json_filter/filter.go

// Package filter ...
//
// Description : filter ...
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 2022-07-04 17:47
package filter

import (
	"encoding/json"
	"fmt"
	"strings"

	"github.com/tidwall/gjson"
	"github.com/tidwall/sjson"

	"errors"

	"git.zhangdeman.cn/zhangdeman/util"
)

// NewFilter 过滤器实例
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 11:54 2022/7/4
func NewFilter(sourceData string, filterRuleList []MapRule) *filter {
	return &filter{
		sourceData:     sourceData,
		formatResult:   "{}",
		filterRuleList: filterRuleList,
	}
}

// filter 数据过滤
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 11:58 2022/7/4
type filter struct {
	sourceData     string
	formatResult   string
	filterRuleList []MapRule
}

// Deal ...
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 11:59 2022/7/4
func (f *filter) Deal() error {
	var (
		err       error
		formatVal interface{}
	)

	for _, rule := range f.filterRuleList {
		if f.IsArray(rule) {
			// 对于list的处理
			if err = f.handleArray(rule); nil != err {
				return err
			}
			continue
		}
		sourceResult := gjson.Get(f.sourceData, rule.SourcePath)
		var (
			sourceVal string
		)

		if !sourceResult.Exists() {
			// 不存在, 使用默认值
			sourceVal = rule.DefaultValue
		} else {
			sourceVal = sourceResult.String()
		}
		if formatVal, err = f.getValue(rule.DataType, sourceVal); nil != err {
			return fmt.Errorf("%s = %v can not convert to %s : %s", rule.SourcePath, sourceResult.Value(), rule.DataType, err.Error())
		}
		if f.formatResult, err = sjson.Set(f.formatResult, rule.MapPath, formatVal); nil != err {
			return err
		}
	}
	return nil
}

// IsArray 判断是否为数组
//
// Author : zhangdeman001@ke.com<张德满>
//
// Date : 17:48 2023/1/1
func (f *filter) IsArray(rule MapRule) bool {
	return strings.Contains(rule.SourcePath, "[]")
}

// handleArray 处理数组(最复杂的场景)
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 17:41 2023/1/1
func (f *filter) handleArray(rule MapRule) error {
	var (
		err error
	)

	sourcePathArray := strings.Split(rule.SourcePath, "[]")
	for idx, item := range sourcePathArray {
		sourcePathArray[idx] = strings.Trim(item, ".")
	}
	mapPathArray := strings.Split(strings.TrimRight(rule.MapPath, ".[]"), "[]")
	for idx, item := range mapPathArray {
		mapPathArray[idx] = strings.Trim(item, ".")
	}
	if len(sourcePathArray) != len(mapPathArray) {
		if len(mapPathArray) != 1 {
			return errors.New("map rule is invalid")
		}
		// 提取某一个list下的字段, 组成一个list
		res := make([]string, 0)
		if len(sourcePathArray[0]) == 0 {
			f.getAllFinalData(&res, gjson.Parse(f.sourceData).Array(), sourcePathArray[1:])
		} else {
			f.getAllFinalData(&res, gjson.Get(f.sourceData, sourcePathArray[0]).Array(), sourcePathArray[1:])
		}
		if f.formatResult, err = sjson.Set(f.formatResult, mapPathArray[0], res); nil != err {
			return err
		}
		return nil
	}
	return nil
}

// extraFinalResult 提取全部最底层结果
//
// Author : zhangdeman001@ke.com<张德满>
//
// Date : 14:00 2023/1/2
func (f *filter) getAllFinalData(res *[]string, resultList []gjson.Result, pathArr []string) {
	if len(pathArr) == 1 {
		for _, item := range resultList {
			*res = append(*res, item.Get(pathArr[0]).String())
		}
		return
	}
	for _, item := range resultList {
		f.getAllFinalData(res, item.Array(), pathArr[1:])
	}
	return
}

// String 获取格式化之后的字符串
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 21:18 2022/12/31
func (f *filter) String() string {
	return f.formatResult
}

// Byte 获取格式化之后的字节数组
//
// Author : zhangdeman001@ke.com<张德满>
//
// Date : 21:18 2022/12/31
func (f *filter) Byte() []byte {
	return []byte(f.String())
}

// Parse 解析返回结果
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 21:20 2022/12/31
func (f *filter) Parse(receiver interface{}) error {
	if nil == receiver {
		return errors.New("receiver is nil")
	}
	return json.Unmarshal(f.Byte(), receiver)
}

// getValue 获取值
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 12:25 2022/7/4
func (f *filter) getValue(dataType string, defaultValue string) (interface{}, error) {
	switch dataType {
	case "int8":
		fallthrough
	case "int16":
		fallthrough
	case "int32":
		fallthrough
	case "int64":
		fallthrough
	case "int":
		var (
			err error
			val int64
		)
		err = util.ConvertAssign(&val, defaultValue)
		return val, err
	case "uint8":
		fallthrough
	case "uint16":
		fallthrough
	case "uint32":
		fallthrough
	case "uint64":
		fallthrough
	case "uint":
		var (
			err error
			val uint64
		)
		err = util.ConvertAssign(&val, defaultValue)
		return val, err
	case "bool":
		var (
			err error
			val bool
		)
		err = util.ConvertAssign(&val, defaultValue)
		return val, err
	case "float32":
		fallthrough
	case "float64":
		var (
			err error
			val float64
		)
		err = util.ConvertAssign(&val, defaultValue)
		return val, err
	case "string":
		return defaultValue, nil
	default:
		return nil, errors.New(dataType + " is not support!")
	}
}