tiny-rdm/backend/utils/string/convert.go

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package strutil
import (
"bytes"
"compress/flate"
"compress/gzip"
"encoding/base64"
"encoding/hex"
"encoding/json"
"errors"
"fmt"
"github.com/andybalholm/brotli"
"io"
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"strconv"
"strings"
"tinyrdm/backend/types"
"unicode/utf8"
)
// ConvertTo convert string to specified type
// @param decodeType empty string indicates automatic detection
// @param formatType empty string indicates automatic detection
func ConvertTo(str, decodeType, formatType string) (value, resultDecode, resultFormat string) {
if len(str) <= 0 {
// empty content
if len(formatType) <= 0 {
resultFormat = types.VIEWAS_PLAIN_TEXT
} else {
resultFormat = formatType
}
if len(decodeType) <= 0 {
resultDecode = types.DECODE_NONE
} else {
resultDecode = decodeType
}
return
}
// decode first
value, resultDecode = decodeWith(str, decodeType)
// then format content
value, resultFormat = viewAs(value, formatType)
return
}
func decodeWith(str, decodeType string) (value, resultDecode string) {
if len(decodeType) > 0 {
switch decodeType {
case types.DECODE_NONE:
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value = str
resultDecode = decodeType
return
case types.DECODE_BASE64:
if base64Str, ok := decodeBase64(str); ok {
value = base64Str
} else {
value = str
}
resultDecode = decodeType
return
case types.DECODE_GZIP:
if gzipStr, ok := decodeGZip(str); ok {
value = gzipStr
} else {
value = str
}
resultDecode = decodeType
return
case types.DECODE_DEFLATE:
if gzipStr, ok := decodeDeflate(str); ok {
value = gzipStr
} else {
value = str
}
resultDecode = decodeType
return
case types.DECODE_BROTLI:
if gzipStr, ok := decodeBrotli(str); ok {
value = gzipStr
} else {
value = str
}
resultDecode = decodeType
return
}
}
return autoDecode(str)
}
// attempt try possible decode method
// if no decode is possible, it will return the origin string value and "none" decode type
func autoDecode(str string) (value, resultDecode string) {
if len(str) > 0 {
var ok bool
if value, ok = decodeBase64(str); ok {
resultDecode = types.DECODE_BASE64
return
}
if value, ok = decodeGZip(str); ok {
resultDecode = types.DECODE_GZIP
return
}
if value, ok = decodeDeflate(str); ok {
resultDecode = types.DECODE_DEFLATE
return
}
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if value, ok = decodeBrotli(str); ok {
resultDecode = types.DECODE_BROTLI
return
}
}
value = str
resultDecode = types.DECODE_NONE
return
}
func viewAs(str, formatType string) (value, resultFormat string) {
if len(formatType) > 0 {
switch formatType {
case types.VIEWAS_PLAIN_TEXT:
value = str
resultFormat = formatType
return
case types.VIEWAS_JSON:
if jsonStr, ok := decodeJson(str); ok {
value = jsonStr
} else {
value = str
}
resultFormat = formatType
return
case types.VIEWAS_HEX:
if hexStr, ok := decodeToHex(str); ok {
value = hexStr
} else {
value = str
}
resultFormat = formatType
return
case types.VIEWAS_BINARY:
if binStr, ok := decodeBinary(str); ok {
value = binStr
} else {
value = str
}
resultFormat = formatType
return
}
}
return autoViewAs(str)
}
// attempt automatic convert to possible types
// if no conversion is possible, it will return the origin string value and "plain text" type
func autoViewAs(str string) (value, resultFormat string) {
if len(str) > 0 {
var ok bool
if value, ok = decodeJson(str); ok {
resultFormat = types.VIEWAS_JSON
return
}
if containsBinary(str) {
if value, ok = decodeToHex(str); ok {
resultFormat = types.VIEWAS_HEX
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return
}
}
}
value = str
resultFormat = types.VIEWAS_PLAIN_TEXT
return
}
func decodeJson(str string) (string, bool) {
if (strings.HasPrefix(str, "{") && strings.HasSuffix(str, "}")) ||
(strings.HasPrefix(str, "[") && strings.HasSuffix(str, "]")) {
var out bytes.Buffer
if err := json.Indent(&out, []byte(str), "", " "); err == nil {
return out.String(), true
}
}
return str, false
}
func decodeBase64(str string) (string, bool) {
if decodedStr, err := base64.StdEncoding.DecodeString(str); err == nil {
if s := string(decodedStr); utf8.ValidString(s) {
return s, true
}
}
return str, false
}
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func decodeBinary(str string) (string, bool) {
var binary strings.Builder
for _, char := range str {
binary.WriteString(fmt.Sprintf("%08b", int(char)))
}
return binary.String(), true
