Refactor UX (#17)

Huge refactor to restructure the code so each harness (internal/clients)
has its own implementation. This allows specific logic to easier to
manage and in an intuitive location.

Author: mostlygeek

Makefile

@@ -1,13 +1,14 @@
 .PHONY: build test clean install
 
 BUILD_DATE := $(shell date -u +"%Y-%m-%dT%H:%M:%SZ")
+GIT_HEIGHT := $(shell git rev-list --count HEAD 2>/dev/null || echo 0)
 
 GIT_DESC := $(shell git describe --always)
 ifneq ($(shell git status --porcelain),)
     GIT_DESC := $(GIT_DESC)-dirty
 endif
 
-LDFLAGS := -X main.buildCommit=$(GIT_DESC) -X main.buildDate=$(BUILD_DATE)
+LDFLAGS := -X main.buildVersion=B$(GIT_HEIGHT) -X main.buildCommit=$(GIT_DESC) -X main.buildDate=$(BUILD_DATE)
 
 build:
 	go build -ldflags "$(LDFLAGS)" -o .build/aperture ./cmd/aperture

cmd/aperture/main.go

@@ -5,18 +5,29 @@ import (
 	"fmt"
 	"log/slog"
 	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
 	"runtime/debug"
+	"strings"
 
 	tea "github.com/charmbracelet/bubbletea"
+	"github.com/tailscale/aperture-cli/internal/config"
 	"github.com/tailscale/aperture-cli/internal/profiles"
 	"github.com/tailscale/aperture-cli/internal/tui"
+
+	// Side-effect imports register each client with internal/clients.
+	_ "github.com/tailscale/aperture-cli/internal/clients/claudecode"
+	_ "github.com/tailscale/aperture-cli/internal/clients/codex"
+	_ "github.com/tailscale/aperture-cli/internal/clients/gemini"
+	_ "github.com/tailscale/aperture-cli/internal/clients/opencode"
 )
 
 var (
 	flagVersion = flag.Bool("version", false, "print version and exit")
 	flagDebug   = flag.Bool("debug", false, "print env vars set before launching agent")
 
-	buildVersion = "v0.0.0-dev"
+	buildVersion = "B0-dev"
 	buildCommit  = "unknown"
 	buildDate    = "unknown"
 )
@@ -27,8 +38,12 @@ func init() {
 		return
 	}
 
-	if buildVersion == "v0.0.0-dev" && info.Main.Version != "" && info.Main.Version != "(devel)" {
-		buildVersion = info.Main.Version
+	if buildVersion == "B0-dev" {
+		if height := gitCommitHeight(); height != "" {
+			buildVersion = "B" + height
+		} else if info.Main.Version != "" && info.Main.Version != "(devel)" {
+			buildVersion = info.Main.Version
+		}
 	}
 
 	// Only fill in VCS info when ldflags haven't already set these values.
@@ -56,6 +71,41 @@ func init() {
 	}
 }
 
+func gitCommitHeight() string {
+	_, file, _, ok := runtime.Caller(0)
+	if !ok {
+		return ""
+	}
+	for dir := filepath.Dir(file); ; dir = filepath.Dir(dir) {
+		if _, err := os.Stat(filepath.Join(dir, ".git")); err == nil {
+			return gitCommitHeightInDir(dir)
+		}
+		parent := filepath.Dir(dir)
+		if parent == dir {
+			return ""
+		}
+	}
+}
+
+func gitCommitHeightInDir(dir string) string {
+	cmd := exec.Command("git", "rev-list", "--count", "HEAD")
+	cmd.Dir = dir
+	out, err := cmd.Output()
+	if err != nil {
+		return ""
+	}
+	height := strings.TrimSpace(string(out))
+	if height == "" {
+		return ""
+	}
+	for _, r := range height {
+		if r < '0' || r > '9' {
+			return ""
+		}
+	}
+	return height
+}
+
 func main() {
 	flag.Parse()
 
@@ -68,16 +118,17 @@ func main() {
 		os.Exit(0)
 	}
 
-	settings, _ := profiles.LoadSettings()
-	state, _ := profiles.LoadState()
-
-	// Use the first saved endpoint as the active host; fall back to the default.
-	host := "http://ai"
-	if len(settings.Endpoints) > 0 {
-		host = settings.Endpoints[0].URL
+	g, err := config.Load()
+	if err != nil {
+		slog.Error("loading launcher config", "err", err)
+		os.Exit(1)
 	}
+	g.Debug = *flagDebug
+
+	// Register Claude Desktop on supported platforms (darwin, windows).
+	profiles.RegisterIfSupported()
 
