(function () {
  'use strict';

  let schema = [];
  let state = { content: null, theme: null };
  const statusEl = document.getElementById('status');
  const sectionsEl = document.getElementById('sections');
  const navEl = document.getElementById('section-nav');

  function setStatus(text, kind) {
    statusEl.textContent = text;
    statusEl.className = 'status' + (kind ? ' ' + kind : '');
  }

  function el(tag, attrs, children) {
    const node = document.createElement(tag);
    if (attrs) {
      for (const [key, value] of Object.entries(attrs)) {
        if (key === 'class') node.className = value;
        else if (key.startsWith('on') && typeof value === 'function') node.addEventListener(key.slice(2), value);
        else if (value !== undefined && value !== null) node.setAttribute(key, value);
      }
    }
    (children || []).forEach((child) => {
      if (child === null || child === undefined) return;
      node.appendChild(typeof child === 'string' ? document.createTextNode(child) : child);
    });
    return node;
  }

  async function api(path, options) {
    const res = await fetch(path, {
      ...options,
      headers: {
        'X-Admin-Request': '1',
        ...(options && options.body && !(options.body instanceof FormData) ? { 'Content-Type': 'application/json' } : {}),
        ...(options ? options.headers : {}),
      },
    });
    if (res.status === 401) {
      window.location.href = '/admin/login';
      throw new Error('Nicht angemeldet.');
    }
    const data = await res.json().catch(() => ({}));
    if (!res.ok) {
      throw new Error(data.error || `Fehler (${res.status})`);
    }
    return data;
  }

  // --- Field renderers ---

  function textField(field, getValue, setValue) {
    const isArea = field.type === 'textarea' || field.type === 'richtext';
    const input = isArea
      ? el('textarea', { rows: 4, oninput: (e) => setValue(e.target.value) })
      : el('input', {
          type: field.type === 'email' ? 'email' : 'text',
          oninput: (e) => setValue(e.target.value),
        });
    input.value = getValue() || '';
    return el('div', { class: 'field' }, [
      el('label', {}, [field.label]),
      input,
      field.type === 'richtext' ? el('p', { class: 'field-hint' }, ['**fett**, *kursiv* möglich']) : null,
    ]);
  }

  function selectField(field, getValue, setValue) {
    const select = el(
      'select',
      { onchange: (e) => setValue(e.target.value) },
      (field.options || []).map((opt) => {
        const optEl = el('option', { value: opt }, [opt]);
        if (opt === getValue()) optEl.selected = true;
        return optEl;
      })
    );
    return el('div', { class: 'field' }, [el('label', {}, [field.label]), select]);
  }

  function sizeField(field, getValue, setValue) {
    const raw = getValue() || '1rem';
    const numeric = parseFloat(raw) || 1;
    const numberOut = el('span', { class: 'size-value' }, [raw]);
    const slider = el('input', {
      type: 'range',
      min: String(field.min ?? 0.5),
      max: String(field.max ?? 4),
      step: String(field.step ?? 0.025),
      oninput: (e) => {
        const v = `${e.target.value}rem`;
        setValue(v);
        numberOut.textContent = v;
      },
    });
    slider.value = String(numeric);
    return el('div', { class: 'field' }, [el('label', {}, [field.label]), el('div', { class: 'size-field' }, [slider, numberOut])]);
  }

  function boolField(field, getValue, setValue) {
    const input = el('input', { type: 'checkbox', onchange: (e) => setValue(e.target.checked) });
    input.checked = Boolean(getValue());
    const id = 'b_' + Math.random().toString(36).slice(2);
    input.id = id;
    return el('div', { class: 'field field-bool' }, [input, el('label', { for: id }, [field.label])]);
  }

  function clamp255(n) {
    return Math.max(0, Math.min(255, Math.round(n)));
  }

  function toHex(color) {
    const h = (n) => clamp255(n).toString(16).padStart(2, '0');
    return `#${h(color.r)}${h(color.g)}${h(color.b)}`;
  }

