feat(output): implement configurable color and emoji output

Add new output formatting system with flags for color and emoji control:
- Introduce OutputConfig and Writer structs for flexible output handling
- Add --colors and --emoji/--no-emoji global flags
- Refactor commands to use new Writer for consistent formatting
- Separate error content from presentation for better flexibility

internal/core/errors.go

@@ -0,0 +1,84 @@
+package core
+
+import "fmt"
+
+// LnkError represents a structured error with separate content and formatting hints
+type LnkError struct {
+	Message    string
+	Suggestion string
+	Path       string
+	ErrorType  string
+}
+
+func (e *LnkError) Error() string {
+	if e.Suggestion != "" {
+		return fmt.Sprintf("%s\n   %s", e.Message, e.Suggestion)
+	}
+	return e.Message
+}
+
+// Error constructors that separate content from presentation
+
+func ErrDirectoryContainsManagedFiles(path string) error {
+	return &LnkError{
+		Message:    fmt.Sprintf("Directory %s already contains managed files", path),
+		Suggestion: "Use 'lnk pull' to update from remote instead of 'lnk init -r'",
+		Path:       path,
+		ErrorType:  "managed_files_exist",
+	}
+}
+
+func ErrDirectoryContainsGitRepo(path string) error {
+	return &LnkError{
+		Message:    fmt.Sprintf("Directory %s contains an existing Git repository", path),
+		Suggestion: "Please backup or move the existing repository before initializing lnk",
+		Path:       path,
+		ErrorType:  "git_repo_exists",
+	}
+}
+
+func ErrFileAlreadyManaged(path string) error {
+	return &LnkError{
+		Message:   fmt.Sprintf("File is already managed by lnk: %s", path),
+		Path:      path,
+		ErrorType: "already_managed",
+	}
+}
+
+func ErrFileNotManaged(path string) error {
+	return &LnkError{
+		Message:   fmt.Sprintf("File is not managed by lnk: %s", path),
+		Path:      path,
+		ErrorType: "not_managed",
+	}
+}
+
+func ErrRepositoryNotInitialized() error {
+	return &LnkError{
+		Message:    "Lnk repository not initialized",
+		Suggestion: "Run 'lnk init' first",
+		ErrorType:  "not_initialized",
+	}
+}
+
+func ErrBootstrapScriptNotFound(script string) error {
+	return &LnkError{
+		Message:   fmt.Sprintf("Bootstrap script not found: %s", script),
+		Path:      script,
+		ErrorType: "script_not_found",
+	}
+}
+
+func ErrBootstrapScriptFailed(err error) error {
+	return &LnkError{
+		Message:   fmt.Sprintf("Bootstrap script failed with error: %v", err),
+		ErrorType: "script_failed",
+	}
+}
+
+func ErrBootstrapScriptNotExecutable(err error) error {
+	return &LnkError{
+		Message:   fmt.Sprintf("Failed to make bootstrap script executable: %v", err),
+		ErrorType: "script_permissions",
+	}
+}

internal/core/lnk.go

@@ -156,7 +156,7 @@ func (l *Lnk) InitWithRemoteForce(remoteURL string, force bool) error {
 		// Safety check: prevent data loss by checking for existing managed files
 		if l.HasUserContent() {
 			if !force {
-				return fmt.Errorf("❌ Directory \033[31m%s\033[0m already contains managed files\n   💡 Use 'lnk pull' to update from remote instead of 'lnk init -r'", l.repoPath)
+				return ErrDirectoryContainsManagedFiles(l.repoPath)
 			}
 		}
 		// Clone from remote
@@ -176,7 +176,7 @@ func (l *Lnk) InitWithRemoteForce(remoteURL string, force bool) error {
 			return nil
 		} else {
 			// It's not a lnk repository, error to prevent data loss
-			return fmt.Errorf("❌ Directory \033[31m%s\033[0m contains an existing Git repository\n   💡 Please backup or move the existing repository before initializing lnk", l.repoPath)
+			return ErrDirectoryContainsGitRepo(l.repoPath)
 		}
 	}
 
@@ -230,7 +230,7 @@ func (l *Lnk) Add(filePath string) error {
 	}
 	for _, item := range managedItems {
 		if item == relativePath {
-			return fmt.Errorf("❌ File is already managed by lnk: \033[31m%s\033[0m", relativePath)
+			return ErrFileAlreadyManaged(relativePath)
 		}
 	}
 
