1 files changed, 264 insertions, 0 deletions
diff --git a/modules/util/util.go b/modules/util/util.go
new file mode 100644
index 0000000..dcd7cf4
--- /dev/null
+++ b/modules/util/util.go
@@ -0,0 +1,264 @@
+// Copyright 2017 The Gitea Authors. All rights reserved.
+// Copyright 2024 The Forgejo Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package util
+
+import (
+	"bytes"
+	"crypto/ed25519"
+	"crypto/rand"
+	"encoding/pem"
+	"fmt"
+	"math/big"
+	"strconv"
+	"strings"
+
+	"code.gitea.io/gitea/modules/optional"
+
+	"golang.org/x/crypto/ssh"
+	"golang.org/x/text/cases"
+	"golang.org/x/text/language"
+)
+
+// OptionalBoolParse get the corresponding optional.Option[bool] of a string using strconv.ParseBool
+func OptionalBoolParse(s string) optional.Option[bool] {
+	v, e := strconv.ParseBool(s)
+	if e != nil {
+		return optional.None[bool]()
+	}
+	return optional.Some(v)
+}
+
+// IsEmptyString checks if the provided string is empty
+func IsEmptyString(s string) bool {
+	return len(strings.TrimSpace(s)) == 0
+}
+
+// NormalizeEOL will convert Windows (CRLF) and Mac (CR) EOLs to UNIX (LF)
+func NormalizeEOL(input []byte) []byte {
+	var right, left, pos int
+	if right = bytes.IndexByte(input, '\r'); right == -1 {
+		return input
+	}
+	length := len(input)
+	tmp := make([]byte, length)
+
+	// We know that left < length because otherwise right would be -1 from IndexByte.
+	copy(tmp[pos:pos+right], input[left:left+right])
+	pos += right
+	tmp[pos] = '\n'
+	left += right + 1
+	pos++
+
+	for left < length {
+		if input[left] == '\n' {
+			left++
+		}
+
+		right = bytes.IndexByte(input[left:], '\r')
+		if right == -1 {
+			copy(tmp[pos:], input[left:])
+			pos += length - left
+			break
+		}
+		copy(tmp[pos:pos+right], input[left:left+right])
+		pos += right
+		tmp[pos] = '\n'
+		left += right + 1
+		pos++
+	}
+	return tmp[:pos]
+}
+
+// CryptoRandomInt returns a crypto random integer between 0 and limit, inclusive
+func CryptoRandomInt(limit int64) (int64, error) {
+	rInt, err := rand.Int(rand.Reader, big.NewInt(limit))
+	if err != nil {
+		return 0, err
+	}
+	return rInt.Int64(), nil
+}
+
+const alphanumericalChars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+
+// CryptoRandomString generates a crypto random alphanumerical string, each byte is generated by [0,61] range
+func CryptoRandomString(length int64) (string, error) {
+	buf := make([]byte, length)
+	limit := int64(len(alphanumericalChars))
+	for i := range buf {
+		num, err := CryptoRandomInt(limit)
+		if err != nil {
+			return "", err
+		}
+		buf[i] = alphanumericalChars[num]
+	}
+	return string(buf), nil
+}
+
+// CryptoRandomBytes generates `length` crypto bytes
+// This differs from CryptoRandomString, as each byte in CryptoRandomString is generated by [0,61] range
+// This function generates totally random bytes, each byte is generated by [0,255] range
+func CryptoRandomBytes(length int64) ([]byte, error) {
+	buf := make([]byte, length)
+	_, err := rand.Read(buf)
+	return buf, err
+}
+
+// ToUpperASCII returns s with all ASCII letters mapped to their upper case.
+func ToUpperASCII(s string) string {
+	b := []byte(s)
+	for i, c := range b {
+		if 'a' <= c && c <= 'z' {
+			b[i] -= 'a' - 'A'
+		}
+	}
+	return string(b)
+}
+
+// ToTitleCase returns s with all english words capitalized
+func ToTitleCase(s string) string {
+	// `cases.Title` is not thread-safe, do not use global shared variable for it
+	return cases.Title(language.English).String(s)
+}
+
+// ToTitleCaseNoLower returns s with all english words capitalized without lower-casing
+func ToTitleCaseNoLower(s string) string {
+	// `cases.Title` is not thread-safe, do not use global shared variable for it
+	return cases.Title(language.English, cases.NoLower).String(s)
+}
+
+// ToInt64 transform a given int into int64.
