import assert from "node:assert/strict";
import { readFileSync } from "node:fs";
import test from "node:test";
import React from "react";

import { PersonalReportPage } from "../src/components/personal-report/personal-report-page";
import { SidebarProvider } from "../src/components/ui/sidebar";
import { assembleReportFactTables } from "../src/lib/report-fact-tables";
import { containsHan } from "../src/lib/report-language";
import { createClientLifecycleHarness } from "./react-client-lifecycle-test-support";

// BUG-1126: the reader and the fact tables were sibling elements keyed by the
// same language, so switching editions left the first edition's reader on
// screen and appended the new one below it. Real reports always carry fact
// tables, so the whole page is rendered with them. Fixtures are real engine
// output for a fictional birth (AGENTS §7-4).
Object.assign(globalThis, { React });

const engine = JSON.parse(readFileSync(new URL("./fixtures/report-density-fictional-engine.json", import.meta.url), "utf8"));
const en = JSON.parse(readFileSync(new URL("./fixtures/report-reader-main-fictional-en.json", import.meta.url), "utf8"));
const zh = JSON.parse(readFileSync(new URL("./fixtures/report-reader-main-fictional-zh-pair.json", import.meta.url), "utf8"));

const REPORT_ID = "00000000-0000-4000-8000-000000001126";
const BODY = {
  report: { id: REPORT_ID, status: "ready", createdAt: "2026-09-30T00:00:00.000Z" },
  englishEdition: "ready",
  longformMarkdown: zh.markdown,
  longformMarkdownEn: en.markdown,
  factTables: assembleReportFactTables(engine),
  factTablesEn: assembleReportFactTables(engine, "en"),
};

type Node = ReturnType<ReturnType<typeof createClientLifecycleHarness>["elements"]>[number];
const hasClass = (node: Node, name: string) => (node.getAttribute("class") ?? "").split(/\s+/).includes(name);

async function openReader(initialLanguage: "zh" | "en") {
  const h = createClientLifecycleHarness();
  const location = { href: `https://staging.example/reports/${REPORT_ID}${initialLanguage === "en" ? "?lang=en" : ""}` };
  const history = { state: null, replaceState: (_state: unknown, _title: string, url: URL) => { location.href = String(url); } };
  Object.assign(globalThis.window as object, { location, history });
  Object.assign(globalThis.document as object, { hidden: false, querySelector: () => null, querySelectorAll: () => [] });
  const originalFetch = globalThis.fetch;
  // Lazy sections and the chapter jump schedule frames on the global; the harness only has them on window.
  const frameWindow = globalThis.window as unknown as { requestAnimationFrame: typeof requestAnimationFrame; cancelAnimationFrame: typeof cancelAnimationFrame };
  const originalFrames = { request: globalThis.requestAnimationFrame, cancel: globalThis.cancelAnimationFrame };
  Object.assign(globalThis, { requestAnimationFrame: frameWindow.requestAnimationFrame, cancelAnimationFrame: frameWindow.cancelAnimationFrame });
  globalThis.fetch = (async () => new Response(JSON.stringify(BODY), { status: 200, headers: { "content-type": "application/json" } })) as typeof fetch;
  await h.render(<SidebarProvider><PersonalReportPage reportId={REPORT_ID} initialLanguage={initialLanguage} /></SidebarProvider>);
  for (let i = 0; i < 5 && !h.elements().some(node => hasClass(node, "personal-report-md-layout")); i += 1) await h.idle();
  const read = () => {
    const layouts = h.elements().filter(node => hasClass(node, "personal-report-md-layout"));
    const toc = h.elements().find(node => hasClass(node, "personal-report-toc-desktop"));
    const pressed = h.elements().find(node => node.tagName === "BUTTON" && node.getAttribute("aria-pressed") === "true");
    // The article only: the 「到底部」 jump beside it is app chrome and stays Chinese (English edition decision 6).
    const articles = h.elements().filter(node => hasClass(node, "personal-report-md-article"));
    return { layouts: layouts.length, reader: articles.map(node => node.text).join(""), toc: toc?.childNodes[0]?.text, pressed: pressed?.text, url: location.href };
  };
  const pick = async (label: string) => {
    const button = h.elements().find(node => node.tagName === "BUTTON" && node.text === label);
    assert.ok(button, `${label} switch button`);
    await h.event(button);
    await h.idle();
  };
  const close = async () => {
    globalThis.fetch = originalFetch;
    Object.assign(globalThis, { requestAnimationFrame: originalFrames.request, cancelAnimationFrame: originalFrames.cancel });
    await h.close();
  };
  return { h, read, pick, close };
}

test("switching editions replaces the reader, fact tables and all (BUG-1126)", async () => {
  const page = await openReader("zh");
  try {
    let state = page.read();
    assert.equal(state.layouts, 1);
    assert.equal(state.toc, "目录");
    assert.equal(state.pressed, "中文");

    await page.pick("English");
    state = page.read();
    assert.equal(state.pressed, "English");
    assert.match(state.url, /\?lang=en$/);
    assert.equal(state.layouts, 1, "the Chinese reader must not stay on screen");
    assert.equal(state.toc, "Contents");
    assert.equal(containsHan(state.reader), false, "the English reader carries no Chinese");

    await page.pick("中文");
    state = page.read();
    assert.equal(state.pressed, "中文");
    assert.equal(state.layouts, 1, "the English reader must not stay on screen");
    assert.equal(state.toc, "目录");
    assert.equal(page.h.errors.length, 0);
  } finally { await page.close(); }
});

test("a report opened in English switches back to Chinese (BUG-1126)", async () => {
  const page = await openReader("en");
  try {
    let state = page.read();
    assert.equal(state.layouts, 1);
    assert.equal(state.toc, "Contents");

    await page.pick("中文");
    state = page.read();
    assert.equal(state.layouts, 1);
    assert.equal(state.toc, "目录");
    assert.ok(containsHan(state.reader));
    assert.doesNotMatch(state.url, /lang=en/);
  } finally { await page.close(); }
});