can swap themes dynamicallyv0.12.0

author: Paul Buetow <paul@buetow.org> 2026-04-25 22:13:32 +0300
committer: Paul Buetow <paul@buetow.org> 2026-04-25 22:13:32 +0300
commit: a5cb9f7ad4b2bcb7ac367854147f661ab83c5ec1 (patch)
tree: 96db490ed72dec49c4bc2aba8539fd57f3246f47 /internal/generator
parent: cc9c69ce748416ad1d9b28592ec463434023d63c (diff)
77 files changed, 5457 insertions, 5841 deletions
diff --git a/internal/generator/doc.go b/internal/generator/doc.go
index d7d4a53..be82bdc 100644
--- a/internal/generator/doc.go
+++ b/internal/generator/doc.go
@@ -4,21 +4,26 @@
 // Responsibilities by area (file → role):
 //
 //   - generator.go — Orchestration: load posts from disk, sort newest-first,
-//     paginate, parse theme+nav templates, write index.html / pageN.html,
-//     then call atom.Generate.
-//   - themes.go — Theme registry (name → template string) and getTheme /
-//     ListThemes for the CLI.
-//   - theme_*.go — One file per visual theme: full-page HTML that invokes
-//     {{template "navSharedCSSInner"}} inside <style>, then {{template "splashGate"}},
-//     {{template "navhints" .}}, {{template "navmodal" .}},
-//     {{template "navscript" .}}.
-//   - shared.go — navDefs: shared {{define}} blocks merged at parse time with
-//     the chosen theme so a single html/template parse sees every name.
-//   - theme_sounds.go — Per-theme Web Audio parameters (splash arpeggio, nav blip,
-//     modal open/close); embedded in pages as ThemeSoundsJSON for navscript.
-//   - templates.go — Short pointer: where templates and registry live.
+//     paginate, parse shell+nav templates, write index.html / pageN.html plus
+//     shared.css/shared.js and per-theme assets, then call atom.Generate.
+//   - themes.go — ListThemes / validThemeName helpers backed by the embedded FS.
+//   - shared.go — navDefs: shared {{define}} blocks (splashGate, navhints,
+//     navmodal) merged at parse time with shell.tmpl so a single html/template
+//     parse sees every name.
+//   - theme_sounds.go — Per-theme Web Audio parameters; one file is written per
+//     theme to dist/themes/<name>/sounds.json and the default theme's preset is
+//     also baked into shell.tmpl as window.SNONUX_SOUNDS so the splash chime
+//     can fire instantly.
+//   - favicon.go — Generates the 32×32 .ico binary written into the output dir.
+//   - templates.go — Short pointer: where templates and helpers live.
 //
-// Dependency direction: themes and shared nav templates are composed only for
+// Theme assets live as separate files under templates/themes/<name>/theme.css,
+// theme.js, and meta.json. The single shell.tmpl loads the active theme's CSS
+// synchronously in <head> (chosen from localStorage by a boot script) and
+// shared.js orchestrates the rest. Switching themes is a localStorage write
+// followed by location.reload().
+//
+// Dependency direction: shell and shared nav templates are composed only for
 // the HTML path (generator.go). Package atom depends on config and post only,
 // not on themes or html/template, so feed logic stays isolated from page chrome.
 package generator
diff --git a/internal/generator/favicon.go b/internal/generator/favicon.go
index a4a8251..8664183 100644
--- a/internal/generator/favicon.go
+++ b/internal/generator/favicon.go
@@ -6,35 +6,12 @@ import (
 	"fmt"
 	"image"
 	"image/color"
-	"log"
 	"os"
 	"path/filepath"
-	"strings"
-
-	"codeberg.org/snonux/snonux/internal/generator/templates"
 )
 
