const fileInput = document.getElementById("file-input");
const fileNameEl = document.getElementById("file-name");
const importBtn = document.getElementById("import-btn");
const dropZone = document.getElementById("drop-zone");
const progress = document.getElementById("progress");
const alertSection = document.getElementById("alert-section");
const alertMessage = document.getElementById("alert-message");
const summarySection = document.getElementById("summary-section");
const summaryGrid = document.getElementById("summary-grid");
const mappingSection = document.getElementById("mapping-section");
const mappingList = document.getElementById("mapping-list");
const previewSection = document.getElementById("preview-section");
const previewTable = document.getElementById("preview-table");
const resultsSection = document.getElementById("results-section");
const resultsTable = document.getElementById("results-table");
const healthBanner = document.getElementById("health-banner");
const healthMessage = document.getElementById("health-message");

let selectedFile = null;

function showAlert(text, type = "error") {
  alertSection.hidden = false;
  alertMessage.textContent = text;
  alertMessage.className = `alert ${type}`;
}

function hideAlert() {
  alertSection.hidden = true;
}

function setFile(file) {
  selectedFile = file;
  fileNameEl.textContent = file ? file.name : "Nenhum arquivo selecionado";
  importBtn.disabled = !file;
}

fileInput.addEventListener("change", () => {
  const file = fileInput.files?.[0];
  if (file) setFile(file);
});

dropZone.addEventListener("dragover", (e) => {
  e.preventDefault();
  dropZone.classList.add("dragover");
});

dropZone.addEventListener("dragleave", () => {
  dropZone.classList.remove("dragover");
});

dropZone.addEventListener("drop", (e) => {
  e.preventDefault();
  dropZone.classList.remove("dragover");
  const file = e.dataTransfer?.files?.[0];
  if (file) {
    setFile(file);
    const dt = new DataTransfer();
    dt.items.add(file);
    fileInput.files = dt.files;
  }
});

function renderPreview(preview) {
  if (!preview?.headers?.length) return;
  previewSection.hidden = false;
  const thead = previewTable.querySelector("thead");
  const tbody = previewTable.querySelector("tbody");
  thead.innerHTML = `<tr>${preview.headers.map((h) => `<th>${escapeHtml(h)}</th>`).join("")}</tr>`;
  tbody.innerHTML = (preview.rows ?? [])
    .map(
      (row) =>
        `<tr>${row.map((cell) => `<td>${escapeHtml(formatCell(cell))}</td>`).join("")}</tr>`,
    )
    .join("");
}

function renderHeaderMapping(headerMapping) {
  const entries = Object.entries(headerMapping ?? {});
  if (!entries.length) return;
  mappingSection.hidden = false;
  mappingList.innerHTML = entries
    .map(
      ([excel, api]) =>
        `<li><span class="excel-col">${escapeHtml(excel)}</span><span class="arrow">→</span><span class="api-col">${escapeHtml(api)}</span></li>`,
    )
    .join("");
}

function renderSummary(summary) {
  summarySection.hidden = false;
  const items = [
    { label: "Total", value: summary.total },
    { label: "Criados", value: summary.created },
    { label: "Atualizados", value: summary.updated },
    { label: "Erros", value: summary.errors },
  ];
  summaryGrid.innerHTML = items
    .map(
      (item) =>
        `<li><strong>${item.value}</strong><span>${item.label}</span></li>`,
    )
    .join("");
}

function statusLabel(status) {
  const map = { created: "Criado", updated: "Atualizado", error: "Erro" };
  return map[status] ?? status;
}

function renderResults(results) {
  if (!results?.length) return;
  resultsSection.hidden = false;
  const tbody = resultsTable.querySelector("tbody");
  tbody.innerHTML = results
    .map((r) => {
      const idPart = [r.id, r.externalId].filter(Boolean).join(" / ") || "—";
      return `<tr>
        <td>${r.row}</td>
        <td><span class="badge ${r.status}">${statusLabel(r.status)}</span></td>
        <td>${escapeHtml(idPart)}</td>
        <td>${escapeHtml(r.message)}</td>
      </tr>`;
    })
    .join("");
}

function escapeHtml(str) {
  return String(str)
    .replace(/&/g, "&amp;")
    .replace(/</g, "&lt;")
    .replace(/>/g, "&gt;")
    .replace(/"/g, "&quot;");
}

function formatCell(cell) {
  if (cell === null || cell === undefined) return "";
  return String(cell);
}

importBtn.addEventListener("click", async () => {
  if (!selectedFile) return;

  hideAlert();
  previewSection.hidden = true;
  summarySection.hidden = true;
  mappingSection.hidden = true;
  resultsSection.hidden = true;
  progress.hidden = false;
  importBtn.disabled = true;

  const formData = new FormData();
  formData.append("file", selectedFile);

  try {
    const res = await fetch("/api/import", {
      method: "POST",
      body: formData,
    });

    const data = await res.json().catch(() => ({}));

    if (!res.ok) {
      showAlert(data.error ?? `Erro ${res.status} ao importar`);
      return;
    }

    renderSummary(data.summary);
    renderHeaderMapping(data.headerMapping);
    renderPreview(data.preview);
    renderResults(data.results);

    const { errors, total } = data.summary ?? {};
    if (errors === 0) {
      showAlert(`Importação concluída: ${total} linha(s) processada(s).`, "success");
    } else {
      showAlert(
        `Importação concluída com ${errors} erro(s) em ${total} linha(s).`,
        "error",
      );
    }
  } catch (err) {
    showAlert(err instanceof Error ? err.message : "Falha de rede ao importar");
  } finally {
    progress.hidden = true;
    importBtn.disabled = !selectedFile;
  }
});

async function checkHealth() {
  try {
    const res = await fetch("/api/health");
    const data = await res.json();
    healthBanner.hidden = false;

    if (data.ok) {
      healthBanner.className = "card banner-ok";
      healthMessage.textContent = `Conectado ao Clarizen (usuário: ${data.userId})`;
    } else {
      healthBanner.className = "card banner-warn";
      healthMessage.textContent =
        data.error ?? "Não foi possível autenticar no Clarizen";
    }
  } catch {
    healthBanner.hidden = false;
    healthBanner.className = "card banner-warn";
    healthMessage.textContent =
      "Servidor indisponível. Inicie com npm start.";
  }
}

checkHealth();