feat: implement hgctl agent module (#3267)

hgctl/pkg/util/env.go

@@ -0,0 +1,79 @@
+// Copyright (c) 2025 Alibaba Group Holding Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package util
+
+import (
+	"fmt"
+	"os/exec"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+func GetPythonVersion() (string, error) {
+	re := regexp.MustCompile(`\d+\.\d+(\.\d+)?`)
+
+	for _, cmd := range []string{"python3", "python"} {
+		out, err := exec.Command(cmd, "--version").CombinedOutput()
+		if err != nil {
+			continue
+		}
+
+		version := strings.TrimSpace(string(out))
+		match := re.FindString(version)
+		if match != "" {
+			return match, nil
+		}
+	}
+
+	return "", fmt.Errorf("python not found")
+}
+
+// compareVersions compares two version strings like "3.11.2" and "3.10".
+// Returns:
+//
+//	 1  if v1 > v2
+//	 0  if v1 == v2
+//	-1  if v1 < v2
+func CompareVersions(v1, v2 string) int {
+	// Extract numeric parts only (e.g. "3.12.0b1" → "3.12.0")
+	re := regexp.MustCompile(`\d+`)
+	nums1 := re.FindAllString(v1, -1)
+	nums2 := re.FindAllString(v2, -1)
+
+	maxLen := len(nums1)
+	if len(nums2) > maxLen {
+		maxLen = len(nums2)
+	}
+
+	// Compare each part
+	for i := 0; i < maxLen; i++ {
+		var n1, n2 int
+		if i < len(nums1) {
+			n1, _ = strconv.Atoi(nums1[i])
+		}
+		if i < len(nums2) {
+			n2, _ = strconv.Atoi(nums2[i])
+		}
+
+		if n1 > n2 {
+			return 1
+		} else if n1 < n2 {
+			return -1
+		}
+	}
+
+	return 0
+}

hgctl/pkg/util/util.go

@@ -16,9 +16,11 @@ package util
 
 import (
 	"bufio"
+	"errors"
 	"fmt"
 	"net/url"
 	"os"
+	"path/filepath"
 	"strconv"
 	"strings"
 )
@@ -93,3 +95,33 @@ func WriteFileString(fileName string, content string, perm os.FileMode) error {
 	writer.Flush()
 	return nil
 }
+
+// This function return ~/.hgctl file_path string (Currently Linux only)
+func GetHomeHgctlDir() string {
+	homeDir, _ := os.UserHomeDir()
+	targetDir := filepath.Join(homeDir, ".hgctl")
+	return targetDir
+}
+
+func GetSpecificAgentDir(name string) (string, error) {
+	homeDir, err := os.UserHomeDir()
+	if err != nil {
+		return "", fmt.Errorf("failed to get user home directory: %w", err)
+	}
+
+	targetDir := filepath.Join(homeDir, ".hgctl", "agents", name)
+
+	info, err := os.Stat(targetDir)
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			return "", fmt.Errorf("agent %q does not exist", name)
+		}
+		return "", fmt.Errorf("failed to stat agent directory %q: %w", targetDir, err)
+	}
+
+	if !info.IsDir() {
+		return "", fmt.Errorf("agent %q exists but is not a directory", name)
+	}
+
+	return targetDir, nil
+}