(function () {
  const EMAIL_STORAGE_KEY = 'ff_member_form_email_v1';
  const boot = window.APP_BOOT || { steps: [], csrf: '', contactEmail: '' };

  const state = {
    email: '',
    currentStep: 1,
    totalSteps: boot.steps.length,
    autosaveId: null,
  };

  const startForm = document.getElementById('startForm');
  const startEmailInput = document.getElementById('startEmail');
  const resetDataBtn = document.getElementById('resetDataBtn');
  const wizardSection = document.getElementById('wizardSection');
  const statusMessage = document.getElementById('statusMessage');
  const applicationForm = document.getElementById('applicationForm');
  const applicationEmail = document.getElementById('applicationEmail');
  const progress = document.getElementById('progress');
  const prevBtn = document.getElementById('prevBtn');
  const nextBtn = document.getElementById('nextBtn');
  const submitBtn = document.getElementById('submitBtn');
  const uploadNowBtn = document.getElementById('uploadNowBtn');

  const stepElements = Array.from(document.querySelectorAll('.step'));

  function showMessage(text) {
    statusMessage.textContent = text || '';
  }

  function normalizeEmail(email) {
    return (email || '').trim().toLowerCase();
  }

  function isValidEmail(email) {
    return /^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(email);
  }

  function rememberEmail(email) {
    try {
      localStorage.setItem(EMAIL_STORAGE_KEY, email);
    } catch (_err) {
      // ignore localStorage errors
    }
  }

  function getRememberedEmail() {
    try {
      return localStorage.getItem(EMAIL_STORAGE_KEY) || '';
    } catch (_err) {
      return '';
    }
  }

  function forgetRememberedEmail() {
    try {
      localStorage.removeItem(EMAIL_STORAGE_KEY);
    } catch (_err) {
      // ignore localStorage errors
    }
  }

  function lockEmail(email) {
    state.email = email;
    applicationEmail.value = email;
    startEmailInput.value = email;
    startEmailInput.readOnly = true;
    startEmailInput.setAttribute('aria-readonly', 'true');
    resetDataBtn.classList.remove('hidden');
    rememberEmail(email);
  }

  function unlockEmail(clearInput) {
    state.email = '';
    applicationEmail.value = '';
    startEmailInput.readOnly = false;
    startEmailInput.removeAttribute('aria-readonly');
    resetDataBtn.classList.add('hidden');
    if (clearInput) {
      startEmailInput.value = '';
    }
    forgetRememberedEmail();
  }

  function stopAutosave() {
    if (state.autosaveId) {
      clearInterval(state.autosaveId);
      state.autosaveId = null;
    }
  }

  function startAutosave() {
    stopAutosave();
    state.autosaveId = setInterval(async () => {
      if (!state.email || wizardSection.classList.contains('hidden')) {
        return;
      }
      try {
        await saveDraft(false, false);
      } catch (_err) {
        // visible on next manual action
      }
    }, 15000);
  }

  function clearErrors() {
    document.querySelectorAll('[data-error-for]').forEach((el) => {
      el.textContent = '';
    });
  }

  function showErrors(errors) {
    clearErrors();
    Object.keys(errors || {}).forEach((key) => {
      const el = document.querySelector('[data-error-for="' + key + '"]');
      if (el) {
        el.textContent = errors[key];
      }
    });
  }

  function clearWizardData() {
    applicationForm.reset();
    clearErrors();
    renderUploadInfo({});
    state.currentStep = 1;
    submitBtn.disabled = false;
    nextBtn.disabled = false;
    prevBtn.disabled = false;
    updateProgress();
  }

  function updateProgress() {
    progress.textContent = 'Schritt ' + state.currentStep + ' von ' + state.totalSteps;
    stepElements.forEach((el) => {
      const step = Number(el.getAttribute('data-step'));
      el.classList.toggle('hidden', step !== state.currentStep);
    });

    prevBtn.disabled = state.currentStep === 1;
    nextBtn.classList.toggle('hidden', state.currentStep === state.totalSteps);
    submitBtn.classList.toggle('hidden', state.currentStep !== state.totalSteps);
  }

  function fillFormData(data) {
    Object.keys(data || {}).forEach((key) => {
      const field = applicationForm.querySelector('[name="form_data[' + key + ']"]');
      if (!field) return;

      if (field.type === 'checkbox') {
        field.checked = ['1', 'on', 'true', true].includes(data[key]);
      } else {
        field.value = data[key] || '';
      }
    });
  }

  function renderUploadInfo(uploads) {
    document.querySelectorAll('[data-upload-list]').forEach((el) => {
      el.innerHTML = '';
    });