-// faviconHeadHTML is the <link rel="icon"> fragment injected into every theme's
-// <head>. Loaded at startup from the embedded templates FS so no HTML lives in
-// the Go sources.
-var faviconHeadHTML = loadFaviconHeadHTML()
-
-func loadFaviconHeadHTML() string {
-	s, err := templates.Shared("favicon_head")
-	if err != nil {
-		log.Printf("warning: could not load favicon_head template: %v", err)
-		return ""
-	}
-	return s
-}
-
-func injectSharedHead(theme string) string {
-	if strings.Contains(theme, `rel="icon"`) {
-		return theme
-	}
-
-	return strings.Replace(theme, "</head>", faviconHeadHTML+"</head>", 1)
-}
+// shell.tmpl now embeds the favicon <link> directly, so no head-injection
+// helper is needed; favicon.go only generates and writes the .ico binary.
 
 func writeFavicon(outputDir string) error {
 	data, err := generateFaviconICO()
diff --git a/internal/generator/generator.go b/internal/generator/generator.go
index dc1f236..079cc38 100644
--- a/internal/generator/generator.go
+++ b/internal/generator/generator.go
@@ -12,17 +12,29 @@ import (
 
 	"codeberg.org/snonux/snonux/internal/config"
 	"codeberg.org/snonux/snonux/internal/generator/atom"
+	"codeberg.org/snonux/snonux/internal/generator/templates"
 	"codeberg.org/snonux/snonux/internal/post"
 )
 
 // pageData holds the template variables for a single HTML page.
+// Theme-specific values come from the default theme's meta.json — they are
+// what the user sees on first paint. shared.js may swap them out at runtime
+// when a non-default theme is saved in localStorage.
 type pageData struct {
-	Posts           []postView
-	PrevPage        string // URL of the newer page, empty if none
-	NextPage        string // URL of the older page, empty if none
-	PrevPageJSON    template.JS
-	NextPageJSON    template.JS
-	ThemeSoundsJSON template.JS // Web Audio preset for this theme (splash + nav)
+	Posts        []postView
+	PrevPage     string // URL of the newer page, empty if none
+	NextPage     string // URL of the older page, empty if none
+	PrevPageJSON template.JS
+	NextPageJSON template.JS
+
+	DefaultTheme      string        // baked into the shell as SNONUX_DEFAULT_THEME
+	AllThemesJSON     template.JS   // [...] of all available theme names, JS literal
+	DefaultTitle      string        // <title> contents for the default theme
+	DefaultHeaderHTML template.HTML // <header> innerHTML for the default theme
+	DefaultSplashHTML template.HTML // #splash-overlay innerHTML for the default theme
+	DefaultPrevText   template.HTML // pagination prev anchor text (theme-styled)
+	DefaultNextText   template.HTML // pagination next anchor text
+	DefaultSoundsJSON template.JS   // default theme's Web Audio preset (literal)
 }
 
 // postView is a render-friendly representation of a post for the HTML template.
@@ -32,23 +44,62 @@ type postView struct {
 	ContentHTML   template.HTML // pre-rendered; trusted — generated by this tool
 }
 
-// Run loads all posts, generates all HTML pages, and writes atom.xml.
+// themeMeta mirrors the JSON structure written by the migration tool and used
+// at runtime by shared.js to swap theme markup in.
+type themeMeta struct {
+	Title           string `json:"title"`
+	HeaderHTML      string `json:"header_html"`
+	SplashInnerHTML string `json:"splash_inner_html"`
+	PrevPageText    string `json:"prev_page_text"`
+	NextPageText    string `json:"next_page_text"`
+}
+
+func loadThemeMeta(name string) (themeMeta, error) {
+	var m themeMeta
+	b, err := templates.ThemeMeta(name)
+	if err != nil {
+		return m, fmt.Errorf("read theme meta %q: %w", name, err)
+	}
+	if err := json.Unmarshal(b, &m); err != nil {
+		return m, fmt.Errorf("parse theme meta %q: %w", name, err)
+	}
+	return m, nil
+}
+
+// allThemesJSON returns a JS array literal of all theme names.
+func allThemesJSON() (template.JS, error) {
+	names, err := templates.ThemeNames()
+	if err != nil {
+		return "", err
+	}
+	b, err := json.Marshal(names)
+	if err != nil {
+		return "", err
+	}
+	return template.JS(b), nil //nolint:gosec // marshalled from a fixed string slice
+}
+
+// Run loads all posts, generates all HTML pages, and writes atom.xml plus the
+// shared CSS/JS bundles and per-theme asset files.
 func Run(cfg *config.Config) error {
 	posts, err := loadAllPosts(cfg.OutputDir)
 	if err != nil {
 		return err
 	}
 
