feat: ctask doctor command with 5 health checks

Checks: workspace root, agent on PATH, status line helper, Claude settings, existing workspaces. Actionable fix guidance for each failure.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

cmd/doctor.go

@@ -0,0 +1,175 @@
+package cmd
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+
+	"github.com/spf13/cobra"
+	"github.com/warrenronsiek/ctask/internal/config"
+	"github.com/warrenronsiek/ctask/internal/workspace"
+)
+
+var doctorCmd = &cobra.Command{
+	Use:          "doctor",
+	Short:        "Verify ctask setup and diagnose configuration problems",
+	Args:         cobra.NoArgs,
+	SilenceUsage: true,
+	RunE:         runDoctor,
+}
+
+func init() {
+	rootCmd.AddCommand(doctorCmd)
+}
+
+func runDoctor(cmd *cobra.Command, args []string) error {
+	passed := 0
+	failed := 0
+
+	// Check 1: Workspace root exists and is writable
+	root := config.ResolveRoot()
+	if info, err := os.Stat(root); err == nil && info.IsDir() {
+		// Test writability by creating a temp file
+		testFile := filepath.Join(root, ".ctask-doctor-test")
+		if err := os.WriteFile(testFile, []byte("test"), 0644); err == nil {
+			os.Remove(testFile)
+			fmt.Printf("  [PASS] Workspace root exists: %s\n", root)
+			passed++
+		} else {
+			fmt.Printf("  [FAIL] Workspace root not writable: %s\n", root)
+			fmt.Printf("         Fix: check permissions on %s\n", root)
+			failed++
+		}
+	} else {
+		fmt.Printf("  [FAIL] Workspace root not found: %s\n", root)
+		fmt.Printf("         Fix: create it with: mkdir %s\n", root)
+		failed++
+	}
+
+	// Check 2: Default agent on PATH
+	agent := config.ResolveAgent()
+	if _, err := exec.LookPath(agent); err == nil {
+		fmt.Printf("  [PASS] Default agent found: %s\n", agent)
+		passed++
+	} else {
+		fmt.Printf("  [FAIL] Agent command not found: %s\n", agent)
+		fmt.Printf("         Fix: install it or set CTASK_AGENT to a different command\n")
+		failed++
+	}
+
+	// Check 3: Status line helper exists
+	// The canonical location is next to the ctask binary in GOPATH/bin,
+	// or on Unix in ~/.local/bin. We check both the bash and powershell variants.
+	statusLineFound := false
+	statusLinePath := ""
+
+	// Determine expected locations based on platform
+	var searchPaths []string
+	home, _ := os.UserHomeDir()
+	gopath := os.Getenv("GOPATH")
+	if gopath == "" {
+		gopath = filepath.Join(home, "go")
+	}
+	gopathBin := filepath.Join(gopath, "bin")
+
+	if runtime.GOOS == "windows" {
+		searchPaths = []string{
+			filepath.Join(gopathBin, "ctask-statusline.sh"),
+			filepath.Join(gopathBin, "ctask-statusline.ps1"),
+		}
+	} else {
+		searchPaths = []string{
+			filepath.Join(home, ".local", "bin", "ctask-statusline.sh"),
+			filepath.Join(gopathBin, "ctask-statusline.sh"),
+			"/usr/local/bin/ctask-statusline.sh",
+		}
+	}
+
+	for _, p := range searchPaths {
+		if _, err := os.Stat(p); err == nil {
+			statusLineFound = true
+			statusLinePath = p
+			break
+		}
+	}
+
+	if statusLineFound {
+		fmt.Printf("  [PASS] Status line helper found: %s\n", statusLinePath)
+		passed++
+	} else {
+		fmt.Printf("  [FAIL] Status line helper not found\n")
+		fmt.Printf("         Fix: copy ctask-statusline.sh to %s\n", searchPaths[0])
+		failed++
+	}
+
+	// Check 4: Claude Code status line configured
+	claudeSettingsPath := filepath.Join(home, ".claude", "settings.json")
+	statusLineConfigured := false
+
+	if data, err := os.ReadFile(claudeSettingsPath); err == nil {
+		var settings map[string]interface{}
+		if err := json.Unmarshal(data, &settings); err == nil {
+			if sl, ok := settings["statusLine"].(map[string]interface{}); ok {
+				slType, _ := sl["type"].(string)
+				slCmd, _ := sl["command"].(string)
+				if slType == "command" && slCmd != "" {
+					// Check if the referenced file in the command exists
+					// Extract the file path from the command (last argument typically)
+					statusLineConfigured = true
+					fmt.Printf("  [PASS] Claude Code status line configured\n")
+					passed++
+				}
+			}
+		}
+	}
+
+	if !statusLineConfigured {
+		fmt.Printf("  [FAIL] Claude Code status line not configured or misconfigured\n")
+		fmt.Printf("         Fix: add to %s:\n", claudeSettingsPath)
+		if runtime.GOOS == "windows" {
+			fmt.Printf("         \"statusLine\": {\"type\": \"command\", \"command\": \"bash /c/Users/<you>/go/bin/ctask-statusline.sh\"}\n")
+		} else {
+			fmt.Printf("         \"statusLine\": {\"type\": \"command\", \"command\": \"bash ~/.local/bin/ctask-statusline.sh\"}\n")
+		}
+		failed++
+	}
+
+	// Check 5: Workspace root has workspaces
+	results, err := workspace.ListWorkspaces(root, workspace.ListOpts{
+		IncludeArchived: true,
+		Limit:           0, // no limit
+	})
+	if err == nil && len(results) > 0 {
+		activeCount := 0
+		archivedCount := 0
+		for _, r := range results {
+			if r.Meta.Status == "archived" {
+				archivedCount++
+			} else {
+				activeCount++
+			}
+		}
+		fmt.Printf("  [PASS] Workspaces found: %d tasks", len(results))
+		if archivedCount > 0 {
+			fmt.Printf(" (%d archived)", archivedCount)
+		}
+		fmt.Println()
+		passed++
+	} else {
+		fmt.Printf("  [FAIL] No workspaces found\n")
+		fmt.Printf("         Fix: create one with: ctask new \"my first task\"\n")
+		failed++
+	}
+
+	// Summary
+	fmt.Println()
+	fmt.Printf("%d checks passed, %d failed\n", passed, failed)
+
+	if failed > 0 {
+		return fmt.Errorf("%d checks failed", failed)
+	}
+	return nil
+}