@@ -332,7 +332,7 @@ func (l *Lnk) AddMultiple(paths []string) error {
 		}
 		for _, item := range managedItems {
 			if item == relativePath {
-				return fmt.Errorf("❌ File is already managed by lnk: \033[31m%s\033[0m", relativePath)
+				return ErrFileAlreadyManaged(relativePath)
 			}
 		}
 
@@ -476,7 +476,7 @@ func (l *Lnk) Remove(filePath string) error {
 		}
 	}
 	if !found {
-		return fmt.Errorf("❌ File is not managed by lnk: \033[31m%s\033[0m", relativePath)
+		return ErrFileNotManaged(relativePath)
 	}
 
 	// Get the target path in the repository
@@ -551,7 +551,7 @@ type StatusInfo struct {
 func (l *Lnk) Status() (*StatusInfo, error) {
 	// Check if repository is initialized
 	if !l.git.IsGitRepository() {
-		return nil, fmt.Errorf("❌ Lnk repository not initialized\n   💡 Run \033[1mlnk init\033[0m first")
+		return nil, ErrRepositoryNotInitialized()
 	}
 
 	gitStatus, err := l.git.GetStatus()
@@ -571,7 +571,7 @@ func (l *Lnk) Status() (*StatusInfo, error) {
 func (l *Lnk) Push(message string) error {
 	// Check if repository is initialized
 	if !l.git.IsGitRepository() {
-		return fmt.Errorf("❌ Lnk repository not initialized\n   💡 Run \033[1mlnk init\033[0m first")
+		return ErrRepositoryNotInitialized()
 	}
 
 	// Check if there are any changes
@@ -601,7 +601,7 @@ func (l *Lnk) Push(message string) error {
 func (l *Lnk) Pull() ([]string, error) {
 	// Check if repository is initialized
 	if !l.git.IsGitRepository() {
-		return nil, fmt.Errorf("❌ Lnk repository not initialized\n   💡 Run \033[1mlnk init\033[0m first")
+		return nil, ErrRepositoryNotInitialized()
 	}
 
 	// Pull changes from remote (this will be a no-op in tests since we don't have real remotes)
@@ -622,7 +622,7 @@ func (l *Lnk) Pull() ([]string, error) {
 func (l *Lnk) List() ([]string, error) {
 	// Check if repository is initialized
 	if !l.git.IsGitRepository() {
-		return nil, fmt.Errorf("❌ Lnk repository not initialized\n   💡 Run \033[1mlnk init\033[0m first")
+		return nil, ErrRepositoryNotInitialized()
 	}
 
 	// Get managed items from .lnk file
@@ -822,7 +822,7 @@ func (l *Lnk) writeManagedItems(items []string) error {
 func (l *Lnk) FindBootstrapScript() (string, error) {
 	// Check if repository is initialized
 	if !l.git.IsGitRepository() {
-		return "", fmt.Errorf("❌ Lnk repository not initialized\n   💡 Run \033[1mlnk init\033[0m first")
+		return "", ErrRepositoryNotInitialized()
 	}
 
 	// Look for bootstrap.sh - simple, opinionated choice
@@ -840,12 +840,12 @@ func (l *Lnk) RunBootstrapScript(scriptName string) error {
 
 	// Verify the script exists
 	if _, err := os.Stat(scriptPath); os.IsNotExist(err) {
-		return fmt.Errorf("❌ Bootstrap script not found: \033[31m%s\033[0m", scriptName)
+		return ErrBootstrapScriptNotFound(scriptName)
 	}
 
 	// Make sure it's executable
 	if err := os.Chmod(scriptPath, 0755); err != nil {
-		return fmt.Errorf("❌ Failed to make bootstrap script executable: %w", err)
+		return ErrBootstrapScriptNotExecutable(err)
 	}
 
 	// Run with bash (since we only support bootstrap.sh)
@@ -861,7 +861,7 @@ func (l *Lnk) RunBootstrapScript(scriptName string) error {
 
