document.addEventListener("DOMContentLoaded", () => {
  const dropZone = document.getElementById("drop-zone");
  const fileInput = document.getElementById("file-input");
  const modeBtns = document.querySelectorAll(".mode-btn");
  const progress = document.getElementById("progress");
  const progressBar = progress.querySelector(".progress-bar");
  const progressText = document.getElementById("progress-text");
  const result = document.getElementById("result");

  let currentMode = "basic";

  modeBtns.forEach((btn) => {
    btn.addEventListener("click", () => {
      modeBtns.forEach((b) => b.classList.remove("active"));
      btn.classList.add("active");
      currentMode = btn.dataset.mode || "basic";
    });
  });

  ["dragenter", "dragover"].forEach((e) =>
    dropZone.addEventListener(e, (ev) => {
      ev.preventDefault();
      dropZone.classList.add("dragover");
    })
  );

  ["dragleave", "drop"].forEach((e) =>
    dropZone.addEventListener(e, (ev) => {
      ev.preventDefault();
      dropZone.classList.remove("dragover");
    })
  );

  dropZone.addEventListener("drop", (e) => {
    e.preventDefault();
    fileInput.files = e.dataTransfer.files;
    processFiles();
  });

  fileInput.addEventListener("change", processFiles);

  dropZone.querySelector("label")?.addEventListener("click", (e) => {
    e.preventDefault();
    fileInput.click();
  });

  function processFiles() {
    const files = fileInput.files;
    if (!files || !files.length) return;

    const endpoint =
      currentMode === "advanced" ? "/api/upload-advanced" : "/api/upload";

    const formData = new FormData();
    Array.from(files).forEach((file) => formData.append("files", file));

    showProgress(currentMode.toUpperCase(), files.length);

    fetch(endpoint, { method: "POST", body: formData })
      .then((r) => r.json())
      .then((data) => {
        hideProgress();
        if (data && data.success) showResult(data);
        else showError(data?.error || "Unknown error");
      })
      .catch((e) => {
        hideProgress();
        showError(e?.message || "Request failed");
      });
  }

  function showProgress(mode, count) {
    progress.classList.remove("d-none");
    progressText.classList.remove("d-none");
    progressText.textContent = `${mode} - ${count} files`;
    progressBar.style.width = "45%";
  }

  function hideProgress() {
    progress.classList.add("d-none");
    progressText.classList.add("d-none");
  }

  async function showResult(data) {
    const sizeKB = ((data.size || 0) / 1024).toFixed(1);

    const rawHtml =
      typeof data.aio_html === "string" ? data.aio_html : String(data.aio_html ?? "");

    const formattedHtml = await formatHtml(rawHtml);

    result.innerHTML = `
      <div class="alert alert-success">
        <div class="d-flex align-items-start gap-3">
          <i class="fa-solid fa-circle-check mt-1 flex-shrink-0"></i>
          <div class="flex-grow-1">
            <h5 class="mb-1">${escapeHtml(data.message ?? "Done")}</h5>
            <div class="mb-2">
              <small><code>${escapeHtml(data.original ?? "")}</code> → <strong>${sizeKB}KB</strong></small>
            </div>
          </div>
          <div class="btn-group-vertical btn-group-sm">
            <button class="btn btn-success btn-copy-sm" type="button">
              <i class="fa-solid fa-copy me-1"></i>Copy
            </button>
            <a
              href="data:text/html;charset=utf-8,${encodeURIComponent(rawHtml)}"
              download="aio.html"
              class="btn btn-outline-primary btn-sm"
            >
              <i class="fa-solid fa-download me-1"></i>Save
            </a>
          </div>
        </div>
      </div>

      <div class="row g-3">
        <div class="col-12 col-xl-6">
          <div class="card result-card">
            <div class="card-header bg-light">
              <h6 class="mb-0"><i class="fa-regular fa-eye me-2"></i>Preview</h6>
            </div>
            <iframe id="previewFrame" class="preview-iframe" style="height:70vh; min-height:520px;"></iframe>
          </div>
        </div>

        <div class="col-12 col-xl-6">
          <div class="card result-card">
            <div class="card-header bg-light d-flex justify-content-between align-items-center">
              <h6 class="mb-0"><i class="fa-solid fa-code me-2"></i>Code</h6>
              <button class="btn btn-sm btn-success btn-copy-all" type="button">
                <i class="fa-solid fa-copy me-1"></i>Copy All
              </button>
            </div>
            <pre class="code-preview mb-0" style="max-height:70vh; min-height:520px; overflow:auto;">
<code class="language-markup">${escapeHtml(formattedHtml)}</code></pre>
          </div>
        </div>
      </div>

      <div class="text-center mt-4">
        <button class="btn btn-outline-secondary px-4" type="button" id="btn-new">
          <i class="fa-solid fa-arrow-rotate-right me-2"></i>New
        </button>
      </div>
    `;

    result.classList.remove("d-none");

    const frame = result.querySelector("#previewFrame");
    if (frame) frame.srcdoc = rawHtml;

    if (window.Prism) window.Prism.highlightAllUnder(result);

    result.querySelectorAll(".btn-copy-sm, .btn-copy-all").forEach((btn) => {
      const originalHtml = btn.innerHTML;
      btn.addEventListener("click", () => {
        navigator.clipboard
          .writeText(rawHtml)
          .then(() => {
            btn.innerHTML = '<i class="fa-solid fa-check me-1"></i>Copied';
            setTimeout(() => (btn.innerHTML = originalHtml), 1200);
          })
          .catch(() => fallbackCopy(rawHtml, btn, originalHtml));
      });
    });

    result.querySelector("#btn-new")?.addEventListener("click", () => {
      location.reload();
    });

    result.scrollIntoView({ behavior: "smooth" });
  }

  function fallbackCopy(text, btn, originalHtml) {
    try {
      const ta = document.createElement("textarea");
      ta.value = text;
      document.body.appendChild(ta);
      ta.select();
      document.execCommand("copy");
      document.body.removeChild(ta);
      btn.innerHTML = '<i class="fa-solid fa-check me-1"></i>Copied';
      setTimeout(() => (btn.innerHTML = originalHtml), 1200);
    } catch {
      showError("Clipboard blocked by browser");
    }
  }

  function showError(msg) {
    result.innerHTML = `
      <div class="alert alert-danger">
        <i class="fa-solid fa-circle-xmark me-2"></i>${escapeHtml(msg)}
      </div>
      <div class="text-center">
        <button class="btn btn-outline-primary" type="button" id="btn-try">Try Again</button>
      </div>
    `;
    result.classList.remove("d-none");
    result.querySelector("#btn-try")?.addEventListener("click", () => location.reload());
  }
});

async function formatHtml(html) {
  html = typeof html === "string" ? html : String(html ?? "");
  try {
    if (window.prettier && window.prettierPlugins?.html) {
      return await window.prettier.format(html, {
        parser: "html",
        plugins: [window.prettierPlugins.html],
        printWidth: 100,
        tabWidth: 2,
        useTabs: false,
      });
    }
  } catch (e) {
    console.error(e);
  }
  return html;
}

function escapeHtml(text) {
  text = typeof text === "string" ? text : String(text ?? "");
  const map = { "&": "&amp;", "<": "&lt;", ">": "&gt;", '"': "&quot;", "'": "&#039;" };
  return text.replace(/[&<>"']/g, (m) => map[m]);
}