/**
 * browser-cli Extension — Background Service Worker
 *
 * Connects to the native host (com.browsercli.host) via Native Messaging.
 * The native host relays commands from the CLI Unix socket to this extension,
 * and relays responses back.
 */

const NATIVE_HOST = "com.browsercli.host";
let port = null;

// ── Connection management ─────────────────────────────────────────────────────

async function getProfileAlias() {
  const { profileAlias } = await chrome.storage.local.get("profileAlias");
  return profileAlias || "default";
}

async function connect() {
  if (port) return;
  try {
    port = chrome.runtime.connectNative(NATIVE_HOST);
    port.onMessage.addListener(onMessage);
    port.onDisconnect.addListener(() => {
      port = null;
      const err = chrome.runtime.lastError;
      if (err) console.warn("[browser-cli] Native host disconnected:", err.message);
    });
    // Send hello so native host knows which profile/alias this is
    const alias = await getProfileAlias();
    port.postMessage({ type: "hello", alias });
    console.log("[browser-cli] Connected to native host as profile:", alias);
  } catch (e) {
    port = null;
    console.error("[browser-cli] Failed to connect:", e);
  }
}

chrome.runtime.onInstalled.addListener(connect);
chrome.runtime.onStartup.addListener(connect);

// Keepalive alarm — prevents service worker suspension and reconnects if needed
chrome.alarms.create("keepalive", { periodInMinutes: 0.4 });
chrome.alarms.onAlarm.addListener((alarm) => {
  if (alarm.name === "keepalive") {
    if (!port) connect();
  }
});

// ── Message dispatcher ────────────────────────────────────────────────────────

async function onMessage(msg) {
  const { id, command, args } = msg;
  if (!id || !command) return;

  console.log("[browser-cli] ←", command, args);

  let data, error;
  try {
    data = await dispatch(command, args || {});
  } catch (e) {
    error = e.message || String(e);
  }

  if (error !== undefined) {
    console.log("[browser-cli] → ERROR", command, error);
    port.postMessage({ id, success: false, error });
  } else {
    console.log("[browser-cli] →", command, data);
    port.postMessage({ id, success: true, data });
  }
}

async function dispatch(command, args) {
  switch (command) {
    // ── Navigation ────────────────────────────────────────────────────────
    case "navigate.open":    return navOpen(args);
    case "navigate.reload":  return navReload(args, false);
    case "navigate.hard_reload": return navReload(args, true);
    case "navigate.back":    return navBack(args);
    case "navigate.forward": return navForward(args);
    case "navigate.focus":   return navFocus(args);

    // ── Tabs ──────────────────────────────────────────────────────────────
    case "tabs.list":         return tabsList();
    case "tabs.close":        return tabsClose(args);
    case "tabs.move":         return tabsMove(args);
    case "tabs.active":       return tabsActive(args);
    case "tabs.filter":       return tabsFilter(args);
    case "tabs.count":        return tabsCount(args);
    case "tabs.query":        return tabsQuery(args);
    case "tabs.html":         return tabsHtml(args);
    case "tabs.dedupe":       return tabsDedupe();
    case "tabs.sort":         return tabsSort(args);
    case "tabs.merge_windows": return tabsMergeWindows();

    // ── Groups ────────────────────────────────────────────────────────────
    case "group.list":   return groupList();
    case "group.tabs":   return groupTabs(args);
    case "group.count":  return groupCount();
    case "group.query":  return groupQuery(args);
    case "group.close":   return groupClose(args);
    case "group.open":    return groupOpen(args);
    case "group.add_tab": return groupAddTab(args);
    case "group.move":    return groupMove(args);

    // ── Windows ───────────────────────────────────────────────────────────
    case "windows.list":   return windowsList();
    case "windows.rename": return windowsRename(args);
    case "windows.close":  return windowsClose(args);
    case "windows.open":   return windowsOpen(args);

