const ext = globalThis.browser ?? globalThis.chrome;
const nativeHost = "com.keepassgo.browser";
const isNodeTestEnv = typeof module !== "undefined" && module.exports;
const usePromiseAPI = typeof globalThis.browser !== "undefined";
const defaultSettings = {
  bearerToken: ""
};
const pageStatePrefix = "keepassgo-page-state:";
const matchCacheTTL = 30 * 1000;
const pendingPollMillis = 1500;
const pageStates = new Map();
const refreshJobs = new Map();
const pendingPollers = new Map();

function storageGet(keys) {
  if (usePromiseAPI) {
    return ext.storage.local.get(keys);
  }
  return new Promise((resolve, reject) => {
    ext.storage.local.get(keys, (value) => {
      const error = ext.runtime.lastError;
      if (error) {
        reject(new Error(error.message));
        return;
      }
      resolve(value);
    });
  });
}

function storageSet(value) {
  if (usePromiseAPI) {
    return ext.storage.local.set(value);
  }
  return new Promise((resolve, reject) => {
    ext.storage.local.set(value, () => {
      const error = ext.runtime.lastError;
      if (error) {
        reject(new Error(error.message));
        return;
      }
      resolve();
    });
  });
}

function sessionArea() {
  return ext.storage?.session ?? null;
}

function sessionStorageGet(keys) {
  const area = sessionArea();
  if (!area) {
    return Promise.resolve({});
  }
  if (usePromiseAPI) {
    return area.get(keys).then((value) => value || {});
  }
  return new Promise((resolve, reject) => {
    area.get(keys, (value) => {
      const error = ext.runtime.lastError;
      if (error) {
        reject(new Error(error.message));
        return;
      }
      resolve(value || {});
    });
  });
}

function sessionStorageSet(value) {
  const area = sessionArea();
  if (!area) {
    return Promise.resolve();
  }
  if (usePromiseAPI) {
    return area.set(value);
  }
  return new Promise((resolve, reject) => {
    area.set(value, () => {
      const error = ext.runtime.lastError;
      if (error) {
        reject(new Error(error.message));
        return;
      }
      resolve();
    });
  });
}

function sessionStorageRemove(keys) {
  const area = sessionArea();
  if (!area) {
    return Promise.resolve();
  }
  if (usePromiseAPI) {
    return area.remove(keys);
  }
  return new Promise((resolve, reject) => {
    area.remove(keys, () => {
      const error = ext.runtime.lastError;
      if (error) {
        reject(new Error(error.message));
        return;
      }
      resolve();
    });
  });
}

function tabsQuery(query) {
  if (usePromiseAPI) {
    return ext.tabs.query(query);
  }
  return new Promise((resolve, reject) => {
    ext.tabs.query(query, (tabs) => {
      const error = ext.runtime.lastError;
      if (error) {
        reject(new Error(error.message));
        return;
      }
      resolve(tabs);
    });
  });
}

function tabsGet(tabId) {
  if (usePromiseAPI) {
    return ext.tabs.get(tabId);
  }
  return new Promise((resolve, reject) => {
    ext.tabs.get(tabId, (tab) => {
      const error = ext.runtime.lastError;
      if (error) {
        reject(new Error(error.message));
        return;
      }
      resolve(tab);
    });
  });
}

function tabsSendMessage(tabId, message) {
  if (usePromiseAPI) {
    return ext.tabs.sendMessage(tabId, message);
  }
  return new Promise((resolve, reject) => {
    ext.tabs.sendMessage(tabId, message, (response) => {
      const error = ext.runtime.lastError;
      if (error) {
        reject(new Error(error.message));
        return;
      }
      resolve(response);
    });
  });
}

function connectNative(message) {
  if (usePromiseAPI) {
    return ext.runtime.sendNativeMessage(nativeHost, message);
  }
  return new Promise((resolve, reject) => {
    ext.runtime.sendNativeMessage(nativeHost, message, (response) => {
      const error = ext.runtime.lastError;
      if (error) {
        reject(new Error(error.message));
        return;
      }
      resolve(response);
    });
  });
}

async function loadSettings() {
  const stored = await storageGet(["bearerToken"]);
  return {
    bearerToken: (stored.bearerToken || defaultSettings.bearerToken).trim()
  };
}

function supportsPageStateURL(rawURL) {
  return typeof rawURL === "string" && /^https?:\/\//i.test(rawURL);
}

