import json
from datetime import datetime

from fastapi import APIRouter, Depends, File, Form, UploadFile
from sqlalchemy import func, select
from sqlalchemy.orm import Session

from app.auth import require_admin
from app.database import get_db
from app.import_service import parse_batch_exam_ids, purge_batch, run_import
from app.models import ExaminationExamExaminee, ExaminationPaperSource, ImportBatch, User

router = APIRouter(prefix="/api/admin/import", tags=["admin-import"])


@router.get("/batches")
def list_batches(
    db: Session = Depends(get_db),
    admin: User = Depends(require_admin),
):
    batches = db.scalars(select(ImportBatch).order_by(ImportBatch.imported_at.desc())).all()
    out = []
    for b in batches:
        cnt = db.scalar(
            select(func.count())
            .select_from(ExaminationExamExaminee)
            .where(ExaminationExamExaminee.import_batch_id == b.id)
        )
        paper_name = None
        if b.paper_source_id:
            ps = db.get(ExaminationPaperSource, b.paper_source_id)
            paper_name = ps.paper_name if ps else None
        out.append(
            {
                "id": b.id,
                "subject_name": b.subject_name,
                "exam_id": b.exam_id,
                "exam_ids": parse_batch_exam_ids(b),
                "zip_filename": b.zip_filename,
                "imported_at": b.imported_at.isoformat() if b.imported_at else "",
                "status": b.status,
                "attempt_count": cnt or 0,
                "paper_name": paper_name,
                "report": json.loads(b.report_json or "{}"),
            }
        )
    return {"items": out}


@router.post("")
async def import_zip(
    subject_name: str = Form(...),
    file: UploadFile = File(...),
    db: Session = Depends(get_db),
    admin: User = Depends(require_admin),
):
    data = await file.read()
    return run_import(
        db,
        subject_name=subject_name,
        zip_filename=file.filename or "upload.zip",
        file_bytes=data,
        user_id=admin.id,
    )


@router.delete("/batches/{batch_id}")
def delete_batch(
    batch_id: int,
    db: Session = Depends(get_db),
    admin: User = Depends(require_admin),
):
    counts = purge_batch(db, batch_id)
    return {"deleted_counts": counts}