    // ── DOM ───────────────────────────────────────────────────────────────
    case "dom.query":  return domOp("domQuery",  args);
    case "dom.click":  return domOp("domClick",  args);
    case "dom.type":   return domOp("domType",   args);
    case "dom.attr":   return domOp("domAttr",   args);
    case "dom.text":   return domOp("domText",   args);
    case "dom.exists": return domOp("domExists", args);

    // ── Extract ───────────────────────────────────────────────────────────
    case "extract.links":  return domOp("extractLinks",  args);
    case "extract.images": return domOp("extractImages", args);
    case "extract.text":   return domOp("extractText",   args);
    case "extract.json":   return domOp("extractJson",   args);
    case "extract.html":   return tabsHtml({});

    // ── Session ───────────────────────────────────────────────────────────
    case "session.save":      return sessionSave(args);
    case "session.load":      return sessionLoad(args);
    case "session.list":      return sessionList();
    case "session.remove":    return sessionRemove(args);
    case "session.diff":      return sessionDiff(args);
    case "session.auto_save": return sessionAutoSave(args);

    // ── Misc ──────────────────────────────────────────────────────────────
    case "clients.list":           return clientsList();
    case "clients.rename_profile": return clientsRenameProfile(args);

    default:
      throw new Error(`Unknown command: ${command}`);
  }
}

// ── Navigation ────────────────────────────────────────────────────────────────

async function navOpen({ url, background, window: windowName, group: groupNameOrId }) {
  let windowId;
  if (windowName) {
    const aliases = await getAliases();
    const entry = Object.entries(aliases).find(([, v]) => v === windowName);
    if (entry) windowId = parseInt(entry[0]);
  }
  const tab = await chrome.tabs.create({ url, active: !background, windowId });
  if (groupNameOrId != null) {
    const groupId = await resolveGroupId(groupNameOrId);
    // Close any blank placeholder tabs that were created when the group was made
    const groupTabs = await chrome.tabs.query({ groupId });
    const placeholders = groupTabs.filter(t =>
      t.id !== tab.id &&
      (t.url === "chrome://newtab/" || t.url === "about:blank" || t.pendingUrl === "chrome://newtab/")
    );
    await chrome.tabs.group({ tabIds: [tab.id], groupId });
    if (placeholders.length) await chrome.tabs.remove(placeholders.map(t => t.id));
  }
  return { id: tab.id, url: tab.url };
}

async function navReload({ tabId }, bypassCache) {
  const tab = tabId ? { id: tabId } : await getActiveTab();
  await chrome.tabs.reload(tab.id, { bypassCache });
  return { tabId: tab.id };
}

async function navBack({ tabId }) {
  const tab = tabId ? { id: tabId } : await getActiveTab();
  await chrome.tabs.goBack(tab.id);
  return { tabId: tab.id };
}

async function navForward({ tabId }) {
  const tab = tabId ? { id: tabId } : await getActiveTab();
  await chrome.tabs.goForward(tab.id);
  return { tabId: tab.id };
}

async function navFocus({ pattern }) {
  // If pattern is a plain integer, treat it as a tab ID
  const asInt = parseInt(pattern);
  let match;
  if (!isNaN(asInt) && String(asInt) === String(pattern)) {
    match = await chrome.tabs.get(asInt);
  } else {
    const all = await chrome.tabs.query({});
    match = all.find(t => (t.url && t.url.includes(pattern)) || (t.pendingUrl && t.pendingUrl.includes(pattern)));
  }
  if (!match) return null;
  await chrome.windows.update(match.windowId, { focused: true });
  await chrome.tabs.update(match.id, { active: true });
  return { id: match.id, url: match.url || match.pendingUrl, title: match.title };
}

