import { spawn } from "node:child_process";
import { existsSync } from "node:fs";
import { mkdir, mkdtemp, rm, writeFile } from "node:fs/promises";
import net from "node:net";
import os from "node:os";
import path from "node:path";
import process from "node:process";
import { fileURLToPath } from "node:url";

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const screenshotDir = path.join(__dirname, "screenshots");
const baseUrl = process.env.BRAINWAVE_PROTOTYPE_URL ?? "http://127.0.0.1:4173/prototype/";

const cases = [
  { view: "welcome", file: "01-welcome.png", fullPage: true },
  { view: "question", file: "02-question.png", fullPage: true },
  { view: "casting", file: "03-casting.png", fullPage: true },
  { view: "result", file: "04-result-moving.png", fullPage: true },
  { view: "static", file: "05-result-static.png", fullPage: true },
  { view: "consent", file: "06-ai-consent.png", fullPage: false },
  { view: "explanation", file: "07-ai-explanation.png", fullPage: true },
  { view: "error", file: "08-ai-error.png", fullPage: true }
];

function findChrome() {
  const candidates = process.platform === "win32"
    ? [
        "C:\\Program Files\\Google\\Chrome\\Application\\chrome.exe",
        "C:\\Program Files (x86)\\Google\\Chrome\\Application\\chrome.exe",
        "C:\\Program Files (x86)\\Microsoft\\Edge\\Application\\msedge.exe",
        "C:\\Program Files\\Microsoft\\Edge\\Application\\msedge.exe"
      ]
    : process.platform === "darwin"
      ? ["/Applications/Google Chrome.app/Contents/MacOS/Google Chrome"]
      : ["/usr/bin/google-chrome", "/usr/bin/chromium", "/usr/bin/chromium-browser"];

  const executable = candidates.find(existsSync);
  if (!executable) {
    throw new Error("未找到 Chrome/Edge。请安装浏览器，或扩展 capture.mjs 中的候选路径。");
  }
  return executable;
}

function getFreePort() {
  return new Promise((resolve, reject) => {
    const server = net.createServer();
    server.unref();
    server.on("error", reject);
    server.listen(0, "127.0.0.1", () => {
      const address = server.address();
      server.close(() => resolve(address.port));
    });
  });
}

function delay(milliseconds) {
  return new Promise((resolve) => setTimeout(resolve, milliseconds));
}

async function waitForDebugTarget(port) {
  const endpoint = `http://127.0.0.1:${port}/json/list`;
  for (let attempt = 0; attempt < 50; attempt += 1) {
    try {
      const response = await fetch(endpoint);
      if (response.ok) {
        const targets = await response.json();
        const page = targets.find((target) => target.type === "page");
        if (page?.webSocketDebuggerUrl) return page.webSocketDebuggerUrl;
      }
    } catch {
      // Chrome may still be starting; retry within the bounded loop.
    }
    await delay(100);
  }
  throw new Error("Chrome DevTools endpoint did not become ready.");
}

class CdpClient {
  constructor(webSocketUrl) {
    this.socket = new WebSocket(webSocketUrl);
    this.nextId = 1;
    this.pending = new Map();
    this.listeners = new Map();
  }

  async connect() {
    await new Promise((resolve, reject) => {
      this.socket.addEventListener("open", resolve, { once: true });
      this.socket.addEventListener("error", reject, { once: true });
    });
    this.socket.addEventListener("message", (event) => this.#handleMessage(event));
  }

  #handleMessage(event) {
    const message = JSON.parse(String(event.data));
    if (message.id) {
      const pending = this.pending.get(message.id);
      if (!pending) return;
      this.pending.delete(message.id);
      if (message.error) pending.reject(new Error(message.error.message));
      else pending.resolve(message.result);
      return;
    }

    const listeners = this.listeners.get(message.method) ?? [];
    for (const listener of listeners) listener(message.params);
  }

  send(method, params = {}) {
    const id = this.nextId;
    this.nextId += 1;
    return new Promise((resolve, reject) => {
      this.pending.set(id, { resolve, reject });
      this.socket.send(JSON.stringify({ id, method, params }));
    });
  }

