From 4ff8f5ea38b8ad00fb019f8c70bcfeab624d02cb Mon Sep 17 00:00:00 2001
From: Jon Gallant <2163001+jongio@users.noreply.github.com>
Date: Sun, 26 Jul 2026 11:21:32 -0700
Subject: [PATCH] Show resolved theme details

Closes #379

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Copilot-Session: 3f892a21-0f5d-41e7-aebb-afbda057615d
---
 cmd/theme.go      | 55 +++++++++++++++++++++++++++++++++++++++++++++++
 cmd/theme_test.go | 37 +++++++++++++++++++++++++++++++
 2 files changed, 92 insertions(+)

diff --git a/cmd/theme.go b/cmd/theme.go
index d43d4060..a95a1a59 100644
--- a/cmd/theme.go
+++ b/cmd/theme.go
@@ -16,6 +16,7 @@ func newThemeCmd() *cobra.Command {
 		Short: "Inspect grut themes",
 	}
 	themeCmd.AddCommand(newThemeListCmd(theme.ListThemes))
+	themeCmd.AddCommand(newThemeShowCmd(theme.Load))
 	return themeCmd
 }
 
@@ -41,3 +42,57 @@ func newThemeListCmd(list themeListFunc) *cobra.Command {
 	listCmd.Flags().BoolVar(&asJSON, "json", false, "Print theme names as JSON")
 	return listCmd
 }
+
+type themeLoadFunc func(string) (*theme.Theme, error)
+
+type themeShowReport struct {
+	Name    string       `json:"name"`
+	Variant string       `json:"variant"`
+	Mode    string       `json:"mode"`
+	Colors  theme.Colors `json:"colors"`
+}
+
+func newThemeShowCmd(load themeLoadFunc) *cobra.Command {
+	var asJSON bool
+	showCmd := &cobra.Command{
+		Use:   "show <name>",
+		Short: "Show resolved theme details",
+		Args:  cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			resolved, err := load(args[0])
+			if err != nil {
+				return err
+			}
+			report := themeShowReport{
+				Name:    resolved.Name,
+				Variant: resolved.Variant,
+				Mode:    string(resolved.Mode),
+				Colors:  resolved.Colors,
+			}
+			if asJSON {
+				enc := json.NewEncoder(cmd.OutOrStdout())
+				enc.SetIndent("", "  ")
+				return enc.Encode(report)
+			}
+			_, _ = fmt.Fprintf(cmd.OutOrStdout(), "Name:    %s\n", report.Name)
+			_, _ = fmt.Fprintf(cmd.OutOrStdout(), "Variant: %s\n", report.Variant)
+			_, _ = fmt.Fprintf(cmd.OutOrStdout(), "Mode:    %s\n", report.Mode)
+			_, _ = fmt.Fprintf(cmd.OutOrStdout(), "Colors:  %d slots\n", themeColorSlotCount(report.Colors))
+			return nil
+		},
+	}
+	showCmd.Flags().BoolVar(&asJSON, "json", false, "Print resolved theme details as JSON")
+	return showCmd
+}
+
+func themeColorSlotCount(colors theme.Colors) int {
+	data, err := json.Marshal(colors)
+	if err != nil {
+		return 0
+	}
+	var slots map[string]string
+	if err := json.Unmarshal(data, &slots); err != nil {
+		return 0
+	}
+	return len(slots)
+}
diff --git a/cmd/theme_test.go b/cmd/theme_test.go
index 91fef375..899b8e23 100644
--- a/cmd/theme_test.go
+++ b/cmd/theme_test.go
@@ -5,6 +5,8 @@ import (
 	"encoding/json"
 	"testing"
 
+	"github.com/jongio/grut/internal/theme"
+
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -34,6 +36,41 @@ func TestThemeListCommandPrintsJSON(t *testing.T) {
 	assert.Equal(t, []string{"default", "gruvbox"}, names)
 }
 
+func TestThemeShowCommandPrintsText(t *testing.T) {
+	cmd := newThemeShowCmd(func(string) (*theme.Theme, error) {
+		return &theme.Theme{Name: "default", Variant: "dark", Mode: theme.ModeColor, Colors: theme.Colors{Background: "#000000"}}, nil
+	})
+	cmd.SetArgs([]string{"default"})
+	var out bytes.Buffer
+	cmd.SetOut(&out)
+
+	err := cmd.Execute()
+
+	require.NoError(t, err)
+	assert.Contains(t, out.String(), "Name:    default")
+	assert.Contains(t, out.String(), "Variant: dark")
+	assert.Contains(t, out.String(), "Mode:    color")
+}
+
+func TestThemeShowCommandPrintsJSON(t *testing.T) {
+	cmd := newThemeShowCmd(func(string) (*theme.Theme, error) {
+		return &theme.Theme{Name: "gruvbox", Variant: "dark", Mode: theme.ModeColor, Colors: theme.Colors{Background: "#282828"}}, nil
+	})
+	cmd.SetArgs([]string{"gruvbox", "--json"})
+	var out bytes.Buffer
+	cmd.SetOut(&out)
+
+	err := cmd.Execute()
+
+	require.NoError(t, err)
+	var report themeShowReport
+	require.NoError(t, json.Unmarshal(out.Bytes(), &report))
+	assert.Equal(t, "gruvbox", report.Name)
+	assert.Equal(t, "dark", report.Variant)
+	assert.Equal(t, "color", report.Mode)
+	assert.Equal(t, "#282828", report.Colors.Background)
+}
+
 func TestRootRegistersThemeListCommand(t *testing.T) {
 	root, cleanup := newRootCommand()
 	defer cleanup()