// ── Tabs ──────────────────────────────────────────────────────────────────────

async function tabsList() {
  const windows = await chrome.windows.getAll({ populate: true });
  const aliases = await getAliases();
  const tabs = [];
  for (const w of windows) {
    for (const t of w.tabs) {
      tabs.push({
        id: t.id,
        windowId: t.windowId,
        windowAlias: aliases[t.windowId] || null,
        active: t.active,
        pinned: t.pinned,
        title: t.title,
        url: t.url,
        favIconUrl: t.favIconUrl,
        groupId: t.groupId >= 0 ? t.groupId : null,
      });
    }
  }
  return tabs;
}

async function tabsClose({ tabId, inactive, duplicates }) {
  let toClose = [];
  if (duplicates) {
    const all = await chrome.tabs.query({});
    const seen = new Set();
    for (const t of all) {
      if (seen.has(t.url)) toClose.push(t.id);
      else seen.add(t.url);
    }
  } else if (inactive) {
    const all = await chrome.tabs.query({});
    toClose = all.filter(t => !t.active).map(t => t.id);
  } else if (tabId) {
    toClose = [tabId];
  }
  if (toClose.length) await chrome.tabs.remove(toClose);
  return { closed: toClose.length };
}

async function tabsMove({ tabId, groupId, windowId, index, forward, backward }) {
  const moveProps = {};
  if (windowId != null) moveProps.windowId = windowId;

  if (forward || backward) {
    const tab = await chrome.tabs.get(tabId);
    if (forward) moveProps.index = tab.index + 2; // +2 because Chrome shifts after removal
    else moveProps.index = Math.max(0, tab.index - 1);
  } else if (index != null) {
    moveProps.index = index;
  } else {
    moveProps.index = -1;
  }

  await chrome.tabs.move(tabId, moveProps);
  if (groupId != null) {
    await chrome.tabs.group({ tabIds: [tabId], groupId });
  }
  return { tabId };
}

async function tabsActive({ tabId }) {
  const tab = await chrome.tabs.get(tabId);
  await chrome.windows.update(tab.windowId, { focused: true });
  await chrome.tabs.update(tabId, { active: true });
  return { tabId };
}

async function tabsFilter({ pattern }) {
  const all = await chrome.tabs.query({});
  return all.filter(t => t.url && t.url.includes(pattern)).map(tabInfo);
}

async function tabsCount({ pattern }) {
  const all = await chrome.tabs.query({});
  if (pattern) return all.filter(t => t.url && t.url.includes(pattern)).length;
  return all.length;
}

async function tabsQuery({ search }) {
  const q = search.toLowerCase();
  const all = await chrome.tabs.query({});
  return all.filter(t =>
    (t.url && t.url.toLowerCase().includes(q)) ||
    (t.title && t.title.toLowerCase().includes(q))
  ).map(tabInfo);
}

async function executeScript(options, retries = 3) {
  for (let i = 0; i < retries; i++) {
    try {
      return await chrome.scripting.executeScript(options);
    } catch (e) {
      if (i < retries - 1 && e.message && (e.message.includes("Frame with ID") || e.message.includes("No tab with id")) && !e.message.includes("error page")) {
        await new Promise(r => setTimeout(r, 300));
        continue;
      }
      throw e;
    }
  }
}

async function tabsHtml({ tabId }) {
  for (let i = 0; i < 3; i++) {
    const tab = tabId ? await chrome.tabs.get(tabId) : await getActiveTab();
    if (!isScriptableUrl(tab.url || tab.pendingUrl || "")) {
      throw new Error(`Cannot get HTML of ${tab.url || tab.pendingUrl} — navigate to a regular web page first`);
    }
    try {
      const results = await executeScript({
        target: { tabId: tab.id },
        func: () => document.documentElement.outerHTML,
      });
      return results[0]?.result || "";
    } catch (e) {
      const transient = e.message && (e.message.includes("Frame with ID") || e.message.includes("No tab with id")) && !e.message.includes("error page");
      if (i < 2 && transient) {
        await new Promise(r => setTimeout(r, 300));
        continue;
      }
      throw e;
    }
  }
}

async function tabsDedupe() {
  return tabsClose({ duplicates: true });
}

async function tabsSort({ by }) {
  const windows = await chrome.windows.getAll({ populate: true });
  let moved = 0;
  for (const w of windows) {
    const sorted = [...w.tabs].sort((a, b) => {
      if (by === "title") return (a.title || "").localeCompare(b.title || "");
      if (by === "time")  return a.id - b.id; // lower id = opened earlier
      // domain (default)
      const da = new URL(a.url || "about:blank").hostname;
      const db = new URL(b.url || "about:blank").hostname;
      return da.localeCompare(db);
    });
    for (let i = 0; i < sorted.length; i++) {
      await chrome.tabs.move(sorted[i].id, { index: i });
      moved++;
    }
  }
  return { moved };
}

