/* Progressive enhancement for Adlist Converter. No framework and no network
   calls while composing a link: only /convert retrieves source data. */
(() => {
  'use strict';
  const $ = (selector, parent = document) => parent.querySelector(selector);
  const $$ = (selector, parent = document) => Array.from(parent.querySelectorAll(selector));

  const toastEl = $('#toast');
  let toastTimer;
  function toast(message, isError = false) {
    if (!toastEl) return;
    toastEl.textContent = message;
    toastEl.classList.toggle('error', isError);
    toastEl.classList.add('show');
    clearTimeout(toastTimer);
    toastTimer = setTimeout(() => toastEl.classList.remove('show'), 2600);
  }
  function setTheme(theme) {
    const value = theme === 'light' ? 'light' : 'dark';
    document.documentElement.dataset.theme = value;
    const themeColor = $('meta[name="theme-color"]');
    if (themeColor) themeColor.content = value === 'light' ? '#f4f6f2' : '#131615';
    try { localStorage.setItem('adlist-theme', value); } catch (_) {}
  }
  setTheme(document.documentElement.dataset.theme || 'dark');

  function isValidIPv4(ip) {
    const octets = ip.split('.');
    return octets.length === 4 && octets.every(octet => {
      if (!/^(0|[1-9]\d{0,2})$/.test(octet)) return false;
      return Number(octet) <= 255;
    });
  }
  function isValidIPv6(ip) {
    if (!ip.includes(':') || ip.includes('%') || ip.split('::').length > 2) return false;
    let raw = ip;
    let ipv4Count = 0;
    if (raw.includes('.')) {
      const cut = raw.lastIndexOf(':');
      if (cut < 0 || !isValidIPv4(raw.slice(cut + 1))) return false;
      raw = raw.slice(0, cut) + ':0:0';
      ipv4Count = 1;
    }
    const parts = raw.split(':').filter(Boolean);
    if (!parts.every(part => /^[a-f\d]{1,4}$/i.test(part))) return false;
    if (raw.includes('::')) return parts.length < 8;
    return parts.length === 8 && !raw.startsWith(':') && !raw.endsWith(':');
  }
  function isValidIP(ip) { return isValidIPv4(ip) || isValidIPv6(ip); }

  function normalizeSource(input) {
    const value = (input || '').trim();
    if (!value || /[\r\n]/.test(value)) return null;
    try {
      const candidate = /^[a-z][a-z\d+.-]*:\/\//i.test(value) ? value : `https://${value}`;
      const parsed = new URL(candidate);
      if (!['https:', 'http:'].includes(parsed.protocol) || !parsed.hostname) return null;
      return parsed.toString();
    } catch (_) { return null; }
  }
  function conversionUrl(source, target) {
    const origin = /^https?:$/.test(window.location.protocol) ? window.location.origin : 'https://listapp.linuxiarz.pl';
    const url = new URL('/convert', origin);
    url.searchParams.set('url', source);
    url.searchParams.set('ip', target);
    return url.href;
  }
  function setError(input, message) {
    if (!input) return;
    input.setAttribute('aria-invalid', message ? 'true' : 'false');
    const error = $(`#${input.id === 'url-input' ? 'url-error' : 'ip-error'}`);
    if (error) { error.textContent = message; error.hidden = !message; }
  }
  const urlInput = $('#url-input');
  const ipInput = $('#ip-input');
  const result = $('#generated-link');
  const openLink = $('#open-link');
  const copyBtn = $('#copy-btn');
  const linkState = $('#link-state');
  const validationStatus = $('#validation-status');

  function updateOutput(showErrors = false) {
    if (!urlInput || !ipInput || !result) return;
    const rawSource = urlInput.value.trim();
    const ip = ipInput.value.trim();
    const source = normalizeSource(rawSource);
    const ipValid = isValidIP(ip);
    if (showErrors || rawSource && !source) setError(urlInput, !source && rawSource ? 'Enter a valid HTTP or HTTPS address.' : '');
    if (showErrors || ip && !ipValid) setError(ipInput, !ipValid && ip ? 'Enter a valid IPv4 or IPv6 address.' : '');