function pageStateKey(tabId) {
  return `${pageStatePrefix}${String(tabId)}`;
}

function cloneTarget(target) {
  return target && typeof target === "object" ? { ...target } : null;
}

function normalizePageState(state) {
  return {
    tabId: Number.isInteger(state?.tabId) ? state.tabId : null,
    pageUrl: typeof state?.pageUrl === "string" ? state.pageUrl : "",
    configured: Boolean(state?.configured),
    success: state?.success !== false,
    status: state?.status ?? null,
    matches: Array.isArray(state?.matches) ? state.matches : [],
    error: typeof state?.error === "string" ? state.error : "",
    pageHasLoginForm: Boolean(state?.pageHasLoginForm),
    signature: typeof state?.signature === "string" ? state.signature : "",
    focusTarget: cloneTarget(state?.focusTarget),
    pendingFill: Boolean(state?.pendingFill),
    pendingEntryId: typeof state?.pendingEntryId === "string" ? state.pendingEntryId : "",
    pendingTarget: cloneTarget(state?.pendingTarget),
    pendingMessage: typeof state?.pendingMessage === "string" ? state.pendingMessage : "",
    lastFilledEntryId: typeof state?.lastFilledEntryId === "string" ? state.lastFilledEntryId : "",
    updatedAt: Number.isFinite(state?.updatedAt) ? state.updatedAt : 0
  };
}

function defaultPageState(tabId, pageUrl) {
  return normalizePageState({
    tabId,
    pageUrl,
    configured: true,
    success: true,
    status: null,
    matches: [],
    error: "",
    pageHasLoginForm: false,
    signature: "",
    focusTarget: null,
    pendingFill: false,
    pendingEntryId: "",
    pendingTarget: null,
    pendingMessage: "",
    lastFilledEntryId: "",
    updatedAt: 0
  });
}

async function getPageState(tabId, pageUrl) {
  if (!Number.isInteger(tabId)) {
    return defaultPageState(null, pageUrl || "");
  }
  const existing = pageStates.get(tabId);
  if (existing && (!pageUrl || existing.pageUrl === pageUrl)) {
    return normalizePageState(existing);
  }
  const stored = await sessionStorageGet(pageStateKey(tabId));
  const state = normalizePageState(stored[pageStateKey(tabId)] || defaultPageState(tabId, pageUrl || ""));
  if (pageUrl && state.pageUrl !== pageUrl) {
    return defaultPageState(tabId, pageUrl);
  }
  pageStates.set(tabId, state);
  return state;
}

async function setPageState(tabId, nextState) {
  const state = normalizePageState({ ...nextState, tabId });
  if (!Number.isInteger(tabId)) {
    return state;
  }
  pageStates.set(tabId, state);
  await sessionStorageSet({ [pageStateKey(tabId)]: state });
  await updateActionState(tabId, state);
  await notifyContentState(tabId, state);
  return state;
}

function clearPendingPoll(tabId) {
  const timer = pendingPollers.get(tabId);
  if (timer !== undefined) {
    clearTimeout(timer);
    pendingPollers.delete(tabId);
  }
}

async function clearPageState(tabId) {
  if (!Number.isInteger(tabId)) {
    return;
  }
  pageStates.delete(tabId);
  refreshJobs.delete(tabId);
  clearPendingPoll(tabId);
  await sessionStorageRemove(pageStateKey(tabId));
  await clearActionState(tabId);
}

function describeError(error) {
  return error instanceof Error ? error.message : String(error || "Unknown error");
}

function approvalHintForState(state) {
  if (!state.pendingFill) {
    return "";
  }
  return state.pendingMessage || "Approve or deny the fill request in KeePassGO.";
}

function schedulePendingPoll(tabId, pageUrl) {
  if (!Number.isInteger(tabId)) {
    return;
  }
  clearPendingPoll(tabId);
  const timer = setTimeout(() => {
    pendingPollers.delete(tabId);
    void refreshPageState(tabId, pageUrl, { force: true }).catch(() => null);
  }, pendingPollMillis);
  pendingPollers.set(tabId, timer);
}

async function notifyContentState(tabId, state) {
  if (!Number.isInteger(tabId)) {
    return;
  }
  try {
    await tabsSendMessage(tabId, {
      type: "keepassgo-page-state",
      state
    });
  } catch (_error) {
    // Ignore pages without a ready content script.
  }
}

async function clearActionState(tabId) {
  if (!Number.isInteger(tabId) || !ext.action) {
    return;
  }
  await Promise.allSettled([
    ext.action.setBadgeText({ tabId, text: "" }),
    ext.action.setTitle({ tabId, title: "KeePassGO Browser" })
  ]);
}

