFile, Form, HTTPException, Request, Depends
from fastapi.responses import JSONResponse
from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
from pydantic import BaseModel, HttpUrl
from typing import Optional
import uvicorn
from fastapi.middleware.cors import CORSMiddleware
from utils import read_file, fetch_job_description, optimize_resume_api
import logging

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

app = FastAPI(title="Resume Optimizer API")

app.add_middleware(CORSMiddleware, allow_origins=["*"], allow_credentials=True, allow_methods=["*"], allow_headers=["*"])

security = HTTPBearer()

class OptimizationResponse(BaseModel):
    optimizedResume: str
    metadata: dict

class ErrorResponse(BaseModel):
    detail: str

def verify_token(credentials: HTTPAuthorizationCredentials = Depends(security)):
    token = credentials.credentials
    if token != "your_secret_token":
        raise HTTPException(status_code=401, detail="Invalid authentication token")
    return token

@app.post("/api/optimize-resume", response_model=OptimizationResponse, responses={400: {"model": ErrorResponse}, 401: {"model": ErrorResponse}, 500: {"model": ErrorResponse}})
async def optimize_resume(
    resume: Optional[UploadFile] = File(None),
    resumeText: Optional[str] = Form(None),
    jobDescription: Optional[str] = Form(None),
    jobDescriptionUrl: Optional[HttpUrl] = Form(None),
    token: str = Depends(verify_token)
):
    try:
        # Input validation
        if (resume is None) == (resumeText is None):
            raise ValueError("Provide either resume file or resume text, but not both")
        if (jobDescription is None) == (jobDescriptionUrl is None):
            raise ValueError("Provide either job description text or URL, but not both")
        
        # Process resume
        if resume:
            resume_content = read_file(resume)
        else:
            resume_content = resumeText
        
        # Process job description
        if jobDescription:
            job_description_content = jobDescription
        else:
            job_description_content = fetch_job_description(jobDescriptionUrl)

        # Perform optimization
        optimized_resume = optimize_resume_api(resume_content, job_description_content)

        metadata = {
            "original_resume":resume_content,
            "original_jd": job_description_content}

        return OptimizationResponse(
            optimizedResume=optimized_resume,
            metadata=metadata
        )
    except ValueError as ve:
        logger.error(f"ValueError occurred: {str(ve)}", exc_info=True)
        raise HTTPException(status_code=400, detail=str(ve))
    except Exception as e:
        logger.error(f"Unexpected error occurred: {str(e)}", exc_info=True)
        raise HTTPException(status_code=500, detail=f"An unexpected error occurred: {str(e)}")
    
@app.exception_handler(HTTPException)
async def http_exception_handler(request: Request, exc: HTTPException):
    return JSONResponse(status_code=exc.status_code, content={"detail": exc.detail})

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