async function tabsMergeWindows() {
  const [focused] = await chrome.windows.getAll({ populate: false });
  const current = await chrome.windows.getCurrent();
  const all = await chrome.windows.getAll({ populate: true });
  let moved = 0;
  for (const w of all) {
    if (w.id === current.id) continue;
    const ids = w.tabs.map(t => t.id);
    await chrome.tabs.move(ids, { windowId: current.id, index: -1 });
    moved += ids.length;
  }
  return { moved };
}

function tabInfo(t) {
  return { id: t.id, windowId: t.windowId, active: t.active, title: t.title, url: t.url };
}

// ── Groups ────────────────────────────────────────────────────────────────────

async function groupList() {
  const groups = await chrome.tabGroups.query({});
  const all = await chrome.tabs.query({});
  return groups.map(g => ({
    id: g.id,
    title: g.title,
    color: g.color,
    collapsed: g.collapsed,
    windowId: g.windowId,
    tabCount: all.filter(t => t.groupId === g.id).length,
  }));
}

async function groupTabs({ groupId }) {
  const all = await chrome.tabs.query({});
  return all.filter(t => t.groupId === groupId).map(tabInfo);
}

async function groupCount() {
  const groups = await chrome.tabGroups.query({});
  return groups.length;
}

async function groupQuery({ search }) {
  const q = search.toLowerCase();
  const groups = await chrome.tabGroups.query({});
  return groups.filter(g => g.title && g.title.toLowerCase().includes(q));
}

async function groupClose({ groupId }) {
  const tabs = await chrome.tabs.query({});
  const groupTabs = tabs.filter(t => t.groupId === groupId);
  await chrome.tabs.ungroup(groupTabs.map(t => t.id));
  return { groupId };
}

async function groupOpen({ name }) {
  const tab = await chrome.tabs.create({ active: true });
  const groupId = await chrome.tabs.group({ tabIds: [tab.id] });
  await chrome.tabGroups.update(groupId, { title: name });
  return { id: groupId, name };
}

async function groupAddTab({ group, url }) {
  const groupId = await resolveGroupId(group);
  const existingTabs = await chrome.tabs.query({ groupId });
  const tab = await chrome.tabs.create({ url: url || "chrome://newtab/", active: true });
  await chrome.tabs.group({ tabIds: [tab.id], groupId });
  // If a URL was provided, close any blank placeholder tabs left from group creation
  if (url) {
    const placeholders = existingTabs.filter(t =>
      t.url === "chrome://newtab/" || t.url === "about:blank" || t.pendingUrl === "chrome://newtab/"
    );
    if (placeholders.length) await chrome.tabs.remove(placeholders.map(t => t.id));
  }
  return { tabId: tab.id, groupId };
}

async function groupMove({ group, forward, backward }) {
  const groupId = await resolveGroupId(group);
  const groupInfo = await chrome.tabGroups.get(groupId);
  const allTabs = await chrome.tabs.query({ windowId: groupInfo.windowId });
  allTabs.sort((a, b) => a.index - b.index);

  const groupTabs = allTabs.filter(t => t.groupId === groupId);
  if (!groupTabs.length) throw new Error(`No tabs found in group '${group}'`);

  const firstIdx = groupTabs[0].index;
  const lastIdx  = groupTabs[groupTabs.length - 1].index;

  if (forward) {
    const tabAfter = allTabs.find(t => t.index > lastIdx && t.groupId !== groupId);
    if (!tabAfter) return { groupId, moved: false };
    await chrome.tabs.move(groupTabs.map(t => t.id), { index: tabAfter.index + 1 });
  } else if (backward) {
    const tabsBefore = allTabs.filter(t => t.index < firstIdx && t.groupId !== groupId);
    const tabBefore = tabsBefore[tabsBefore.length - 1];
    if (!tabBefore) return { groupId, moved: false };
    await chrome.tabs.move(groupTabs.map(t => t.id), { index: tabBefore.index });
  }
  return { groupId, moved: true };
}