  function fromHex(hex, alpha) {
    const m = /^#?([0-9a-f]{2})([0-9a-f]{2})([0-9a-f]{2})$/i.exec(hex.trim());
    if (!m) return null;
    return { r: parseInt(m[1], 16), g: parseInt(m[2], 16), b: parseInt(m[3], 16), a: alpha };
  }

  function colorField(field, getValue, setValue) {
    const color = Object.assign({ r: 0, g: 0, b: 0, a: 1 }, getValue());
    const swatch = el('div', { class: 'color-swatch' });
    const hexInput = el('input', { type: 'text', class: 'color-hex' });
    const nativePicker = el('input', { type: 'color' });

    const channelInputs = {};
    const channelNumbers = {};
    ['r', 'g', 'b'].forEach((ch) => {
      channelInputs[ch] = el('input', { type: 'range', min: '0', max: '255', step: '1' });
      channelNumbers[ch] = el('span', { class: 'channel-value' });
    });
    const alphaInput = el('input', { type: 'range', min: '0', max: '100', step: '1' });
    const alphaNumber = el('span', { class: 'channel-value' });

    function refresh() {
      const hex = toHex(color);
      swatch.style.background = `rgba(${color.r}, ${color.g}, ${color.b}, ${color.a})`;
      hexInput.value = hex;
      nativePicker.value = hex;
      ['r', 'g', 'b'].forEach((ch) => {
        channelInputs[ch].value = String(color[ch]);
        channelNumbers[ch].textContent = String(clamp255(color[ch]));
      });
      alphaInput.value = String(Math.round(color.a * 100));
      alphaNumber.textContent = `${Math.round(color.a * 100)}%`;
    }

    function commit() {
      setValue({ ...color });
      refresh();
    }

    hexInput.addEventListener('change', () => {
      const parsed = fromHex(hexInput.value, color.a);
      if (parsed) {
        color.r = parsed.r;
        color.g = parsed.g;
        color.b = parsed.b;
        commit();
      } else {
        refresh(); // revert invalid input
      }
    });

    nativePicker.addEventListener('input', () => {
      const parsed = fromHex(nativePicker.value, color.a);
      if (parsed) {
        color.r = parsed.r;
        color.g = parsed.g;
        color.b = parsed.b;
        commit();
      }
    });

    ['r', 'g', 'b'].forEach((ch) => {
      channelInputs[ch].addEventListener('input', (e) => {
        color[ch] = clamp255(Number(e.target.value));
        commit();
      });
    });

    alphaInput.addEventListener('input', (e) => {
      color.a = Math.max(0, Math.min(100, Number(e.target.value))) / 100;
      commit();
    });

    refresh();

    return el('div', { class: 'field' }, [
      el('label', {}, [field.label]),
      el('div', { class: 'color-field' }, [
        swatch,
        el('div', { class: 'color-field-controls' }, [
          el('div', { class: 'color-field-row' }, [nativePicker, hexInput]),
          el('div', { class: 'color-channels' }, [
            el('span', { class: 'channel-label' }, ['R']),
            channelInputs.r,
            channelNumbers.r,
            el('span', { class: 'channel-label' }, ['G']),
            channelInputs.g,
            channelNumbers.g,
            el('span', { class: 'channel-label' }, ['B']),
            channelInputs.b,
            channelNumbers.b,
            el('span', { class: 'channel-label' }, ['A']),
            alphaInput,
            alphaNumber,
          ]),
        ]),
      ]),
    ]);
  }

  function imageField(field, getValue, setValue) {
    const preview = el('img', { class: 'image-preview', alt: '' });
    const urlInput = el('input', { type: 'text', placeholder: '/uploads/...' });
    const fileInput = el('input', { type: 'file', accept: 'image/png,image/jpeg,image/webp,image/svg+xml', hidden: true });

    function refresh() {
      const v = getValue() || '';
      if (v) preview.setAttribute('src', v);
      else preview.removeAttribute('src');
      preview.style.visibility = v ? 'visible' : 'hidden';
      urlInput.value = v;
    }

    urlInput.addEventListener('change', () => {
      setValue(urlInput.value.trim());
      refresh();
    });

