first commit

pigo/internal/pkgmgr/layout.go

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+// This file defines pigo's install directory layout (#154): where each pi
+// package type is placed so pigo's existing discovery mechanisms load it with
+// no extra configuration. The paths intentionally match the conventions already
+// used elsewhere in cmd/pigo and internal/*:
+//
+//   - extensions → $PIGO_HOME/plugins   (internal/plugin.Discover)
+//   - prompts    → $PIGO_HOME/commands  (runtime.LoadUserCommandsDir)
+//   - themes     → $PIGO_HOME/themes    (no runtime consumer yet)
+//   - skills     → skills dir           (~/.agents/skills, PIGO_SKILLS_DIR override)
+//
+// Skills are the one exception to the $PIGO_HOME root: pigo loads skills from
+// ~/.agents/skills (overridable with PIGO_SKILLS_DIR), so SkillsDir honors that
+// rather than nesting under $PIGO_HOME.
+package pkgmgr
+
+import (
+	"os"
+	"path/filepath"
+)
+
+// Home returns the pigo home directory: $PIGO_HOME, or ~/.pigo when unset. It
+// returns "" when the home directory cannot be resolved and no override is set,
+// matching trust.DefaultPath's "unavailable" contract.
+func Home() string {
+	if dir := os.Getenv("PIGO_HOME"); dir != "" {
+		return dir
+	}
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return ""
+	}
+	return filepath.Join(home, ".pigo")
+}
+
+// PluginsDir returns $PIGO_HOME/plugins, where installed extensions (including
+// MCP adapters) are laid down for internal/plugin.Discover. It returns "" when
+// Home is unavailable.
+func PluginsDir() string {
+	h := Home()
+	if h == "" {
+		return ""
+	}
+	return filepath.Join(h, "plugins")
+}
+
+// CommandsDir returns $PIGO_HOME/commands, the legacy location for installed
+// prompt/command templates (still loaded by runtime.LoadUserCommandsDir for
+// back-compat). New installs go to PromptsDir. It returns "" when Home is
+// unavailable.
+func CommandsDir() string {
+	h := Home()
+	if h == "" {
+		return ""
+	}
+	return filepath.Join(h, "commands")
+}
+
+// PromptsDir returns $PIGO_HOME/prompts, the pi-aligned location where installed
+// prompt templates are laid down for runtime.LoadUserCommandsDir (which loads
+// both prompts/ and the legacy commands/). It returns "" when Home is
+// unavailable.
+func PromptsDir() string {
+	h := Home()
+	if h == "" {
+		return ""
+	}
+	return filepath.Join(h, "prompts")
+}
+
+// ThemesDir returns $PIGO_HOME/themes, where installed themes are stored. pigo
+// has no theme runtime yet, so this is a holding location for a future consumer.
+// It returns "" when Home is unavailable.
+func ThemesDir() string {
+	h := Home()
+	if h == "" {
+		return ""
+	}
+	return filepath.Join(h, "themes")
+}
+
+// SkillsDir returns the directory installed skills are placed in: PIGO_SKILLS_DIR
+// when set, else ~/.agents/skills — matching cmd/pigo's skill loader. It returns
+// "" when the home directory cannot be resolved and no override is set.
+func SkillsDir() string {
+	if dir := os.Getenv("PIGO_SKILLS_DIR"); dir != "" {
+		return dir
+	}
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return ""
+	}
+	return filepath.Join(home, ".agents", "skills")
+}
+
+// DirForType returns the install directory for a package type, or "" when the
+// type is unknown or the underlying home directory is unavailable.
+func DirForType(t PackageType) string {
+	switch t {
+	case TypeExtension:
+		return PluginsDir()
+	case TypePrompt:
+		return CommandsDir()
+	case TypeTheme:
+		return ThemesDir()
+	case TypeSkill:
+		return SkillsDir()
+	default:
+		return ""
+	}
+}