feat: inline theme declaration in explore (#6015)

* inline theme wip

* conditionally create resource

* remove comments

* remove comments

* err check

* test fix

* cleanup

* Review

* Improve comment

---------

Co-authored-by: Benjamin Egelund-Müller <b@egelund-muller.com>

runtime/compilers/rillv1/parse_explore.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/google/uuid"
 	runtimev1 "github.com/rilldata/rill/proto/gen/rill/runtime/v1"
 	"golang.org/x/exp/maps"
 	"gopkg.in/yaml.v3"
@@ -19,7 +20,7 @@ type ExploreYAML struct {
 	MetricsView string                 `yaml:"metrics_view"`
 	Dimensions  *FieldSelectorYAML     `yaml:"dimensions"`
 	Measures    *FieldSelectorYAML     `yaml:"measures"`
-	Theme       string                 `yaml:"theme"`
+	Theme       yaml.Node              `yaml:"theme"` // Name (string) or inline theme definition (map)
 	TimeRanges  []ExploreTimeRangeYAML `yaml:"time_ranges"`
 	TimeZones   []string               `yaml:"time_zones"`
 	Defaults    *struct {
@@ -152,9 +153,14 @@ func (p *Parser) parseExplore(node *Node) error {
 		measuresSelector = tmp.Measures.Proto()
 	}
 
-	// Add theme to refs
-	if tmp.Theme != "" {
-		node.Refs = append(node.Refs, ResourceName{Kind: ResourceKindTheme, Name: tmp.Theme})
+	// Parse theme if present.
+	// If it returns a themeSpec, it will be inserted as a separate resource later in this function.
+	themeName, themeSpec, err := p.parseExploreTheme(node.Name, &tmp.Theme)
+	if err != nil {
+		return err
+	}
+	if themeName != "" {
+		node.Refs = append(node.Refs, ResourceName{Kind: ResourceKindTheme, Name: themeName})
 	}
 
 	// Build and validate time ranges
@@ -259,12 +265,64 @@ func (p *Parser) parseExplore(node *Node) error {
 	r.ExploreSpec.DimensionsSelector = dimensionsSelector
 	r.ExploreSpec.Measures = measures
 	r.ExploreSpec.MeasuresSelector = measuresSelector
-	r.ExploreSpec.Theme = tmp.Theme
+	r.ExploreSpec.Theme = themeName
 	r.ExploreSpec.TimeRanges = timeRanges
 	r.ExploreSpec.TimeZones = tmp.TimeZones
 	r.ExploreSpec.DefaultPreset = defaultPreset
 	r.ExploreSpec.EmbedsHidePivot = tmp.Embeds.HidePivot
 	r.ExploreSpec.SecurityRules = rules
 
+	if themeSpec != nil {
+		r, err := p.insertResource(ResourceKindTheme, themeName, node.Paths)
+		if err != nil {
+			// Normally we could return the error, but we can't do that here because we've already inserted the explore.
+			// Since the theme has been validated with insertDryRun in parseExploreTheme, this error should never happen in practice.
+			// So let's panic.
+			panic(err)
+		}
+		r.ThemeSpec = themeSpec
+	}
+
 	return nil
 }
+
+func (p *Parser) parseExploreTheme(exploreName string, n *yaml.Node) (string, *runtimev1.ThemeSpec, error) {
+	if n == nil || n.IsZero() {
+		return "", nil, nil
+	}
+
+	switch n.Kind {
+	case yaml.ScalarNode: // It's the name of an existing theme
+		var name string
+		err := n.Decode(&name)
+		if err != nil {
+			return "", nil, err
+		}
+		return name, nil, nil
+	case yaml.MappingNode: // It's an inline definition of a new theme
+		tmp := &ThemeYAML{}
+		err := n.Decode(tmp)
+		if err != nil {
+			return "", nil, err
+		}
+
+		name := fmt.Sprintf("%s--theme", exploreName)
+		err = p.insertDryRun(ResourceKindTheme, name)
+		if err != nil {
+			name = fmt.Sprintf("%s--theme-%s", exploreName, uuid.New())
+			err = p.insertDryRun(ResourceKindTheme, name)
+			if err != nil {
+				return "", nil, err
+			}
+		}
+
+		spec, err := p.parseThemeYAML(tmp)
+		if err != nil {
+			return "", nil, err
+		}
+
+		return name, spec, nil
+	default:
+		return "", nil, fmt.Errorf("invalid theme: should be a string or mapping, got kind %q", n.Kind)
+	}
+}

runtime/compilers/rillv1/parse_theme.go

@@ -22,39 +22,41 @@ func (p *Parser) parseTheme(node *Node) error {
 		return err
 	}
 
