from fastapi import APIRouter, Depends, Query
from sqlalchemy.orm import Session
from sqlalchemy import text
from app.models.database import get_db, get_active_sessions_count, get_long_running_sessions
from app.core.response import success_response, ResponseModel
from app.core.db_monitor import DBConnectionMonitor

router = APIRouter()

@router.get("/health", response_model=ResponseModel)
async def health_check(db: Session = Depends(get_db)):
    """健康检查端点，检查API和数据库连接状态"""
    # 尝试执行简单查询以验证数据库连接
    try:
        db.execute(text("SELECT 1")).scalar()
        db_status = "healthy"
    except Exception as e:
        db_status = f"unhealthy: {str(e)}"
    
    # 获取连接池状态和性能统计
    all_stats = DBConnectionMonitor.get_all_stats()
    
    # 获取活跃会话信息
    active_sessions_count = get_active_sessions_count()
    long_running_sessions = get_long_running_sessions(threshold_seconds=30)
    
    return success_response(data={
        "status": "ok",
        "database": {
            "status": db_status,
            "connection_pool": all_stats["connection_pool"],
            "active_sessions": active_sessions_count,
            "long_running_sessions": len(long_running_sessions)
        }
    })

@router.get("/stats", response_model=ResponseModel)
async def performance_stats(
    include_slow_queries: bool = Query(False, description="是否包含慢查询记录"),
    include_long_sessions: bool = Query(False, description="是否包含长时间运行的会话详情"),
    db: Session = Depends(get_db)
):
    """获取详细的性能统计信息"""
    # 获取所有统计信息
    all_stats = DBConnectionMonitor.get_all_stats()
    
    # 如果不需要包含慢查询记录，则移除它们以减少响应大小
    if not include_slow_queries and "slow_queries" in all_stats["performance_stats"]:
        all_stats["performance_stats"]["slow_queries_count"] = len(all_stats["performance_stats"]["slow_queries"])
        del all_stats["performance_stats"]["slow_queries"]
    
    # 添加会话信息
    all_stats["sessions"] = {
        "active_count": get_active_sessions_count()
    }
    
    # 如果需要包含长时间运行的会话详情
    if include_long_sessions:
        all_stats["sessions"]["long_running"] = get_long_running_sessions(threshold_seconds=30)
    else:
        all_stats["sessions"]["long_running_count"] = len(get_long_running_sessions(threshold_seconds=30))
    
    return success_response(data=all_stats)