const CAPTURE_FILE = "capture.js";
const RUNNER_FILE = "runner.js";
const SETTINGS_KEY = "webToPixsoSettings";
const DEFAULT_SETTINGS = {
  useProxy: false,
  concurrency: "8",
  captureMode: "mixed",
  captureWidth: null
};
const MIN_CAPTURE_WIDTH = 320;
const MAX_CAPTURE_WIDTH = 3840;

let lastCaptureData = null;

const delay = ms => new Promise(resolve => setTimeout(resolve, ms));

function normalizeSettings(value = {}) {
  const concurrency = String(value.concurrency || DEFAULT_SETTINGS.concurrency);
  const captureWidth = normalizeCaptureWidth(value.captureWidth, null);
  return {
    useProxy: Boolean(value.useProxy),
    concurrency: ["4", "6", "8", "10", "12", "16", "20", "infinite"].includes(concurrency)
      ? concurrency
      : DEFAULT_SETTINGS.concurrency,
    captureMode: value.captureMode === "editable" ? "editable" : "mixed",
    captureWidth
  };
}

function normalizeCaptureWidth(value, fallback = null) {
  const number = Number.parseInt(String(value || "").replace(/\D+/g, ""), 10);
  if (!Number.isFinite(number)) return fallback;
  return Math.max(MIN_CAPTURE_WIDTH, Math.min(MAX_CAPTURE_WIDTH, number));
}

function definedWindowBounds(bounds = {}) {
  return Object.fromEntries(
    Object.entries(bounds).filter(([, value]) => Number.isFinite(value))
  );
}

function assertCaptureableTab(tab) {
  if (!tab?.id || !tab.url) {
    throw new Error("没有可采集的当前标签页");
  }
  if (/^(chrome|edge|about|devtools|chrome-extension):/i.test(tab.url)) {
    throw new Error("浏览器内置页面不支持采集，请切换到普通网页");
  }
}

async function getActiveTab() {
  const [tab] = await chrome.tabs.query({ active: true, currentWindow: true });
  assertCaptureableTab(tab);
  return tab;
}

async function runCapture(tabId, options) {
  await chrome.scripting.executeScript({ target: { tabId }, files: [CAPTURE_FILE] });
  await chrome.scripting.executeScript({ target: { tabId }, files: [RUNNER_FILE] });
  const [{ result }] = await chrome.scripting.executeScript({
    target: { tabId },
    func: captureOptions => window.__webToPPTRunCapture(captureOptions),
    args: [options]
  });
  if (!result) throw new Error("页面没有返回采集结果");
  return result;
}

async function getTabViewportWidth(tabId) {
  try {
    const [{ result }] = await chrome.scripting.executeScript({
      target: { tabId },
      func: () => Math.round(window.innerWidth || document.documentElement.clientWidth || 0)
    });
    return normalizeCaptureWidth(result, null);
  } catch { return null; }
}

async function prepareCaptureViewport(tab, requestedWidth) {
  const targetWidth = normalizeCaptureWidth(requestedWidth, null);
  const beforeViewportWidth = await getTabViewportWidth(tab.id);
  const noop = async () => {};
  if (!targetWidth || !beforeViewportWidth || Math.abs(beforeViewportWidth - targetWidth) <= 2) {
    return { restore: noop, requestedWidth: targetWidth || beforeViewportWidth, beforeViewportWidth, actualViewportWidth: beforeViewportWidth, resizedWindow: false };
  }
  if (!tab.windowId || !chrome.windows?.get || !chrome.windows?.update) {
    throw new Error("当前浏览器不支持临时调整采集视口宽度");
  }
  const originalWindow = await chrome.windows.get(tab.windowId);
  const originalState = originalWindow.state || "normal";
  const originalBounds = { left: originalWindow.left, top: originalWindow.top, width: originalWindow.width, height: originalWindow.height };
  const restore = async () => {
    try {
      if (originalState !== "normal") { await chrome.windows.update(tab.windowId, { state: "normal" }); await delay(120); }
      const restoreBounds = definedWindowBounds(originalBounds);
      if (Object.keys(restoreBounds).length) await chrome.windows.update(tab.windowId, restoreBounds);
      if (originalState !== "normal") { await delay(120); await chrome.windows.update(tab.windowId, { state: originalState }); }
      await delay(250);
    } catch {}
  };
  try {
    if (originalState !== "normal") { await chrome.windows.update(tab.windowId, { state: "normal" }); await delay(250); }
    let currentViewportWidth = beforeViewportWidth;
    let currentWindow = await chrome.windows.get(tab.windowId);
    for (let attempt = 0; attempt < 2; attempt += 1) {
      const delta = targetWidth - currentViewportWidth;
      const nextWidth = Math.max(360, Math.round((currentWindow.width || targetWidth) + delta));
      await chrome.windows.update(tab.windowId, { width: nextWidth });
      await delay(650);
      currentViewportWidth = await getTabViewportWidth(tab.id) || currentViewportWidth;
      if (Math.abs(currentViewportWidth - targetWidth) <= 2) break;
      currentWindow = await chrome.windows.get(tab.windowId);
    }
    if (Math.abs(currentViewportWidth - targetWidth) > 2) throw new Error(`采集视口未生效：目标 ${targetWidth}px，实际 ${currentViewportWidth}px`);
    return { restore, requestedWidth: targetWidth, beforeViewportWidth, actualViewportWidth: currentViewportWidth, resizedWindow: true };
  } catch (error) { await restore(); throw error; }
}

