// markdown.js — markdown rendering + embed-URL converters extracted from helpers.js.
// windyToEmbedUrl/youtubeToEmbedUrl/mapsToEmbedUrl + renderMarkdown (hand-rolled).
// Generates inline onclick strings referencing functions in media.js/files.js/
// helpers-core.js (resolved at click time, so load order is not runtime-critical).
function windyToEmbedUrl(url) {
  try {
    var u = new URL(url);
    // Already an embed URL — use as-is
    if (u.hostname === 'embed.windy.com') return url;
    // windy.com map URL → convert to embed
    if (/windy\.com/.test(u.hostname)) {
      var lat = u.searchParams.get('lat') || '';
      var lon = u.searchParams.get('lon') || '';
      var zoom = u.searchParams.get('zoom') || '';
      var overlay = u.searchParams.get('overlay') || '';
      var level = u.searchParams.get('level') || 'surface';
      // Handle windy.com comma format: ?overlay,lat,lon,zoom or pathname /-overlay?overlay,lat,lon,zoom
      if (!lat || !lon) {
        var qs = u.search.slice(1); // e.g. 'radar,36.545,127.974,7'
        var parts = qs.split(',');
        if (parts.length >= 3) {
          overlay = overlay || parts[0];
          lat = parts[1];
          lon = parts[2];
          zoom = zoom || parts[3] || '7';
        }
      }
      lat = lat || '37.5';
      lon = lon || '126.9';
      zoom = zoom || '7';
      overlay = overlay || 'rain';
      // Map radar overlay name
      if (overlay === '-radar' || overlay === 'radar') overlay = 'radar';
      return 'https://embed.windy.com/embed2.html?lat=' + lat + '&lon=' + lon +
             '&zoom=' + zoom + '&level=' + level + '&overlay=' + overlay +
             '&menu=&message=true&marker=&calendar=now&pressure=&type=map' +
             '&location=coordinates&detail=&metricWind=m%2Fs&metricTemp=%C2%B0C';
    }
    return null;
  } catch(e) { return null; }
}

function youtubeToEmbedUrl(url) {
  try {
    var u = new URL(url);
    var id = null;
    if (u.hostname === 'youtu.be') {
      id = u.pathname.slice(1).split(/[/?]/)[0];
    } else if (/youtube\.com/.test(u.hostname)) {
      id = u.searchParams.get('v');
      if (!id) {
        var m = u.pathname.match(/\/(?:shorts|embed)\/([^/?]+)/);
        if (m) id = m[1];
      }
    }
    if (!id) return null;
    var start = u.searchParams.get('t') || u.searchParams.get('start');
    return 'https://www.youtube.com/embed/' + id + (start ? '?start=' + parseInt(start, 10) : '');
  } catch(e) { return null; }
}

function mapsToEmbedUrl(url) {
  try {
    var u = new URL(url);
    var q = null;
    var placeMatch = u.pathname.match(/\/maps\/place\/([^/@?]+)/);
    if (placeMatch) q = decodeURIComponent(placeMatch[1].replace(/\+/g, ' '));
    if (!q) {
      var searchMatch = u.pathname.match(/\/maps\/search\/([^/@?]+)/);
      if (searchMatch) q = decodeURIComponent(searchMatch[1].replace(/\+/g, ' '));
    }
    if (!q) {
      var coordMatch = u.pathname.match(/\/@(-?\d+\.?\d*),(-?\d+\.?\d*)/);
      if (coordMatch) q = coordMatch[1] + ',' + coordMatch[2];
    }
    if (!q) q = u.searchParams.get('q') || u.searchParams.get('query');
    if (!q) return null;
    return 'https://maps.google.com/maps?q=' + encodeURIComponent(q) + '&output=embed&hl=ko';
  } catch(e) { return null; }
}

function renderMarkdown(text, opts) {
  if (!text) return '';

  // Extract existing <img> tags before escaping so they survive escHtml()
  var imgPlaceholders = [];
  var imgRe = /<img\s+[^>]*class=["']md-img["'][^>]*>/gi;
  var textSafe = text.replace(imgRe, function(m) {
    var idx = imgPlaceholders.length;
    imgPlaceholders.push(m);
    return '\x00IMG' + idx + '\x00';
  });

  var html = escHtml(textSafe);

  // Restore <img> tags (already safe HTML)
  imgPlaceholders.forEach(function(img, i) {
    html = html.replace('\x00IMG' + i + '\x00', img);
  });

