feat: complete TASK-WP4-03 text templates

apps/web/src/text-font-loader.ts

@@ -0,0 +1,75 @@
+export type ArchivedFontStatus = "idle" | "loading" | "ready" | "unavailable";
+
+interface LoadableFontFace {
+  load: () => Promise<unknown>;
+}
+
+interface FontSetPort {
+  add: (face: unknown) => unknown;
+  check: (font: string) => boolean;
+  ready: Promise<unknown>;
+}
+
+export interface ArchivedFontReference {
+  fontId: string;
+  url: string;
+}
+
+export function fontFamilyName(fontId: string) {
+  if (!/^[A-Za-z0-9][A-Za-z0-9_.:-]{0,119}$/.test(fontId)) throw new Error("font_id_invalid");
+  return `Dada_${fontId.replaceAll(/[^A-Za-z0-9_]/g, "_")}`;
+}
+
+export class ArchivedFontLoader {
+  private readonly createFace: (family: string, source: string) => LoadableFontFace;
+  private readonly fontSet: FontSetPort;
+  private readonly pending = new Map<string, Promise<ArchivedFontStatus>>();
+  private readonly statuses = new Map<string, ArchivedFontStatus>();
+
+  constructor(input: { createFace: (family: string, source: string) => LoadableFontFace; fontSet: FontSetPort }) {
+    this.createFace = input.createFace;
+    this.fontSet = input.fontSet;
+  }
+
+  status(fontId: string): ArchivedFontStatus {
+    return this.statuses.get(fontId) ?? "idle";
+  }
+
+  ensure(reference: ArchivedFontReference): Promise<ArchivedFontStatus> {
+    const existing = this.pending.get(reference.fontId);
+    if (existing) return existing;
+    const operation = this.load(reference);
+    this.pending.set(reference.fontId, operation);
+    return operation;
+  }
+
+  retry(reference: ArchivedFontReference) {
+    this.pending.delete(reference.fontId);
+    this.statuses.delete(reference.fontId);
+    return this.ensure(reference);
+  }
+
+  private async load(reference: ArchivedFontReference): Promise<ArchivedFontStatus> {
+    const family = fontFamilyName(reference.fontId);
+    this.statuses.set(reference.fontId, "loading");
+    try {
+      const face = this.createFace(family, `url("${reference.url}")`);
+      const loaded = await face.load();
+      this.fontSet.add(loaded);
+      await this.fontSet.ready;
+      if (!this.fontSet.check(`16px "${family}"`)) throw new Error("font_not_ready");
+      this.statuses.set(reference.fontId, "ready");
+      return "ready";
+    } catch {
+      this.statuses.set(reference.fontId, "unavailable");
+      return "unavailable";
+    }
+  }
+}
+
+export function createBrowserArchivedFontLoader() {
+  return new ArchivedFontLoader({
+    createFace: (family, source) => new FontFace(family, source),
+    fontSet: document.fonts as unknown as FontSetPort,
+  });
+}