refactor: move packages to internal/

1 files changed, 91 insertions, 0 deletions

diff --git a/internal/git/utils.go b/internal/git/utils.go
new file mode 100644
index 0000000..68e4497
--- /dev/null
+++ b/internal/git/utils.go
@@ -0,0 +1,91 @@
+package git
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+// ParseFileMode converts a git-style file mode (e.g. "100644")
+// into a human-readable string like "rw-r--r--".
+func ParseFileMode(modeStr string) (string, error) {
+	// Git modes are typically 6 digits. The last 3 represent permissions.
+	// e.g. 100644 → 644
+	if len(modeStr) < 3 {
+		return "", fmt.Errorf("invalid mode: %s", modeStr)
+	}
+
+	permStr := modeStr[len(modeStr)-3:]
+	permVal, err := strconv.Atoi(permStr)
+	if err != nil {
+		return "", err
+	}
+
+	return numericPermToLetters(permVal), nil
+}
+
+func numericPermToLetters(perm int) string {
+	// Map each octal digit to rwx letters
+	lookup := map[int]string{
+		0: "---",
+		1: "--x",
+		2: "-w-",
+		3: "-wx",
+		4: "r--",
+		5: "r-x",
+		6: "rw-",
+		7: "rwx",
+	}
+
+	u := perm / 100       // user
+	g := (perm / 10) % 10 // group
+	o := perm % 10        // others
+
+	return lookup[u] + lookup[g] + lookup[o]
+}
+
+// IsBinary performs a heuristic check to determine if data is binary.
+// Rules:
+//   - Any NUL byte => binary
+//   - Consider only a sample (up to 8 KiB). If >30% of bytes are control characters
+//     outside the common whitespace/newline range, treat as binary.
+func IsBinary(b []byte) bool {
+	n := len(b)
+	if n == 0 {
+		return false
+	}
+	if n > 8192 {
+		n = 8192
+	}
+	sample := b[:n]
+	bad := 0
+	for _, c := range sample {
+		if c == 0x00 {
+			return true
+		}
+		// Allow common whitespace and control: tab(9), LF(10), CR(13)
+		if c == 9 || c == 10 || c == 13 {
+			continue
+		}
+		// Count other control chars and DEL as non-text
+		if c < 32 || c == 127 {
+			bad++
+		}
+	}
+	// If more than 30% of sampled bytes are non-text, consider binary
+	return bad*100 > n*30
+}
+
+func RefToFileName(ref string) string {
+	var result strings.Builder
+	for _, c := range ref {
+		if (c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') || c == '-' || c == '.' {
+			result.WriteByte(byte(c))
+		} else if c >= 'A' && c <= 'Z' {
+			result.WriteByte(byte(c - 'A' + 'a'))
+		} else {
+			result.WriteByte('-')
+		}
+	}
+	return result.String()
+}