refactor: Rewrote in golang.

app/env_file.go

@@ -0,0 +1,169 @@
+package app
+
+import (
+	"crypto/sha256"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+)
+
+type EnvFile struct {
+	Path     string
+	Dir      string
+	Remotes  []string // []string
+	Sha256   string
+	contents string
+}
+
+// The result returned by [EnvFile.Sync]
+type EnvFileSyncResult int
+
+const (
+	// The struct has been updated from the filesystem
+	// and should be updated in the database.
+	Updated EnvFileSyncResult = iota
+	// The filesystem has been restored to match the struct
+	// no further action is required.
+	Restored
+	Error
+	// The filesystem contents matches the struct
+	// no further action is required.
+	Noop
+)
+
+func NewEnvFile(path string) EnvFile {
+	// Get absolute path and directory
+	absPath, err := filepath.Abs(path)
+	if err != nil {
+		panic(fmt.Errorf("failed to get absolute path: %w", err))
+	}
+	dir := filepath.Dir(absPath)
+
+	// Get git remotes
+	remotes := getGitRemotes(dir)
+
+	// Read the file contents
+	contents, err := os.ReadFile(path)
+	if err != nil {
+		panic(fmt.Errorf("failed to read file %s: %w", path, err))
+	}
+
+	// Calculate SHA256 hash
+	hash := sha256.Sum256(contents)
+	sha256Hash := fmt.Sprintf("%x", hash)
+
+	return EnvFile{
+		Path:     absPath,
+		Dir:      dir,
+		Remotes:  remotes,
+		Sha256:   sha256Hash,
+		contents: string(contents),
+	}
+}
+
+func getGitRemotes(dir string) []string {
+	// TODO: Check for Git flag and change behaviour if unset.
+	cmd := exec.Command("git", "remote", "-v")
+	cmd.Dir = dir
+
+	output, err := cmd.Output()
+	if err != nil {
+		// Not a git repository or git command failed
+		return []string{}
+	}
+
+	lines := strings.Split(strings.TrimSpace(string(output)), "\n")
+	remoteSet := make(map[string]bool)
+
+	for _, line := range lines {
+		if line == "" {
+			continue
+		}
+		parts := strings.Fields(line)
+		if len(parts) >= 2 {
+			remoteSet[parts[1]] = true
+		}
+	}
+
+	remotes := make([]string, 0, len(remoteSet))
+	for remote := range remoteSet {
+		remotes = append(remotes, remote)
+	}
+
+	return remotes
+}
+
+// Install the file into the file system
+func (file EnvFile) Restore() error {
+	// TODO: Handle restores more cleanly
+	// Ensure the directory exists
+	if err := os.MkdirAll(filepath.Dir(file.Path), 0755); err != nil {
+		return fmt.Errorf("failed to create directory: %w", err)
+	}
+
+	// Check if file already exists
+	if _, err := os.Stat(file.Path); err == nil {
+		return fmt.Errorf("file already exists: %s", file.Path)
+	}
+
+	// Write the contents to the file
+	if err := os.WriteFile(file.Path, []byte(file.contents), 0644); err != nil {
+		return fmt.Errorf("failed to write file: %w", err)
+	}
+
+	return nil
+}
+
+// Try to reconcile the EnvFile with the filesystem.
+//
+// If Updated is returned, [Db.Insert] should be called on file.
+func (file *EnvFile) Sync() (result EnvFileSyncResult, err error) {
+	// Check if the path exists in the file system
+	_, err = os.Stat(file.Path)
+	if err == nil {
+		contents, err := os.ReadFile(file.Path)
+		if err != nil {
+			return Error, fmt.Errorf("failed to read file for SHA comparison: %w", err)
+		}
+
+		// Check if sha matches by reading the current file and calculating its hash
+		hash := sha256.Sum256(contents)
+		currentSha := fmt.Sprintf("%x", hash)
+		if file.Sha256 == currentSha {
+			// Nothing to do
+			return Noop, nil
+		} else {
+			if err = file.Backup(); err != nil {
+				return Error, err
+			} else {
+				return Updated, nil
+			}
+		}
+	} else {
+		if err = file.Restore(); err != nil {
+			return Error, err
+		} else {
+			return Restored, nil
+		}
+	}
+}
+
+// Update the EnvFile using the file system
+func (file *EnvFile) Backup() error {
+	// Read the contents of the file
+	contents, err := os.ReadFile(file.Path)
+	if err != nil {
+		return fmt.Errorf("failed to read file %s: %w", file.Path, err)
+	}
+
+	// Update file.contents to match
+	file.contents = string(contents)
+
+	// Update file.sha256
+	hash := sha256.Sum256(contents)
+	file.Sha256 = fmt.Sprintf("%x", hash)
+
+	return nil
+}