    Object.keys(uploads || {}).forEach((field) => {
      const target = document.querySelector('[data-upload-list="' + field + '"]');
      if (!target || !Array.isArray(uploads[field])) return;

      uploads[field].forEach((item) => {
        const div = document.createElement('div');
        div.className = 'upload-item';
        div.textContent = item.original_filename + ' (' + item.uploaded_at + ')';
        target.appendChild(div);
      });
    });
  }

  function updateUploadSelectionText(fieldKey) {
    const target = document.querySelector('[data-upload-selected="' + fieldKey + '"]');
    if (!target) {
      return;
    }

    const fileInput = applicationForm.querySelector('[name="' + fieldKey + '"]');
    const cameraInput = applicationForm.querySelector('[name="' + fieldKey + '__camera"]');

    let label = 'Keine Datei gewählt';
    if (fileInput && fileInput.files && fileInput.files[0]) {
      label = 'Ausgewählt: ' + fileInput.files[0].name;
    }
    if (cameraInput && cameraInput.files && cameraInput.files[0]) {
      label = 'Ausgewählt: ' + cameraInput.files[0].name + ' (Foto)';
    }

    target.textContent = label;
  }

  function initUploadControls() {
    const controls = Array.from(document.querySelectorAll('[data-upload-key]'));

    controls.forEach((control) => {
      const fieldKey = control.getAttribute('data-upload-key') || '';
      if (!fieldKey) {
        return;
      }

      const fileInput = applicationForm.querySelector('[name="' + fieldKey + '"]');
      const cameraInput = applicationForm.querySelector('[name="' + fieldKey + '__camera"]');

      if (fileInput) {
        fileInput.addEventListener('change', () => {
          if (fileInput.files && fileInput.files[0] && cameraInput) {
            cameraInput.value = '';
          }
          updateUploadSelectionText(fieldKey);
        });
      }

      if (cameraInput) {
        cameraInput.addEventListener('change', () => {
          if (cameraInput.files && cameraInput.files[0] && fileInput) {
            fileInput.value = '';
          }
          updateUploadSelectionText(fieldKey);
        });
      }

      updateUploadSelectionText(fieldKey);
    });
  }

  async function postForm(url, formData) {
    const response = await fetch(url, {
      method: 'POST',
      body: formData,
      credentials: 'same-origin',
      headers: { 'X-Requested-With': 'XMLHttpRequest' },
    });

    const payload = await response.json();
    if (!response.ok || payload.ok === false) {
      const err = new Error(payload.message || 'Anfrage fehlgeschlagen');
      err.payload = payload;
      throw err;
    }

    return payload;
  }

  function collectPayload(includeFiles) {
    const fd = new FormData();
    fd.append('csrf', boot.csrf);
    fd.append('email', state.email);
    fd.append('step', String(state.currentStep));
    fd.append('website', '');

    Array.from(applicationForm.elements).forEach((el) => {
      if (!el.name) return;
      if (!el.name.startsWith('form_data[')) return;

      if (el.type === 'checkbox') {
        fd.append(el.name, el.checked ? '1' : '0');
      } else {
        fd.append(el.name, el.value || '');
      }
    });

    if (includeFiles) {
      Array.from(applicationForm.querySelectorAll('input[type="file"]')).forEach((input) => {
        if (input.files && input.files[0]) {
          fd.append(input.name, input.files[0]);
        }
      });
    }

    return fd;
  }

  async function loadDraft(email) {
    const fd = new FormData();
    fd.append('csrf', boot.csrf);
    fd.append('email', email);
    fd.append('website', '');
    return postForm('/api/load-draft.php', fd);
  }

  async function resetSavedData(email) {
    const fd = new FormData();
    fd.append('csrf', boot.csrf);
    fd.append('email', email);
    fd.append('website', '');
    return postForm('/api/reset.php', fd);
  }

  async function saveDraft(includeFiles, showSavedText) {
    const payload = collectPayload(includeFiles);
    const response = await postForm('/api/save-draft.php', payload);

    if (response.upload_errors && Object.keys(response.upload_errors).length > 0) {
      showErrors(response.upload_errors);
      showMessage('Einige Dateien konnten nicht gespeichert werden.');
    } else if (showSavedText) {
      showMessage('Entwurf gespeichert: ' + (response.updated_at || ''));
    }