  on(method, listener) {
    const listeners = this.listeners.get(method) ?? [];
    listeners.push(listener);
    this.listeners.set(method, listeners);
  }

  waitFor(method, timeoutMs = 5000) {
    return new Promise((resolve, reject) => {
      const timeout = setTimeout(() => reject(new Error(`Timed out waiting for ${method}`)), timeoutMs);
      const listener = (params) => {
        clearTimeout(timeout);
        const listeners = this.listeners.get(method) ?? [];
        this.listeners.set(method, listeners.filter((candidate) => candidate !== listener));
        resolve(params);
      };
      this.on(method, listener);
    });
  }

  close() {
    this.socket.close();
  }
}

async function evaluate(client, expression) {
  const result = await client.send("Runtime.evaluate", {
    expression,
    returnByValue: true,
    awaitPromise: true
  });
  if (result.exceptionDetails) {
    throw new Error(result.exceptionDetails.text ?? "Runtime evaluation failed.");
  }
  return result.result.value;
}

async function navigate(client, view) {
  const loaded = client.waitFor("Page.loadEventFired");
  await client.send("Page.navigate", { url: `${baseUrl}?view=${view}` });
  await loaded;
  await delay(320);
}

async function capture(client, item) {
  await navigate(client, item.view);
  const dimensions = await evaluate(client, `(() => ({
    width: document.documentElement.scrollWidth,
    height: Math.max(document.documentElement.scrollHeight, document.body.scrollHeight)
  }))()`);
  const height = item.fullPage ? dimensions.height : 792;
  const screenshot = await client.send("Page.captureScreenshot", {
    format: "png",
    fromSurface: true,
    captureBeyondViewport: true,
    clip: { x: 0, y: 0, width: 360, height, scale: 1 }
  });
  await writeFile(path.join(screenshotDir, item.file), Buffer.from(screenshot.data, "base64"));
  return { view: item.view, file: item.file, width: 360, height };
}

async function auditView(client, view) {
  await navigate(client, view);
  return evaluate(client, `(() => {
    const visible = (element) => {
      const style = getComputedStyle(element);
      const rect = element.getBoundingClientRect();
      return style.display !== "none" && style.visibility !== "hidden" && rect.width > 0 && rect.height > 0;
    };
    const buttons = [...document.querySelectorAll("button")].filter(visible);
    const touchIssues = buttons.map((button) => {
      const rect = button.getBoundingClientRect();
      return {
        name: button.getAttribute("aria-label") || button.innerText.trim(),
        width: Math.round(rect.width),
        height: Math.round(rect.height)
      };
    }).filter((item) => item.width < 48 || item.height < 48);
    const unnamedButtons = buttons
      .filter((button) => !(button.getAttribute("aria-label") || button.innerText.trim()))
      .length;
    const checkboxes = [...document.querySelectorAll('input[type="checkbox"]')].filter(visible);
    const smallCheckboxLabels = checkboxes.filter((checkbox) => {
      const label = checkbox.closest("label");
      if (!label) return true;
      const rect = label.getBoundingClientRect();
      return rect.width < 48 || rect.height < 48;
    }).length;
    return { view: ${JSON.stringify(view)}, unnamedButtons, touchIssues, smallCheckboxLabels };
  })()`);
}

async function run() {
  const health = await fetch(baseUrl);
  if (!health.ok) {
    throw new Error(`原型服务不可用：${baseUrl} (${health.status})`);
  }

  const chrome = findChrome();
  const port = await getFreePort();
  const profileDir = await mkdtemp(path.join(os.tmpdir(), "brainwave-prototype-capture-"));
  const chromeProcess = spawn(chrome, [
    "--headless=new",
    "--disable-gpu",
    "--no-first-run",
    "--no-default-browser-check",
    `--remote-debugging-port=${port}`,
    `--user-data-dir=${profileDir}`,
    "about:blank"
  ], { stdio: "ignore", windowsHide: true });