}
func decodeToHex(str string) (string, bool) {
decodeStr := hex.EncodeToString([]byte(str))
var resultStr strings.Builder
for i := 0; i < len(decodeStr); i += 2 {
resultStr.WriteString("\\x")
resultStr.WriteString(decodeStr[i : i+2])
}
return resultStr.String(), true
}
func decodeGZip(str string) (string, bool) {
if reader, err := gzip.NewReader(strings.NewReader(str)); err == nil {
defer reader.Close()
var decompressed []byte
if decompressed, err = io.ReadAll(reader); err == nil {
return string(decompressed), true
}
}
return str, false
}
func decodeDeflate(str string) (string, bool) {
reader := flate.NewReader(strings.NewReader(str))
defer reader.Close()
if decompressed, err := io.ReadAll(reader); err == nil {
return string(decompressed), true
}
return str, false
}
func decodeBrotli(str string) (string, bool) {
reader := brotli.NewReader(strings.NewReader(str))
if decompressed, err := io.ReadAll(reader); err == nil {
return string(decompressed), true
}
return str, false
}
func SaveAs(str, viewType, decodeType string) (value string, err error) {
value = str
switch viewType {
case types.VIEWAS_JSON:
if jsonStr, ok := encodeJson(str); ok {
value = jsonStr
} else {
err = errors.New("invalid json data")
return
}
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case types.VIEWAS_HEX:
if hexStr, ok := encodeHex(str); ok {
value = hexStr
} else {
err = errors.New("invalid hex data")
return
}
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case types.VIEWAS_BINARY:
if binStr, ok := encodeBinary(str); ok {
value = binStr
} else {
err = errors.New("invalid binary data")
return
}
}
switch decodeType {
case types.DECODE_NONE:
return
case types.DECODE_BASE64:
value, _ = encodeBase64(value)
return
case types.DECODE_GZIP:
if gzipStr, ok := encodeGZip(str); ok {
value = gzipStr
} else {
err = errors.New("fail to build gzip")
}
return
case types.DECODE_DEFLATE:
if deflateStr, ok := encodeDeflate(str); ok {
value = deflateStr
} else {
err = errors.New("fail to build deflate")
}
return
case types.DECODE_BROTLI:
if brotliStr, ok := encodeBrotli(str); ok {
value = brotliStr
} else {
err = errors.New("fail to build brotli")
}
return
}
return str, errors.New("fail to save with unknown error")
}
func encodeJson(str string) (string, bool) {
var data any
if (strings.HasPrefix(str, "{") && strings.HasSuffix(str, "}")) ||
(strings.HasPrefix(str, "[") && strings.HasSuffix(str, "]")) {
if err := json.Unmarshal([]byte(str), &data); err == nil {
var jsonByte []byte
if jsonByte, err = json.Marshal(data); err == nil {
return string(jsonByte), true
}
}
}
return str, false
}
func encodeBase64(str string) (string, bool) {
return base64.StdEncoding.EncodeToString([]byte(str)), true
}
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func encodeBinary(str string) (string, bool) {
var result strings.Builder
total := len(str)
for i := 0; i < total; i += 8 {
b, _ := strconv.ParseInt(str[i:i+8], 2, 8)
result.WriteByte(byte(b))
}
return result.String(), true
}
func encodeHex(str string) (string, bool) {
hexStrArr := strings.Split(str, "\\x")
hexStr := strings.Join(hexStrArr, "")
if decodeStr, err := hex.DecodeString(hexStr); err == nil {
return string(decodeStr), true
}
return str, false
}
func encodeGZip(str string) (string, bool) {
var compress = func(b []byte) (string, error) {
var buf bytes.Buffer
writer := gzip.NewWriter(&buf)
if _, err := writer.Write([]byte(str)); err != nil {
writer.Close()
return "", err
}
writer.Close()
return string(buf.Bytes()), nil
}
if gzipStr, err := compress([]byte(str)); err == nil {
return gzipStr, true
}
return str, false
}
func encodeDeflate(str string) (string, bool) {
var compress = func(b []byte) (string, error) {
var buf bytes.Buffer
writer, err := flate.NewWriter(&buf, flate.DefaultCompression)
if err != nil {
return "", err
}
if _, err = writer.Write([]byte(str)); err != nil {
writer.Close()
return "", err
}
writer.Close()
return string(buf.Bytes()), nil
}
if deflateStr, err := compress([]byte(str)); err == nil {
return deflateStr, true
}
return str, false
}
func encodeBrotli(str string) (string, bool) {
var compress = func(b []byte) (string, error) {
var buf bytes.Buffer
writer := brotli.NewWriter(&buf)
if _, err := writer.Write([]byte(str)); err != nil {
writer.Close()
return "", err
}
writer.Close()
return string(buf.Bytes()), nil
}
if brotliStr, err := compress([]byte(str)); err == nil {
return brotliStr, true
}
return str, false
}