frontend.ts

const form = document.getElementById("form") as HTMLFormElement;
const fromInput = document.getElementById("from") as HTMLInputElement;
const toInput = document.getElementById("to") as HTMLInputElement;
const submitBtn = document.getElementById("submit") as HTMLButtonElement;
const statusEl = document.getElementById("status") as HTMLDivElement;
const resultEl = document.getElementById("result") as HTMLDivElement;
const outputEl = document.getElementById("output") as HTMLDivElement;
const titleEl = document.getElementById("title") as HTMLHeadingElement;
const statPrs = document.getElementById("stat-prs") as HTMLDivElement;
const statRepos = document.getElementById("stat-repos") as HTMLDivElement;
const statContributors = document.getElementById("stat-contributors") as HTMLDivElement;
const copyBtn = document.getElementById("copy") as HTMLButtonElement;
const versionEl = document.getElementById("version") as HTMLElement;

const today = new Date();
const firstOfThisMonth = new Date(today.getFullYear(), today.getMonth(), 1);
const lastMonthStart = new Date(firstOfThisMonth);
lastMonthStart.setMonth(lastMonthStart.getMonth() - 1);
const lastMonthEnd = new Date(firstOfThisMonth);
lastMonthEnd.setDate(lastMonthEnd.getDate() - 1);

const toISO = (d: Date) => d.toISOString().slice(0, 10);
fromInput.value = toISO(lastMonthStart);
toInput.value = toISO(lastMonthEnd);

form.addEventListener("submit", async (e) => {
  e.preventDefault();

  const from = fromInput.value;
  const to = toInput.value;
  if (!from || !to) return;

  submitBtn.disabled = true;
  statusEl.className = "status";
  statusEl.innerHTML = `<span class="spinner"></span>Fetching merged PRs…`;
  resultEl.classList.add("hidden");

  try {
    const res = await fetch("/api/changelog", {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({ from, to }),
    });

    const data = await res.json();

    if (!res.ok) {
      statusEl.className = "status error";
      statusEl.textContent = data.error;
      return;
    }

    statusEl.classList.add("hidden");
    statPrs.textContent = data.prCount;
    statRepos.textContent = data.repoCount;
    statContributors.textContent = data.contributorCount;
    outputEl.textContent = data.changelog;
    resultEl.classList.remove("hidden");
  } catch {
    statusEl.className = "status error";
    statusEl.textContent = "Request failed. Is the server running?";
  } finally {
    submitBtn.disabled = false;
  }
});

fetch("/api/version")
  .then((r) => r.json())
  .then((data: { sha: string; repoUrl: string; org: string }) => {
    titleEl.textContent = `${data.org} changelog generator`;
    const link = document.createElement("a");
    link.href = `${data.repoUrl}/commit/${data.sha}`;
    link.textContent = data.sha.slice(0, 7);
    link.target = "_blank";
    versionEl.appendChild(link);
  });

copyBtn.addEventListener("click", async () => {
  const text = outputEl.textContent ?? "";
  await navigator.clipboard.writeText(text);
  copyBtn.textContent = "Copied!";
  setTimeout(() => {
    copyBtn.textContent = "Copy";
  }, 1500);
});