    $$('.preset').forEach(button => {
      const selected = ip === button.dataset.ip;
      button.classList.toggle('active', selected);
      button.setAttribute('aria-pressed', String(selected));
    });
    const ready = Boolean(source && ipValid);
    const href = ready ? conversionUrl(source, ip) : '';
    result.value = href;
    if (copyBtn) copyBtn.disabled = !ready;
    if (openLink) {
      openLink.href = href || '#';
      openLink.setAttribute('aria-disabled', String(!ready));
      openLink.tabIndex = ready ? 0 : -1;
    }
    if (linkState) {
      linkState.textContent = ready ? 'LINK READY' : 'AWAITING INPUT';
      linkState.classList.toggle('live', ready);
    }
    const status = validationStatus?.parentElement;
    if (status && validationStatus) {
      status.classList.toggle('ready', ready);
      status.classList.toggle('invalid', Boolean(rawSource && !source || ip && !ipValid));
      validationStatus.textContent = ready ? 'Endpoint ready to copy' : !rawSource ? 'Waiting for a source URL' : !source ? 'Invalid source URL' : !ipValid ? 'Invalid target address' : 'Waiting for valid input';
    }
  }
  [urlInput, ipInput].forEach(input => {
    if (!input) return;
    input.addEventListener('input', () => { setError(input, ''); updateOutput(); });
    input.addEventListener('blur', () => updateOutput(true));
  });
  $('#converter-form')?.addEventListener('submit', event => event.preventDefault());
  $$('.preset').forEach(button => button.addEventListener('click', () => {
    if (!ipInput) return;
    ipInput.value = button.dataset.ip || '';
    setError(ipInput, '');
    updateOutput();
  }));
  updateOutput();

  async function copy(text) {
    if (!text) { toast('Nothing to copy', true); return; }
    try {
      if (!navigator.clipboard?.writeText) throw new Error('Clipboard API unavailable');
      await navigator.clipboard.writeText(text);
      toast('Copied to clipboard');
    } catch (_) {
      const temporary = document.createElement('textarea');
      temporary.value = text;
      temporary.setAttribute('readonly', '');
      temporary.style.cssText = 'position:fixed;left:-9999px;top:0';
      document.body.append(temporary);
      temporary.select();
      try {
        if (!document.execCommand('copy')) throw new Error('Copy rejected');
        toast('Copied to clipboard');
      } catch (_) {
        toast('Copy failed — select the text manually', true);
      } finally { temporary.remove(); }
    }
  }

  document.addEventListener('click', event => {
    const trigger = event.target.closest('[data-action]');
    if (!trigger) return;
    const action = trigger.dataset.action;
    if (action === 'toggle-theme') {
      setTheme(document.documentElement.dataset.theme === 'light' ? 'dark' : 'light');
    } else if (action === 'menu') {
      const open = document.body.classList.toggle('menu-open');
      trigger.setAttribute('aria-expanded', String(open));
    } else if (action === 'clear') {
      if (!urlInput || !ipInput) return;
      urlInput.value = '';
      ipInput.value = '195.187.6.34';
      setError(urlInput, ''); setError(ipInput, '');
      updateOutput();
      urlInput.focus();
    } else if (action === 'copy') {
      const node = $(trigger.dataset.target || '');
      void copy(node?.value ?? node?.textContent ?? '');
    } else if (action === 'copy-text') {
      const value = trigger.dataset.text || '';
      const absolute = value.startsWith('/') ? window.location.origin + value : value;
      void copy(absolute);
    } else if (action === 'use-source') {
      if (!urlInput || !ipInput) return;
      urlInput.value = trigger.dataset.url || '';
      ipInput.value = trigger.dataset.ip || '195.187.6.34';
      setError(urlInput, ''); setError(ipInput, '');
      updateOutput();
      $('#generator')?.scrollIntoView({behavior: 'smooth', block: 'start'});
      toast('Source loaded into generator');
    } else if (action === 'try-again') {
      window.location.reload();
    } else if (action === 'show-all') {
      const table = $(trigger.dataset.target || '');
      if (!table) return;
      $$('[data-extra-row]', table).forEach(row => { row.hidden = false; row.removeAttribute('data-extra-row'); });
      trigger.closest('.table-footer')?.remove();
    }
  });
  document.addEventListener('keydown', event => {
    if (event.key === 'Escape' && document.body.classList.contains('menu-open')) {
      document.body.classList.remove('menu-open');
      $('[data-action="menu"]')?.setAttribute('aria-expanded', 'false');
    }
  });
  document.addEventListener('click', event => {
    if (!document.body.classList.contains('menu-open')) return;
    if (event.target.closest('.sidebar,.menu-toggle')) {
      if (event.target.closest('.sidebar a')) {
        document.body.classList.remove('menu-open');
        $('[data-action="menu"]')?.setAttribute('aria-expanded', 'false');
      }
      return;
    }
    document.body.classList.remove('menu-open');
    $('[data-action="menu"]')?.setAttribute('aria-expanded', 'false');
  });

  $$('[data-filter]').forEach(filter => filter.addEventListener('input', () => {
    const table = $(filter.dataset.filter || '');
    if (!table) return;
    const query = filter.value.trim().toLowerCase();
    let visible = 0;
    $$('tbody tr:not(.empty-row)', table).forEach(row => {
      const match = row.textContent.toLowerCase().includes(query);
      const limited = !query && row.hasAttribute('data-extra-row');
      row.hidden = !match || limited;
      if (!row.hidden) visible++;
    });
    const empty = $(table.id === 'recent-table' ? '#recent-empty' : `[data-empty-for="#${table.id}"]`);
    if (empty) empty.hidden = !query || visible > 0;
  }));
})();