done

internal/config/manager.go

@@ -0,0 +1,218 @@
+package config
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"git.gostacks.org/iwasforcedtobehere/fastestmirror/internal/distro"
+)
+
+// ConfigManager handles backup and modification of distribution config files
+type ConfigManager struct {
+	DistroInfo *distro.DistroInfo
+	BackupDir  string
+}
+
+// NewConfigManager creates a new configuration manager
+func NewConfigManager(distroInfo *distro.DistroInfo) *ConfigManager {
+	return &ConfigManager{
+		DistroInfo: distroInfo,
+		BackupDir:  "/etc/fastestmirror/backups",
+	}
+}
+
+// BackupConfig creates a backup of the current configuration
+func (cm *ConfigManager) BackupConfig() (string, error) {
+	configFile := cm.DistroInfo.GetConfigFile()
+	if configFile == "" {
+		return "", fmt.Errorf("no configuration file defined for %s", cm.DistroInfo.Family)
+	}
+
+	// Create backup directory if it doesn't exist
+	if err := os.MkdirAll(cm.BackupDir, 0755); err != nil {
+		return "", fmt.Errorf("failed to create backup directory: %w", err)
+	}
+
+	// Generate backup filename with timestamp
+	timestamp := time.Now().Format("20060102-150405")
+	backupName := fmt.Sprintf("%s.backup.%s", filepath.Base(configFile), timestamp)
+	backupPath := filepath.Join(cm.BackupDir, backupName)
+
+	// Copy original file to backup location
+	if err := cm.copyFile(configFile, backupPath); err != nil {
+		return "", fmt.Errorf("failed to create backup: %w", err)
+	}
+
+	return backupPath, nil
+}
+
+// ApplyMirror applies the fastest mirror to the configuration
+func (cm *ConfigManager) ApplyMirror(mirrorURL string) error {
+	switch cm.DistroInfo.Family {
+	case "debian":
+		return cm.applyDebianMirror(mirrorURL)
+	case "arch":
+		return cm.applyArchMirror(mirrorURL)
+	default:
+		return fmt.Errorf("configuration management for %s family not implemented yet", cm.DistroInfo.Family)
+	}
+}
+
+// applyDebianMirror updates /etc/apt/sources.list for Debian-based systems
+func (cm *ConfigManager) applyDebianMirror(mirrorURL string) error {
+	configFile := "/etc/apt/sources.list"
+
+	// Read current configuration
+	file, err := os.Open(configFile)
+	if err != nil {
+		return fmt.Errorf("failed to read %s: %w", configFile, err)
+	}
+	defer file.Close()
+
+	var lines []string
+	scanner := bufio.NewScanner(file)
+
+	// Process each line and replace mirror URLs
+	for scanner.Scan() {
+		line := scanner.Text()
+		if strings.TrimSpace(line) == "" || strings.HasPrefix(strings.TrimSpace(line), "#") {
+			// Keep comments and empty lines as-is
+			lines = append(lines, line)
+			continue
+		}
+
+		// Parse and update deb/deb-src lines
+		if strings.HasPrefix(strings.TrimSpace(line), "deb") {
+			updatedLine := cm.updateDebianLine(line, mirrorURL)
+			lines = append(lines, updatedLine)
+		} else {
+			lines = append(lines, line)
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		return fmt.Errorf("error reading %s: %w", configFile, err)
+	}
+
+	// Write updated configuration
+	return cm.writeLines(configFile, lines)
+}
+
+// updateDebianLine updates a single deb line with the new mirror URL
+func (cm *ConfigManager) updateDebianLine(line, newMirrorURL string) string {
+	parts := strings.Fields(line)
+	if len(parts) < 3 {
+		return line // Invalid line, keep as-is
+	}
+
+	// parts[0] = "deb" or "deb-src"
+	// parts[1] = URL
+	// parts[2] = suite/codename
+	// parts[3+] = components
+
+	parts[1] = strings.TrimSuffix(newMirrorURL, "/") + "/"
+	return strings.Join(parts, " ")
+}
+
+// applyArchMirror updates /etc/pacman.d/mirrorlist for Arch-based systems
+func (cm *ConfigManager) applyArchMirror(mirrorURL string) error {
+	configFile := "/etc/pacman.d/mirrorlist"
+
+	// Read current configuration
+	file, err := os.Open(configFile)
+	if err != nil {
+		return fmt.Errorf("failed to read %s: %w", configFile, err)
+	}
+	defer file.Close()
+
+	var lines []string
+	firstMirrorAdded := false
+	scanner := bufio.NewScanner(file)
+
+	// Add the fastest mirror at the top (uncommented)
+	lines = append(lines, fmt.Sprintf("# FastestMirror: Added %s", time.Now().Format("2006-01-02 15:04:05")))
+	lines = append(lines, fmt.Sprintf("Server = %s/$repo/os/$arch", strings.TrimSuffix(mirrorURL, "/")))
+	lines = append(lines, "")
+	firstMirrorAdded = true
+
+	// Process existing lines, commenting out other Server entries
+	for scanner.Scan() {
+		line := scanner.Text()
+		trimmed := strings.TrimSpace(line)
+
+		// Comment out existing Server lines (but keep them for reference)
+		if strings.HasPrefix(trimmed, "Server = ") && firstMirrorAdded {
+			lines = append(lines, "#"+line)
+		} else {
+			lines = append(lines, line)
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		return fmt.Errorf("error reading %s: %w", configFile, err)
+	}
+
+	// Write updated configuration
+	return cm.writeLines(configFile, lines)
+}
+
+// copyFile copies a file from src to dst
+func (cm *ConfigManager) copyFile(src, dst string) error {
+	sourceFile, err := os.Open(src)
+	if err != nil {
+		return err
+	}
+	defer sourceFile.Close()
+
+	destFile, err := os.Create(dst)
+	if err != nil {
+		return err
+	}
+	defer destFile.Close()
+
+	_, err = io.Copy(destFile, sourceFile)
+	if err != nil {
+		return err
+	}
+
+	// Copy file permissions
+	srcInfo, err := os.Stat(src)
+	if err != nil {
+		return err
+	}
+
+	return os.Chmod(dst, srcInfo.Mode())
+}
+
+// writeLines writes lines to a file
+func (cm *ConfigManager) writeLines(filename string, lines []string) error {
+	file, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	writer := bufio.NewWriter(file)
+	for _, line := range lines {
+		if _, err := writer.WriteString(line + "\n"); err != nil {
+			return err
+		}
+	}
+
+	return writer.Flush()
+}
+
+// RestoreBackup restores a configuration from backup
+func (cm *ConfigManager) RestoreBackup(backupPath string) error {
+	configFile := cm.DistroInfo.GetConfigFile()
+	if configFile == "" {
+		return fmt.Errorf("no configuration file defined for %s", cm.DistroInfo.Family)
+	}
+
+	return cm.copyFile(backupPath, configFile)
+}