-	p := tea.NewProgram(tui.NewModel(host, settings, state, *flagDebug))
+	p := tea.NewProgram(tui.NewModel(g, buildVersion))
 	if _, err := p.Run(); err != nil {
 		slog.Error("launcher error", "err", err)
 		os.Exit(1)

internal/clients/binary.go

@@ -0,0 +1,77 @@
+// Package clients holds the registry of AI coding agent clients (Claude Code,
+// Codex, Gemini, OpenCode, ...). Each client owns its own install, launch,
+// and configuration logic inside a sub-package; this file provides shared
+// helpers for discovering client binaries on disk.
+package clients
+
+import (
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strings"
+)
+
+// FindBinary returns the resolved path to a client binary. It checks
+// exec.LookPath (i.e. $PATH) first, then the client-supplied extra paths,
+// then general well-known user-local binary directories. Returns "" if the
+// binary cannot be found.
+func FindBinary(name string, extraPaths []string) string {
+	if name == "" {
+		return ""
+	}
+	if path, err := exec.LookPath(name); err == nil {
+		return path
+	}
+	for _, p := range extraPaths {
+		if isExecutable(p) {
+			return p
+		}
+	}
+	for _, dir := range commonBinDirs() {
+		p := filepath.Join(dir, name)
+		if isExecutable(p) {
+			return p
+		}
+	}
+	return ""
+}
+
+// IsInstalled reports whether the named binary can be found on disk.
+func IsInstalled(name string, extraPaths []string) bool {
+	if name == "" {
+		return true
+	}
+	return FindBinary(name, extraPaths) != ""
+}
+
+// commonBinDirs returns well-known user-local directories that may not be on
+// PATH yet (e.g. after a fresh install that updated shell profiles but the
+// running shell still has the old PATH). System-wide directories are
+// intentionally excluded: binaries there are found by exec.LookPath.
+func commonBinDirs() []string {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return nil
+	}
+	return []string{
+		filepath.Join(home, ".local", "bin"),
+		filepath.Join(home, "bin"),
+		filepath.Join(home, ".npm-global", "bin"),
+	}
+}
+
+func isExecutable(path string) bool {
+	info, err := os.Stat(path)
+	if err != nil {
+		return false
+	}
+	if info.IsDir() {
+		return false
+	}
+	if runtime.GOOS == "windows" {
+		ext := strings.ToLower(filepath.Ext(path))
+		return ext == ".exe" || ext == ".cmd" || ext == ".bat" || ext == ".com"
+	}
+	return info.Mode()&0o111 != 0
+}

