package handler

import (
	"context"
	"errors"
	"net/http"
	"time"

	"carrotskin/pkg/database"
	"carrotskin/pkg/redis"

	"github.com/gin-gonic/gin"
)

// HealthCheck 健康检查，检查依赖服务状态
func HealthCheck(c *gin.Context) {
	ctx, cancel := context.WithTimeout(c.Request.Context(), 5*time.Second)
	defer cancel()

	checks := make(map[string]string)
	status := "ok"

	// 检查数据库
	if err := checkDatabase(ctx); err != nil {
		checks["database"] = "unhealthy: " + err.Error()
		status = "degraded"
	} else {
		checks["database"] = "healthy"
	}

	// 检查Redis
	if err := checkRedis(ctx); err != nil {
		checks["redis"] = "unhealthy: " + err.Error()
		status = "degraded"
	} else {
		checks["redis"] = "healthy"
	}

	// 根据状态返回相应的HTTP状态码
	httpStatus := http.StatusOK
	if status == "degraded" {
		httpStatus = http.StatusServiceUnavailable
	}

	c.JSON(httpStatus, gin.H{
		"status":    status,
		"message":   "CarrotSkin API health check",
		"checks":    checks,
		"timestamp": time.Now().Unix(),
	})
}

// checkDatabase 检查数据库连接
func checkDatabase(ctx context.Context) error {
	db, err := database.GetDB()
	if err != nil {
		return err
	}

	sqlDB, err := db.DB()
	if err != nil {
		return err
	}

	// 使用Ping检查连接
	if err := sqlDB.PingContext(ctx); err != nil {
		return err
	}

	// 执行简单查询验证
	var result int
	if err := db.WithContext(ctx).Raw("SELECT 1").Scan(&result).Error; err != nil {
		return err
	}

	return nil
}

// checkRedis 检查Redis连接
func checkRedis(ctx context.Context) error {
	client, err := redis.GetClient()
	if err != nil {
		return err
	}
	if client == nil {
		return errors.New("Redis客户端未初始化")
	}

	// 使用Ping检查连接
	if err := client.Ping(ctx).Err(); err != nil {
		return err
	}

	return nil
}