from fastapi import FastAPI, File, UploadFile, HTTPException
from fastapi.responses import FileResponse
from fastapi.middleware.cors import CORSMiddleware
import os
import tempfile
import shutil
from pdf2docx import Converter
import uvicorn

app = FastAPI(title="PDF to Word Converter API")

# CORS configuration for Next.js
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],  # In production, replace with your Next.js domain
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Create temp directory if it doesn't exist
TEMP_DIR = "/tmp/conversions"
os.makedirs(TEMP_DIR, exist_ok=True)

@app.get("/")
def read_root():
    return {
        "message": "PDF to Word Converter API",
        "endpoints": {
            "/convert": "POST - Upload PDF to convert to Word",
            "/health": "GET - Health check"
        }
    }

@app.get("/health")
def health_check():
    return {"status": "healthy"}

@app.post("/convert")
async def convert_pdf_to_word(file: UploadFile = File(...)):
    """
    Convert uploaded PDF file to Word document
    """
    # Validate file type
    if not file.filename.endswith('.pdf'):
        raise HTTPException(status_code=400, detail="Only PDF files are allowed")
    
    # Create unique temporary files
    temp_pdf = tempfile.NamedTemporaryFile(delete=False, suffix='.pdf', dir=TEMP_DIR)
    temp_docx = tempfile.NamedTemporaryFile(delete=False, suffix='.docx', dir=TEMP_DIR)
    
    try:
        # Save uploaded PDF
        content = await file.read()
        temp_pdf.write(content)
        temp_pdf.close()
        
        # Convert PDF to DOCX
        cv = Converter(temp_pdf.name)
        cv.convert(temp_docx.name)
        cv.close()
        
        # Get original filename without extension
        original_name = os.path.splitext(file.filename)[0]
        output_filename = f"{original_name}.docx"
        
        # Return the converted file
        return FileResponse(
            temp_docx.name,
            media_type="application/vnd.openxmlformats-officedocument.wordprocessingml.document",
            filename=output_filename,
            background=None
        )
        
    except Exception as e:
        # Clean up on error
        if os.path.exists(temp_pdf.name):
            os.unlink(temp_pdf.name)
        if os.path.exists(temp_docx.name):
            os.unlink(temp_docx.name)
        raise HTTPException(status_code=500, detail=f"Conversion failed: {str(e)}")
    
    finally:
        # Schedule cleanup (files will be removed after response is sent)
        if os.path.exists(temp_pdf.name):
            try:
                os.unlink(temp_pdf.name)
            except:
                pass

if __name__ == "__main__":
    port = int(os.environ.get("PORT", 7860))
    uvicorn.run(app, host="0.0.0.0", port=port)