internal/clients/binary_test.go

@@ -0,0 +1,116 @@
+package clients_test
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/tailscale/aperture-cli/internal/clients"
+)
+
+func TestFindBinary_PrefersPath(t *testing.T) {
+	tmp := t.TempDir()
+	t.Setenv("HOME", tmp)
+
+	pathBin := filepath.Join(tmp, "pathbin")
+	if err := os.MkdirAll(pathBin, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	pathBinary := filepath.Join(pathBin, "opencode")
+	if err := os.WriteFile(pathBinary, []byte("#!/bin/sh\n"), 0o755); err != nil {
+		t.Fatal(err)
+	}
+
+	commonBin := filepath.Join(tmp, ".opencode", "bin")
+	if err := os.MkdirAll(commonBin, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	commonBinary := filepath.Join(commonBin, "opencode")
+	if err := os.WriteFile(commonBinary, []byte("#!/bin/sh\n"), 0o755); err != nil {
+		t.Fatal(err)
+	}
+
+	t.Setenv("PATH", pathBin)
+
+	got := clients.FindBinary("opencode", []string{commonBinary})
+	if got != pathBinary {
+		t.Errorf("FindBinary() = %q, want %q (PATH should be preferred)", got, pathBinary)
+	}
+}
+
+func TestFindBinary_FallbackToExtraPaths(t *testing.T) {
+	tmp := t.TempDir()
+	t.Setenv("PATH", tmp)
+	t.Setenv("HOME", tmp)
+
+	binDir := filepath.Join(tmp, ".opencode", "bin")
+	if err := os.MkdirAll(binDir, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	fakeBinary := filepath.Join(binDir, "opencode")
+	if err := os.WriteFile(fakeBinary, []byte("#!/bin/sh\n"), 0o755); err != nil {
+		t.Fatal(err)
+	}
+
+	got := clients.FindBinary("opencode", []string{fakeBinary})
+	if got != fakeBinary {
+		t.Errorf("FindBinary() = %q, want %q", got, fakeBinary)
+	}
+	if !clients.IsInstalled("opencode", []string{fakeBinary}) {
+		t.Error("IsInstalled() = false, want true")
+	}
+}
+
+func TestFindBinary_FallbackToCommonBinDirs(t *testing.T) {
+	tmp := t.TempDir()
+	t.Setenv("PATH", tmp)
+	t.Setenv("HOME", tmp)
+
+	localBin := filepath.Join(tmp, ".local", "bin")
+	if err := os.MkdirAll(localBin, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	fakeBinary := filepath.Join(localBin, "claude")
+	if err := os.WriteFile(fakeBinary, []byte("#!/bin/sh\n"), 0o755); err != nil {
+		t.Fatal(err)
+	}
+
+	got := clients.FindBinary("claude", nil)
+	if got != fakeBinary {
+		t.Errorf("FindBinary() = %q, want %q", got, fakeBinary)
+	}
+}
+
+func TestFindBinary_NotFound(t *testing.T) {
+	tmp := t.TempDir()
+	t.Setenv("PATH", tmp)
+	t.Setenv("HOME", tmp)
+
+	got := clients.FindBinary("claude", nil)
+	if got != "" {
+		t.Errorf("FindBinary() = %q, want empty", got)
+	}
+	if clients.IsInstalled("claude", nil) {
+		t.Error("IsInstalled() = true, want false")
+	}
+}
+
+func TestFindBinary_SkipsNonExecutable(t *testing.T) {
+	tmp := t.TempDir()
+	t.Setenv("PATH", tmp)
+	t.Setenv("HOME", tmp)
+
+	binDir := filepath.Join(tmp, ".local", "bin")
+	if err := os.MkdirAll(binDir, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	nonExec := filepath.Join(binDir, "claude")
+	if err := os.WriteFile(nonExec, []byte("not executable"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	got := clients.FindBinary("claude", nil)
+	if got != "" {
+		t.Errorf("FindBinary() = %q, want empty (not executable)", got)
+	}
+}

internal/clients/claudecode/check.go

@@ -0,0 +1,55 @@
+package claudecode
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// checkClaudeSettings validates that ~/.claude/settings.json does not set
+// environment variables that conflict with what the launcher manages.
+// Claude Code applies env from settings.json at startup, which would
+// override the values the launcher injects via the process environment.
+func checkClaudeSettings() error {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return fmt.Errorf("cannot determine home directory: %w", err)
+	}
+
+	settingsPath := filepath.Join(home, ".claude", "settings.json")
+	data, err := os.ReadFile(settingsPath)
+	if os.IsNotExist(err) {
+		return nil
+	}
+	if err != nil {
+		return fmt.Errorf("cannot read %s\n\nCheck file permissions and try again", settingsPath)
+	}
+
+	var settings struct {
+		Env map[string]any `json:"env"`
+	}
+	if err := json.Unmarshal(data, &settings); err != nil {
+		return fmt.Errorf("%s contains invalid JSON\n\nFix the syntax or delete the file and let Claude Code recreate it", settingsPath)
+	}
+	if len(settings.Env) == 0 {
+		return nil
+	}
+
+	var conflicts []string
+	for _, key := range managedEnvVars {
+		if _, ok := settings.Env[key]; ok {
+			conflicts = append(conflicts, key)
+		}
+	}
+	if len(conflicts) == 0 {
+		return nil
+	}
+	return fmt.Errorf(
+		"~/.claude/settings.json sets env vars that conflict with the launcher:\n\n  %s\n\n"+
+			"The launcher manages these variables automatically.\n"+
+			"Remove them from the \"env\" section of ~/.claude/settings.json",
+		strings.Join(conflicts, "\n  "),
+	)
+}