 	// Run the script
 	if err := cmd.Run(); err != nil {
-		return fmt.Errorf("❌ Bootstrap script failed with error: %w", err)
+		return ErrBootstrapScriptFailed(err)
 	}
 
 	return nil
@@ -988,7 +988,7 @@ func (l *Lnk) addMultipleWithProgress(paths []string, progress ProgressCallback)
 		}
 		for _, item := range managedItems {
 			if item == relativePath {
-				return fmt.Errorf("❌ File is already managed by lnk: \033[31m%s\033[0m", relativePath)
+				return ErrFileAlreadyManaged(relativePath)
 			}
 		}
 

internal/fs/errors.go

@@ -1,28 +1,7 @@
 package fs
 
-import "fmt"
-
-// ANSI color codes for consistent formatting
-const (
-	colorReset = "\033[0m"
-	colorRed   = "\033[31m"
-	colorBold  = "\033[1m"
-)
-
-// formatError creates a consistently formatted error message with ❌ prefix
-func formatError(message string, args ...interface{}) string {
-	return fmt.Sprintf("❌ "+message, args...)
-}
-
-// formatPath formats a file path with red color
-func formatPath(path string) string {
-	return fmt.Sprintf("%s%s%s", colorRed, path, colorReset)
-}
-
-// formatCommand formats a command with bold styling
-func formatCommand(command string) string {
-	return fmt.Sprintf("%s%s%s", colorBold, command, colorReset)
-}
+// Structured errors that separate content from presentation
+// These will be formatted by the cmd package based on user preferences
 
 // FileNotExistsError represents an error when a file does not exist
 type FileNotExistsError struct {
@@ -31,20 +10,25 @@ type FileNotExistsError struct {
 }
 
 func (e *FileNotExistsError) Error() string {
-	return formatError("File or directory not found: %s", formatPath(e.Path))
+	return "File or directory not found: " + e.Path
 }
 
 func (e *FileNotExistsError) Unwrap() error {
 	return e.Err
 }
 
+// GetPath returns the path for formatting purposes
+func (e *FileNotExistsError) GetPath() string {
+	return e.Path
+}
+
 // FileCheckError represents an error when failing to check a file
 type FileCheckError struct {
 	Err error
 }
 
 func (e *FileCheckError) Error() string {
-	return formatError("Unable to access file. Please check file permissions and try again.")
+	return "Unable to access file. Please check file permissions and try again."
 }
 
 func (e *FileCheckError) Unwrap() error {
@@ -57,7 +41,15 @@ type UnsupportedFileTypeError struct {
 }
 
 func (e *UnsupportedFileTypeError) Error() string {
-	return formatError("Cannot manage this type of file: %s\n   💡 lnk can only manage regular files and directories", formatPath(e.Path))
+	return "Cannot manage this type of file: " + e.Path
+}
+
+func (e *UnsupportedFileTypeError) GetPath() string {
+	return e.Path
+}
+
+func (e *UnsupportedFileTypeError) GetSuggestion() string {
+	return "lnk can only manage regular files and directories"
 }
 
 func (e *UnsupportedFileTypeError) Unwrap() error {
@@ -70,8 +62,15 @@ type NotManagedByLnkError struct {
 }
 
 func (e *NotManagedByLnkError) Error() string {
-	return formatError("File is not managed by lnk: %s\n   💡 Use %s to manage this file first",
-		formatPath(e.Path), formatCommand("lnk add"))
+	return "File is not managed by lnk: " + e.Path
+}
+
+func (e *NotManagedByLnkError) GetPath() string {
+	return e.Path
+}
+
+func (e *NotManagedByLnkError) GetSuggestion() string {
+	return "Use 'lnk add' to manage this file first"
 }
 
 func (e *NotManagedByLnkError) Unwrap() error {
@@ -84,7 +83,7 @@ type SymlinkReadError struct {
 }
 
 func (e *SymlinkReadError) Error() string {
-	return formatError("Unable to read symlink. The file may be corrupted or have invalid permissions.")
+	return "Unable to read symlink. The file may be corrupted or have invalid permissions."
 }
 
 func (e *SymlinkReadError) Unwrap() error {
@@ -98,7 +97,7 @@ type DirectoryCreationError struct {
 }
 
 func (e *DirectoryCreationError) Error() string {
-	return formatError("Failed to create directory. Please check permissions and available disk space.")
+	return "Failed to create directory. Please check permissions and available disk space."
 }
 
 func (e *DirectoryCreationError) Unwrap() error {
@@ -111,9 +110,21 @@ type RelativePathCalculationError struct {
 }
 