    fileInput.addEventListener('change', async () => {
      const file = fileInput.files[0];
      if (!file) return;
      const formData = new FormData();
      formData.append('file', file);
      setStatus('Bild wird hochgeladen …');
      try {
        const data = await api('/admin/api/upload', { method: 'POST', body: formData });
        setValue(data.url);
        refresh();
        setStatus('Bild hochgeladen.', 'ok');
      } catch (err) {
        setStatus(err.message, 'error');
      }
    });

    const uploadBtn = el('button', { type: 'button', onclick: () => fileInput.click() }, ['Hochladen']);
    const clearBtn = el('button', {
      type: 'button',
      class: 'btn-ghost',
      onclick: () => {
        setValue('');
        refresh();
      },
    }, ['Entfernen']);

    refresh();

    return el('div', { class: 'field' }, [
      el('label', {}, [field.label]),
      el('div', { class: 'image-field' }, [
        preview,
        el('div', { class: 'image-field-controls' }, [uploadBtn, clearBtn, urlInput, fileInput]),
      ]),
    ]);
  }

  function renderFieldGroup(fields, getObj) {
    const container = el('div', {}, []);
    fields.forEach((field) => {
      const getValue = () => getObj()[field.key];
      const setValue = (v) => {
        getObj()[field.key] = v;
      };
      if (field.type === 'boolean') {
        container.appendChild(boolField(field, getValue, setValue));
      } else if (field.type === 'image') {
        container.appendChild(imageField(field, getValue, setValue));
      } else if (field.type === 'select') {
        container.appendChild(selectField(field, getValue, setValue));
      } else if (field.type === 'size') {
        container.appendChild(sizeField(field, getValue, setValue));
      } else if (field.type === 'color') {
        container.appendChild(colorField(field, getValue, setValue));
      } else if (field.type === 'group') {
        container.appendChild(
          el('fieldset', { class: 'group-field' }, [
            el('legend', {}, [field.label]),
            renderFieldGroup(field.itemFields, () => getObj()[field.key]),
          ])
        );
      } else if (field.type === 'list-string' || field.type === 'list-richtext') {
        container.appendChild(renderStringList(field, getObj));
      } else if (field.type === 'list-object') {
        container.appendChild(renderObjectList(field, getObj));
      } else {
        container.appendChild(textField(field, getValue, setValue));
      }
    });
    return container;
  }

  function renderStringList(field, getObj) {
    const wrap = el('div', { class: 'field' }, [el('label', {}, [field.label])]);
    const listEl = el('div', {}, []);

    function draw() {
      listEl.innerHTML = '';
      const arr = getObj()[field.key];
      arr.forEach((_, i) => {
        const input = field.type === 'list-richtext'
          ? el('textarea', { rows: 2 })
          : el('input', { type: 'text' });
        input.value = arr[i];
        input.addEventListener('input', (e) => {
          arr[i] = e.target.value;
        });
        const removeBtn = el('button', {
          type: 'button',
          class: 'remove-btn',
          onclick: () => {
            arr.splice(i, 1);
            draw();
          },
        }, ['✕']);
        listEl.appendChild(el('div', { class: 'list-string-row' }, [input, removeBtn]));
      });
    }

    draw();

    const addBtn = el('button', {
      type: 'button',
      class: 'add-btn',
      onclick: () => {
        getObj()[field.key].push('');
        draw();
      },
    }, ['+ hinzufügen']);

    wrap.appendChild(listEl);
    wrap.appendChild(addBtn);
    return wrap;
  }

  function emptyItemFor(itemFields) {
    const obj = {};
    itemFields.forEach((f) => {
      if (f.type === 'boolean') obj[f.key] = false;
      else if (f.type === 'list-string' || f.type === 'list-richtext' || f.type === 'list-object') obj[f.key] = [];
      else if (f.type === 'color') obj[f.key] = { r: 0, g: 0, b: 0, a: 1 };
      else if (f.type === 'group') obj[f.key] = emptyItemFor(f.itemFields);
      else obj[f.key] = '';
    });
    return obj;
  }

