// Changes: the pending changeset — its operations, the check, and the
// ruleset's diff — to apply together or discard. Other open changesets
// (from hc or the API) can be taken over here.
import { h, mount, table, input, toast, errorBox, confirmDialog, diffView, problemsList, time, plural, badge } from "../ui.js";
import { api, state, useDraft, refreshDraft, can } from "../api.js";
import { rerender, applyDraft } from "../app.js";

export async function render(el) {
  await refreshDraft();
  const open = await api("GET", "/changesets", { query: { status: "open", limit: 50 } });
  const d = state.draft;
  const parts = [h("div", { class: "page-head" },
    h("div", { class: "grow" }, h("h1", null, "Pending changes"),
      h("div", { class: "muted" }, "Edits are collected in a changeset. Nothing reaches the firewall until you apply it; then the whole changeset is checked by Housecarl and nftables and put in force in one step, as one entry in the history. Over the network it is on probation: confirm it, or it rolls back.")))];
  if (state.immediate) {
    parts.push(h("div", { class: "msg info" }, "Live edits are on (the switch at the top): edits are applied right away, not collected here."));
  }
  if (!d || !(d.ops || []).length) {
    parts.push(h("div", { class: "panel" }, h("div", { class: "empty" }, "No pending changes. Edit rules, NAT, objects or settings and they show up here.")));
  } else {
    parts.push(draftPanel(d));
  }
  const others = open.filter((c) => !d || c.id !== d.id);
  if (others.length) {
    parts.push(h("div", { class: "panel" }, h("h2", null, "Other open changesets"),
      h("p", { class: "muted small" }, "Made with hc or the API, by others, or earlier here. Switch to one to review and apply it."),
      table([
        { label: "#", render: (c) => String(c.id) },
        { label: "Description", render: (c) => c.description || h("span", { class: "muted" }, "(none)") },
        { label: "Operations", render: (c) => String((c.ops || []).length) },
        { label: "By", render: (c) => [c.username, h("span", { class: "muted small" }, " via " + c.via)] },
        { label: "Updated", render: (c) => time(c.updated_at) },
        can("config", true) ? { label: "", tdClass: "actions-cell", render: (c) => [
          h("button", { class: "small", onclick: () => { useDraft(c); rerender(); } }, "Switch to"), " ",
          h("button", { class: "small danger", onclick: async () => {
            if (!(await confirmDialog("Discard", "Discard changeset #" + c.id + "?", "Discard", "danger"))) return;
            try { await api("POST", "/changesets/" + c.id + "/discard"); } catch (e) { toast(e.message, "err"); }
            rerender();
          } }, "Discard")] } : null,
      ].filter(Boolean), others)));
  }
  mount(el, parts);
}

function draftPanel(d) {
  const ops = d.ops || [];
  const desc = input({ value: d.description || "", placeholder: "Describe this change (it becomes the history entry's description)", class: "wide" });
  const preview = h("div", { class: "muted" }, "Checking…");
  const result = h("div");
  const applyBtn = h("button", { class: "primary", disabled: true }, "Apply changes");
  const removeOp = async (seq) => {
    try {
      useDraft(await api("DELETE", "/changesets/" + d.id + "/ops/" + seq));
      rerender();
    } catch (e) { toast(e.message, "err", 8000); }
  };
  const opsTable = table([
    { label: "#", render: (o) => String(o.seq) },
    { label: "Change", render: (o) => o.summary || o.op },
    { label: "Added", render: (o) => time(o.added_at) },
    { label: "", tdClass: "actions-cell", render: (o) => h("button", { class: "small", title: "Take this operation out of the changeset", onclick: () => removeOp(o.seq) }, "Remove") },
  ], ops);
  // failedOp marks the operation that no longer applies, and offers to
  // take it out.
  const failedOp = (err) => {
    const i = ops.findIndex((o) => o.seq === err.op);
    const rows = opsTable.querySelectorAll("tbody tr");
    if (i < 0 || !rows[i]) return errorBox({ message: err.message, details: err });
    rows[i].classList.add("op-failed");
    return h("div", { class: "msg err" },
      h("div", null, err.message),
      h("div", { class: "form-actions" },
        h("button", { class: "small", onclick: () => removeOp(err.op) }, "Remove operation " + err.op),
        " ", h("span", { class: "muted small" }, "It is marked in the list above. Something it names changed since it was staged.")));
  };
  (async () => {
    try {
      const p = await api("GET", "/changesets/" + d.id + "/preview");
      applyBtn.disabled = !p.valid;
      mount(preview,
        p.error ? (p.error.op ? failedOp(p.error) : errorBox({ message: p.error.message, details: p.error })) : null,
        p.valid ? h("div", { class: "msg ok" }, "Valid: Housecarl's checks pass and nftables accepts the new ruleset.") : null,
        !p.error && !p.valid ? h("div", { class: "msg info" }, "Together these operations change nothing.") : null,
        problemsList(p.warnings),
        h("h3", null, "The ruleset (/var/lib/housecarl/ruleset.nft)"),
        p.valid ? diffView(p.diff) : h("div", { class: "muted" }, "No diff until the changeset can be applied."));
    } catch (e) { mount(preview, errorBox(e)); }
  })();
  applyBtn.addEventListener("click", async () => {
    mount(result);
    if (desc.value !== (d.description || "")) {
      try { await api("PATCH", "/changesets/" + d.id, { body: { description: desc.value } }); } catch { /* the apply says it */ }
    }
    const r = await applyDraft(applyBtn, d, desc.value);
    if (r && r.history_id) location.hash = "#/history/" + r.history_id;
  });
  const discard = h("button", { class: "danger", onclick: async () => {
    if (!(await confirmDialog("Discard changes", "Throw away all " + plural(ops.length, "pending change") + "?", "Discard", "danger"))) return;
    try { await api("POST", "/changesets/" + d.id + "/discard"); } catch (e) { toast(e.message, "err"); }
    useDraft(null);
    rerender();
  } }, "Discard all");
  return h("div", null,
    h("div", { class: "panel" },
      h("h2", null, "Changeset #" + d.id + " ", badge(plural(ops.length, "operation"), "warn")),
      desc,
      h("div", { class: "form-actions" }, opsTable),
      h("div", { class: "actions form-actions" }, applyBtn, discard),
      result),
    h("div", { class: "panel" }, h("h2", null, "Review"), preview));
}