feat(cmd): add doctor command for diagnosing configuration issues

src/cmd/doctor.go

@@ -0,0 +1,190 @@
+package cmd
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/CodingWithCalvin/dtvem.cli/src/internal/doctor"
+	"github.com/CodingWithCalvin/dtvem.cli/src/internal/ui"
+	"github.com/spf13/cobra"
+)
+
+var (
+	doctorFix   bool
+	doctorYes   bool
+	doctorNoFix bool
+)
+
+var doctorCmd = &cobra.Command{
+	Use:   "doctor",
+	Short: "Diagnose dtvem configuration issues",
+	Long: `Run a battery of checks against your dtvem installation and surface any
+configuration problems it finds.
+
+By default, doctor is read-only: it prints a report and exits non-zero
+when an error-severity finding is present, but it does not modify any
+state. Pass --fix to enable interactive remediation; pair with --yes
+to apply every fixable finding without prompting.
+
+Findings are grouped by severity. Each one is marked either [fixable]
+(doctor knows how to remediate it) or [manual] (you'll see step-by-step
+instructions). Manual findings are never auto-applied, even with --fix.
+
+Examples:
+  dtvem doctor              # Report problems, don't change anything
+  dtvem doctor --fix        # Prompt to fix each fixable finding
+  dtvem doctor --fix --yes  # Apply every fixable finding non-interactively
+  dtvem doctor --no-fix     # Explicit read-only mode (for scripts)`,
+	Run: func(cmd *cobra.Command, args []string) {
+		if doctorFix && doctorNoFix {
+			ui.Error("--fix and --no-fix are mutually exclusive")
+			os.Exit(2)
+		}
+
+		result := doctor.RunAll()
+		renderReport(result)
+
+		// Apply fixes if requested. We run this even when there are no
+		// error-severity findings — warnings can also be fixable, and
+		// nothing prevents the user from cleaning those up too.
+		if doctorFix {
+			applyFixes(result, doctorYes)
+		}
+
+		if result.HasErrors() {
+			// Non-zero exit so CI / wrapping scripts can react. We use
+			// os.Exit rather than returning an error from Run so we
+			// don't trigger Cobra's "Error:" prefix on the rendered
+			// report.
+			os.Exit(1)
+		}
+	},
+}
+
+// renderReport prints findings grouped into a passing section and a
+// problems section. We deliberately keep the layout close to the
+// example in the GitHub issue so the report is greppable and the user
+// can find specific finding shapes by eye.
+func renderReport(r doctor.Result) {
+	ui.Header("dtvem doctor")
+	fmt.Println()
+
+	var ok, problems []doctor.CheckResult
+	for _, cr := range r.Results {
+		if cr.Finding.OK {
+			ok = append(ok, cr)
+		} else {
+			problems = append(problems, cr)
+		}
+	}
+
+	for _, cr := range problems {
+		printFinding(cr.Finding)
+	}
+
+	for _, cr := range ok {
+		ui.Success("%s", cr.Finding.Title)
+	}
+
+	fmt.Println()
+	summarize(len(ok), len(problems), r.HasErrors())
+}
+
+// printFinding renders a single non-OK finding: a severity-colored
+// title line with [fixable] or [manual] tag, the aligned details
+// block, and the resolution text.
+func printFinding(f doctor.Finding) {
+	tag := "[manual]"
+	if f.Fixable() {
+		tag = "[fixable]"
+	}
+
+	header := fmt.Sprintf("%s  %s", f.Title, tag)
+	switch f.Severity {
+	case doctor.SeverityError:
+		ui.Error("%s", header)
+	case doctor.SeverityWarning:
+		ui.Warning("%s", header)
+	default:
+		ui.Info("%s", header)
+	}
+
+	// Align the keys so the values form a tidy column. The longest key
+	// drives column width; we don't pad past it.
+	maxKey := 0
+	for _, d := range f.Details {
+		if l := len(d.Key); l > maxKey {
+			maxKey = l
+		}
+	}
+	for _, d := range f.Details {
+		pad := strings.Repeat(" ", maxKey-len(d.Key))
+		fmt.Printf("  %s:%s  %s\n", d.Key, pad, d.Value)
+	}
+
+	if f.Resolution != "" {
+		// Indent every line of the resolution so multi-line manual
+		// instructions stay visually grouped under the finding.
+		for _, line := range strings.Split(f.Resolution, "\n") {
+			fmt.Printf("  %s\n", line)
+		}
+	}
+	fmt.Println()
+}
+
+// summarize prints the closing one-liner so users (and CI logs) see a
+// quick result without having to count findings themselves.
+func summarize(ok, problems int, hasErrors bool) {
+	if problems == 0 {
+		ui.Success("All %d check(s) passed", ok)
+		return
+	}
+	if hasErrors {
+		ui.Error("%d problem(s) found across %d check(s)", problems, ok+problems)
+	} else {
+		ui.Warning("%d non-error problem(s) found across %d check(s)", problems, ok+problems)
+	}
+}
+
+// applyFixes walks the fixable findings and applies each one — either
+// after a y/N prompt, or immediately when --yes was passed. We print a
+// running tally so users see what doctor did, in the order it did it.
+func applyFixes(r doctor.Result, yes bool) {
+	fixable := r.Fixable()
+	if len(fixable) == 0 {
+		ui.Info("No fixable findings to apply.")
+		return
+	}
+
+	fmt.Println()
+	ui.Header("Applying fixes")
+	fmt.Println()
+
+	reader := bufio.NewReader(os.Stdin)
+	for _, cr := range fixable {
+		if !yes {
+			fmt.Printf("Fix: %s? [y/N] ", cr.Finding.Title)
+			line, _ := reader.ReadString('\n')
+			line = strings.ToLower(strings.TrimSpace(line))
+			if line != "y" && line != "yes" {
+				ui.Info("Skipped: %s", cr.Finding.Title)
+				continue
+			}
+		}
+
+		if err := cr.Finding.Fix(); err != nil {
+			ui.Error("Fix failed for %s: %v", cr.Finding.Title, err)
+			continue
+		}
+		ui.Success("Fixed: %s", cr.Finding.Title)
+	}
+}
+
+func init() {
+	doctorCmd.Flags().BoolVar(&doctorFix, "fix", false, "Interactively apply fixes for fixable findings")
+	doctorCmd.Flags().BoolVarP(&doctorYes, "yes", "y", false, "Skip prompts when --fix is set; apply all fixable findings")
+	doctorCmd.Flags().BoolVar(&doctorNoFix, "no-fix", false, "Explicit read-only mode (for scripts)")
+	rootCmd.AddCommand(doctorCmd)
+}