-	// Sort newest-first so page 1 (index.html) has the latest content.
 	sort.Slice(posts, func(i, j int) bool {
 		return posts[i].Timestamp.After(posts[j].Timestamp)
 	})
 
 	pages := paginate(posts, config.PostsPerPage)
 
-	// Combine the theme HTML (which uses {{template "navhints"}} etc.) with the
-	// shared navDefs sub-templates so a single parse call resolves all references.
-	combined := injectSharedHead(getTheme(cfg.Theme)) + "\n" + navDefs
+	// Combine shell.tmpl with nav.tmpl partials so a single parse call resolves
+	// references to splashGate, navhints, navmodal.
+	shellSrc, err := templates.Shell()
+	if err != nil {
+		return fmt.Errorf("load shell template: %w", err)
+	}
+	combined := shellSrc + "\n" + navDefs
 	tmpl, err := template.New("page").Parse(combined)
 	if err != nil {
 		return fmt.Errorf("parse page template: %w", err)
@@ -57,9 +108,25 @@ func Run(cfg *config.Config) error {
 	if err := writeFavicon(cfg.OutputDir); err != nil {
 		return err
 	}
+	if err := writeSharedAssets(cfg.OutputDir); err != nil {
+		return err
+	}
+	if err := writeAllThemeAssets(cfg.OutputDir); err != nil {
+		return err
+	}
+
+	defaultTheme := validThemeName(cfg.Theme)
+	defaultMeta, err := loadThemeMeta(defaultTheme)
+	if err != nil {
+		return err
+	}
+	all, err := allThemesJSON()
+	if err != nil {
+		return err
+	}
 
 	for i, page := range pages {
-		if err := writePage(tmpl, page, i, len(pages), cfg); err != nil {
+		if err := writePage(tmpl, page, i, len(pages), cfg, defaultTheme, defaultMeta, all); err != nil {
 			return err
 		}
 	}
@@ -126,8 +193,8 @@ func pageFilename(index int) string {
 const indexPageNavURL = "index.html?splash=0"
 
 // writePage renders one HTML page and writes it to cfg.OutputDir.
-func writePage(tmpl *template.Template, posts []*post.Post, pageIndex, totalPages int, cfg *config.Config) error {
-	data := buildPageData(posts, pageIndex, totalPages, cfg.Theme)
+func writePage(tmpl *template.Template, posts []*post.Post, pageIndex, totalPages int, cfg *config.Config, defaultTheme string, defaultMeta themeMeta, all template.JS) error {
+	data := buildPageData(posts, pageIndex, totalPages, defaultTheme, defaultMeta, all)
 
 	filename := pageFilename(pageIndex)
 	path := filepath.Join(cfg.OutputDir, filename)
@@ -146,7 +213,7 @@ func writePage(tmpl *template.Template, posts []*post.Post, pageIndex, totalPage
 }
 
 // buildPageData constructs the template data for a single page.
-func buildPageData(posts []*post.Post, pageIndex, totalPages int, theme string) pageData {
+func buildPageData(posts []*post.Post, pageIndex, totalPages int, defaultTheme string, meta themeMeta, all template.JS) pageData {
 	views := make([]postView, len(posts))
 	for i, p := range posts {
 		views[i] = postView{
@@ -173,12 +240,19 @@ func buildPageData(posts []*post.Post, pageIndex, totalPages int, theme string)
 	}
 
