// Housecarl web UI: router, layout, login and the probation banner.
import { h, mount, toast, errorBox, modal } from "./ui.js";
import { wordmark, logo } from "./brand.js";
import { api, get, state, can, setUnauthorizedHandler, setChangeHandler, loadDraft, onDraftChange, setImmediate, useDraft } from "./api.js";
import * as changes from "./pages/changes.js";
import * as dashboard from "./pages/dashboard.js";
import * as rules from "./pages/rules.js";
import * as nat from "./pages/nat.js";
import * as zones from "./pages/zones.js";
import * as sets from "./pages/sets.js";
import * as services from "./pages/services.js";
import * as log from "./pages/log.js";
import * as settings from "./pages/settings.js";
import * as importPage from "./pages/import.js";
import * as history from "./pages/history.js";
import * as audit from "./pages/audit.js";
import * as users from "./pages/users.js";
import * as account from "./pages/account.js";
import * as certificate from "./pages/certificate.js";

const routes = [
  { pattern: /^$/, page: dashboard, nav: "dashboard" },
  { pattern: /^rules$/, page: rules, nav: "rules" },
  { pattern: /^nat$/, page: nat, nav: "nat" },
  { pattern: /^zones$/, page: zones, nav: "zones" },
  { pattern: /^sets$/, page: sets, nav: "sets" },
  { pattern: /^services$/, page: services, nav: "services" },
  { pattern: /^log$/, page: log, nav: "log" },
  { pattern: /^settings$/, page: settings, nav: "settings" },
  { pattern: /^import$/, page: importPage, nav: "import" },
  { pattern: /^changes$/, page: changes, nav: "changes" },
  { pattern: /^history$/, page: history, nav: "history" },
  { pattern: /^history\/(\d+)$/, page: history, nav: "history", params: ["id"] },
  { pattern: /^audit$/, page: audit, nav: "audit" },
  { pattern: /^users$/, page: users, nav: "users" },
  { pattern: /^account$/, page: account, nav: "account" },
  { pattern: /^certificate$/, page: certificate, nav: "certificate" },
];

// The top bar. ["key", "#/href", "Label", permission?]
const navItems = [
  ["dashboard", "#/", "Dashboard"],
  ["rules", "#/rules", "Rules", "config"],
  ["nat", "#/nat", "NAT", "config"],
  { menu: "Objects", items: [
    ["zones", "#/zones", "Zones", "config"],
    ["sets", "#/sets", "Address sets", "config"],
    ["services", "#/services", "Services", "config"],
  ] },
  ["log", "#/log", "Log", "log"],
  ["changes", "#/changes", "Changes", "config"],
  ["history", "#/history", "History", "config"],
  { menu: "Server", items: [
    ["settings", "#/settings", "Settings and built-ins", "config"],
    ["import", "#/import", "Import a ruleset", "config"],
    ["certificate", "#/certificate", "Certificate", "admin"],
    ["audit", "#/audit", "Audit log", "audit"],
  ] },
];

const app = document.getElementById("app");
let mainEl, navEl, bannerEl, barEl, modeHolder, current = { key: "" }, routeGen = 0;

function parseHash() {
  const raw = location.hash.replace(/^#\/?/, "");
  const [path, qs] = raw.split("?");
  return { path: path.replace(/\/$/, ""), query: new URLSearchParams(qs || "") };
}

function renderLogin(message) {
  const user = h("input", { name: "username", autocomplete: "username", placeholder: "Username", required: true });
  const pass = h("input", { name: "password", type: "password", autocomplete: "current-password", placeholder: "Password", required: true });
  const err = h("div");
  const form = h("form", { onsubmit: async (e) => {
    e.preventDefault();
    mount(err);
    try {
      const me = await api("POST", "/auth/login", { body: { username: user.value, password: pass.value } });
      await loggedIn(me);
    } catch (ex) {
      mount(err, errorBox(ex));
      pass.select();
    }
  } }, user, pass, h("button", { class: "primary", type: "submit" }, "Log in"), err);
  mount(app, h("div", { class: "login panel" },
    logo(120, { cls: "login-logo" }),
    h("h1", null, wordmark()),
    h("div", { class: "tag" }, "Keeper of the hold's door"),
    message ? h("div", { class: "msg warn" }, message) : null,
    form));
  user.focus();
}