 func (e *RelativePathCalculationError) Error() string {
-	return formatError("Unable to create symlink due to path configuration issues. Please check file locations.")
+	return "Unable to create symlink due to path configuration issues. Please check file locations."
 }
 
 func (e *RelativePathCalculationError) Unwrap() error {
 	return e.Err
 }
+
+// ErrorWithPath is an interface for errors that have an associated file path
+type ErrorWithPath interface {
+	error
+	GetPath() string
+}
+
+// ErrorWithSuggestion is an interface for errors that provide helpful suggestions
+type ErrorWithSuggestion interface {
+	error
+	GetSuggestion() string
+}

internal/git/errors.go

@@ -1,29 +1,7 @@
 package git
 
-import "fmt"
-
-// ANSI color codes for consistent formatting
-const (
-	colorReset  = "\033[0m"
-	colorBold   = "\033[1m"
-	colorGreen  = "\033[32m"
-	colorYellow = "\033[33m"
-)
-
-// formatError creates a consistently formatted error message with ❌ prefix
-func formatError(message string, args ...interface{}) string {
-	return fmt.Sprintf("❌ "+message, args...)
-}
-
-// formatURL formats a URL with styling
-func formatURL(url string) string {
-	return fmt.Sprintf("%s%s%s", colorBold, url, colorReset)
-}
-
-// formatRemote formats a remote name with styling
-func formatRemote(remote string) string {
-	return fmt.Sprintf("%s%s%s", colorGreen, remote, colorReset)
-}
+// Structured errors that separate content from presentation
+// These will be formatted by the cmd package based on user preferences
 
 // GitInitError represents an error during git initialization
 type GitInitError struct {
@@ -32,7 +10,7 @@ type GitInitError struct {
 }
 
 func (e *GitInitError) Error() string {
-	return formatError("Failed to initialize git repository. Please ensure git is installed and try again.")
+	return "Failed to initialize git repository. Please ensure git is installed and try again."
 }
 
 func (e *GitInitError) Unwrap() error {
@@ -45,7 +23,7 @@ type BranchSetupError struct {
 }
 
 func (e *BranchSetupError) Error() string {
-	return formatError("Failed to set up the default branch. Please check your git installation.")
+	return "Failed to set up the default branch. Please check your git installation."
 }
 
 func (e *BranchSetupError) Unwrap() error {
@@ -60,8 +38,19 @@ type RemoteExistsError struct {
 }
 
 func (e *RemoteExistsError) Error() string {
-	return formatError("Remote %s is already configured with a different repository (%s). Cannot add %s.",
-		formatRemote(e.Remote), formatURL(e.ExistingURL), formatURL(e.NewURL))
+	return "Remote " + e.Remote + " is already configured with a different repository (" + e.ExistingURL + "). Cannot add " + e.NewURL + "."
+}
+
+func (e *RemoteExistsError) GetRemote() string {
+	return e.Remote
+}
+
+func (e *RemoteExistsError) GetExistingURL() string {
+	return e.ExistingURL
+}
+
+func (e *RemoteExistsError) GetNewURL() string {
+	return e.NewURL
 }
 
 func (e *RemoteExistsError) Unwrap() error {
@@ -79,24 +68,28 @@ func (e *GitCommandError) Error() string {
 	// Provide user-friendly messages based on common command types
 	switch e.Command {
 	case "add":
-		return formatError("Failed to stage files for commit. Please check file permissions and try again.")
+		return "Failed to stage files for commit. Please check file permissions and try again."
 	case "commit":
-		return formatError("Failed to create commit. Please ensure you have staged changes and try again.")
+		return "Failed to create commit. Please ensure you have staged changes and try again."
 	case "remote add":
-		return formatError("Failed to add remote repository. Please check the repository URL and try again.")
+		return "Failed to add remote repository. Please check the repository URL and try again."
 	case "rm":
-		return formatError("Failed to remove file from git tracking. Please check if the file exists and try again.")
+		return "Failed to remove file from git tracking. Please check if the file exists and try again."
 	case "log":
-		return formatError("Failed to retrieve commit history.")
+		return "Failed to retrieve commit history."
 	case "remote":
-		return formatError("Failed to retrieve remote repository information.")
+		return "Failed to retrieve remote repository information."
 	case "clone":
-		return formatError("Failed to clone repository. Please check the repository URL and your network connection.")
+		return "Failed to clone repository. Please check the repository URL and your network connection."
 	default:
-		return formatError("Git operation failed. Please check your repository state and try again.")
+		return "Git operation failed. Please check your repository state and try again."
 	}
 }
 
