from fastapi import FastAPI, File, UploadFile
from fastapi.responses import FileResponse, PlainTextResponse
from fastapi.middleware.cors import CORSMiddleware
import zipfile
import os
import shutil
from pathlib import Path
from qc_validator import validate_shapefiles

app = FastAPI()

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

TEMP_DIR = Path("../temp")
TEMP_DIR.mkdir(exist_ok=True)

@app.post("/upload")
async def upload_shapefile(file: UploadFile = File(...)):
    """Handle shapefile ZIP upload and QC validation"""

    # Clear temp directory
    for item in TEMP_DIR.glob("*"):
        if item.is_file():
            item.unlink()
        elif item.is_dir():
            shutil.rmtree(item)

    # Save uploaded file
    zip_path = TEMP_DIR / file.filename
    with open(zip_path, "wb") as f:
        content = await file.read()
        f.write(content)

    # Unzip file
    try:
        with zipfile.ZipFile(zip_path, 'r') as zip_ref:
            zip_ref.extractall(TEMP_DIR)
    except Exception as e:
        return PlainTextResponse(f"Error extracting ZIP file: {str(e)}", status_code=400)

    # Run QC validation
    qc_result = validate_shapefiles(TEMP_DIR)

    if qc_result["passed"]:
        return {"message": "success"}
    else:
        # Generate QC report
        report_path = TEMP_DIR / "QC_report.txt"
        with open(report_path, "w") as f:
            f.write("QC VALIDATION FAILED\n")
            f.write("=" * 50 + "\n\n")
            for error in qc_result["errors"]:
                f.write(f"{error}\n")

        return FileResponse(
            path=report_path,
            media_type="text/plain",
            filename="QC_report.txt"
        )

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