async function captureCurrentTab(tab, settings) {
  const viewport = await prepareCaptureViewport(tab, settings.captureWidth);
  try {
    const data = await runCapture(tab.id, { ...settings, captureWidth: viewport.requestedWidth });
    data.capture = { ...(data.capture || {}), resizedWindow: viewport.resizedWindow, usedTemporaryWindow: viewport.resizedWindow, requestedWidth: viewport.requestedWidth || data.source?.actualViewportWidth || data.canvas?.width, beforeViewportWidth: viewport.beforeViewportWidth, actualViewportWidth: data.source?.actualViewportWidth || viewport.actualViewportWidth };
    return data;
  } finally { await viewport.restore(); }
}

function arrayBufferToBase64(buffer) {
  const bytes = new Uint8Array(buffer);
  const chunkSize = 0x8000;
  let binary = "";
  for (let index = 0; index < bytes.length; index += chunkSize) {
    binary += String.fromCharCode(...bytes.subarray(index, index + chunkSize));
  }
  return btoa(binary);
}

// 消息处理
chrome.runtime.onMessage.addListener((message, sender, sendResponse) => {
  // 采集并缓存数据
  if (message?.type === "WEB_TO_PPT_CAPTURE_START") {
    (async () => {
      const settings = normalizeSettings(message.options);
      await chrome.storage.local.set({ [SETTINGS_KEY]: settings });
      const tab = sender?.tab || await getActiveTab();
      assertCaptureableTab(tab);
      const data = await captureCurrentTab(tab, settings);
      lastCaptureData = data;

      return { ok: true, actualViewportWidth: data.source?.actualViewportWidth };
    })()
      .then(sendResponse)
      .catch(error => sendResponse({ ok: false, error: error.message || String(error) }));
    return true;
  }

  // 获取缓存数据
  if (message?.type === "WEB_TO_PPT_GET_DATA") {
    if (lastCaptureData) {
      sendResponse({ ok: true, data: lastCaptureData });
    } else {
      (async () => {
        const settings = normalizeSettings({});
        const tab = await getActiveTab();
        const data = await captureCurrentTab(tab, settings);
        lastCaptureData = data;
        return { ok: true, data };
      })()
        .then(sendResponse)
        .catch(error => sendResponse({ ok: false, error: error.message || String(error) }));
    }
    return true;
  }

  // 下载 PPTX（从 storage 读取 base64）
  if (message?.type === "WEB_TO_PPT_DOWNLOAD") {
    (async () => {
      const stored = await chrome.storage.session.get(['pptxBase64', 'pptxFilename']);
      if (!stored.pptxBase64) throw new Error('没有待下载的数据');
      const dataUrl = 'data:application/vnd.openxmlformats-officedocument.presentationml.presentation;base64,' + stored.pptxBase64;
      await chrome.downloads.download({ url: dataUrl, filename: stored.pptxFilename });
      await chrome.storage.session.remove(['pptxBase64', 'pptxFilename']);
      return { ok: true };
    })()
      .then(sendResponse)
      .catch(error => sendResponse({ ok: false, error: error.message || String(error) }));
    return true;
  }

  return false;
});

chrome.runtime.onInstalled.addListener(() => {
  chrome.storage.local.get({ [SETTINGS_KEY]: DEFAULT_SETTINGS }).then(result => {
    chrome.storage.local.set({ [SETTINGS_KEY]: normalizeSettings(result[SETTINGS_KEY]) });
  });
});