// SvxPortal — web front-end for SvxReflector
// Copyright (C) 2026 SA7AUX (Björn)
// SPDX-License-Identifier: AGPL-3.0-or-later
//
// This program is free software: you can redistribute it and/or modify it under
// the terms of the GNU Affero General Public License as published by the Free
// Software Foundation, either version 3 of the License, or (at your option) any
// later version. See the LICENSE file for details.

// changelog.js — shared "recent updates" viewer (dmr-web, svx-web).
// Canonical copy: callmgr2/www-mumien/lib/changelog.js; other repos carry a COPY.
// Reads changelog.json (newest first, {date, repo, hash, type, summary}) and
// renders a client-side paginated list. Needs lib/fmt.js (escHtml).
//
//   const ch = changelogViewer({ body: 'chBody', pager: 'chPager', fetchAt: 'chFetchAt',
//                                url: 'changelog.json', perPage: 6 });
//   ch.load();   // fetch once, render; later calls just re-render
(function () {
  'use strict';
  function changelogViewer(opts) {
    opts = opts || {};
    const ids = { body: opts.body || 'chBody', pager: opts.pager || 'chPager', fetchAt: opts.fetchAt || 'chFetchAt' };
    const url = opts.url || 'changelog.json';
    const perPage = opts.perPage || 6;
    const $ = id => document.getElementById(id);
    let entries = null, page = 0, wired = false;

    function typeBadge(t) {
      const m = { feature: ['Added', 'bg-success'], fix: ['Fix', 'bg-danger'],
                  change: ['Change', 'bg-info text-dark'] };
      const x = m[String(t || '').toLowerCase()] || [t || '—', 'bg-secondary'];
      return `<span class="badge ${x[1]}" style="font-size:9px;">${escHtml(x[0])}</span>`;
    }
    function render() {
      const body = $(ids.body), pager = $(ids.pager);
      if (!body || !entries) return;
      const n = entries.length, pages = Math.max(1, Math.ceil(n / perPage));
      page = Math.min(Math.max(0, page), pages - 1);
      const start = page * perPage;
      const rows = entries.slice(start, start + perPage).map(e => `
        <div class="d-flex align-items-start gap-2 py-1" style="border-bottom:1px solid rgba(128,128,128,.15);">
          <span class="text-secondary mono" style="min-width:78px;">${escHtml(e.date || '')}</span>
          ${typeBadge(e.type)}
          <span class="flex-grow-1">${escHtml(e.summary || '')}</span>
          <span class="text-secondary mono" style="font-size:10px;" title="${escHtml(e.repo || '')} ${escHtml(e.hash || '')}">${escHtml(e.repo || '')} ${escHtml(e.hash || '')}</span>
        </div>`).join('');
      body.innerHTML = rows || '<div class="text-secondary">No entries.</div>';
      if (!pager) return;
      if (pages <= 1) { pager.innerHTML = ''; return; }
      const btn = (label, p, dis, act) =>
        `<button class="btn btn-sm ${act ? 'btn-primary' : 'btn-outline-secondary'}" style="padding:1px 8px;" ${dis ? 'disabled' : ''} data-chpage="${p}">${label}</button>`;
      let h = btn('«', 0, page === 0) + btn('‹', page - 1, page === 0);
      const lo = Math.max(0, page - 2), hi = Math.min(pages - 1, page + 2);
      for (let p = lo; p <= hi; p++) h += btn(String(p + 1), p, false, p === page);
      h += btn('›', page + 1, page === pages - 1) + btn('»', pages - 1, page === pages - 1);
      h += `<select class="form-select form-select-sm" style="width:auto;padding:1px 6px;" id="chPageSel" title="Jump to page">` +
        Array.from({ length: pages }, (_, p) => `<option value="${p}" ${p === page ? 'selected' : ''}>${p + 1}/${pages}</option>`).join('') + `</select>`;
      pager.innerHTML = h;
    }
    async function load() {
      if (!wired) {
        wired = true;
        const pager = $(ids.pager);
        if (pager) {
          pager.addEventListener('click', ev => {
            const b = ev.target.closest('[data-chpage]'); if (!b) return;
            page = parseInt(b.dataset.chpage, 10) || 0; render();
          });
          pager.addEventListener('change', ev => {
            if (ev.target && ev.target.id === 'chPageSel') { page = parseInt(ev.target.value, 10) || 0; render(); }
          });
        }
      }
      if (entries) { render(); return; }
      try {
        const r = await fetch(url + '?_=' + Date.now(), { credentials: 'omit' });
        const j = await r.json();
        entries = Array.isArray(j) ? j : (j.entries || []);
        const fa = $(ids.fetchAt);
        if (fa && entries[0]) fa.textContent = 'latest ' + (entries[0].date || '');
        render();
      } catch (_) {
        const b = $(ids.body); if (b) b.innerHTML = '<div class="text-secondary">Changelog unavailable.</div>';
      }
    }
    return { load, render };
  }
  window.changelogViewer = changelogViewer;
})();