  function renderObjectList(field, getObj) {
    const wrap = el('div', { class: 'field' }, [el('label', {}, [field.label])]);
    const listEl = el('div', {}, []);

    function draw() {
      listEl.innerHTML = '';
      const arr = getObj()[field.key];
      arr.forEach((item, i) => {
        const header = el('div', { class: 'list-item-card-header' }, [
          el('span', {}, [`${field.itemLabel || 'Eintrag'} ${i + 1}`]),
          el('button', {
            type: 'button',
            class: 'remove-btn',
            onclick: () => {
              arr.splice(i, 1);
              draw();
            },
          }, ['Entfernen']),
        ]);
        const body = renderFieldGroup(field.itemFields, () => arr[i]);
        listEl.appendChild(el('div', { class: 'list-item-card' }, [header, body]));
      });
    }

    draw();

    const addBtn = el('button', {
      type: 'button',
      class: 'add-btn',
      onclick: () => {
        getObj()[field.key].push(emptyItemFor(field.itemFields));
        draw();
      },
    }, [`+ ${field.itemLabel || 'Eintrag'} hinzufügen`]);

    wrap.appendChild(listEl);
    wrap.appendChild(addBtn);
    return wrap;
  }

  function renderSection(section) {
    const id = 'section-' + section.key;
    const fileKind = section.file || 'content';
    const block = el('section', { class: 'section-block', id }, [el('h2', {}, [section.label])]);

    if (section.type === 'array-root') {
      const listField = { key: '__root__', itemLabel: section.itemLabel, itemFields: section.itemFields, label: '' };
      const fakeGetObj = () => ({ __root__: state[fileKind][section.key] });
      const wrap = renderObjectList(listField, fakeGetObj);
      wrap.querySelector('label').remove();
      block.appendChild(wrap);
    } else {
      block.appendChild(renderFieldGroup(section.fields, () => state[fileKind][section.key]));
    }

    return block;
  }

  function renderAll() {
    sectionsEl.innerHTML = '';
    navEl.innerHTML = '';
    schema.forEach((section) => {
      sectionsEl.appendChild(renderSection(section));
      navEl.appendChild(el('a', { href: '#section-' + section.key }, [section.label]));
    });
  }

  async function load() {
    setStatus('Lädt …');
    const [fetchedSchema, content, theme] = await Promise.all([
      api('/admin/api/schema'),
      api('/admin/api/content'),
      api('/admin/api/theme'),
    ]);
    schema = fetchedSchema;
    state = { content, theme };
    renderAll();
    setStatus('Bereit.');
  }

  async function save() {
    setStatus('Speichert …');
    document.getElementById('save-btn').disabled = true;
    document.getElementById('publish-btn').disabled = true;
    try {
      await Promise.all([
        api('/admin/api/content', { method: 'PUT', body: JSON.stringify(state.content) }),
        api('/admin/api/theme', { method: 'PUT', body: JSON.stringify(state.theme) }),
      ]);
      setStatus('Gespeichert.', 'ok');
      return true;
    } catch (err) {
      setStatus(err.message, 'error');
      return false;
    } finally {
      document.getElementById('save-btn').disabled = false;
      document.getElementById('publish-btn').disabled = false;
    }
  }

  async function publish() {
    const saved = await save();
    if (!saved) return;
    setStatus('Veröffentlicht wird gebaut …');
    const logEl = document.getElementById('log');
    const logOutput = document.getElementById('log-output');
    try {
      const result = await api('/admin/api/publish', { method: 'POST' });
      logOutput.textContent = result.output || '';
      logEl.hidden = false;
      setStatus('Veröffentlicht.', 'ok');
    } catch (err) {
      setStatus(err.message, 'error');
      logOutput.textContent = err.message;
      logEl.hidden = false;
    }
  }

  document.getElementById('save-btn').addEventListener('click', save);
  document.getElementById('publish-btn').addEventListener('click', publish);
  document.getElementById('log-close').addEventListener('click', () => {
    document.getElementById('log').hidden = true;
  });

  load().catch((err) => setStatus(err.message, 'error'));
})();