 	return pageData{
-		Posts:           views,
-		PrevPage:        prevPage,
-		NextPage:        nextPage,
-		PrevPageJSON:    jsonStringOrNull(prevPage),
-		NextPageJSON:    jsonStringOrNull(nextPage),
-		ThemeSoundsJSON: themeSoundsJSON(theme),
+		Posts:             views,
+		PrevPage:          prevPage,
+		NextPage:          nextPage,
+		PrevPageJSON:      jsonStringOrNull(prevPage),
+		NextPageJSON:      jsonStringOrNull(nextPage),
+		DefaultTheme:      defaultTheme,
+		AllThemesJSON:     all,
+		DefaultTitle:      meta.Title,
+		DefaultHeaderHTML: template.HTML(meta.HeaderHTML),      //nolint:gosec // source is in-tree theme metadata
+		DefaultSplashHTML: template.HTML(meta.SplashInnerHTML), //nolint:gosec // same
+		DefaultPrevText:   template.HTML(meta.PrevPageText),    //nolint:gosec // same
+		DefaultNextText:   template.HTML(meta.NextPageText),    //nolint:gosec // same
+		DefaultSoundsJSON: themeSoundsJSON(defaultTheme),
 	}
 }
 
@@ -202,3 +276,85 @@ func jsonStringOrNull(s string) template.JS {
 
 	return template.JS(strings.TrimSpace(string(b))) //nolint:gosec // filename is tool-generated
 }
+
+// writeSharedAssets dumps shared.css and shared.js to the output dir. They are
+// linked from every page and cached by browsers across navigations.
+func writeSharedAssets(outputDir string) error {
+	css, err := templates.SharedCSS()
+	if err != nil {
+		return fmt.Errorf("read shared.css: %w", err)
+	}
+	if err := os.WriteFile(filepath.Join(outputDir, "shared.css"), css, 0o644); err != nil {
+		return fmt.Errorf("write shared.css: %w", err)
+	}
+
+	js, err := templates.SharedJS()
+	if err != nil {
+		return fmt.Errorf("read shared.js: %w", err)
+	}
+	if err := os.WriteFile(filepath.Join(outputDir, "shared.js"), js, 0o644); err != nil {
+		return fmt.Errorf("write shared.js: %w", err)
+	}
+
+	return nil
+}
+
+// writeAllThemeAssets copies each theme's CSS, JS, meta.json, and writes its
+// sounds.json to dist/themes/<name>/. shared.js fetches these on theme switch.
+func writeAllThemeAssets(outputDir string) error {
+	names, err := templates.ThemeNames()
+	if err != nil {
+		return err
+	}
+
+	root := filepath.Join(outputDir, "themes")
+	if err := os.MkdirAll(root, 0o755); err != nil {
+		return fmt.Errorf("create themes dir: %w", err)
+	}
+
+	for _, name := range names {
+		dir := filepath.Join(root, name)
+		if err := os.MkdirAll(dir, 0o755); err != nil {
+			return fmt.Errorf("create theme dir %q: %w", name, err)
+		}
+		if err := writeThemeAsset(dir, name); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// writeThemeAsset copies the four per-theme files into dir.
+func writeThemeAsset(dir, name string) error {
+	css, err := templates.ThemeCSS(name)
+	if err != nil {
+		return fmt.Errorf("read %s/theme.css: %w", name, err)
+	}
+	if err := os.WriteFile(filepath.Join(dir, "theme.css"), css, 0o644); err != nil {
+		return fmt.Errorf("write %s/theme.css: %w", name, err)
+	}
+
+	js, err := templates.ThemeJS(name)
+	if err != nil {
+		return fmt.Errorf("read %s/theme.js: %w", name, err)
+	}
+	if err := os.WriteFile(filepath.Join(dir, "theme.js"), js, 0o644); err != nil {
+		return fmt.Errorf("write %s/theme.js: %w", name, err)
+	}
+
+	meta, err := templates.ThemeMeta(name)
+	if err != nil {
+		return fmt.Errorf("read %s/meta.json: %w", name, err)
+	}
+	if err := os.WriteFile(filepath.Join(dir, "meta.json"), meta, 0o644); err != nil {
+		return fmt.Errorf("write %s/meta.json: %w", name, err)
+	}
+
+	soundsJSON := themeSoundsJSON(name)
+	if err := os.WriteFile(filepath.Join(dir, "sounds.json"), []byte(soundsJSON), 0o644); err != nil {
+		return fmt.Errorf("write %s/sounds.json: %w", name, err)
+	}
+
+	return nil
+}
diff --git a/internal/generator/generator_test.go b/internal/generator/generator_test.go
index 7b0009c..d477275 100644
--- a/internal/generator/generator_test.go
+++ b/internal/generator/generator_test.go
@@ -179,10 +179,19 @@ func TestBuildPageData_navLinks(t *testing.T) {
 		},
 	}
 