  let client;
  try {
    const webSocketUrl = await waitForDebugTarget(port);
    client = new CdpClient(webSocketUrl);
    await client.connect();
    await Promise.all([
      client.send("Page.enable"),
      client.send("Runtime.enable"),
      client.send("Network.enable"),
      client.send("Log.enable"),
      client.send("Emulation.setDeviceMetricsOverride", {
        width: 360,
        height: 792,
        deviceScaleFactor: 1,
        mobile: false,
        screenWidth: 360,
        screenHeight: 792
      })
    ]);

    const consoleErrors = [];
    const runtimeErrors = [];
    const externalRequests = [];
    client.on("Log.entryAdded", ({ entry }) => {
      if (entry.level === "error") consoleErrors.push(entry.text);
    });
    client.on("Runtime.exceptionThrown", ({ exceptionDetails }) => {
      runtimeErrors.push(exceptionDetails.exception?.description ?? exceptionDetails.text);
    });
    client.on("Network.requestWillBeSent", ({ request }) => {
      const url = new URL(request.url);
      if (!["127.0.0.1", "localhost"].includes(url.hostname) && url.protocol !== "data:") {
        externalRequests.push(request.url);
      }
    });

    await mkdir(screenshotDir, { recursive: true });
    const screenshots = [];
    for (const item of cases) screenshots.push(await capture(client, item));

    await navigate(client, "result");
    const movingResult = await evaluate(client, `(() => ({
      names: [...document.querySelectorAll(".hexagram-name")].map((node) => node.textContent.trim()),
      numbers: [...document.querySelectorAll(".hexagram-number")].map((node) => node.textContent.trim()),
      moving: document.querySelector(".result-kicker")?.textContent.replace(/\\s+/g, " ").trim()
    }))()`);

    await navigate(client, "static");
    const staticResult = await evaluate(client, `(() => ({
      names: [...document.querySelectorAll(".hexagram-name")].map((node) => node.textContent.trim()),
      transformCount: document.querySelectorAll(".transform-arrow").length,
      label: document.querySelector(".static-indicator")?.textContent.trim()
    }))()`);

    await navigate(client, "consent");
    const consentBefore = await evaluate(client, "document.querySelector('[data-action=\"confirm-ai\"]')?.disabled");
    await evaluate(client, `(() => {
      document.querySelector('[data-action="consent-toggle"]').click();
      return document.querySelector('[data-action="confirm-ai"]').disabled;
    })()`);
    const consentAfter = await evaluate(client, "document.querySelector('[data-action=\"confirm-ai\"]')?.disabled");
    await evaluate(client, "document.querySelector('[data-action=\"confirm-ai\"]')?.click()");
    await delay(1050);
    const explanationSource = await evaluate(client, "document.querySelector('.source-badge')?.textContent.trim()");

    const accessibility = [];
    for (const item of cases) accessibility.push(await auditView(client, item.view));

    const report = {
      chrome,
      baseUrl,
      screenshots,
      movingResult,
      staticResult,
      consentGate: {
        disabledBeforeConsent: consentBefore,
        disabledAfterConsent: consentAfter,
        explanationSource
      },
      consoleErrors,
      runtimeErrors,
      externalRequests: [...new Set(externalRequests)],
      accessibility
    };

    const failed =
      movingResult.names.join(",") !== "复,坤" ||
      movingResult.numbers.join(",") !== "第 24 卦,第 2 卦" ||
      !movingResult.moving.includes("1 个动爻") ||
      staticResult.names.join(",") !== "乾" ||
      staticResult.transformCount !== 0 ||
      consentBefore !== true ||
      consentAfter !== false ||
      explanationSource !== "AI 生成" ||
      consoleErrors.length > 0 ||
      runtimeErrors.length > 0 ||
      externalRequests.length > 0 ||
      accessibility.some((item) =>
        item.unnamedButtons > 0 || item.touchIssues.length > 0 || item.smallCheckboxLabels > 0
      );

    console.log(JSON.stringify(report, null, 2));
    if (failed) process.exitCode = 1;
  } finally {
    client?.close();
    chromeProcess.kill();
    await delay(150);
    await rm(profileDir, { recursive: true, force: true });
  }
}

run().catch((error) => {
  console.error(error.stack ?? error.message);
  process.exitCode = 1;
});