// Address match list helpers: suggestions for the ACLs, TSIG keys and
// built-in names that can be used where named expects an address match
// list (options such as allow-query, view match-clients, ACL elements),
// and a check for names that don't exist, so nobody has to switch pages
// to look up an ACL's exact name.
import { h, mount } from "./ui.js";
import { get } from "./api.js";

export const builtins = ["any", "none", "localhost", "localnets"];

// amlContext loads the names that can be referred to. Users who may not
// read ACLs or keys simply get fewer suggestions.
export async function amlContext() {
  const [acls, keys] = await Promise.all([get("/acls").catch(() => []), get("/tsig-keys").catch(() => [])]);
  return { acls: acls.map((a) => ({ name: a.name, detail: a.elements.join("; ") })), keys: keys.map((k) => k.name) };
}

const ipRe = /^(\d{1,3}(\.\d{1,3}){0,3}|[0-9a-f:]*:[0-9a-f:.]*)(\/\d{1,3})?$/i;
// rangeRe finds address ranges (START-END); the server checks them.
const rangeRe = /!?\s*[0-9a-f]*[.:][0-9a-f:.]*\s*-\s*[0-9a-f]*[.:][0-9a-f:.]*/gi;

// checkElement returns a problem with one element, or "".
function checkElement(line, ctx, exclude) {
  let e = line.trim().replace(/;$/, "").trim();
  if (!e) return "";
  if (e.startsWith("!")) e = e.slice(1).trim();
  const lower = e.toLowerCase();
  if (builtins.includes(lower) || ipRe.test(e) || e.startsWith("{") || lower.startsWith("geoip ")) return "";
  if (e.replace(rangeRe, "").trim() === "") return ""; // a range: rangeHints explains it
  const key = e.match(/^key\s+"?([^"\s]+)"?$/i);
  if (key) return ctx.keys.some((k) => k.toLowerCase() === key[1].toLowerCase()) ? "" : "no TSIG key called " + key[1];
  if (/\s/.test(e)) return "";
  const name = e.replace(/^"|"$/g, "");
  if (exclude && name.toLowerCase() === exclude.toLowerCase()) return "an ACL can't include itself";
  return ctx.acls.some((a) => a.name.toLowerCase() === name.toLowerCase()) ? "" : "no ACL called " + name + (ctx.acls.length ? "" : " (there are no ACLs yet)");
}

// rangeHints shows, below a field, what each address range in it
// (10.0.10.101-10.0.10.199) becomes in named.conf, which only knows
// prefixes, and what is wrong with a range that can't be used.
export function rangeHints(field) {
  const box = h("div", { class: "range-hints" });
  let timer, last = "";
  const update = async () => {
    const found = (field.value.match(rangeRe) || []).map((r) => r.replace(/\s+/g, ""));
    const key = found.join(",");
    if (key === last) return;
    last = key;
    if (!found.length) { mount(box); return; }
    try {
      const info = await get("/catalog/ranges", { r: key });
      if (key !== last) return;
      mount(box, info.map((x) => x.error
        ? h("div", { class: "msg warn small" }, x.error)
        : h("details", { class: "range-hint small" },
          h("summary", null, h("span", { class: "mono" }, x.input), " = " + x.size + ", written to named.conf as " + (x.prefixes.length === 1 ? "1 prefix" : x.prefixes.length + " prefixes")),
          h("div", { class: "prefixes mono" }, x.prefixes.map((p) => h("span", null, p))))));
    } catch { mount(box); }
  };
  field.addEventListener("input", () => { clearTimeout(timer); timer = setTimeout(update, 300); });
  update();
  return box;
}

// suggestions adds clickable names below a text field. mode "lines" adds
// one element per line (and checks the names); "inline" inserts
// "name; " at the cursor in named.conf syntax.
export function suggestions(field, ctx, { mode = "lines", exclude = "" } = {}) {
  const problems = h("div", { class: "aml-problems" });
  const insert = (text) => {
    if (mode === "lines") {
      const lines = field.value.split("\n").map((l) => l.trim()).filter(Boolean);
      if (!lines.includes(text)) lines.push(text);
      field.value = lines.join("\n");
    } else {
      const at = field.selectionStart ?? field.value.length;
      const before = field.value.slice(0, at), after = field.value.slice(at);
      const sep = before && !/[\s{]$/.test(before) ? " " : "";
      field.value = before + sep + text + "; " + after;
      field.selectionStart = field.selectionEnd = (before + sep + text + "; ").length;
    }
    field.focus();
    field.dispatchEvent(new Event("input"));
  };
  const chip = (label, text, title) => h("button", { type: "button", class: "chip", title: title || "", onclick: () => insert(text) }, label);
  const acls = ctx.acls.filter((a) => a.name.toLowerCase() !== exclude.toLowerCase());
  const row = h("div", { class: "aml-suggest" },
    acls.length ? [h("span", { class: "muted small" }, "ACLs:"), acls.map((a) => chip(a.name, a.name, a.detail))] : null,
    ctx.keys.length ? [h("span", { class: "muted small" }, "Keys:"), ctx.keys.map((k) => chip("key " + k, "key " + k, "TSIG key"))] : null,
    h("span", { class: "muted small" }, "Built-in:"), builtins.map((b) => chip(b, b, { any: "every address", none: "no address", localhost: "this server's own addresses", localnets: "networks this server is directly attached to" }[b])),
    mode === "lines" ? h("span", { class: "muted small" }, "Prefix a line with ! to exclude it. Ranges: 10.0.10.101-10.0.10.199.") : null);
  if (mode === "lines") {
    const check = () => {
      const msgs = field.value.split("\n").map((l) => [l.trim(), checkElement(l, ctx, exclude)]).filter(([, m]) => m);
      mount(problems, msgs.map(([l, m]) => h("div", { class: "msg warn small" }, l + ": " + m)));
    };
    field.addEventListener("input", check);
    check();
  }
  return h("div", { class: "aml" }, row, problems, rangeHints(field));
}