-	// Parse the colors now to get the parse error before inserting resource
-	var pc csscolorparser.Color
-	hasPc := false
-	var sc csscolorparser.Color
-	hasSc := false
-	if tmp.Colors.Primary != "" {
-		pc, err = csscolorparser.Parse(tmp.Colors.Primary)
-		if err != nil {
-			return err
-		}
-		hasPc = true
-	}
-	if tmp.Colors.Secondary != "" {
-		sc, err = csscolorparser.Parse(tmp.Colors.Secondary)
-		if err != nil {
-			return err
-		}
-		hasSc = true
+	spec, err := p.parseThemeYAML(tmp)
+	if err != nil {
+		return err
 	}
 
 	r, err := p.insertResource(ResourceKindTheme, node.Name, node.Paths, node.Refs...)
 	if err != nil {
 		return err
 	}
 
-	if hasPc {
-		r.ThemeSpec.PrimaryColor = toThemeColor(pc)
+	r.ThemeSpec = spec
+
+	return nil
+}
+
+func (p *Parser) parseThemeYAML(tmp *ThemeYAML) (*runtimev1.ThemeSpec, error) {
+	spec := &runtimev1.ThemeSpec{}
+
+	if tmp.Colors.Primary != "" {
+		pc, err := csscolorparser.Parse(tmp.Colors.Primary)
+		if err != nil {
+			return nil, err
+		}
+		spec.PrimaryColor = toThemeColor(pc)
 	}
-	if hasSc {
-		r.ThemeSpec.SecondaryColor = toThemeColor(sc)
+
+	if tmp.Colors.Secondary != "" {
+		sc, err := csscolorparser.Parse(tmp.Colors.Secondary)
+		if err != nil {
+			return nil, err
+		}
+		spec.SecondaryColor = toThemeColor(sc)
 	}
 
-	return nil
+	return spec, nil
 }
 
 func toThemeColor(c csscolorparser.Color) *runtimev1.Color {

runtime/compilers/rillv1/parser_test.go

@@ -1503,12 +1503,27 @@ func TestTheme(t *testing.T) {
 	ctx := context.Background()
 	repo := makeRepo(t, map[string]string{
 		`rill.yaml`: ``,
+		// Theme resource
 		`themes/t1.yaml`: `
 type: theme
 
 colors:
   primary: red
   secondary: grey
+`,
+		// Explore referencing the external theme resource
+		`explores/e1.yaml`: `
+type: explore
+metrics_view: missing
+theme: t1
+`,
+		// Explore that defines an inline theme
+		`explores/e2.yaml`: `
+type: explore
+metrics_view: missing
+theme:
+  colors:
+    primary: red
 `,
 	})
 
@@ -1531,6 +1546,40 @@ colors:
 				},
 			},
 		},
+		{
+			Name:  ResourceName{Kind: ResourceKindExplore, Name: "e1"},
+			Paths: []string{"/explores/e1.yaml"},
+			Refs:  []ResourceName{{Kind: ResourceKindMetricsView, Name: "missing"}, {Kind: ResourceKindTheme, Name: "t1"}},
+			ExploreSpec: &runtimev1.ExploreSpec{
+				MetricsView:        "missing",
+				DimensionsSelector: &runtimev1.FieldSelector{Selector: &runtimev1.FieldSelector_All{All: true}},
+				MeasuresSelector:   &runtimev1.FieldSelector{Selector: &runtimev1.FieldSelector_All{All: true}},
+				Theme:              "t1",
+			},
+		},
+		{
+			Name:  ResourceName{Kind: ResourceKindExplore, Name: "e2"},
+			Paths: []string{"/explores/e2.yaml"},
+			Refs:  []ResourceName{{Kind: ResourceKindMetricsView, Name: "missing"}, {Kind: ResourceKindTheme, Name: "e2--theme"}},
+			ExploreSpec: &runtimev1.ExploreSpec{
+				MetricsView:        "missing",
+				DimensionsSelector: &runtimev1.FieldSelector{Selector: &runtimev1.FieldSelector_All{All: true}},
+				MeasuresSelector:   &runtimev1.FieldSelector{Selector: &runtimev1.FieldSelector_All{All: true}},
+				Theme:              "e2--theme",
+			},
+		},
+		{
+			Name:  ResourceName{Kind: ResourceKindTheme, Name: "e2--theme"},
+			Paths: []string{"/explores/e2.yaml"},
+			ThemeSpec: &runtimev1.ThemeSpec{
+				PrimaryColor: &runtimev1.Color{
+					Red:   1,
+					Green: 0,
+					Blue:  0,
+					Alpha: 1,
+				},
+			},
+		},
 	}
 
 	p, err := Parse(ctx, repo, "", "", "duckdb")