package middleware

import (
	"bytes"
	"encoding/json"
	"io"
	"net/http"
	"net/url"
	"wails-app/internal/dao"
	"strconv"
	"strings"
	"time"

	"wails-app/internal/pkg"

	"github.com/gin-gonic/gin"
	"go.uber.org/zap"
	"wails-app/internal/global"
	"wails-app/internal/service"
)

var operationRecordService = service.ServiceGroupApp.SystemServiceGroup.OperationRecordService

var bufferSize = 1024

// sensitiveFields 操作日志脱敏字段（不区分大小写）：密码、令牌、密钥、支付敏感字段。
var sensitiveFields = map[string]bool{
	"password": true, "old_password": true, "new_password": true,
	"confirm_password": true, "pwd": true, "pass": true,
	"token": true, "access_token": true, "refresh_token": true, "jwt": true,
	"secret": true, "private_key": true,
}

// maskSensitiveJSON 对 JSON 文本中的敏感字段值脱敏（非 JSON 原样返回）。
func maskSensitiveJSON(data []byte) []byte {
	var obj interface{}
	if err := json.Unmarshal(data, &obj); err != nil {
		return data
	}
	out, err := json.Marshal(maskValue(obj))
	if err != nil {
		return data
	}
	return out
}

// maskValue 递归脱敏：命中敏感字段名时值替换为 "******"（空值保留）。
func maskValue(v interface{}) interface{} {
	switch value := v.(type) {
	case map[string]interface{}:
		for key, child := range value {
			if sensitiveFields[strings.ToLower(key)] {
				if child != nil {
					value[key] = "******"
				}
				continue
			}
			value[key] = maskValue(child)
		}
		return value
	case []interface{}:
		for i := range value {
			value[i] = maskValue(value[i])
		}
		return value
	default:
		return v
	}
}

// maskResponse 响应体脱敏并截断（修复旧代码只对下载类响应截断、且误写 record.Body 字段的问题）。
func maskResponse(resp string) string {
	masked := maskSensitiveJSON([]byte(resp))
	if len(masked) > bufferSize {
		return "[超出记录长度]"
	}
	return string(masked)
}

func OperationRecord() gin.HandlerFunc {
	return func(c *gin.Context) {
		var body []byte
		var userId int
		if c.Request.Method != http.MethodGet {
			var err error
			body, err = io.ReadAll(c.Request.Body)
			if err != nil {
				global.GVA_LOG.Error("read body from request error:", zap.Error(err))
			} else {
				c.Request.Body = io.NopCloser(bytes.NewBuffer(body))
			}
		} else {
			query := c.Request.URL.RawQuery
			query, _ = url.QueryUnescape(query)
			split := strings.Split(query, "&")
			m := make(map[string]string)
			for _, v := range split {
				kv := strings.Split(v, "=")
				if len(kv) == 2 {
					m[kv[0]] = kv[1]
				}
			}
			body, _ = json.Marshal(&m)
		}
		claims, _ := utils.GetClaims(c)
		if claims != nil && claims.BaseClaims.ID != 0 {
			userId = int(claims.BaseClaims.ID)
		} else {
			id, err := strconv.Atoi(c.Request.Header.Get("x-user-id"))
			if err != nil {
				userId = 0
			}
			userId = id
		}
		record := dao.SysOperationRecord{
			Ip:     c.ClientIP(),
			Method: c.Request.Method,
			Path:   c.Request.URL.Path,
			Agent:  c.Request.UserAgent(),
			Body:   "",
			UserID: userId,
		}

		// 上传文件时候 中间件日志进行裁断操作
		if strings.Contains(c.GetHeader("Content-Type"), "multipart/form-data") {
			record.Body = "[文件]"
		} else {
			masked := maskSensitiveJSON(body)
			if len(masked) > bufferSize {
				record.Body = "[超出记录长度]"
			} else {
				record.Body = string(masked)
			}
		}

		writer := responseBodyWriter{
			ResponseWriter: c.Writer,
			body:           &bytes.Buffer{},
		}
		c.Writer = writer
		now := time.Now()

		c.Next()

		latency := time.Since(now)
		record.ErrorMessage = c.Errors.ByType(gin.ErrorTypePrivate).String()
		record.Status = c.Writer.Status()
		record.Latency = latency
		record.Resp = maskResponse(writer.body.String())

		if err := operationRecordService.CreateSysOperationRecord(record); err != nil {
			global.GVA_LOG.Error("create operation record error:", zap.Error(err))
		}
	}
}

type responseBodyWriter struct {
	gin.ResponseWriter
	body *bytes.Buffer
}

func (r responseBodyWriter) Write(b []byte) (int, error) {
	r.body.Write(b)
	return r.ResponseWriter.Write(b)
}