from sqlalchemy import delete, func, select
from sqlalchemy.orm import Session

from app.models.training_record import TrainingRecord, TrainingScoreDetail


class EvaluationRepository:
    """评价仓储：负责完整训练结束后的 training_record 读写。"""

    def __init__(self, db: Session) -> None:
        self.db = db

    def create_record(self, record: TrainingRecord) -> TrainingRecord:
        """评价保存：把 AI 评分报告保存为训练记录。"""
        self.db.add(record)
        self.db.flush()
        return record

    def replace_score_details(self, record_id: int, details: list[TrainingScoreDetail]) -> list[TrainingScoreDetail]:
        """评分明细保存：按训练记录覆盖写入维度评分明细。"""
        self.db.execute(delete(TrainingScoreDetail).where(TrainingScoreDetail.record_id == record_id))
        for detail in details:
            detail.record_id = record_id
            self.db.add(detail)
        self.db.flush()
        return details

    def list_score_details(self, record_id: int) -> list[TrainingScoreDetail]:
        """评分明细读取：按训练记录查询全部维度明细。"""
        stmt = select(TrainingScoreDetail).where(TrainingScoreDetail.record_id == record_id).order_by(TrainingScoreDetail.id)
        return list(self.db.scalars(stmt).all())

    def get_by_session(self, session_id: int, user_id: str) -> TrainingRecord | None:
        """评价读取：按会话 ID 和外部 user_id 查询训练记录。"""
        stmt = select(TrainingRecord).where(
            TrainingRecord.session_id == session_id,
            TrainingRecord.external_user_id == user_id,
        )
        return self.db.scalar(stmt)

    def get_owned_record(self, evaluation_id: int, user_id: str) -> TrainingRecord | None:
        """评价归属校验：按训练记录 ID 和外部 user_id 查询记录。"""
        stmt = select(TrainingRecord).where(
            TrainingRecord.id == evaluation_id,
            TrainingRecord.external_user_id == user_id,
        )
        return self.db.scalar(stmt)

    def count_by_user(self, user_id: str) -> int:
        """历史评价计数：按外部 user_id 统计完整训练后的评价记录总数。"""
        stmt = select(func.count()).select_from(TrainingRecord).where(TrainingRecord.external_user_id == user_id)
        return int(self.db.scalar(stmt) or 0)

    def list_by_user(self, user_id: str, limit: int, offset: int) -> list[TrainingRecord]:
        """历史评价：按外部 user_id 查询完整训练后的评价记录。"""
        stmt = (
            select(TrainingRecord)
            .where(TrainingRecord.external_user_id == user_id)
            .order_by(TrainingRecord.created_at.desc())
            .limit(limit)
            .offset(offset)
        )
        return list(self.db.scalars(stmt).all())

    def flush(self) -> None:
        """记录更新：刷新 PDF 路径等派生字段。"""
        self.db.flush()