const BLOCK_ICONS = { morning: '🌅', school: '🎒', after: '⚽', evening: '🌙' };
const WEEKDAYS = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday'];
const WEEKEND = ['Saturday', 'Sunday'];

function debounce(fn, ms) {
  let t;
  return (...args) => {
    clearTimeout(t);
    t = setTimeout(() => fn(...args), ms);
  };
}

// Renders the weekly board. `editable` gates every mutation affordance
// (contenteditable, delete buttons, add-task buttons) — the kiosk view passes
// editable:false and gets a board with nothing but working checkboxes.
function renderCalendar({ calendar, editable, weekdayBoard, weekendWrap, handlers, todayName }) {
  weekdayBoard.innerHTML = '';
  weekendWrap.innerHTML = '';

  const currentLabels = {};
  calendar.blocks.forEach((b) => { currentLabels[b.key] = b.label; });

  function syncLabel(key, sourceEl) {
    document.querySelectorAll(`.label[data-block="${key}"]`).forEach((el) => {
      if (el !== sourceEl) el.textContent = sourceEl.textContent;
    });
    document.querySelectorAll(`.legend-label[data-block="${key}"]`).forEach((el) => {
      el.textContent = sourceEl.textContent;
    });
  }

  function makeTask(dayName, blockKey, task) {
    const row = document.createElement('div');
    row.className = 'task' + (task.done ? ' done' : '') + (editable ? '' : ' kiosk');
    row.dataset.taskId = task.id;

    const cb = document.createElement('input');
    cb.type = 'checkbox';
    cb.checked = task.done;
    cb.onchange = () => {
      row.classList.toggle('done', cb.checked);
      handlers.onToggleDone(task.id, cb.checked);
    };

    const span = document.createElement('div');
    span.className = 'task-text';
    span.textContent = task.text;

    row.appendChild(cb);
    row.appendChild(span);

    if (!editable) {
      // Kiosk mode: the 24px checkbox alone is a poor touch target, so the
      // whole row toggles it. Skip when the tap landed on the checkbox
      // itself — it already handles its own toggle+change natively.
      row.addEventListener('click', (e) => {
        if (e.target === cb) return;
        cb.checked = !cb.checked;
        cb.dispatchEvent(new Event('change'));
      });
    }

    if (editable) {
      span.contentEditable = 'true';
      span.addEventListener('keydown', (e) => {
        if (e.key === 'Enter') { e.preventDefault(); span.blur(); }
      });
      const debouncedEdit = debounce(() => {
        if (span.textContent.trim()) handlers.onTextEdit(task.id, span.textContent.trim());
      }, 500);
      span.addEventListener('input', debouncedEdit);
      span.addEventListener('blur', () => {
        if (!span.textContent.trim()) span.textContent = task.text;
      });

      const del = document.createElement('button');
      del.className = 'del';
      del.textContent = '✕';
      del.onclick = () => {
        row.remove();
        handlers.onDeleteTask(task.id);
      };
      row.appendChild(del);
    }

    return row;
  }

  function makeDayCard(dayName) {
    const card = document.createElement('div');
    card.className = 'day-card' + (dayName === todayName ? ' today' : '');

    const head = document.createElement('div');
    head.className = 'day-head';
    head.innerHTML = `<div class="day-name">${dayName}</div>` +
      (dayName === todayName ? `<div class="today-badge">TODAY</div>` : '');
    card.appendChild(head);

    calendar.blocks.forEach((block) => {
      const blockEl = document.createElement('div');
      blockEl.className = 'block ' + block.key;

      const title = document.createElement('div');
      title.className = 'block-title';

      const iconSpan = document.createElement('span');
      iconSpan.className = 'icon';
      iconSpan.textContent = BLOCK_ICONS[block.key] || '';

      const labelSpan = document.createElement('span');
      labelSpan.className = 'label';
      labelSpan.dataset.block = block.key;
      labelSpan.textContent = currentLabels[block.key];

      if (editable) {
        labelSpan.contentEditable = 'true';
        labelSpan.addEventListener('keydown', (e) => {
          if (e.key === 'Enter') { e.preventDefault(); labelSpan.blur(); }
        });
        const debouncedLabel = debounce(() => {
          if (labelSpan.textContent.trim()) {
            currentLabels[block.key] = labelSpan.textContent.trim();
            handlers.onLabelEdit(block.key, labelSpan.textContent.trim());
          }
        }, 500);
        labelSpan.addEventListener('input', () => { syncLabel(block.key, labelSpan); debouncedLabel(); });
      }

      title.appendChild(iconSpan);
      title.appendChild(labelSpan);
      blockEl.appendChild(title);

      const list = document.createElement('div');
      list.className = 'task-list';
      (calendar.days[dayName][block.key] || []).forEach((task) => {
        list.appendChild(makeTask(dayName, block.key, task));
      });
      blockEl.appendChild(list);

      if (editable) {
        const addBtn = document.createElement('button');
        addBtn.className = 'add-task';
        addBtn.textContent = '+ add task';
        addBtn.onclick = async () => {
          const newTask = await handlers.onAddTask(dayName, block.key, 'New task');
          const row = makeTask(dayName, block.key, newTask);
          list.appendChild(row);
          const span = row.querySelector('.task-text');
          span.focus();
          document.execCommand('selectAll', false, null);
        };
        blockEl.appendChild(addBtn);
      }

      card.appendChild(blockEl);
    });

    return card;
  }

  WEEKDAYS.forEach((d) => weekdayBoard.appendChild(makeDayCard(d)));
  WEEKEND.forEach((d) => weekendWrap.appendChild(makeDayCard(d)));

  return { currentLabels };
}

function renderLegend(legendEl, calendar) {
  legendEl.innerHTML = '';
  calendar.blocks.forEach((block) => {
    const item = document.createElement('span');
    item.className = 'item';
    item.innerHTML = `<span class="dot" style="background:var(--${block.key})"></span>` +
      `<span class="legend-label" data-block="${block.key}">${block.label}</span>`;
    legendEl.appendChild(item);
  });
}