// Package filter ...
//
// Description : filter ...
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 2024-04-07 21:59
package filter

import (
	"errors"
	"fmt"
	"git.zhangdeman.cn/zhangdeman/data_mask/define"
	"github.com/tidwall/gjson"
	"github.com/tidwall/sjson"
	"strings"
)

// Execute 数据转换
//
// Author : go_developer@163.com<张德满>
//
// Date : 12:39 2024/3/26
func Execute(sourceData string, convertRule []*define.FilterRule) *Transform {
	sourceData = strings.TrimSpace(sourceData)
	t := &Transform{
		sourceData: sourceData,
		ruleList:   convertRule,
		result:     "{}",
	}
	return t
}

// Transform 转换
//
// Author : go_developer@163.com<张德满>
//
// Date : 10:56 2024/3/27
type Transform struct {
	sourceData string
	ruleList   []*define.FilterRule
	result     string
}

// Execute 执行
//
// Author : go_developer@163.com<张德满>
//
// Date : 10:57 2024/3/27
func (t *Transform) Execute() error {
	sourceResult := gjson.Parse(t.sourceData)
	if !sourceResult.IsObject() {
		return errors.New("source data is not object")
	}
	if err := t.checkRule(); nil != err {
		return err
	}
	for _, itemRule := range t.ruleList {
		if err := t.rewrite(itemRule); nil != err {
			return err
		}
	}
	return nil
}

// GetResult 获取处理结果
//
// Author : go_developer@163.com<张德满>
//
// Date : 11:32 2024/3/27
func (t *Transform) GetResult() string {
	return t.result
}

// checkRule 校验规则
//
// Author : go_developer@163.com<张德满>
//
// Date : 11:18 2024/3/27
func (t *Transform) checkRule() error {
	for _, itemRule := range t.ruleList {
		itemRule.SourceDataPath = strings.TrimRight(itemRule.SourceDataPath, ".[]")
		itemRule.TargetDataPath = strings.TrimRight(itemRule.TargetDataPath, ".[]")
		fromPathArr := strings.Split(itemRule.SourceDataPath, "[]")
		targetPathArr := strings.Split(itemRule.TargetDataPath, "[]")
		if len(targetPathArr) > len(fromPathArr) {
			return errors.New("slice path config invalid : " + itemRule.SourceDataPath + " -> " + itemRule.TargetDataPath)
		}
	}
	return nil
}

// rewrite 数据重写
//
// Author : go_developer@163.com<张德满>
//
// Date : 11:25 2024/3/27
func (t *Transform) rewrite(rule *define.FilterRule) error {
	var (
		err error
	)

	sourceResult := gjson.Get(t.sourceData, rule.SourceDataPath)
	if !sourceResult.Exists() {
		if rule.IsRequired {
			return errors.New(rule.SourceDataPath + " is not exist, but required")
		}
		if strings.Contains(rule.SourceDataPath, "[]") {
			return t.rewriteForSlice(rule)
		}
		if t.result, err = sjson.Set(t.result, rule.TargetDataPath, rule.DefaultValue); nil != err {
			return err
		}
		return nil
	}
	t.result, err = sjson.Set(t.result, rule.TargetDataPath, sourceResult.Value())
	return nil
}

// rewriteForSlice 数组重写
//
// Author : go_developer@163.com<张德满>
//
// Date : 15:22 2024/3/27
func (t *Transform) rewriteForSlice(rule *define.FilterRule) error {
	pathArr := strings.Split(rule.SourceDataPath, ".[].")
	sliceUnfoldResult := t.unfoldSourceSliceData(t.sourceData, pathArr[0:len(pathArr)-1], nil)
	targetArr := strings.Split(rule.TargetDataPath, ".[].")
	for idx, itemRes := range sliceUnfoldResult {
		t.result, _ = sjson.Set(t.result, fmt.Sprintf("%v.%v.%v", targetArr[0], idx, targetArr[1]), itemRes.Get(pathArr[len(pathArr)-1]).Value())
	}
	return nil
}

// unfoldSourceSliceData 展开元数据的数组, 平铺
//
// Author : go_developer@163.com<张德满>
//
// Date : 17:39 2024/3/27
func (t *Transform) unfoldSourceSliceData(sourceData string, pathList []string, res []gjson.Result) []gjson.Result {
	if nil == res {
		res = make([]gjson.Result, 0)
	}

	arrRes := gjson.Get(sourceData, pathList[0]).Array()
	if len(pathList) == 1 {
		for _, itemRes := range arrRes {
			res = append(res, itemRes)
		}
		return res
	}

	for i := 0; i < len(arrRes)-1; i++ {
		res = t.unfoldSourceSliceData(arrRes[i].String(), pathList[1:], res)
	}

	return t.unfoldSourceSliceData(arrRes[len(arrRes)-1].String(), pathList[1:], res)
}