// Shared table logic for history (/api/public) and saved (/api/mine) pages (#57).
// Provides: live search, client-side sort with indicators, row rendering via
// a page-supplied rowHtml(), pagination state, and row click-through.
const PaletteTable = (() => {
  const $ = id => document.getElementById(id);
  const esc = s => { const d = document.createElement('div'); d.textContent = s == null ? '' : s; return d.innerHTML; };
  const fmtSize = n => { if (n == null) return 'none'; if (n < 1024) return n + ' B'; if (n < 1048576) return (n/1024).toFixed(1) + ' KB'; return (n/1048576).toFixed(1) + ' MB'; };
  const ago = ts => {
    const s = Math.floor(Date.now()/1000) - ts;
    if (s < 60) return s + 's ago';
    if (s < 3600) return Math.floor(s/60) + 'm ago';
    if (s < 86400) return Math.floor(s/3600) + 'h ago';
    return Math.floor(s/86400) + 'd ago';
  };

  const sortVal = (it, k) => {
    let v = it[k];
    if (k === 'title' || k === 'custom_slug') v = (v == null || v === '') ? null : String(v).toLowerCase();
    if (k === 'language') v = (v == null || v === '') ? 'text' : String(v).toLowerCase();
    if (k === 'size' || k === 'view_count' || k === 'created_at') return v == null ? -1 : v;
    return v == null ? null : v;
  };

  function init(opts) {
    // opts: {endpoint, perPage, hasPager, rowHtml(it), emptyFiltered, emptyAll}
    const state = { filter: '', sortKey: null, sortDir: 1, page: 1, total: 0 };
    let timer = null;

    function sortItems(items) {
      if (!state.sortKey) return items;
      const k = state.sortKey, dir = state.sortDir;
      return items.slice().sort((a, b) => {
        const va = sortVal(a, k), vb = sortVal(b, k);
        const na = va == null, nb = vb == null;
        if (na && nb) return 0;
        if (na) return 1;
        if (nb) return -1;
        if (va < vb) return -1 * dir;
        if (va > vb) return 1 * dir;
        return (a.created_at || 0) < (b.created_at || 0) ? 1 : -1;
      });
    }

    function matches(it) {
      if (!state.filter) return true;
      const f = state.filter.toLowerCase();
      return (it.title || '').toLowerCase().includes(f) || (it.id || '').toLowerCase().includes(f);
    }

    function renderSortIndicators() {
      document.querySelectorAll('th.sortable').forEach(th => {
        th.classList.toggle('sorted', th.dataset.sort === state.sortKey);
        th.classList.toggle('asc', th.dataset.sort === state.sortKey && state.sortDir === 1);
        th.classList.toggle('desc', th.dataset.sort === state.sortKey && state.sortDir === -1);
      });
    }

    async function load() {
      const spinner = $('search-spinner');
      if (spinner) spinner.style.visibility = 'visible';
      try {
        const filtered = state.filter.length > 0;
        const off = (state.page - 1) * opts.perPage;
        const url = (filtered || state.sortKey)
          ? opts.endpoint + '?limit=500&offset=0'
          : opts.endpoint + '?limit=' + opts.perPage + '&offset=' + off;
        const res = await fetch(url);
        const data = await res.json();
        state.total = data.total;
        let items = filtered ? data.items.filter(matches) : data.items;
        items = sortItems(items);

        const count = $('count');
        if (count) count.textContent = filtered
          ? items.length.toLocaleString() + ' matches (of ' + state.total.toLocaleString() + ' total)'
          : state.total.toLocaleString() + ' total';

        const rows = $('rows'), empty = $('empty');
        if (!items.length) {
          rows.innerHTML = '';
          empty.style.display = 'block';
          empty.textContent = filtered ? opts.emptyFiltered : opts.emptyAll;
        } else {
          empty.style.display = 'none';
          rows.innerHTML = items.map(opts.rowHtml).join('');
        }

        const pager = $('pg'), showing = $('showing');
        if (opts.hasPager && pager && showing) {
          const pages = Math.max(1, Math.ceil(state.total / opts.perPage));
          if (filtered || state.sortKey) {
            showing.textContent = state.sortKey
              ? 'Sorted by ' + state.sortKey + ' (' + (state.sortDir === 1 ? 'ascending' : 'descending') + ') · ' + items.length.toLocaleString() + ' of ' + state.total.toLocaleString()
              : 'Showing ' + items.length.toLocaleString() + ' matches for "' + state.filter + '"';
            pager.innerHTML = '';
          } else {
            showing.textContent = state.total === 0 ? 'Nothing here yet' :
              `Showing ${off+1}–${Math.min(off+opts.perPage, state.total)} of ${state.total.toLocaleString()} · page ${state.page} of ${pages}`;
            const btns = [];
            const add = (label, target, o={}) => btns.push(`<button ${o.on?'class="on"':''} ${o.dis?'disabled':''} data-p="${target}">${label}</button>`);
            add('‹', state.page-1, {dis: state.page===1});
            const win = new Set([1, 2, state.page-1, state.page, state.page+1, pages]);
            let last = 0;
            for (let i = 1; i <= pages; i++) {
              if (win.has(i)) {
                if (last && i - last > 1) btns.push('<span class="dim">…</span>');
                add(String(i), i, {on: i===state.page});
                last = i;
              }
            }
            add('›', state.page+1, {dis: state.page===pages});
            pager.innerHTML = btns.join('');
          }
        } else if (showing) {
          showing.textContent = '';
        }
        renderSortIndicators();
      } finally {
        if (spinner) spinner.style.visibility = 'hidden';
      }
    }

    document.querySelector('thead').addEventListener('click', e => {
      const th = e.target.closest('th.sortable');
      if (!th) return;
      const k = th.dataset.sort;
      if (state.sortKey === k) { state.sortDir = -state.sortDir; } else { state.sortKey = k; state.sortDir = 1; }
      renderSortIndicators();
      load();
    });

    const rows = $('rows');
    if (rows) rows.addEventListener('click', e => {
      const tr = e.target.closest('tr.row[data-href]');
      if (!tr || e.target.closest('a') || e.target.closest('button')) return;
      window.location.href = tr.dataset.href;
    });

    const pg = $('pg');
    if (pg) pg.addEventListener('click', e => {
      const b = e.target.closest('button[data-p]');
      if (!b || b.disabled) return;
      state.page = parseInt(b.dataset.p);
      load();
      window.scrollTo(0, 0);
    });

    const filter = $('filter');
    if (filter) filter.addEventListener('input', e => {
      clearTimeout(timer);
      timer = setTimeout(() => {
        state.filter = e.target.value.trim();
        state.page = 1;
        load();
      }, 200);
    });

    return { load, state, esc, fmtSize, ago };
  }

  return { init, esc, fmtSize, ago };
})();