+func (e *GitCommandError) GetCommand() string {
+	return e.Command
+}
+
 func (e *GitCommandError) Unwrap() error {
 	return e.Err
 }
@@ -105,7 +98,7 @@ func (e *GitCommandError) Unwrap() error {
 type NoRemoteError struct{}
 
 func (e *NoRemoteError) Error() string {
-	return formatError("No remote repository is configured. Please add a remote repository first.")
+	return "No remote repository is configured. Please add a remote repository first."
 }
 
 func (e *NoRemoteError) Unwrap() error {
@@ -119,7 +112,11 @@ type RemoteNotFoundError struct {
 }
 
 func (e *RemoteNotFoundError) Error() string {
-	return formatError("Remote repository %s is not configured.", formatRemote(e.Remote))
+	return "Remote repository " + e.Remote + " is not configured."
+}
+
+func (e *RemoteNotFoundError) GetRemote() string {
+	return e.Remote
 }
 
 func (e *RemoteNotFoundError) Unwrap() error {
@@ -133,7 +130,7 @@ type GitConfigError struct {
 }
 
 func (e *GitConfigError) Error() string {
-	return formatError("Failed to configure git settings. Please check your git installation.")
+	return "Failed to configure git settings. Please check your git installation."
 }
 
 func (e *GitConfigError) Unwrap() error {
@@ -146,7 +143,7 @@ type UncommittedChangesError struct {
 }
 
 func (e *UncommittedChangesError) Error() string {
-	return formatError("Failed to check repository status. Please verify your git repository is valid.")
+	return "Failed to check repository status. Please verify your git repository is valid."
 }
 
 func (e *UncommittedChangesError) Unwrap() error {
@@ -160,7 +157,11 @@ type DirectoryRemovalError struct {
 }
 
 func (e *DirectoryRemovalError) Error() string {
-	return formatError("Failed to prepare directory for operation. Please check directory permissions.")
+	return "Failed to prepare directory for operation. Please check directory permissions."
+}
+
+func (e *DirectoryRemovalError) GetPath() string {
+	return e.Path
 }
 
 func (e *DirectoryRemovalError) Unwrap() error {
@@ -174,7 +175,11 @@ type DirectoryCreationError struct {
 }
 
 func (e *DirectoryCreationError) Error() string {
-	return formatError("Failed to create directory. Please check permissions and available disk space.")
+	return "Failed to create directory. Please check permissions and available disk space."
+}
+
+func (e *DirectoryCreationError) GetPath() string {
+	return e.Path
 }
 
 func (e *DirectoryCreationError) Unwrap() error {
@@ -190,9 +195,13 @@ type PushError struct {
 
 func (e *PushError) Error() string {
 	if e.Reason != "" {
-		return formatError("Cannot push changes: %s", e.Reason)
+		return "Cannot push changes: " + e.Reason
 	}
-	return formatError("Failed to push changes to remote repository. Please check your network connection and repository permissions.")
+	return "Failed to push changes to remote repository. Please check your network connection and repository permissions."
+}
+
+func (e *PushError) GetReason() string {
+	return e.Reason
 }
 
 func (e *PushError) Unwrap() error {
@@ -208,11 +217,33 @@ type PullError struct {
 
 func (e *PullError) Error() string {
 	if e.Reason != "" {
-		return formatError("Cannot pull changes: %s", e.Reason)
+		return "Cannot pull changes: " + e.Reason
 	}
-	return formatError("Failed to pull changes from remote repository. Please check your network connection and resolve any conflicts.")
+	return "Failed to pull changes from remote repository. Please check your network connection and resolve any conflicts."
+}
+
+func (e *PullError) GetReason() string {
+	return e.Reason
 }
 
 func (e *PullError) Unwrap() error {
 	return e.Err
 }
+
+// ErrorWithPath is an interface for git errors that have an associated file path
+type ErrorWithPath interface {
+	error
+	GetPath() string
+}
+
+// ErrorWithRemote is an interface for git errors that involve a remote
+type ErrorWithRemote interface {
+	error
+	GetRemote() string
+}
+
+// ErrorWithReason is an interface for git errors that have a specific reason
+type ErrorWithReason interface {
+	error
+	GetReason() string
+}