feat: 实现 DOCX 媒体预处理与跨端 PNG 捕获

apps/server/src/playwright-docx-media-capture.ts

@@ -0,0 +1,75 @@
+import type { Page } from "playwright";
+import type {
+  DocxMediaCaptureAdapter,
+  DocxMediaCaptureRequest
+} from "@md-to-pdf/application";
+import type { DocxMediaCapturePlan } from "@md-to-pdf/core";
+
+interface CaptureScreenshotResult {
+  data: string;
+}
+
+async function renderCapturePlan(
+  page: Page,
+  request: DocxMediaCaptureRequest
+) {
+  return page.evaluate(
+    async ({ payload, dimensions }): Promise<DocxMediaCapturePlan> => {
+      const renderer = (
+        window as typeof window & {
+          __mdToPdfRenderDocxMedia?: (
+            renderPayload: typeof payload,
+            renderDimensions: typeof dimensions
+          ) => Promise<DocxMediaCapturePlan>;
+        }
+      ).__mdToPdfRenderDocxMedia;
+      if (!renderer) {
+        throw new Error("DOCX 媒体渲染运行时不可用");
+      }
+      return renderer(payload, dimensions);
+    },
+    request
+  );
+}
+
+export async function captureDocxMediaWithPlaywrightPage(
+  page: Page,
+  request: DocxMediaCaptureRequest
+) {
+  const plan = await renderCapturePlan(page, request);
+  const session = await page.context().newCDPSession(page);
+  try {
+    const captures = [];
+    for (const target of plan.targets) {
+      const result = (await session.send("Page.captureScreenshot", {
+        format: "png",
+        fromSurface: true,
+        captureBeyondViewport: true,
+        clip: {
+          x: target.captureX,
+          y: target.captureY,
+          width: target.captureWidthPx,
+          height: target.captureHeightPx,
+          scale: target.rasterScale
+        }
+      })) as CaptureScreenshotResult;
+      captures.push({
+        id: target.id,
+        png: Buffer.from(result.data, "base64")
+      });
+    }
+    return { plan, captures };
+  } finally {
+    await session.detach();
+  }
+}
+
+export class PlaywrightDocxMediaCaptureAdapter
+  implements DocxMediaCaptureAdapter
+{
+  constructor(private readonly page: Page) {}
+
+  capture(request: DocxMediaCaptureRequest) {
+    return captureDocxMediaWithPlaywrightPage(this.page, request);
+  }
+}

apps/server/tests/playwright-docx-media-capture.test.ts

@@ -0,0 +1,94 @@
+import { describe, expect, it, vi } from "vitest";
+import type { Page } from "playwright";
+import {
+  createPagedDocumentPayload,
+  defaultExportConfig,
+  type DocxMediaCapturePlan
+} from "@md-to-pdf/core";
+import { captureDocxMediaWithPlaywrightPage } from "../src/playwright-docx-media-capture.js";
+
+const plan: DocxMediaCapturePlan = {
+  targets: [
+    {
+      id: "docx-media-1",
+      kind: "echarts",
+      ordinal: 1,
+      kindOrdinal: 1,
+      altText: "图表",
+      displayWidthPx: 320,
+      displayHeightPx: 180,
+      captureX: 10,
+      captureY: 20,
+      captureWidthPx: 320,
+      captureHeightPx: 180,
+      rasterScale: 3.125
+    }
+  ],
+  echartsErrors: [],
+  mermaidErrors: []
+};
+
+const request = {
+  payload: createPagedDocumentPayload({
+    document: {
+      rendererVersion: 1,
+      articleHtml: '<article id="write"></article>',
+      bodyHtml: "",
+      metadata: {
+        title: "",
+        author: "",
+        subject: "",
+        keywords: [],
+        language: "zh-CN"
+      },
+      features: [],
+      warnings: []
+    },
+    fileName: "test.md",
+    themeCss: "",
+    exportConfig: defaultExportConfig
+  }),
+  dimensions: {
+    contentWidthPx: 600,
+    contentHeightPx: 900
+  }
+};
+
+describe("Playwright DOCX 媒体捕获", () => {
+  it("按运行时计划以目标倍率捕获 PNG", async () => {
+    const detach = vi.fn(async () => undefined);
+    const send = vi.fn(async () => ({
+      data: Buffer.from("png").toString("base64")
+    }));
+    const page = {
+      evaluate: vi.fn(async () => plan),
+      context: () => ({
+        newCDPSession: vi.fn(async () => ({ send, detach }))
+      })
+    } as unknown as Page;
+
+    const result = await captureDocxMediaWithPlaywrightPage(
+      page,
+      request
+    );
+
+    expect(result.plan).toBe(plan);
+    expect(result.captures[0]).toEqual({
+      id: "docx-media-1",
+      png: Buffer.from("png")
+    });
+    expect(send).toHaveBeenCalledWith("Page.captureScreenshot", {
+      format: "png",
+      fromSurface: true,
+      captureBeyondViewport: true,
+      clip: {
+        x: 10,
+        y: 20,
+        width: 320,
+        height: 180,
+        scale: 3.125
+      }
+    });
+    expect(detach).toHaveBeenCalledOnce();
+  });
+});