import { h, mount, table, field, input, select, toast, errorBox, confirmDialog, modal, copyBox } from "../ui.js";
import { get, change, describeResult } from "../api.js";
import { rerender } from "../app.js";

const algorithms = ["hmac-sha256", "hmac-sha512", "hmac-sha384", "hmac-sha224", "hmac-sha1", "hmac-md5"];

// randomSecret returns a base64 secret as long as the algorithm's hash.
function randomSecret(alg) {
  const bytes = { "hmac-sha512": 64, "hmac-sha384": 48, "hmac-sha224": 28, "hmac-sha1": 20, "hmac-md5": 16 }[alg] || 32;
  const raw = new Uint8Array(bytes);
  crypto.getRandomValues(raw);
  return btoa(String.fromCharCode(...raw));
}

export async function render(el) {
  const keys = await get("/tsig-keys");
  mount(el,
    h("div", { class: "page-head" },
      h("div", { class: "grow" }, h("h1", null, "TSIG keys"),
        h("div", { class: "muted" }, "Shared secrets that authenticate zone transfers, NOTIFY and other server-to-server traffic. Use them in ACLs and options as 'key NAME'.")),
      h("div", { class: "actions" }, h("button", { class: "primary", onclick: () => keyDialog() }, "New key"))),
    h("div", { class: "panel" }, table([
      { label: "Name", render: (k) => h("strong", { class: "mono" }, k.name) },
      { label: "Algorithm", render: (k) => k.algorithm, tdClass: "mono" },
      { label: "Used by", render: (k) => k.used_by.length ? k.used_by.join(", ") : h("span", { class: "muted" }, "unused"), tdClass: "small" },
      { label: "Comment", render: (k) => h("span", { class: "muted" }, k.comment || "") },
      { label: "", render: (k) => h("span", null,
        h("button", { class: "small", onclick: () => reveal(k) }, "Show secret"), " ",
        h("button", { class: "small", onclick: () => rotate(k) }, "New secret"), " ",
        h("button", { class: "small danger", disabled: k.used_by.length > 0, onclick: () => del(k) }, "Delete")), tdClass: "actions-cell" },
    ], keys, { empty: "No TSIG keys. The rndc control key normally stays in /etc/bind/rndc.key and is not managed here." })));
}

function snippet(k) {
  return 'key "' + k.name + '" {\n\talgorithm ' + k.algorithm + ';\n\tsecret "' + k.secret + '";\n};';
}

function showSecret(k, title) {
  return modal(title, h("div", null,
    h("p", null, "Secret of ", h("strong", { class: "mono" }, k.name), ":"),
    copyBox(k.secret),
    h("h3", null, "named.conf for the other server"),
    h("pre", null, snippet(k)),
    h("h3", null, "Usage"),
    h("pre", null, "dig @this-server example.com AXFR -y " + k.algorithm + ":" + k.name + ":" + k.secret)));
}

async function keyDialog() {
  const err = h("div");
  const name = input({ placeholder: "xfer-key", class: "mono" });
  const alg = select(algorithms, "hmac-sha256");
  const secret = input({ placeholder: "leave empty to generate a random secret", class: "mono" });
  const comment = input();
  await modal("New TSIG key", h("div", null, h("div", { class: "form-grid" },
    field("Name", name, "Key names are domain names, e.g. xfer-key or secondary.example.com."),
    field("Algorithm", alg),
    field("Secret", secret, "Base64. Must be the same on both servers."),
    field("Comment", comment)), err), [
    { label: "Cancel", value: null },
    { label: "Create key", kind: "primary", onclick: async () => {
      const data = { name: name.value.trim(), algorithm: alg.value, comment: comment.value, secret: secret.value.trim() || randomSecret(alg.value) };
      try {
        const r = await change("POST", "/tsig-keys", data);
        toast(describeResult(r));
        await showSecret({ name: data.name, algorithm: data.algorithm, secret: data.secret }, r.staged ? "Key staged" : "Key created");
        rerender();
        return true;
      } catch (e) { mount(err, errorBox(e)); return false; }
    } },
  ], { sticky: true });
}

async function reveal(k) {
  try {
    const full = await get("/tsig-keys/" + k.id + "?secret=1");
    await showSecret(full, "TSIG key " + k.name);
  } catch (e) { toast(e.message, "err", 8000); }
}

async function rotate(k) {
  if (!(await confirmDialog("New secret", "Generate a new secret for " + k.name + "? Every server using the key must be updated with the new secret.", "Generate", "danger"))) return;
  const secret = randomSecret(k.algorithm);
  try {
    const r = await change("PATCH", "/tsig-keys/" + k.id, { secret });
    toast(describeResult(r));
    await showSecret({ ...k, secret }, "New secret for " + k.name);
    rerender();
  } catch (e) { toast(e.message, "err", 8000); }
}

async function del(k) {
  if (!(await confirmDialog("Delete key", "Delete TSIG key " + k.name + "?", "Delete", "danger"))) return;
  try {
    const r = await change("DELETE", "/tsig-keys/" + k.id);
    toast(describeResult(r));
    rerender();
  } catch (e) { toast(e.message, "err", 8000); }
}