src/internal/doctor/check_configured_runtimes.go

@@ -0,0 +1,140 @@
+package doctor
+
+import (
+	"fmt"
+	"os"
+	"sort"
+	"strings"
+
+	"github.com/CodingWithCalvin/dtvem.cli/src/internal/config"
+	"github.com/CodingWithCalvin/dtvem.cli/src/internal/runtime"
+)
+
+// configuredRuntimesCheck verifies that every runtime/version pair in
+// the global ~/.dtvem/config/runtimes.json points at an installed
+// version. A mismatch means `dtvem current` will report a version
+// dtvem can't actually execute, and shim invocations for that runtime
+// will fail with a confusing "version not installed" error rather
+// than a useful one at config-load time.
+//
+// The fix isn't automatable in general — doctor can't tell whether
+// the user wants to install the configured version or edit the
+// config to match what's installed — so this is a manual check with
+// a one-line `dtvem install` suggestion per mismatch.
+type configuredRuntimesCheck struct {
+	configPath  func() string
+	readConfig  func(path string) (config.RuntimesConfig, error)
+	getProvider func(name string) (runtime.ShimProvider, error)
+}
+
+func newConfiguredRuntimesCheck() *configuredRuntimesCheck {
+	return &configuredRuntimesCheck{
+		configPath:  config.GlobalConfigPath,
+		readConfig:  config.ReadAllRuntimes,
+		getProvider: runtime.GetShimProvider,
+	}
+}
+
+func (configuredRuntimesCheck) Name() string { return "configured-runtimes-installed" }
+
+func (c configuredRuntimesCheck) Run() Finding {
+	cfgPath := c.configPath()
+	cfg, err := c.readConfig(cfgPath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return Finding{OK: true, Title: "No global runtimes config to check"}
+		}
+		return Finding{
+			Severity:   SeverityWarning,
+			Title:      "Could not read global runtimes config",
+			Details:    []Detail{{Key: "Path", Value: cfgPath}, {Key: "Error", Value: err.Error()}},
+			Resolution: "Check that " + cfgPath + " is valid JSON and readable.",
+		}
+	}
+	if len(cfg) == 0 {
+		return Finding{OK: true, Title: "Global runtimes config is empty"}
+	}
+
+	type problem struct {
+		runtimeName string
+		version     string
+		displayName string
+		detail      string
+	}
+	var problems []problem
+
+	for name, version := range cfg {
+		p, err := c.getProvider(name)
+		if err != nil {
+			problems = append(problems, problem{
+				runtimeName: name,
+				version:     version,
+				displayName: name,
+				detail:      "configured runtime is unknown to dtvem (no provider registered)",
+			})
+			continue
+		}
+
+		installed, err := p.IsInstalled(version)
+		if err != nil {
+			problems = append(problems, problem{
+				runtimeName: name,
+				version:     version,
+				displayName: p.DisplayName(),
+				detail:      fmt.Sprintf("could not check install status: %v", err),
+			})
+			continue
+		}
+		if !installed {
+			problems = append(problems, problem{
+				runtimeName: name,
+				version:     version,
+				displayName: p.DisplayName(),
+				detail:      fmt.Sprintf("version %s is not installed (run `dtvem install %s %s`)", version, name, version),
+			})
+		}
+	}
+
+	if len(problems) == 0 {
+		return Finding{OK: true, Title: "All configured runtimes are installed"}
+	}
+
+	// Stable order so the report doesn't shuffle between runs.
+	sort.Slice(problems, func(i, j int) bool {
+		if problems[i].runtimeName == problems[j].runtimeName {
+			return problems[i].version < problems[j].version
+		}
+		return problems[i].runtimeName < problems[j].runtimeName
+	})
+
+	details := make([]Detail, 0, len(problems)+1)
+	details = append(details, Detail{Key: "Config", Value: cfgPath})
+	for _, p := range problems {
+		details = append(details, Detail{Key: p.displayName, Value: p.detail})
+	}
+
+	return Finding{
+		Severity:   SeverityError,
+		Title:      fmt.Sprintf("%d configured runtime version%s not installed", len(problems), plural(len(problems), "", "s")),
+		Details:    details,
+		Resolution: configuredRuntimesResolution(problems[0].runtimeName, problems[0].version),
+	}
+}
+
+// configuredRuntimesResolution suggests the install command for the
+// first problem so the user has a concrete next step. Listing every
+// install command in the resolution would duplicate the detail block
+// without adding info.
+func configuredRuntimesResolution(runtimeName, version string) string {
+	return strings.Join([]string{
+		"Install the missing version(s) listed above, or edit",
+		"  " + config.GlobalConfigPath(),
+		"to reference versions that are installed.",
+		"",
+		fmt.Sprintf("Example: dtvem install %s %s", runtimeName, version),
+	}, "\n")
+}
+
+func init() {
+	Register(newConfiguredRuntimesCheck())
+}