Enable shell completion for configured command aliases

internal/hook/completion.go

@@ -0,0 +1,116 @@
+package hook
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"git.zb-server.de/Sebi/ssh-netbox-wrapper/internal/config"
+	"git.zb-server.de/Sebi/ssh-netbox-wrapper/internal/storage"
+)
+
+const completionMarker = "# netssh command alias completion — generated automatically"
+
+// SyncCommandCompletion installs lazy loaders for the configured command alias.
+// The loaders obtain the canonical completion from the current netssh binary,
+// so aliases configured by the wizard work without a separate completion install.
+func SyncCommandCompletion(alias string) error {
+	if err := config.ValidateCommandAlias(alias); err != nil {
+		return err
+	}
+	statePath := filepath.Join(filepath.Dir(AliasesPath()), "completion_alias")
+	data, err := os.ReadFile(statePath)
+	if err != nil && !os.IsNotExist(err) {
+		return err
+	}
+	previous := strings.TrimSpace(string(data))
+	if err := config.ValidateCommandAlias(previous); err != nil {
+		return fmt.Errorf("invalid completion alias state: %w", err)
+	}
+	if alias == "" && previous == "" {
+		return nil
+	}
+
+	for _, shell := range []string{"bash", "zsh", "fish"} {
+		if previous != "" && previous != alias {
+			path := commandCompletionPath(shell, previous)
+			data, err := os.ReadFile(path)
+			if err != nil && !os.IsNotExist(err) {
+				return err
+			}
+			// Only delete files owned by netssh; preserve any user replacements.
+			if strings.HasPrefix(string(data), completionMarker+"\n") || strings.HasPrefix(string(data), "#compdef "+previous+"\n"+completionMarker+"\n") {
+				if err := os.Remove(path); err != nil && !os.IsNotExist(err) {
+					return err
+				}
+			}
+		}
+		if alias == "" {
+			continue
+		}
+		if shell == "fish" {
+			if _, err := os.Stat(FishConfigDir()); os.IsNotExist(err) {
+				continue
+			} else if err != nil {
+				return err
+			}
+		}
+		path := commandCompletionPath(shell, alias)
+		script := commandCompletionScript(shell, alias)
+		existing, err := os.ReadFile(path)
+		if err != nil && !os.IsNotExist(err) {
+			return err
+		}
+		if string(existing) == script {
+			continue
+		}
+		if err := storage.WriteFile(path, []byte(script), 0o644); err != nil {
+			return fmt.Errorf("writing %s alias completion: %w", shell, err)
+		}
+	}
+	if alias == "" {
+		if err := os.Remove(statePath); err != nil && !os.IsNotExist(err) {
+			return err
+		}
+		return nil
+	}
+	return storage.WriteFile(statePath, []byte(alias+"\n"), 0o600)
+}
+
+func commandCompletionPath(shell, alias string) string {
+	switch shell {
+	case "bash":
+		return filepath.Join(os.Getenv("HOME"), ".local", "share", "bash-completion", "completions", alias)
+	case "zsh":
+		return filepath.Join(os.Getenv("HOME"), ".zfunc", "_"+alias)
+	default:
+		return filepath.Join(FishConfigDir(), "completions", alias+".fish")
+	}
+}
+
+func commandCompletionScript(shell, alias string) string {
+	switch shell {
+	case "bash":
+		return fmt.Sprintf(`%s
+source <(netssh completion bash)
+if [[ $(type -t compopt) == builtin ]]; then
+    complete -o default -F __start_netssh %s
+else
+    complete -o default -o nospace -F __start_netssh %s
+fi
+`, completionMarker, alias, alias)
+	case "zsh":
+		return fmt.Sprintf(`#compdef %s
+%s
+source <(netssh completion zsh)
+compdef _netssh %s
+_netssh "$@"
+`, alias, completionMarker, alias)
+	default:
+		return fmt.Sprintf(`%s
+netssh completion fish | source
+complete --command %s --wraps netssh
+`, completionMarker, alias)
+	}
+}