async function loggedIn(me) {
  state.me = me;
  state.csrf = me.csrf_token || "";
  layout();
  onDraftChange(renderBar);
  if (can("config", true)) await loadDraft();
  window.addEventListener("hashchange", route);
  await route();
}

function layout() {
  navEl = h("nav", { class: "main" });
  mainEl = h("main");
  bannerEl = h("div", { class: "probation-banner hidden", role: "alert" });
  barEl = h("div");
  modeHolder = can("config", true) ? h("span") : null;
  const me = state.me;
  const header = h("header", { class: "top" },
    h("a", { class: "brand", href: "#/", title: "Dashboard" },
      logo(30, { small: true }),
      wordmark({ rule: false, height: 17, cls: "brand-name" })),
    navEl,
    h("div", { class: "header-right" },
      modeHolder,
      menu(h("span", { class: "user", title: (me.permissions || []).join("\n") }, me.user.username), [
        h("a", { href: "#/account" }, "Account"),
        me.admin ? h("a", { href: "#/users" }, "Users") : null,
        h("button", { type: "button", class: "menu-item", onclick: logout }, "Log out"),
      ], { right: true, active: ["account", "users"].includes(current.nav), label: "Account menu" })));
  mount(app, h("div", { class: "shell" }, header, barEl, bannerEl, mainEl, footer(me.build)));
  renderNav();
  refreshProbation();
}

// ---- pending changes: edits are staged for review (as in Jarl)

// renderBar shows the pending-changes bar (while there are pending
// changes) and the Review/Live switch in the header.
function renderBar() {
  if (!barEl) return;
  const d = state.draft;
  const n = d ? (d.ops || []).length : 0;
  if (modeHolder) {
    const live = state.immediate;
    mount(modeHolder, h("button", {
      type: "button", class: "mode-toggle" + (live ? " live" : ""), "aria-pressed": live ? "true" : "false",
      title: live ? "Edits are applied right away (each on probation over the network). Click to collect them for review first."
        : "Edits are collected as pending changes, reviewed with the ruleset's diff and applied together under Changes. Click to apply edits right away.",
      onclick: () => { setImmediate(!live); rerender(); },
    }, h("span", { class: "dot" }), live ? "Live edits" : "Review edits"));
  }
  mount(barEl, n > 0 && !state.immediate ? h("div", { class: "pending-bar" },
    h("strong", null, n === 1 ? "1 pending change" : n + " pending changes"),
    h("span", { class: "muted" }, "Collected in changeset #" + d.id + "; not in force yet."),
    h("a", { class: "button small", href: "#/changes" }, "Review"),
    h("button", { class: "primary small apply-now", title: "Apply the pending changes now, without reviewing them first", onclick: (ev) => applyDraft(ev.target, d) }, "Apply now")) : null);
}

// applyDraft applies the draft changeset from the bar and stays on the
// page. If it is refused, a dialog says why and leads to Changes.
export async function applyDraft(btn, d, description) {
  btn.disabled = true;
  const label = btn.textContent;
  btn.textContent = "Applying…";
  try {
    const r = await api("POST", "/changesets/" + d.id + "/apply", { body: { description: description || "" } });
    useDraft(null);
    if (r.confirm_by && !r.confirm_token) toast("Applied changeset #" + d.id + " on probation (history #" + r.history_id + "): confirm it in the banner", "warn", 8000);
    else toast("Applied changeset #" + d.id + " (history #" + r.history_id + ")");
    for (const w of r.warnings || []) toast(w.message + (w.object ? " (" + w.object + ")" : ""), "warn", 10000);
    if (r.confirm_token) await autoConfirm(r.confirm_token);
    else await refreshProbation();
    return r;
  } catch (e) {
    btn.disabled = false;
    btn.textContent = label;
    const review = await modal("The changes were not applied", errorBox(e), [{ label: "Close", value: false }, { label: "Review changes", kind: "primary", value: true }], { wide: true });
    if (review) location.hash = "#/changes";
    return null;
  } finally {
    rerender();
  }
}