// ── Windows ───────────────────────────────────────────────────────────────────

async function windowsList() {
  const windows = await chrome.windows.getAll({ populate: true });
  const aliases = await getAliases();
  return windows.map(w => ({
    id: w.id,
    alias: aliases[w.id] || null,
    focused: w.focused,
    state: w.state,
    tabCount: (w.tabs || []).length,
  }));
}

async function windowsRename({ windowId, name }) {
  const aliases = await getAliases();
  aliases[windowId] = name;
  await chrome.storage.local.set({ windowAliases: aliases });
  return { windowId, name };
}

async function windowsClose({ windowId }) {
  await chrome.windows.remove(windowId);
  return { windowId };
}

async function windowsOpen({ profile }) {
  // profile support requires launching Chrome with --profile-directory which
  // isn't possible from within an extension — we open a plain new window.
  const w = await chrome.windows.create({ focused: true });
  return { id: w.id };
}

// ── DOM / Extract ─────────────────────────────────────────────────────────────

function isScriptableUrl(url) {
  if (!url) return false;
  return !url.startsWith("chrome://") &&
         !url.startsWith("brave://") &&
         !url.startsWith("about:") &&
         !url.startsWith("edge://") &&
         !url.startsWith("chrome-extension://");
}

async function domOp(funcName, args) {
  const tab = await getActiveTab();
  if (!isScriptableUrl(tab.url)) {
    throw new Error(`Cannot run DOM commands on ${tab.url} — navigate to a regular web page first`);
  }
  const results = await executeScript({
    target: { tabId: tab.id },
    func: contentDispatch,
    args: [funcName, args],
  });
  return results[0]?.result;
}

// This function is serialized and injected into the page by chrome.scripting
function contentDispatch(funcName, args) {
  function domQuery({ selector }) {
    return Array.from(document.querySelectorAll(selector)).map(el => ({
      tag: el.tagName.toLowerCase(),
      text: el.textContent.trim().slice(0, 200),
      attrs: Object.fromEntries(Array.from(el.attributes).map(a => [a.name, a.value])),
    }));
  }
  function domClick({ selector }) {
    const el = document.querySelector(selector);
    if (!el) throw new Error(`No element: ${selector}`);
    el.click();
    return true;
  }
  function domType({ selector, text }) {
    const el = document.querySelector(selector);
    if (!el) throw new Error(`No element: ${selector}`);
    el.focus();
    el.value = text;
    el.dispatchEvent(new Event("input", { bubbles: true }));
    el.dispatchEvent(new Event("change", { bubbles: true }));
    return true;
  }
  function domAttr({ selector, attr }) {
    return Array.from(document.querySelectorAll(selector))
      .map(el => el.getAttribute(attr))
      .filter(v => v !== null);
  }
  function domText({ selector }) {
    return Array.from(document.querySelectorAll(selector))
      .map(el => el.textContent.trim())
      .filter(Boolean);
  }
  function domExists({ selector }) {
    return document.querySelector(selector) !== null;
  }
  function extractLinks() {
    return Array.from(document.querySelectorAll("a[href]")).map(a => ({
      text: a.textContent.trim().slice(0, 100),
      href: a.href,
    }));
  }
  function extractImages() {
    return Array.from(document.querySelectorAll("img")).map(img => {
      const src =
        img.src ||
        img.getAttribute("data-src") ||
        img.getAttribute("data-lazy-src") ||
        img.getAttribute("data-original") ||
        (img.srcset ? img.srcset.split(",")[0].trim().split(" ")[0] : "") ||
        "";
      const FAKE_ALT = new Set(["true", "false", "null", "undefined", "image", "img"]);
      const alt = img.alt && !FAKE_ALT.has(img.alt.trim().toLowerCase()) ? img.alt.trim() : "";
      return { alt, src };
    }).filter(img => img.src !== "");
  }
  function extractText() {
    return document.body.innerText;
  }
  function extractJson({ selector }) {
    const el = document.querySelector(selector);
    if (!el) throw new Error(`No element: ${selector}`);
    return JSON.parse(el.textContent);
  }

  const fns = { domQuery, domClick, domType, domAttr, domText, domExists,
                 extractLinks, extractImages, extractText, extractJson };
  const fn = fns[funcName];
  if (!fn) throw new Error(`Unknown content function: ${funcName}`);
  return fn(args);
}