function actionPresentationForState(state) {
  let badgeText = "";
  let title = "KeePassGO Browser";
  let color = "#255f4a";

  if (state.pendingFill) {
    badgeText = "!";
    color = "#9f5f0e";
    title = approvalHintForState(state) || "KeePassGO approval needed for this page";
  } else if (!state.configured) {
    title = "Configure KeePassGO Browser in extension settings";
  } else if (!state.success) {
    badgeText = "!";
    color = "#9f2f2f";
    title = state.error || "KeePassGO is unavailable for this page";
  } else if (state.status?.locked) {
    title = "Unlock KeePassGO to fill this page";
  } else if (state.pageHasLoginForm && state.matches.length > 0) {
    badgeText = String(Math.min(state.matches.length, 9));
    title = `KeePassGO found ${state.matches.length} matching entr${state.matches.length === 1 ? "y" : "ies"} on this page`;
  } else if (state.pageHasLoginForm) {
    title = "KeePassGO found no matching entries on this page";
  }

  return { badgeText, title, color };
}

async function updateActionState(tabId, state) {
  if (!Number.isInteger(tabId) || !ext.action) {
    return;
  }
  const presentation = actionPresentationForState(state);
  await Promise.allSettled([
    ext.action.setBadgeText({ tabId, text: presentation.badgeText }),
    ext.action.setBadgeBackgroundColor({ tabId, color: presentation.color }),
    ext.action.setTitle({ tabId, title: presentation.title })
  ]);
}

async function activePageContext() {
  const [tab] = await tabsQuery({ active: true, currentWindow: true });
  return {
    tabId: Number.isInteger(tab?.id) ? tab.id : null,
    url: typeof tab?.url === "string" ? tab.url : ""
  };
}

async function scanTabForLoginForm(tabId) {
  if (!Number.isInteger(tabId)) {
    return { pageHasLoginForm: false, focusTarget: null, signature: "" };
  }
  try {
    const response = await tabsSendMessage(tabId, { type: "keepassgo-page-scan" });
    return {
      pageHasLoginForm: Boolean(response?.pageHasLoginForm),
      focusTarget: cloneTarget(response?.focusTarget),
      signature: typeof response?.signature === "string" ? response.signature : ""
    };
  } catch (_error) {
    return { pageHasLoginForm: false, focusTarget: null, signature: "" };
  }
}

function shouldReuseMatches(state, force) {
  if (force || state.pendingFill) {
    return false;
  }
  if (!state.pageHasLoginForm || !Array.isArray(state.matches)) {
    return false;
  }
  return Date.now() - (state.updatedAt || 0) < matchCacheTTL;
}

function tokenPendingApprovalCount(status) {
  return Number(status?.tokenPendingApprovalCount || 0);
}

async function fetchStatus(settings) {
  if (!settings.bearerToken) {
    return {
      success: false,
      configured: false,
      status: null,
      error: "Set an API token in extension settings."
    };
  }
  const status = await connectNative({
    action: "status",
    bearerToken: settings.bearerToken
  });
  return {
    success: Boolean(status?.success),
    configured: true,
    status: status?.status ?? null,
    error: status?.error ?? ""
  };
}

async function refreshPageState(tabId, pageUrl, options = {}) {
  if (!Number.isInteger(tabId)) {
    return defaultPageState(null, pageUrl || "");
  }
  const force = Boolean(options.force);
  const existingJob = refreshJobs.get(tabId);
  if (existingJob && !force) {
    return existingJob;
  }

  const job = (async () => {
    let resolvedURL = typeof pageUrl === "string" ? pageUrl : "";
    if (!supportsPageStateURL(resolvedURL)) {
      const tab = await tabsGet(tabId).catch(() => null);
      resolvedURL = typeof tab?.url === "string" ? tab.url : resolvedURL;
    }
    if (!supportsPageStateURL(resolvedURL)) {
      await clearPageState(tabId);
      return defaultPageState(tabId, resolvedURL || "");
    }

    let state = await getPageState(tabId, resolvedURL);
    if (state.pageUrl !== resolvedURL) {
      state = defaultPageState(tabId, resolvedURL);
    }

    const scan = typeof options.pageHasLoginForm === "boolean"
      ? {
        pageHasLoginForm: options.pageHasLoginForm,
        focusTarget: cloneTarget(options.focusTarget) || state.focusTarget,
        signature: typeof options.signature === "string" ? options.signature : state.signature
      }
      : await scanTabForLoginForm(tabId);