    if (response.uploads) {
      renderUploadInfo(response.uploads);
    }

    if (includeFiles) {
      Array.from(applicationForm.querySelectorAll('input[type="file"]')).forEach((input) => {
        input.value = '';
      });
      Array.from(document.querySelectorAll('[data-upload-key]')).forEach((control) => {
        const fieldKey = control.getAttribute('data-upload-key');
        if (fieldKey) {
          updateUploadSelectionText(fieldKey);
        }
      });
    }

    return response;
  }

  async function submitApplication() {
    const payload = collectPayload(true);
    const response = await postForm('/api/submit.php', payload);
    clearErrors();
    showMessage('Antrag erfolgreich abgeschlossen. Vielen Dank.');
    submitBtn.disabled = true;
    nextBtn.disabled = true;
    prevBtn.disabled = true;
    return response;
  }

  async function startProcess(rawEmail) {
    const email = normalizeEmail(rawEmail);
    if (!isValidEmail(email)) {
      showMessage('Bitte eine gültige E-Mail-Adresse eingeben.');
      startEmailInput.focus();
      return;
    }

    try {
      const result = await loadDraft(email);
      lockEmail(email);

      if (result.already_submitted) {
        wizardSection.classList.add('hidden');
        showMessage(
          (result.message || 'Antrag bereits abgeschlossen.') +
          (boot.contactEmail ? ' Kontakt: ' + boot.contactEmail : '')
        );
        stopAutosave();
        return;
      }

      wizardSection.classList.remove('hidden');
      fillFormData(result.data || {});
      renderUploadInfo(result.uploads || {});

      state.currentStep = Math.min(Math.max(Number(result.step || 1), 1), state.totalSteps);
      updateProgress();
      startAutosave();

      showMessage('Formular geladen. Entwurf wird automatisch gespeichert.');
    } catch (err) {
      const msg = (err.payload && err.payload.message) || err.message || 'Laden fehlgeschlagen.';
      showMessage(msg);
    }
  }

  startForm.addEventListener('submit', async (event) => {
    event.preventDefault();
    await startProcess(startEmailInput.value || '');
  });

  resetDataBtn.addEventListener('click', async () => {
    if (!state.email) {
      showMessage('Keine aktive E-Mail vorhanden.');
      return;
    }

    const confirmed = window.confirm('Alle gespeicherten Daten zu dieser E-Mail endgültig löschen und neu starten?');
    if (!confirmed) {
      return;
    }

    try {
      await resetSavedData(state.email);
      stopAutosave();
      wizardSection.classList.add('hidden');
      clearWizardData();
      unlockEmail(true);
      showMessage('Alle gespeicherten Daten wurden gelöscht. Sie können neu starten.');
      startEmailInput.focus();
    } catch (err) {
      const msg = (err.payload && err.payload.message) || err.message || 'Löschen fehlgeschlagen.';
      showMessage(msg);
    }
  });

  prevBtn.addEventListener('click', async () => {
    if (state.currentStep <= 1) return;

    try {
      await saveDraft(false, true);
      state.currentStep -= 1;
      updateProgress();
    } catch (err) {
      const msg = (err.payload && err.payload.message) || err.message;
      showMessage(msg);
    }
  });

  nextBtn.addEventListener('click', async () => {
    if (state.currentStep >= state.totalSteps) return;

    try {
      await saveDraft(false, true);
      state.currentStep += 1;
      updateProgress();
    } catch (err) {
      const msg = (err.payload && err.payload.message) || err.message;
      showMessage(msg);
    }
  });

  if (uploadNowBtn) {
    uploadNowBtn.addEventListener('click', async () => {
      try {
        await saveDraft(true, true);
      } catch (err) {
        const msg = (err.payload && err.payload.message) || err.message;
        showMessage(msg);
      }
    });
  }

  submitBtn.addEventListener('click', async () => {
    try {
      await submitApplication();
    } catch (err) {
      const payload = err.payload || {};
      if (payload.errors) {
        showErrors(payload.errors);
      }
      const msg = payload.message || err.message || 'Absenden fehlgeschlagen.';
      showMessage(msg);
      if (payload.already_submitted) {
        wizardSection.classList.add('hidden');
      }
    }
  });

  const rememberedEmail = normalizeEmail(getRememberedEmail());
  if (rememberedEmail !== '') {
    if (isValidEmail(rememberedEmail)) {
      startEmailInput.value = rememberedEmail;
      showMessage('Gespeicherte E-Mail erkannt. Formular wird geladen ...');
      startProcess(rememberedEmail);
    } else {
      forgetRememberedEmail();
    }
  }

  initUploadControls();
  updateProgress();
})();