"""Schema 漂移检测 API。"""
from typing import List
from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.core.database import get_db
from app.core.security import get_current_user, require_role
from app.core.crypto import decrypt_password
from app.models.user import User
from app.models.instance import Instance
from app.services.schema_drift_detector import SchemaDriftDetector

router = APIRouter(prefix="/schema-drift", tags=["Schema 漂移检测"])


def _serialize_drift_report(report):
    return report.to_dict() if hasattr(report, "to_dict") else report


@router.post("/instances/{instance_id}/capture")
async def capture_schema(
    instance_id: int,
    database: str = "",
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(require_role("admin", "dba")),
):
    """捕获 Schema 快照并保存为基线。"""
    result = await db.execute(select(Instance).where(Instance.id == instance_id))
    instance = result.scalar_one_or_none()
    if not instance:
        raise HTTPException(status_code=404, detail="数据源不存在")

    if not database:
        database = instance.database or ""

    detector = SchemaDriftDetector()
    instance.password = decrypt_password(instance.password)
    snapshot = await detector.capture_snapshot(instance, database)
    await detector.save_baseline(instance_id, database, snapshot)

    return {
        "message": "Schema 快照已捕获",
        "instance_id": instance_id,
        "database": database,
        "total_columns": len(snapshot),
    }


@router.post("/instances/{instance_id}/check")
async def check_drift(
    instance_id: int,
    database: str = "",
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(require_role("admin", "dba")),
):
    """检测 Schema 漂移。"""
    result = await db.execute(select(Instance).where(Instance.id == instance_id))
    instance = result.scalar_one_or_none()
    if not instance:
        raise HTTPException(status_code=404, detail="数据源不存在")

    if not database:
        database = instance.database or ""

    detector = SchemaDriftDetector()
    instance.password = decrypt_password(instance.password)
    report = await detector.detect_drift(instance, database)

    return _serialize_drift_report(report)


@router.get("/instances/{instance_id}/history")
async def schema_history(
    instance_id: int,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(require_role("admin", "dba")),
):
    """获取 Schema 变更历史。"""
    # 简化实现，实际应从数据库查询
    return {
        "instance_id": instance_id,
        "history": [],
        "message": "Schema 变更历史功能开发中，当前使用内存存储",
    }