package middleware

import (
	"net/http"
	"runtime/debug"
	"time"

	"github.com/gin-gonic/gin"
	"go.uber.org/zap"
)

// PanicRecoveryMiddleware Panic恢复中间件
type PanicRecoveryMiddleware struct {
	logger *zap.Logger
}

// NewPanicRecoveryMiddleware 创建Panic恢复中间件
func NewPanicRecoveryMiddleware(logger *zap.Logger) *PanicRecoveryMiddleware {
	return &PanicRecoveryMiddleware{
		logger: logger,
	}
}

// GetName 返回中间件名称
func (m *PanicRecoveryMiddleware) GetName() string {
	return "panic_recovery"
}

// GetPriority 返回中间件优先级
func (m *PanicRecoveryMiddleware) GetPriority() int {
	return 100 // 最高优先级，第一个执行
}

// Handle 返回中间件处理函数
func (m *PanicRecoveryMiddleware) Handle() gin.HandlerFunc {
	return gin.RecoveryWithWriter(&panicLogger{logger: m.logger})
}

// IsGlobal 是否为全局中间件
func (m *PanicRecoveryMiddleware) IsGlobal() bool {
	return true
}

// panicLogger 实现io.Writer接口，用于记录panic信息
type panicLogger struct {
	logger *zap.Logger
}

// Write 实现io.Writer接口
func (pl *panicLogger) Write(p []byte) (n int, err error) {
	pl.logger.Error("系统发生严重错误",
		zap.String("error_type", "panic"),
		zap.String("stack_trace", string(p)),
		zap.String("timestamp", time.Now().Format("2006-01-02 15:04:05")),
	)
	return len(p), nil
}

// CustomPanicRecovery 自定义panic恢复中间件
func (m *PanicRecoveryMiddleware) CustomPanicRecovery() gin.HandlerFunc {
	return func(c *gin.Context) {
		defer func() {
			if err := recover(); err != nil {
				// 获取请求信息
				requestID := c.GetString("request_id")
				traceID := c.GetString("trace_id")
				userID := c.GetString("user_id")
				clientIP := c.ClientIP()
				method := c.Request.Method
				path := c.Request.URL.Path
				userAgent := c.Request.UserAgent()

				// 记录详细的panic信息
				m.logger.Error("系统发生严重错误",
					zap.Any("panic_error", err),
					zap.String("error_type", "panic"),
					zap.String("request_id", requestID),
					zap.String("trace_id", traceID),
					zap.String("user_id", userID),
					zap.String("client_ip", clientIP),
					zap.String("method", method),
					zap.String("path", path),
					zap.String("user_agent", userAgent),
					zap.String("stack_trace", string(debug.Stack())),
					zap.String("timestamp", time.Now().Format("2006-01-02 15:04:05")),
				)

				// 返回500错误响应
				c.JSON(http.StatusInternalServerError, gin.H{
					"success":    false,
					"message":    "服务器内部错误",
					"error_code": "INTERNAL_SERVER_ERROR",
					"request_id": requestID,
					"timestamp":  time.Now().Unix(),
				})

				// 中止请求处理
				c.Abort()
			}
		}()

		c.Next()
	}
}