feat(hooks): add Claude Code hooks integration with conflict detection

- Support user-wide and project-specific hook installation
- Automatic shush execution on Write|Edit|MultiEdit events
- Cross-scope conflict detection prevents duplicate execution
- JSON settings management with proper merging logic

internal/hooks/hooks.go

@@ -0,0 +1,231 @@
+package hooks
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+
+
+
+
+
+
+type HookScope int
+
+const (
+	ScopeUser HookScope = iota
+	ScopeProject
+)
+
+
+type ClaudeSettings struct {
+	Hooks map[string][]EventConfig `json:"hooks,omitempty"`
+
+}
+
+
+type EventConfig struct {
+	Matcher string      `json:"matcher"`
+	Hooks   []HookEntry `json:"hooks"`
+}
+
+
+type HookEntry struct {
+	Type    string `json:"type"`
+	Command string `json:"command"`
+	Timeout int    `json:"timeout,omitempty"`
+}
+
+
+func GetSettingsPath(scope HookScope) (string, error) {
+	switch scope {
+	case ScopeUser:
+		home, err := os.UserHomeDir()
+		if err != nil {
+			return "", fmt.Errorf("failed to get user home directory: %w", err)
+		}
+		return filepath.Join(home, ".claude", "settings.json"), nil
+	case ScopeProject:
+		cwd, err := os.Getwd()
+		if err != nil {
+			return "", fmt.Errorf("failed to get current directory: %w", err)
+		}
+		return filepath.Join(cwd, ".claude", "settings.json"), nil
+	default:
+		return "", errors.New("invalid hook scope")
+	}
+}
+
+
+func EnsureSettingsDirectory(settingsPath string) error {
+	dir := filepath.Dir(settingsPath)
+	if err := os.MkdirAll(dir, 0755); err != nil {
+		return fmt.Errorf("failed to create settings directory %s: %w", dir, err)
+	}
+	return nil
+}
+
+
+func LoadSettings(path string) (*ClaudeSettings, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+
+			return &ClaudeSettings{
+				Hooks: make(map[string][]EventConfig),
+			}, nil
+		}
+		return nil, fmt.Errorf("failed to read settings file %s: %w", path, err)
+	}
+
+	var settings ClaudeSettings
+	if err := json.Unmarshal(data, &settings); err != nil {
+		return nil, fmt.Errorf("failed to parse settings file %s: %w", path, err)
+	}
+
+
+	if settings.Hooks == nil {
+		settings.Hooks = make(map[string][]EventConfig)
+	}
+
+	return &settings, nil
+}
+
+
+func SaveSettings(path string, settings *ClaudeSettings) error {
+	if err := EnsureSettingsDirectory(path); err != nil {
+		return err
+	}
+
+	data, err := json.MarshalIndent(settings, "", "  ")
+	if err != nil {
+		return fmt.Errorf("failed to marshal settings: %w", err)
+	}
+
+	if err := os.WriteFile(path, data, 0644); err != nil {
+		return fmt.Errorf("failed to write settings file %s: %w", path, err)
+	}
+
+	return nil
+}
+
+
+func CreateShushHookEntry() HookEntry {
+	return HookEntry{
+		Type:    "command",
+		Command: "shush --changes-only",
+		Timeout: 30,
+	}
+}
+
+
+func CreateShushEventConfig() EventConfig {
+	return EventConfig{
+		Matcher: "Write|Edit|MultiEdit",
+		Hooks:   []HookEntry{CreateShushHookEntry()},
+	}
+}
+
+
+func HasShushHook(settings *ClaudeSettings) bool {
+	if settings.Hooks == nil {
+		return false
+	}
+
+	postToolUseConfigs, exists := settings.Hooks["PostToolUse"]
+	if !exists {
+		return false
+	}
+
+	for _, config := range postToolUseConfigs {
+		for _, hook := range config.Hooks {
+			if strings.Contains(hook.Command, "shush --changes-only") {
+				return true
+			}
+		}
+	}
+
+	return false
+}
+
+
+func AddShushHook(settings *ClaudeSettings) error {
+	if settings.Hooks == nil {
+		settings.Hooks = make(map[string][]EventConfig)
+	}
+
+	if HasShushHook(settings) {
+		return errors.New("shush hook already installed")
+	}
+
+
+	postToolUseConfigs, exists := settings.Hooks["PostToolUse"]
+	if !exists {
+
+		settings.Hooks["PostToolUse"] = []EventConfig{CreateShushEventConfig()}
+		return nil
+	}
+
+
+	for i, config := range postToolUseConfigs {
+		if config.Matcher == "Write|Edit|MultiEdit" || config.Matcher == "" {
+
+			postToolUseConfigs[i].Hooks = append(config.Hooks, CreateShushHookEntry())
+			return nil
+		}
+	}
+
+
+	settings.Hooks["PostToolUse"] = append(postToolUseConfigs, CreateShushEventConfig())
+	return nil
+}
+
+
+func RemoveShushHook(settings *ClaudeSettings) error {
+	if settings.Hooks == nil {
+		return errors.New("no hooks configuration found")
+	}
+
+	postToolUseConfigs, exists := settings.Hooks["PostToolUse"]
+	if !exists {
+		return errors.New("shush hook not found")
+	}
+
+	found := false
+	for i, config := range postToolUseConfigs {
+		newHooks := make([]HookEntry, 0, len(config.Hooks))
+		for _, hook := range config.Hooks {
+			if !strings.Contains(hook.Command, "shush --changes-only") {
+				newHooks = append(newHooks, hook)
+			} else {
+				found = true
+			}
+		}
+		postToolUseConfigs[i].Hooks = newHooks
+	}
+
+	if !found {
+		return errors.New("shush hook not found")
+	}
+
+
+	filteredConfigs := make([]EventConfig, 0, len(postToolUseConfigs))
+	for _, config := range postToolUseConfigs {
+		if len(config.Hooks) > 0 {
+			filteredConfigs = append(filteredConfigs, config)
+		}
+	}
+
+	if len(filteredConfigs) == 0 {
+		delete(settings.Hooks, "PostToolUse")
+	} else {
+		settings.Hooks["PostToolUse"] = filteredConfigs
+	}
+
+	return nil
+}