from fastapi import APIRouter, Depends, HTTPException, UploadFile, File, WebSocket, Response
from fastapi.responses import FileResponse
from sqlalchemy.orm import Session
from typing import List
import os
from ...core.config import settings
from ...core.database import get_db
from ...models.file import File as FileModel, FileStatus
from ...services.file_service import process_file
from ...schemas.file import FileResponse as FileResponseSchema, FileList
import asyncio
from fastapi import WebSocketDisconnect

router = APIRouter()

@router.post("/upload", response_model=FileResponseSchema)
async def upload_file(
    file: UploadFile = File(...),
    db: Session = Depends(get_db)
):
    if not file.filename:
        raise HTTPException(status_code=400, detail="No file provided")
    
    if not any(file.filename.lower().endswith(ext) for ext in settings.ALLOWED_EXTENSIONS):
        raise HTTPException(
            status_code=400,
            detail=f"File type not allowed. Allowed types: {', '.join(settings.ALLOWED_EXTENSIONS)}"
        )
    
    # Save file
    file_path = settings.UPLOAD_FOLDER / file.filename
    with open(file_path, "wb") as buffer:
        content = await file.read()
        buffer.write(content)
    
    # Create database entry
    db_file = FileModel(
        filename=file.filename,
        original_path=str(file_path),
        status=FileStatus.NOT_STARTED
    )
    db.add(db_file)
    db.commit()
    db.refresh(db_file)
    
    # Start processing
    process_file.delay(str(db_file.id))
    
    return db_file

@router.get("/files", response_model=List[FileResponseSchema])
def list_files(
    skip: int = 0,
    limit: int = 100,
    db: Session = Depends(get_db)
):
    files = db.query(FileModel).offset(skip).limit(limit).all()
    return files

@router.get("/files/{file_id}", response_model=FileResponseSchema)
def get_file(
    file_id: str,
    db: Session = Depends(get_db)
):
    file = db.query(FileModel).filter(FileModel.id == file_id).first()
    if not file:
        raise HTTPException(status_code=404, detail="File not found")
    return file

@router.get("/files/{file_id}/download")
async def download_file(
    file_id: str,
    db: Session = Depends(get_db)
):
    file = db.query(FileModel).filter(FileModel.id == file_id).first()
    if not file:
        raise HTTPException(status_code=404, detail="File not found")
    
    if file.status != FileStatus.SUCCESS:
        raise HTTPException(status_code=400, detail="File is not ready for download")
    
    if not os.path.exists(file.processed_path):
        raise HTTPException(status_code=404, detail="Processed file not found")
    
    return FileResponse(
        path=file.processed_path,
        filename=file.filename,
        media_type="application/octet-stream"
    )

@router.websocket("/ws/status/{file_id}")
async def websocket_endpoint(websocket: WebSocket, file_id: str, db: Session = Depends(get_db)):
    await websocket.accept()
    try:
        while True:
            file = db.query(FileModel).filter(FileModel.id == file_id).first()
            if not file:
                await websocket.send_json({"error": "File not found"})
                break
            
            await websocket.send_json({
                "status": file.status,
                "error": file.error_message
            })
            
            if file.status in [FileStatus.SUCCESS, FileStatus.FAILED]:
                break
            
            await asyncio.sleep(1)
    except WebSocketDisconnect:
        pass