// ---- probation: changes made here roll back unless confirmed

let probationTimer = null, deadline = 0, pending = 0, checking = false;

// autoConfirm confirms a change with its token. The server closed the
// change's connection, so this request opens a new one through the new
// ruleset: it only gets through if this browser can still reach
// Housecarl. If it can't, the change rolls back by itself.
export async function autoConfirm(token) {
  checking = true;
  await refreshProbation();
  try {
    await api("POST", "/confirm", { body: { token }, timeout: 10000 });
    checking = false;
    toast("Confirmed automatically: this browser reached Housecarl again over a new connection");
  } catch (e) {
    checking = false;
    toast("Couldn't confirm the change (" + (e.name === "AbortError" ? "no answer over a new connection" : e.message) + "): unless it is confirmed, it rolls back by itself", "warn", 10000);
  }
  await refreshProbation();
}

// refreshProbation asks whether changes wait for confirmation, and shows
// the banner with a countdown while they do.
export async function refreshProbation() {
  if (!bannerEl || !can("config", false)) return;
  let pr;
  try { pr = await get("/probation"); } catch { return; }
  pending = (pr.pending || []).length + (pr.takeovers || 0);
  deadline = Date.now() + (pr.seconds_left || 0) * 1000;
  drawBanner();
  clearInterval(probationTimer);
  if (pending) probationTimer = setInterval(drawBanner, 1000);
}

function drawBanner() {
  const left = Math.max(0, Math.round((deadline - Date.now()) / 1000));
  if (!pending) {
    bannerEl.classList.add("hidden");
    return;
  }
  if (left === 0) {
    // Rolled back by now: look again (and redraw the page).
    clearInterval(probationTimer);
    setTimeout(async () => { await refreshProbation(); rerender(); toast("The unconfirmed changes were rolled back", "warn", 8000); }, 1500);
  }
  bannerEl.classList.remove("hidden");
  const write = can("config", true);
  if (checking) {
    mount(bannerEl, h("strong", null, "Checking you can still reach Housecarl…"), " The change is confirmed once this browser gets through over a new connection.");
    return;
  }
  mount(bannerEl,
    h("strong", null, pending === 1 ? "1 change is on probation" : pending + " changes are on probation"),
    " — rolled back in ", h("span", { class: "mono" }, left + "s"), " unless you confirm them. If this page stops answering, wait: the firewall puts itself back.",
    write ? h("span", { class: "banner-actions" },
      h("button", { class: "primary small", onclick: async () => {
        try { await api("POST", "/confirm"); toast("Confirmed: kept, and loaded at boot"); } catch (e) { toast(e.message, "err"); }
        refreshProbation();
      } }, "Confirm"), " ",
      h("button", { class: "small", onclick: async () => {
        try { await api("POST", "/rollback"); toast("Rolled back", "warn"); } catch (e) { toast(e.message, "err"); }
        await refreshProbation();
        rerender();
      } }, "Roll back now")) : null);
}

