// Repeated rows (links, timeline entries, services ...) can be added, removed and moved.
// Their fields use "#" as index placeholder in data-name, the real names are set on submit.

document.addEventListener('click', (event) => {
  const button = event.target.closest('[data-repeat-add], [data-repeat-remove], [data-repeat-up], [data-repeat-down]');
  if (!button) return;

  if (button.hasAttribute('data-repeat-add')) {
    const repeat = button.closest('[data-repeat]');
    const template = repeat.querySelector(':scope > template[data-repeat-template]');
    const list = repeat.querySelector(':scope > [data-repeat-list]');
    list.append(template.content.cloneNode(true));
    list.lastElementChild?.querySelector('input:not([type="hidden"]), textarea, select')?.focus();
    return;
  }

  const row = button.closest('[data-repeat-row]');
  if (button.hasAttribute('data-repeat-remove')) row.remove();
  else if (button.hasAttribute('data-repeat-up')) row.previousElementSibling?.before(row);
  else row.nextElementSibling?.after(row);
});

function rowIndexes(field) {
  const indexes = [];
  for (let row = field.closest('[data-repeat-row]'); row; row = row.parentElement.closest('[data-repeat-row]')) {
    const siblings = [...row.parentElement.children].filter((el) => el.matches('[data-repeat-row]'));
    indexes.unshift(siblings.indexOf(row));
  }
  return indexes;
}

// Images pasted or dropped into a text field are uploaded right away and inserted as Markdown.
// The form says where they go (data-image-upload), the text field opts in with data-images.

let uploading = 0;
let placeholders = 0;

async function uploadImage(form, file, name) {
  const body = new FormData();
  body.set('_csrf', form.elements._csrf.value);
  body.set('bild', file, name);
  const res = await fetch(form.dataset.imageUpload, { method: 'POST', body });
  const type = res.headers.get('content-type') ?? '';
  const data = type.includes('json') ? await res.json() : null;
  if (res.ok && data?.src) return data.src;
  const message = data?.error ?? (type.startsWith('text/plain') ? await res.text() : '');
  throw new Error(message || 'Das Bild konnte nicht hochgeladen werden.');
}

function replaceText(area, search, replacement) {
  const start = area.value.indexOf(search);
  if (start !== -1) area.setRangeText(replacement, start, start + search.length, 'preserve');
}

async function insertImages(area, files, pasted) {
  if (!area.form.dataset.imageUpload) {
    window.alert('Speichere das Projekt einmal, danach kannst du Bilder in den Text einfügen.');
    return;
  }
  // Each image gets a paragraph of its own, glued to the text around it would break headings
  const before = area.value.slice(0, area.selectionStart);
  const after = area.value.slice(area.selectionEnd);
  const lead = !before || before.endsWith('\n\n') ? '' : before.endsWith('\n') ? '\n' : '\n\n';
  const trail = !after || after.startsWith('\n\n') ? '' : after.startsWith('\n') ? '\n' : '\n\n';
  const marks = files.map(() => `![Bild ${++placeholders} wird hochgeladen …]()`);
  area.setRangeText(lead + marks.join('\n\n') + trail, area.selectionStart, area.selectionEnd, 'end');

  // One after the other, so two pasted screenshots don't race for the same file name
  uploading++;
  try {
    for (const [i, file] of files.entries()) {
      try {
        const src = await uploadImage(area.form, file, pasted ? 'bild' : file.name);
        replaceText(area, marks[i], `![](${src})`);
      } catch (err) {
        replaceText(area, marks[i], '');
        window.alert(err.message);
      }
    }
  } finally {
    uploading--;
  }
}

const imagesIn = (list) => [...(list?.files ?? [])].filter((file) => file.type.startsWith('image/'));
const closest = (event, selector) => (event.target instanceof Element ? event.target.closest(selector) : null);
const hasFiles = (event) => [...(event.dataTransfer?.types ?? [])].includes('Files');

document.addEventListener('paste', (event) => {
  const area = closest(event, 'textarea[data-images]');
  const files = imagesIn(event.clipboardData);
  // Office programs put a picture of copied text on the clipboard too, then the text wins
  if (!area || !files.length || event.clipboardData.getData('text/plain').trim()) return;
  event.preventDefault();
  insertImages(area, files, true);
});

// Without this a file dropped next to a text field opens in the tab and the form is gone
document.addEventListener('dragover', (event) => {
  if (!hasFiles(event) || closest(event, 'input[type="file"]')) return;
  event.preventDefault();
  event.dataTransfer.dropEffect = closest(event, 'textarea[data-images]') ? 'copy' : 'none';
});

document.addEventListener('drop', (event) => {
  if (!hasFiles(event) || closest(event, 'input[type="file"]')) return;
  event.preventDefault();
  const area = closest(event, 'textarea[data-images]');
  const files = imagesIn(event.dataTransfer);
  if (!area || !files.length) return;
  // The cursor doesn't follow a dropped file, so without one placed in the field the image goes at the end
  if (document.activeElement !== area) area.setSelectionRange(area.value.length, area.value.length);
  area.focus();
  insertImages(area, files, false);
});

document.addEventListener('submit', (event) => {
  const form = event.target;
  if (uploading) {
    event.preventDefault();
    window.alert('Einen Moment noch, die Bilder werden noch hochgeladen.');
    return;
  }
  if (form.dataset.confirm && !window.confirm(form.dataset.confirm)) {
    event.preventDefault();
    return;
  }
  for (const field of form.querySelectorAll('[data-name]')) {
    const indexes = rowIndexes(field);
    let i = 0;
    field.name = field.dataset.name.replace(/#/g, () => indexes[i++] ?? 0);
  }
});

// New project: fill the URL name from the German title until it is edited by hand
const slug = document.querySelector('[data-slug]');
const title = document.querySelector('[data-title]');
if (slug && title && !slug.value) {
  let touched = false;
  slug.addEventListener('input', () => (touched = true));
  title.addEventListener('input', () => {
    if (touched) return;
    slug.value = title.value
      .toLowerCase()
      .replace(/ä/g, 'ae')
      .replace(/ö/g, 'oe')
      .replace(/ü/g, 'ue')
      .replace(/ß/g, 'ss')
      .normalize('NFKD')
      .replace(/[̀-ͯ]/g, '')
      .replace(/[^a-z0-9]+/g, '-')
      .slice(0, 60)
      .replace(/^-+|-+$/g, '');
  });
}