helper.go

package main

import (
	"bufio"
	"fmt"
	"os"
	"os/user"
	"path/filepath"
	"strings"
)

type SSHConfig struct {
	Host     string
	Hostname string
	User     string
	Port     string
	Identity string
}

func GetDefaultSSHConfigPath() string {
	usr, err := user.Current()
	if err != nil {
		return ""
	}
	return filepath.Join(usr.HomeDir, ".ssh", "config")
}

func ParseSSHConfig(path string) ([]SSHConfig, error) {
	file, err := os.Open(path)
	if err != nil {
		return nil, err
	}
	defer file.Close()

	var configs []SSHConfig
	var currentConfig *SSHConfig

	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		line := strings.TrimSpace(scanner.Text())
		if line == "" || strings.HasPrefix(line, "#") {
			continue
		}

		parts := strings.Fields(line)
		if len(parts) >= 2 {
			key := strings.ToLower(parts[0])
			value := strings.Join(parts[1:], " ")

			if key == "host" {
				if currentConfig != nil {
					configs = append(configs, *currentConfig)
				}
				currentConfig = &SSHConfig{Host: value}
			} else if currentConfig != nil {
				switch key {
				case "hostname":
					currentConfig.Hostname = value
				case "user":
					currentConfig.User = value
				case "port":
					currentConfig.Port = value
				case "identityfile":
					currentConfig.Identity = value
				}
			}
		}
	}

	if currentConfig != nil {
		configs = append(configs, *currentConfig)
	}

	return configs, scanner.Err()
}

func WriteSSHConfig(path string, configs []SSHConfig) error {
	file, err := os.Create(path)
	if err != nil {
		return err
	}
	defer file.Close()

	writer := bufio.NewWriter(file)
	for i, cfg := range configs {
		writer.WriteString(fmt.Sprintf("Host %s\n", cfg.Host))
		if cfg.Hostname != "" {
			writer.WriteString(fmt.Sprintf("    HostName %s\n", cfg.Hostname))
		}
		if cfg.User != "" {
			writer.WriteString(fmt.Sprintf("    User %s\n", cfg.User))
		}
		if cfg.Port != "" {
			writer.WriteString(fmt.Sprintf("    Port %s\n", cfg.Port))
		}
		if cfg.Identity != "" {
			writer.WriteString(fmt.Sprintf("    IdentityFile %s\n", cfg.Identity))
		}
		if i < len(configs)-1 {
			writer.WriteString("\n")
		}
	}
	return writer.Flush()
}