// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
//
// This Source Code Form is subject to the terms of the MIT License.
// If a copy of the MIT was not distributed with this file,
// You can obtain one at https://github.com/gogf/gf.

// Package gxml provides accessing and converting for XML content.
package gxml

import (
	"strings"

	"github.com/clbanning/mxj/v2"
	"github.com/gogf/gf/v2/errors/gerror"

	"github.com/gogf/gf/v2/encoding/gcharset"
	"github.com/gogf/gf/v2/text/gregex"
)

// Decode parses `content` into and returns as map.
func Decode(content []byte) (map[string]interface{}, error) {
	res, err := convert(content)
	if err != nil {
		return nil, err
	}
	m, err := mxj.NewMapXml(res)
	if err != nil {
		err = gerror.Wrapf(err, `mxj.NewMapXml failed`)
	}
	return m, err
}

// DecodeWithoutRoot parses `content` into a map, and returns the map without root level.
func DecodeWithoutRoot(content []byte) (map[string]interface{}, error) {
	res, err := convert(content)
	if err != nil {
		return nil, err
	}
	m, err := mxj.NewMapXml(res)
	if err != nil {
		err = gerror.Wrapf(err, `mxj.NewMapXml failed`)
		return nil, err
	}
	for _, v := range m {
		if r, ok := v.(map[string]interface{}); ok {
			return r, nil
		}
	}
	return m, nil
}

// Encode encodes map `m` to an XML format content as bytes.
// The optional parameter `rootTag` is used to specify the XML root tag.
func Encode(m map[string]interface{}, rootTag ...string) ([]byte, error) {
	b, err := mxj.Map(m).Xml(rootTag...)
	if err != nil {
		err = gerror.Wrapf(err, `mxj.Map.Xml failed`)
	}
	return b, err
}

// EncodeWithIndent encodes map `m` to an XML format content as bytes with indent.
// The optional parameter `rootTag` is used to specify the XML root tag.
func EncodeWithIndent(m map[string]interface{}, rootTag ...string) ([]byte, error) {
	b, err := mxj.Map(m).XmlIndent("", "\t", rootTag...)
	if err != nil {
		err = gerror.Wrapf(err, `mxj.Map.XmlIndent failed`)
	}
	return b, err
}

// ToJson converts `content` as XML format into JSON format bytes.
func ToJson(content []byte) ([]byte, error) {
	res, err := convert(content)
	if err != nil {
		return nil, err
	}
	mv, err := mxj.NewMapXml(res)
	if err == nil {
		err = gerror.Wrapf(err, `mxj.NewMapXml failed`)
		return mv.Json()
	}
	return nil, err
}

// convert does convert the encoding of given XML content from XML root tag into UTF-8 encoding content.
func convert(xml []byte) (res []byte, err error) {
	var (
		patten      = `<\?xml.*encoding\s*=\s*['|"](.*?)['|"].*\?>`
		matchStr, _ = gregex.MatchString(patten, string(xml))
		xmlEncode   = "UTF-8"
	)
	if len(matchStr) == 2 {
		xmlEncode = matchStr[1]
	}
	xmlEncode = strings.ToUpper(xmlEncode)
	res, err = gregex.Replace(patten, []byte(""), xml)
	if err != nil {
		return nil, err
	}
	if xmlEncode != "UTF-8" && xmlEncode != "UTF8" {
		dst, err := gcharset.Convert("UTF-8", xmlEncode, string(res))
		if err != nil {
			return nil, err
		}
		res = []byte(dst)
	}
	return res, nil
}