from fastapi import APIRouter, Depends, HTTPException, UploadFile, File
from sqlalchemy.orm import Session
from typing import List
from fastapi.responses import FileResponse
from ... import schemas, auth, models
from ...database import get_db
from ...db_manager import DbManager

router = APIRouter(
    prefix="/admin/db",
    tags=["Admin Database Backups"]
)

@router.get("/backups", response_model=List[schemas.BackupInfo])
def get_backups(
    db: Session = Depends(get_db),
    current_admin: auth.TokenData = Depends(auth.get_current_admin)
):
    """List available database backups."""
    return DbManager.get_backup_list()

@router.get("/stats", response_model=schemas.DatabaseStats)
def get_db_stats(
    db: Session = Depends(get_db),
    current_admin: auth.TokenData = Depends(auth.get_current_admin)
):
    """Get database backup storage statistics."""
    return DbManager.get_stats()

@router.post("/backup", response_model=schemas.BackupInfo)
def trigger_manual_backup(
    db: Session = Depends(get_db),
    current_admin: auth.TokenData = Depends(auth.get_current_admin)
):
    """Trigger a manual database backup."""
    filename = DbManager.create_backup(db, label="manual", user_id=current_admin.sub)
    backups = DbManager.get_backup_list()
    for b in backups:
        if b.filename == filename:
            return b
    raise HTTPException(status_code=500, detail="Backup created but info not found")

@router.post("/restore")
def restore_database(
    payload: dict,
    db: Session = Depends(get_db),
    current_admin: auth.TokenData = Depends(auth.get_current_admin)
):
    """Restore database from a specific file. DANGEROUS."""
    filename = payload.get("filename")
    confirm = payload.get("confirm", False)
    
    if not filename:
        raise HTTPException(status_code=400, detail="Filename required")
    if not confirm:
        raise HTTPException(status_code=400, detail="Confirmation required")
        
    try:
        DbManager.restore_backup(filename, db, user_id=current_admin.sub)
        return {"status": "success", "message": f"Database restored from {filename}"}
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

@router.get("/export")
def export_database(
    current_admin: auth.TokenData = Depends(auth.get_current_admin)
):
    """Download the current database file."""
    try:
        path = DbManager.export_db()
        return FileResponse(
            path, 
            media_type="application/x-sqlite3", 
            filename="inventory_export.db"
        )
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

@router.post("/import")
async def import_database(
    file: UploadFile = File(...),
    db: Session = Depends(get_db),
    current_admin: auth.TokenData = Depends(auth.get_current_admin)
):
    """Upload and replace the current database. DANGEROUS."""
    contents = await file.read()
    try:
        DbManager.import_db(contents, db, user_id=current_admin.sub)
        return {"status": "success", "message": "Database successfully imported and replaced."}
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))