(() => {
  "use strict";

  const focusError = document.querySelector("[data-error-field]");
  if (focusError) {
    focusError.focus();
  } else {
    const summary = document.querySelector("[data-error-summary]");
    if (summary) summary.focus();
  }

  document.querySelectorAll("[data-loading-form]").forEach((form) => {
    form.addEventListener("submit", () => {
      form.setAttribute("aria-busy", "true");
      const button = form.querySelector("button[type='submit']");
      if (!button) return;
      button.disabled = true;
      button.textContent = button.dataset.loadingLabel || "正在加载…";
    });
  });

  document.querySelectorAll("[data-submit-form]").forEach((form) => {
    form.addEventListener("submit", () => {
      form.dataset.submitting = "true";
      const button = form.querySelector("[data-submit-button]");
      if (!button) return;
      button.disabled = true;
      button.textContent = button.dataset.loadingLabel || "正在提交…";
    });
  });

  const fileInput = document.querySelector("input[type='file'][name='image']");
  const image = document.querySelector("[data-image-preview]");
  const placeholder = document.querySelector("[data-image-placeholder]");
  const imageName = document.querySelector("[data-image-name]");
  let previewURL = "";

  if (fileInput && image && placeholder && imageName) {
    fileInput.addEventListener("change", () => {
      if (previewURL) URL.revokeObjectURL(previewURL);
      const file = fileInput.files && fileInput.files[0];
      if (!file) {
        image.hidden = true;
        placeholder.hidden = false;
        imageName.textContent = "选择后在本地预览";
        return;
      }
      previewURL = URL.createObjectURL(file);
      image.src = previewURL;
      image.hidden = false;
      placeholder.hidden = true;
      imageName.textContent = `${file.name} · ${(file.size / 1024).toFixed(1)} KB`;
    });
    window.addEventListener("pagehide", () => {
      if (previewURL) URL.revokeObjectURL(previewURL);
    });
  }

  const dirtyForm = document.querySelector("[data-dirty-form]");
  const leaveDialog = document.querySelector("[data-leave-dialog]");
  let dirty = false;
  let destination = "";

  if (dirtyForm && leaveDialog) {
    dirtyForm.addEventListener("input", () => {
      dirty = true;
    });
    dirtyForm.addEventListener("change", () => {
      dirty = true;
    });
    dirtyForm.addEventListener("submit", () => {
      dirty = false;
    });

    document.querySelectorAll("a[href]").forEach((link) => {
      link.addEventListener("click", (event) => {
        if (!dirty || link.hasAttribute("data-discard")) return;
        const target = new URL(link.href, window.location.href);
        if (target.origin !== window.location.origin) return;
        event.preventDefault();
        destination = target.href;
        leaveDialog.showModal();
        leaveDialog.querySelector("[data-stay]").focus();
      });
    });

    leaveDialog.querySelector("[data-stay]").addEventListener("click", () => {
      leaveDialog.close();
    });
    leaveDialog.querySelector("[data-discard]").addEventListener("click", (event) => {
      event.preventDefault();
      dirty = false;
      window.location.assign(destination || "/tasks");
    });
  }

  const openCancel = document.querySelector("[data-open-cancel]");
  const cancelDialog = document.querySelector("[data-cancel-dialog]");
  if (openCancel && cancelDialog) {
    openCancel.addEventListener("click", () => {
      cancelDialog.showModal();
      cancelDialog.querySelector("[data-keep-task]").focus();
    });
    cancelDialog.querySelector("[data-keep-task]").addEventListener("click", () => {
      cancelDialog.close();
      openCancel.focus();
    });
  }
})();