package middleware

import (
	"context"
	"net"
	"os"
	"runtime/debug"
	"strings"

	"github.com/go-kratos/kratos/v2/errors"
	"github.com/go-kratos/kratos/v2/log"
	"github.com/go-kratos/kratos/v2/middleware"
)

// Recovery panic恢复中间件
func Recovery(logger log.Logger) middleware.Middleware {
	helper := log.NewHelper(logger)
	return func(handler middleware.Handler) middleware.Handler {
		return func(ctx context.Context, req interface{}) (reply interface{}, err error) {
			defer func() {
				if rerr := recover(); rerr != nil {
					// 检查是否为断开的连接
					var brokenPipe bool
					if ne, ok := rerr.(*net.OpError); ok {
						if se, ok := ne.Err.(*os.SyscallError); ok {
							errStr := strings.ToLower(se.Error())
							if strings.Contains(errStr, "broken pipe") ||
								strings.Contains(errStr, "connection reset by peer") {
								brokenPipe = true
							}
						}
					}

					stack := string(debug.Stack())
					if brokenPipe {
						helper.Errorw(
							"msg", "[Recovery from panic]",
							"error", rerr,
							"broken_pipe", true,
						)
					} else {
						helper.Errorw(
							"msg", "[Recovery from panic]",
							"error", rerr,
							"stack", stack,
						)
					}

					err = errors.InternalServer("PANIC", "服务器内部错误")
				}
			}()
			return handler(ctx, req)
		}
	}
}