import { h, mount, table, input, toast, errorBox, confirmDialog, diffView, problemsList, checkList, time, plural, badge } from "../ui.js";
import { api, get, state, useDraft, refreshDraft } from "../api.js";
import { rerender } from "../app.js";

export async function render(el) {
  await refreshDraft();
  const open = await get("/changesets", { status: "open", mine: 1, 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 named until you apply it; then the whole changeset is checked by Jarl and named-checkconf, written, and loaded together.")))];
  if (!d || !(d.ops || []).length) {
    parts.push(h("div", { class: "panel" }, h("div", { class: "empty" }, "No pending changes. Edit zones, records or options and they will show up here.")));
  } else {
    parts.push(await 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" }, "Created through the API or CLI, or earlier in the web UI. Switch to one to review and apply it here."),
      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: "Via", render: (c) => c.via },
        { label: "Created", render: (c) => time(c.created_at) },
        { label: "", render: (c) => h("span", null,
          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;
            await api("POST", "/changesets/" + c.id + "/discard");
            rerender();
          } }, "Discard")), tdClass: "actions-cell" },
      ], others)));
  }
  mount(el, parts);
}

async function draftPanel(d) {
  const desc = input({ value: d.description || "", placeholder: "Describe this change (shown in the history)", style: { width: "100%" } });
  const preview = h("div", { class: "muted" }, "Checking…");
  const result = h("div");
  let valid = false;
  const applyBtn = h("button", { class: "primary", disabled: true }, "Apply changes");
  const forceBox = h("label", { class: "check small hidden" }, h("input", { type: "checkbox" }), "Overwrite files changed outside Jarl");
  // Changes that open a public view up must be confirmed (docs/exposure.md).
  const riskBox = h("label", { class: "check risk-confirm hidden" }, h("input", { type: "checkbox" }), "");
  let risky = false;
  riskBox.querySelector("input").addEventListener("change", () => { applyBtn.disabled = !valid || (risky && !riskBox.querySelector("input").checked); });
  const ops = d.ops || [];
  const removeOp = async (seq) => {
    try {
      const cs = await api("DELETE", "/changesets/" + d.id + "/ops/" + seq);
      useDraft(cs);
      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, tdClass: "mono small" },
    { label: "Added", render: (o) => time(o.added_at) },
    { label: "", render: (o) => h("button", { class: "small", title: "Remove this operation from the changeset", onclick: () => removeOp(o.seq) }, "Remove"), tdClass: "actions-cell" },
  ], ops);
  // failedOp marks the operation that no longer applies and says how to
  // get past it.
  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, h("strong", null, "Operation " + err.op + " can't be applied: "), err.message),
      h("div", { class: "mono small" }, ops[i].summary || ops[i].op),
      h("div", { style: { marginTop: "8px" } },
        h("button", { class: "small", onclick: () => removeOp(err.op) }, "Remove operation " + err.op),
        " ", h("span", { class: "muted small" }, "It is marked in the list above. Then check the rest again.")));
  };
  const runPreview = async () => {
    try {
      const p = await get("/changesets/" + d.id + "/preview");
      valid = p.valid && !p.error;
      risky = (p.risks || []).length > 0;
      riskBox.classList.toggle("hidden", !risky);
      if (risky) riskBox.lastChild.textContent = " I understand: " + p.risks.map((x) => x.message).join("; ");
      applyBtn.disabled = !valid || (risky && !riskBox.querySelector("input").checked);
      const drift = (p.drift || []);
      forceBox.classList.toggle("hidden", drift.length === 0);
      mount(preview,
        p.error ? (p.error.op ? failedOp(p.error) : errorBox({ message: p.error.message, details: p.error })) : null,
        valid ? h("div", { class: "msg ok" }, "Valid. named-checkconf accepts the new configuration.", (p.serials || []).length ? " Serials: " + p.serials.map((s) => s.zone.replace(/\.$/, "") + " " + s.old + "→" + s.new).join(", ") : "") : null,
        !p.error && !valid ? h("div", { class: "msg err" }, "This changeset can't be applied yet:") : null,
        problemsList(p.problems),
        checkList(p.check),
        drift.length ? h("div", { class: "msg warn" }, "Files changed outside Jarl: ", drift.map((x) => x.path + " (" + x.reason + ")").join(", ")) : null,
        (p.warnings || []).length ? h("div", { class: "msg warn" }, h("ul", null, p.warnings.map((w) => h("li", null, w)))) : null,
        (p.existing_problems || []).filter((x) => x.severity !== "info").length ? h("details", null, h("summary", { class: "muted" }, "Existing problems (not caused by this changeset)"), problemsList(p.existing_problems.filter((x) => x.severity !== "info"))) : null,
        h("h3", null, "Changes to BIND's files" + ((p.files_changed || []).length ? " (" + plural(p.files_changed.length, "file") + ")" : "")),
        diffView(p.diff));
    } catch (e) { mount(preview, errorBox(e)); }
  };
  applyBtn.addEventListener("click", async () => {
    applyBtn.disabled = true;
    mount(result, h("div", { class: "muted" }, "Applying…"));
    try {
      if (desc.value !== (d.description || "")) await api("PATCH", "/changesets/" + d.id, { body: { description: desc.value } });
      const force = forceBox.querySelector("input").checked;
      const r = await api("POST", "/changesets/" + d.id + "/apply", { body: { force, accept_risk: riskBox.querySelector("input").checked } });
      const res = r.result || {};
      toast("Applied changeset #" + d.id + (res.reloaded && res.reloaded.length ? " — named reloaded" : ""));
      (r.warnings || []).forEach((w) => toast(w, "warn", 10000));
      useDraft(null);
      location.hash = "#/history/" + d.id;
    } catch (e) {
      mount(result, errorBox(e));
      applyBtn.disabled = false;
    }
  });
  const discard = h("button", { class: "danger", onclick: async () => {
    if (!(await confirmDialog("Discard changes", "Throw away all " + ops.length + " pending changes?", "Discard", "danger"))) return;
    await api("POST", "/changesets/" + d.id + "/discard");
    useDraft(null);
    rerender();
  } }, "Discard all");
  const panel = h("div", null,
    h("div", { class: "panel" },
      h("h2", null, "Changeset #" + d.id + " ", badge(plural(ops.length, "operation"), "warn")),
      desc,
      h("div", { style: { marginTop: "10px" } }, opsTable),
      riskBox,
      h("div", { class: "actions", style: { marginTop: "12px" } }, applyBtn, discard, forceBox),
      result),
    h("div", { class: "panel" }, h("h2", null, "Review"), preview));
  runPreview();
  return panel;
}