    state = {
      ...state,
      pageUrl: resolvedURL,
      pageHasLoginForm: scan.pageHasLoginForm,
      focusTarget: cloneTarget(scan.focusTarget) || state.focusTarget,
      signature: typeof scan.signature === "string" ? scan.signature : state.signature
    };

    const settings = await loadSettings();
    const statusInfo = await fetchStatus(settings).catch((error) => ({
      success: false,
      configured: true,
      status: null,
      error: describeError(error)
    }));

    state = {
      ...state,
      configured: statusInfo.configured,
      success: statusInfo.success,
      status: statusInfo.status,
      pendingFill: state.pendingFill || tokenPendingApprovalCount(statusInfo.status) > 0,
      pendingMessage: tokenPendingApprovalCount(statusInfo.status) > 0
        ? approvalHintForState(state) || "Approve or deny the browser fill request in KeePassGO."
        : "",
      error: statusInfo.error
    };

    if (!statusInfo.configured || !statusInfo.success || statusInfo.status?.locked || !state.pageHasLoginForm) {
      state.matches = [];
      state.updatedAt = Date.now();
      const saved = await setPageState(tabId, state);
      if (saved.pendingFill) {
        schedulePendingPoll(tabId, resolvedURL);
      } else {
        clearPendingPoll(tabId);
      }
      return saved;
    }

    if (shouldReuseMatches(state, force)) {
      const saved = await setPageState(tabId, state);
      if (saved.pendingFill) {
        schedulePendingPoll(tabId, resolvedURL);
      } else {
        clearPendingPoll(tabId);
      }
      return saved;
    }

    const matches = await connectNative({
      action: "find-logins",
      bearerToken: settings.bearerToken,
      url: resolvedURL
    });

    state = {
      ...state,
      success: Boolean(matches?.success),
      status: matches?.status ?? state.status,
      pendingFill: state.pendingFill || tokenPendingApprovalCount(matches?.status ?? state.status) > 0,
      pendingMessage: tokenPendingApprovalCount(matches?.status ?? state.status) > 0
        ? approvalHintForState(state) || "Approve or deny the browser fill request in KeePassGO."
        : "",
      matches: Array.isArray(matches?.matches) ? matches.matches : [],
      error: matches?.error ?? "",
      updatedAt: Date.now()
    };
    const saved = await setPageState(tabId, state);
    if (saved.pendingFill) {
      schedulePendingPoll(tabId, resolvedURL);
    } else {
      clearPendingPoll(tabId);
    }
    return saved;
  })().finally(() => {
    if (refreshJobs.get(tabId) === job) {
      refreshJobs.delete(tabId);
    }
  });

  refreshJobs.set(tabId, job);
  return job;
}

async function statusForPage(options = {}) {
  let page = await activePageContext();
  if (Number.isInteger(options.tabId)) {
    const tab = await tabsGet(options.tabId).catch(() => null);
    page = {
      tabId: options.tabId,
      url: typeof tab?.url === "string" ? tab.url : ""
    };
  }
  if (page.tabId == null) {
    return defaultPageState(null, page.url);
  }
  if (!options.force) {
    const cached = await getPageState(page.tabId, page.url);
    if (cached.pageUrl === page.url && cached.updatedAt && !cached.pendingFill) {
      return cached;
    }
  }
  return refreshPageState(page.tabId, page.url, options);
}

async function fillLogin(tabId, entryId) {
  if (!Number.isInteger(tabId)) {
    throw new Error("No active tab is available.");
  }
  const tab = await tabsGet(tabId);
  const pageUrl = typeof tab?.url === "string" ? tab.url : "";
  if (!supportsPageStateURL(pageUrl)) {
    throw new Error("This page cannot be filled.");
  }

  let state = await getPageState(tabId, pageUrl);
  state = await setPageState(tabId, {
    ...state,
    pageUrl,
    pendingFill: true,
    pendingEntryId: String(entryId || "").trim(),
    pendingTarget: cloneTarget(state.focusTarget),
    pendingMessage: "Approve or deny the browser fill request in KeePassGO.",
    error: "",
    updatedAt: Date.now()
  });
  schedulePendingPoll(tabId, pageUrl);

  try {
    const settings = await loadSettings();
    if (!settings.bearerToken) {
      throw new Error("API token is not configured.");
    }

