import { describe, expect, it } from "vitest";
import { readFileSync } from "node:fs";
import { resolve } from "node:path";

const HOME_TSX = readFileSync(
  resolve(__dirname, "..", "src", "pages", "Home.tsx"),
  "utf-8",
);
const SLIDE_CANVAS_TSX = readFileSync(
  resolve(__dirname, "..", "src", "components", "SlideCanvas.tsx"),
  "utf-8",
);

function sliceHandleGenerateBody(source: string): string {
  const startMarker = "const handleGenerate = useCallback(async () =>";
  const startIdx = source.indexOf(startMarker);
  if (startIdx === -1) throw new Error("handleGenerate declaration not found");
  const afterStart = source.slice(startIdx + startMarker.length);
  const nextDeclIdx = afterStart.search(/\n {2}const [A-Za-z]/);
  return nextDeclIdx === -1 ? afterStart : afterStart.slice(0, nextDeclIdx);
}

const HANDLE_GENERATE_BODY = sliceHandleGenerateBody(HOME_TSX);

describe("#98 Task 4 render stale guard", () => {
  it("clears prior runMeta before invoking runPipeline", () => {
    const clearIdx = HANDLE_GENERATE_BODY.indexOf("setRunMeta(null)");
    const loadingIdx = HANDLE_GENERATE_BODY.indexOf("isLoading: true");
    const runPipelineIdx = HANDLE_GENERATE_BODY.indexOf("runPipeline(");

    expect(clearIdx).toBeGreaterThan(-1);
    expect(loadingIdx).toBeGreaterThan(-1);
    expect(runPipelineIdx).toBeGreaterThan(-1);
    expect(clearIdx).toBeLessThan(runPipelineIdx);
    expect(loadingIdx).toBeLessThan(runPipelineIdx);
  });

  it("does not pass a finalHtmlUrl to SlideCanvas while a pipeline run is loading", () => {
    expect(HOME_TSX).toContain(
      "finalHtmlUrl={state.isLoading ? undefined : runMeta?.final_html_url}",
    );
  });

  it("forces iframe remounts by keying the iframe on embeddedSrc", () => {
    expect(SLIDE_CANVAS_TSX).toContain("key={embeddedSrc}");
  });

  it("resets iframe-derived overlay state on render url, loading, or pending-layout changes", () => {
    expect(SLIDE_CANVAS_TSX).toContain(
      "}, [finalHtmlUrl, isPipelineRunning, isPendingLayout]);",
    );
    expect(SLIDE_CANVAS_TSX).toContain("setMeasuredZones({});");
    expect(SLIDE_CANVAS_TSX).toContain("setMeasuredImages({});");
    expect(SLIDE_CANVAS_TSX).toContain("setSelectedImageId(null);");
    expect(SLIDE_CANVAS_TSX).toContain("setDragOverZoneId(null);");
    expect(SLIDE_CANVAS_TSX).toContain("setEditMode(\"off\");");
  });
});