// ── Session ───────────────────────────────────────────────────────────────────

async function sessionSave({ name }) {
  const tabs = await chrome.tabs.query({});
  const urls = tabs.map(t => t.url).filter(Boolean);
  const sessions = await getSessions();
  sessions[name] = { urls, savedAt: Date.now() };
  await chrome.storage.local.set({ sessions });
  return { name, tabs: urls.length };
}

async function sessionLoad({ name }) {
  const sessions = await getSessions();
  const session = sessions[name];
  if (!session) throw new Error(`Session '${name}' not found`);
  for (const url of session.urls) {
    await chrome.tabs.create({ url, active: false });
  }
  return { name, tabs: session.urls.length };
}

async function sessionList() {
  const sessions = await getSessions();
  return Object.entries(sessions).map(([name, s]) => ({
    name,
    tabs: (s.urls || []).length,
    savedAt: s.savedAt || null,
  }));
}

async function sessionRemove({ name }) {
  const sessions = await getSessions();
  if (!(name in sessions)) throw new Error(`Session '${name}' not found`);
  delete sessions[name];
  await chrome.storage.local.set({ sessions });
  return { name };
}

async function sessionDiff({ nameA, nameB }) {
  const sessions = await getSessions();
  const a = new Set((sessions[nameA]?.urls) || []);
  const b = new Set((sessions[nameB]?.urls) || []);
  return {
    added:   [...b].filter(u => !a.has(u)),
    removed: [...a].filter(u => !b.has(u)),
  };
}

async function sessionAutoSave({ enabled }) {
  await chrome.storage.local.set({ autoSave: enabled });
  if (enabled) {
    chrome.tabs.onUpdated.addListener(autoSaveHandler);
    chrome.tabs.onRemoved.addListener(autoSaveHandler);
  }
  return { enabled };
}

async function autoSaveHandler() {
  const { autoSave } = await chrome.storage.local.get("autoSave");
  if (!autoSave) return;
  await sessionSave({ name: "__auto__" });
}

// ── Misc ──────────────────────────────────────────────────────────────────────

async function clientsList() {
  const manifest = chrome.runtime.getManifest();
  const alias = await getProfileAlias();
  return [{
    name: "Chrome",
    version: navigator.userAgent.match(/Chrome\/([\d.]+)/)?.[1] || "unknown",
    platform: navigator.platform,
    extensionVersion: manifest.version,
    profile: alias,
  }];
}

async function clientsRenameProfile({ alias }) {
  await chrome.storage.local.set({ profileAlias: alias });
  return { alias };
}

// ── Helpers ───────────────────────────────────────────────────────────────────

async function getActiveTab() {
  const [tab] = await chrome.tabs.query({ active: true, lastFocusedWindow: true });
  if (!tab) throw new Error("No active tab found");
  return tab;
}

async function resolveGroupId(nameOrId) {
  const asInt = parseInt(nameOrId);
  if (!isNaN(asInt)) return asInt;
  const groups = await chrome.tabGroups.query({});
  const match = groups.find(g => g.title && g.title.toLowerCase() === String(nameOrId).toLowerCase());
  if (!match) throw new Error(`No tab group found with name '${nameOrId}'`);
  return match.id;
}

async function getAliases() {
  const { windowAliases } = await chrome.storage.local.get("windowAliases");
  return windowAliases || {};
}

async function getSessions() {
  const { sessions } = await chrome.storage.local.get("sessions");
  return sessions || {};
}