+func ToInt64(number any) (int64, error) {
+	var value int64
+	switch v := number.(type) {
+	case int:
+		value = int64(v)
+	case int8:
+		value = int64(v)
+	case int16:
+		value = int64(v)
+	case int32:
+		value = int64(v)
+	case int64:
+		value = v
+
+	case uint:
+		value = int64(v)
+	case uint8:
+		value = int64(v)
+	case uint16:
+		value = int64(v)
+	case uint32:
+		value = int64(v)
+	case uint64:
+		value = int64(v)
+
+	case float32:
+		value = int64(v)
+	case float64:
+		value = int64(v)
+
+	case string:
+		var err error
+		if value, err = strconv.ParseInt(v, 10, 64); err != nil {
+			return 0, err
+		}
+	default:
+		return 0, fmt.Errorf("unable to convert %v to int64", number)
+	}
+	return value, nil
+}
+
+// ToFloat64 transform a given int into float64.
+func ToFloat64(number any) (float64, error) {
+	var value float64
+	switch v := number.(type) {
+	case int:
+		value = float64(v)
+	case int8:
+		value = float64(v)
+	case int16:
+		value = float64(v)
+	case int32:
+		value = float64(v)
+	case int64:
+		value = float64(v)
+
+	case uint:
+		value = float64(v)
+	case uint8:
+		value = float64(v)
+	case uint16:
+		value = float64(v)
+	case uint32:
+		value = float64(v)
+	case uint64:
+		value = float64(v)
+
+	case float32:
+		value = float64(v)
+	case float64:
+		value = v
+
+	case string:
+		var err error
+		if value, err = strconv.ParseFloat(v, 64); err != nil {
+			return 0, err
+		}
+	default:
+		return 0, fmt.Errorf("unable to convert %v to float64", number)
+	}
+	return value, nil
+}
+
+// ToPointer returns the pointer of a copy of any given value
+func ToPointer[T any](val T) *T {
+	return &val
+}
+
+// Iif is an "inline-if", it returns "trueVal" if "condition" is true, otherwise "falseVal"
+func Iif[T any](condition bool, trueVal, falseVal T) T {
+	if condition {
+		return trueVal
+	}
+	return falseVal
+}
+
+// IfZero returns "def" if "v" is a zero value, otherwise "v"
+func IfZero[T comparable](v, def T) T {
+	var zero T
+	if v == zero {
+		return def
+	}
+	return v
+}
+
+func ReserveLineBreakForTextarea(input string) string {
+	// Since the content is from a form which is a textarea, the line endings are \r\n.
+	// It's a standard behavior of HTML.
+	// But we want to store them as \n like what GitHub does.
+	// And users are unlikely to really need to keep the \r.
+	// Other than this, we should respect the original content, even leading or trailing spaces.
+	return strings.ReplaceAll(input, "\r\n", "\n")
+}
+
+// GenerateSSHKeypair generates a ed25519 SSH-compatible keypair.
+func GenerateSSHKeypair() (publicKey, privateKey []byte, err error) {
+	public, private, err := ed25519.GenerateKey(nil)
+	if err != nil {
+		return nil, nil, fmt.Errorf("ed25519.GenerateKey: %w", err)
+	}
+
+	privPEM, err := ssh.MarshalPrivateKey(private, "")
+	if err != nil {
+		return nil, nil, fmt.Errorf("ssh.MarshalPrivateKey: %w", err)
+	}
+
+	sshPublicKey, err := ssh.NewPublicKey(public)
+	if err != nil {
+		return nil, nil, fmt.Errorf("ssh.NewPublicKey: %w", err)
+	}
+
+	return ssh.MarshalAuthorizedKey(sshPublicKey), pem.EncodeToMemory(privPEM), nil
+}