    const response = await connectNative({
      action: "get-login",
      bearerToken: settings.bearerToken,
      entryId,
      url: pageUrl
    });
    if (!response?.success || !response.credential) {
      throw new Error(response?.error || "KeePassGO did not return a credential.");
    }

    const fillResponse = await tabsSendMessage(tabId, {
      type: "keepassgo-fill-credential",
      credential: response.credential,
      target: state.pendingTarget
    });
    if (!fillResponse?.ok) {
      throw new Error(fillResponse?.error || "The current page could not be filled.");
    }

    state = await setPageState(tabId, {
      ...state,
      pendingFill: false,
      pendingEntryId: "",
      pendingTarget: null,
      pendingMessage: "",
      lastFilledEntryId: String(entryId || "").trim(),
      error: "",
      updatedAt: Date.now()
    });
    clearPendingPoll(tabId);
    return {
      credential: response.credential,
      pageUrl,
      state
    };
  } catch (error) {
    state = await setPageState(tabId, {
      ...state,
      pendingFill: false,
      pendingEntryId: "",
      pendingTarget: null,
      pendingMessage: "",
      error: describeError(error),
      updatedAt: Date.now()
    });
    clearPendingPoll(tabId);
    throw error;
  }
}

async function refreshActivePage(options = {}) {
  const page = await activePageContext();
  if (page.tabId == null) {
    return defaultPageState(null, page.url);
  }
  return refreshPageState(page.tabId, page.url, options);
}

const backgroundTestExports = {
  normalizePageState,
  actionPresentationForState,
  shouldReuseMatches,
  tokenPendingApprovalCount,
  defaultSettings
};

if (isNodeTestEnv) {
  module.exports = backgroundTestExports;
} else {
  ext.runtime.onMessage.addListener((message, sender, sendResponse) => {
    (async () => {
      switch (message?.type) {
        case "keepassgo-popup-state":
          sendResponse(await statusForPage({
            force: Boolean(message.force),
            tabId: Number.isInteger(message?.tabId) ? message.tabId : null
          }));
          return;
        case "keepassgo-fill-entry": {
          const targetTabID = Number.isInteger(message?.tabId)
            ? message.tabId
            : (Number.isInteger(sender?.tab?.id) ? sender.tab.id : (await activePageContext()).tabId);
          if (Number.isInteger(targetTabID) && message.target) {
            const targetState = await getPageState(targetTabID, "");
            await setPageState(targetTabID, {
              ...targetState,
              focusTarget: cloneTarget(message.target)
            });
          }
          sendResponse({ success: true, ...(await fillLogin(targetTabID, message.entryId)) });
          return;
        }
        case "keepassgo-load-settings":
          sendResponse({ success: true, settings: await loadSettings() });
          return;
        case "keepassgo-save-settings":
          await storageSet({
            bearerToken: String(message.settings?.bearerToken || "").trim()
          });
          await refreshActivePage({ force: true }).catch(() => null);
          sendResponse({ success: true });
          return;
        case "keepassgo-page-ready":
          if (Number.isInteger(sender?.tab?.id)) {
            sendResponse(await refreshPageState(sender.tab.id, sender.tab.url, {
              force: Boolean(message.force),
              pageHasLoginForm: Boolean(message.pageHasLoginForm),
              focusTarget: cloneTarget(message.focusTarget),
              signature: typeof message.signature === "string" ? message.signature : ""
            }));
            return;
          }
          sendResponse(defaultPageState(null, ""));
          return;
        case "keepassgo-refresh-page-state":
          if (Number.isInteger(sender?.tab?.id)) {
            sendResponse(await refreshPageState(sender.tab.id, sender.tab.url, { force: true }));
            return;
          }
          sendResponse(defaultPageState(null, ""));
          return;
        default:
          sendResponse({ success: false, error: `Unsupported message ${message?.type || ""}`.trim() });
      }
    })().catch((error) => {
      sendResponse({ success: false, error: describeError(error) });
    });
    return true;
  });

  ext.tabs?.onActivated?.addListener(({ tabId }) => {
    void refreshPageState(tabId, "", { force: false }).catch(() => null);
  });

  ext.tabs?.onUpdated?.addListener((tabId, changeInfo, tab) => {
    if (typeof changeInfo.url === "string") {
      void clearPageState(tabId).catch(() => null);
    }
    if (changeInfo.status === "complete") {
      void refreshPageState(tabId, tab?.url || changeInfo.url || "", { force: false }).catch(() => null);
    }
  });

  ext.tabs?.onRemoved?.addListener((tabId) => {
    void clearPageState(tabId).catch(() => null);
  });
}