// footer names the build: the release, or the commit for other builds.
function footer(b) {
  if (!b) return null;
  let title = b.tag ? "Housecarl " + b.version + " (release " + b.tag + ")" : "Housecarl " + b.version;
  if (!b.tag && b.commit) {
    title = "Development build of commit " + b.commit + (b.modified ? " with uncommitted changes" : "");
    if (b.since) title += b.ahead ? ", " + b.ahead + (b.ahead === 1 ? " commit" : " commits") + " after " + b.since : ", at " + b.since;
  }
  return h("footer", { class: "site" }, "Powered by ",
    h("a", { href: b.url, target: "_blank", rel: "noopener", title }, "Housecarl " + (b.tag || b.commit ? b.label : b.version)));
}

function renderNav() {
  const allowed = (n) => !n[3] || (n[3] === "admin" ? state.me.admin : can(n[3], false));
  const link = ([key, href, label]) => h("a", { href, class: current.nav === key ? "active" : "" }, label);
  mount(navEl, navItems.map((n) => {
    if (!n.menu) return allowed(n) ? link(n) : null;
    const items = n.items.filter(allowed);
    if (!items.length) return null;
    return menu(n.menu, items.map(link), { active: items.some((i) => i[0] === current.nav), label: n.menu + " menu" });
  }));
}

// menu is a drop-down that closes when an item is picked, on a click
// elsewhere and on Escape.
function menu(label, items, opts = {}) {
  const d = h("details", { class: "menu" + (opts.right ? " right" : "") },
    h("summary", { class: opts.active ? "active" : "", "aria-label": opts.label || null }, label, h("span", { class: "caret", "aria-hidden": "true" }, "▾")),
    h("div", { class: "menu-list", role: "menu" }, items.filter(Boolean)));
  d.addEventListener("click", (e) => { if (e.target.closest(".menu-list a, .menu-list button")) d.open = false; });
  return d;
}

document.addEventListener("click", (e) => {
  for (const d of document.querySelectorAll("details.menu[open]")) if (!d.contains(e.target)) d.open = false;
});
document.addEventListener("keydown", (e) => {
  if (e.key !== "Escape") return;
  for (const d of document.querySelectorAll("details.menu[open]")) { d.open = false; d.querySelector("summary").focus(); }
});

async function logout() {
  try { await api("POST", "/auth/logout"); } catch { /* ignore */ }
  state.me = null;
  state.csrf = "";
  window.removeEventListener("hashchange", route);
  renderLogin("You have logged out.");
}

// stopTimers lets a page that refreshes itself stop when it is left.
let pageCleanup = null;
export function onLeave(fn) { pageCleanup = fn; }

async function route() {
  if (!state.me) return;
  if (pageCleanup) { pageCleanup(); pageCleanup = null; }
  const { path, query } = parseHash();
  for (const r of routes) {
    const m = path.match(r.pattern);
    if (!m) continue;
    const params = {};
    (r.params || []).forEach((p, i) => { params[p] = m[i + 1]; });
    current = { key: path, nav: r.nav, page: r.page, params, query };
    renderNav();
    const gen = ++routeGen;
    const old = mainEl.firstChild;
    const slow = setTimeout(() => { if (gen === routeGen && mainEl.firstChild === old) mount(mainEl, h("div", { class: "muted" }, "Loading…")); }, 300);
    try {
      await r.page.render(mainEl, params, query);
    } catch (e) {
      if (gen === routeGen) mount(mainEl, h("h1", null, "Something went wrong"), errorBox(e));
    } finally {
      clearTimeout(slow);
    }
    return;
  }
  mount(mainEl, h("h1", null, "Not found"), h("p", null, h("a", { href: "#/" }, "Back to the dashboard")));
}

// rerender draws the current page again (after a change).
export function rerender() {
  if (current.page) route();
}

setChangeHandler((r) => r && r.confirm_token ? autoConfirm(r.confirm_token) : refreshProbation());

setUnauthorizedHandler(() => {
  if (state.me) {
    state.me = null;
    window.removeEventListener("hashchange", route);
    renderLogin("Your session has expired. Please log in again.");
  }
});

(async function boot() {
  try {
    await loggedIn(await get("/auth/whoami"));
  } catch (e) {
    if (e.status === 401) renderLogin();
    else mount(app, h("div", { class: "login panel" }, h("h1", null, "Housecarl"), errorBox(e)));
  }
})();

window.addEventListener("unhandledrejection", (e) => {
  toast(e.reason && e.reason.message ? e.reason.message : String(e.reason), "err");
});