+	meta, err := loadThemeMeta("neon")
+	if err != nil {
+		t.Fatalf("loadThemeMeta: %v", err)
+	}
+	all, err := allThemesJSON()
+	if err != nil {
+		t.Fatalf("allThemesJSON: %v", err)
+	}
+
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			t.Parallel()
-			data := buildPageData([]*post.Post{p}, tt.pageIndex, tt.totalPages, "neon")
+			data := buildPageData([]*post.Post{p}, tt.pageIndex, tt.totalPages, "neon", meta, all)
 			if data.PrevPage != tt.wantPrev {
 				t.Fatalf("PrevPage=%q; want %q", data.PrevPage, tt.wantPrev)
 			}
@@ -202,19 +211,24 @@ func TestBuildPageData_navLinks(t *testing.T) {
 	}
 }
 
-func TestGetTheme_unknownFallsBackToNeon(t *testing.T) {
+func TestValidThemeName_unknownFallsBackToNeon(t *testing.T) {
 	t.Parallel()
-	if got, want := getTheme("no-such-theme-"), getTheme("neon"); got != want {
-		t.Fatal("expected neon fallback")
+	if got := validThemeName("no-such-theme-"); got != "neon" {
+		t.Fatalf("validThemeName(\"no-such-theme-\") = %q; want \"neon\"", got)
+	}
+	if got := validThemeName("matrix"); got != "matrix" {
+		t.Fatalf("validThemeName(\"matrix\") = %q; want \"matrix\"", got)
 	}
 }
 
-func TestInjectSharedHead_addsFaviconLink(t *testing.T) {
+func TestLoadThemeMeta_neonHasFields(t *testing.T) {
 	t.Parallel()
-
-	got := injectSharedHead(getTheme("neon"))
-	if !strings.Contains(got, `rel="icon" href="favicon.ico"`) {
-		t.Fatalf("favicon link missing from theme head")
+	m, err := loadThemeMeta("neon")
+	if err != nil {
+		t.Fatalf("loadThemeMeta(neon): %v", err)
+	}
+	if m.Title == "" || m.HeaderHTML == "" || m.SplashInnerHTML == "" {
+		t.Fatalf("neon meta missing required fields: %+v", m)
 	}
 }
 
diff --git a/internal/generator/templates.go b/internal/generator/templates.go
index f50601a..df854ab 100644
--- a/internal/generator/templates.go
+++ b/internal/generator/templates.go
@@ -1,9 +1,10 @@
 package generator
 
-// HTML theme templates and shared sub-templates live as separate files under
-// internal/generator/templates/{themes,shared}/*.tmpl and are loaded into the
+// The unified shell template, shared CSS/JS bundles, and per-theme asset
+// triples live under internal/generator/templates/ and are loaded into the
 // binary via embed.FS; see internal/generator/templates/embed.go.
 //
-/
author	Paul Buetow <paul@buetow.org>	2026-04-25 22:13:32 +0300
committer	Paul Buetow <paul@buetow.org>	2026-04-25 22:13:32 +0300
commit	a5cb9f7ad4b2bcb7ac367854147f661ab83c5ec1 (patch)
tree	96db490ed72dec49c4bc2aba8539fd57f3246f47 /internal/generator
parent	cc9c69ce748416ad1d9b28592ec463434023d63c (diff)