  // Code blocks (``` ... ```) — escHtml() above already turned literal backticks into
  // &#96; (it escapes backtick/backslash/$ too, not just &<>"'), so matching on literal
  // backticks here never matched anything — every special widget block (midi-widget, abc,
  // lilypond, tradingview, kstock, smiles) silently fell through as escaped plain text.
  // Rendered widget HTML (smiles data-smiles attrs especially) can itself contain raw
  // "[X](Y)"-shaped substrings (SMILES stereo notation like [C@@H](C) reads exactly like
  // markdown link syntax) that the later link/image/bold regexes would then mangle mid-
  // attribute. Stash each block's final HTML behind a placeholder and restore it after
  // all other text transforms have run, the same trick used for <img> above.
  var codeBlockPlaceholders = [];
  html = html.replace(/&#96;&#96;&#96;([\w-]*)\n([\s\S]*?)&#96;&#96;&#96;/g, function(_, lang, code) {
    var result = (function() {
    // code.trim() would strip leading whitespace off only the FIRST line (it operates on
    // the whole string, not per-line), misaligning ASCII-art whose top row is indented
    // (e.g. a right-shifted "O" over a left-aligned structure below it). Only drop fully
    // blank leading/trailing lines so every line's own indentation survives intact.
    var trimmed = code.replace(/^\n+/, '').replace(/\n+$/, '');
    if (lang === 'midi-widget') {
      try {
        var mwRaw = trimmed.replace(/&amp;/g,'&').replace(/&lt;/g,'<').replace(/&gt;/g,'>').replace(/&quot;/gi,'"').replace(/&#39;/g,"'");
        var mwData = JSON.parse(mwRaw);
        var mwFilename = mwData.filename || (mwData.saved_to ? mwData.saved_to.split('/').pop() : 'score.mid');
        return buildMidiPickerWidget(mwData, mwFilename).html;
      } catch(e) {
        return '<pre class="md-code-block"><code>' + escHtml(trimmed) + '</code></pre>';
      }
    }
    if (lang === 'abc' || lang === 'lilypond') {
      var encoded = encodeURIComponent(trimmed);
      var widgetId = 'music-' + Math.random().toString(36).slice(2, 9);
      return '<div class="music-widget" id="' + widgetId + '">' +
        '<div class="music-widget-header">' +
          '<span class="music-widget-label">🎵 ' + (lang === 'abc' ? 'ABC Notation' : 'LilyPond') + '</span>' +
          '<div style="display:flex;gap:6px;align-items:center">' +
            '<button class="music-render-btn" onclick="renderMusicBlock(\'' + widgetId + '\', decodeURIComponent(\'' + encoded + '\'))">악보 렌더링</button>' +
            '<button onclick="toggleMusicWidget(\'' + widgetId + '\')" style="background:none;border:none;cursor:pointer;font-size:14px;color:var(--muted);padding:2px 4px" title="접기/펼치기">▾</button>' +
            '<button onclick="closeMusicWidget(\'' + widgetId + '\')" style="background:none;border:none;cursor:pointer;font-size:14px;color:var(--muted);padding:2px 4px" title="닫기">✕</button>' +
          '</div>' +
        '</div>' +
        '<div class="music-widget-body">' +
          '<pre class="md-code-block music-source" style="margin:0;border-radius:0;border:none;border-bottom:1px solid var(--line);max-height:120px;overflow-y:auto;font-size:11px"><code>' + escHtml(trimmed) + '</code></pre>' +
          '<div class="music-output" style="display:none"></div>' +
        '</div>' +
      '</div>';
    }
    if (lang === 'tradingview') {
      var tvSymbol = '', tvInterval = 'D';
      // code content is already HTML-escaped at this point — unescape before parsing
      var tvRaw = trimmed.replace(/&amp;/g,'&').replace(/&lt;/g,'<').replace(/&gt;/g,'>').replace(/&quot;/gi,'"').replace(/&#39;/g,"'").trim();
      if (tvRaw.startsWith('{')) {
        try {
          var tvJson = JSON.parse(tvRaw);
          tvSymbol = (tvJson.symbol || tvJson.SYMBOL || '').toString().toUpperCase();
          tvInterval = (tvJson.interval || tvJson.INTERVAL || 'D').toString().toUpperCase();
        } catch(e) { tvSymbol = tvRaw.split('|')[0].trim().toUpperCase(); }
      } else {
        var parts = tvRaw.split('|');
        tvSymbol = (parts[0] || '').trim().toUpperCase();
        tvInterval = (parts[1] || 'D').trim().toUpperCase();
      }
      if (!tvSymbol) return '<pre class="md-code-block"><code>' + trimmed + '</code></pre>';
      var tvId = 'tv-' + Math.random().toString(36).slice(2, 9);
      return '<div class="music-widget" id="' + tvId + '">' +
        '<div class="music-widget-header">' +
          '<span class="music-widget-label">📈 ' + escHtml(tvSymbol) + ' · ' + escHtml(tvInterval) + '</span>' +
          '<div style="display:flex;gap:6px;align-items:center">' +
            '<button class="music-render-btn" onclick="renderTVChart(this,\'' + tvId + '-c\',\'' + escHtml(tvSymbol) + '\',\'' + escHtml(tvInterval) + '\')">📈 차트 불러오기</button>' +
            '<button onclick="toggleMusicWidget(\'' + tvId + '\')" style="background:none;border:none;cursor:pointer;font-size:14px;color:var(--muted);padding:2px 4px" title="접기/펼치기">▾</button>' +
            '<button onclick="closeMusicWidget(\'' + tvId + '\')" style="background:none;border:none;cursor:pointer;font-size:14px;color:var(--muted);padding:2px 4px" title="닫기">✕</button>' +
          '</div>' +
        '</div>' +
        '<div class="music-widget-body">' +
          '<div id="' + tvId + '-c" style="height:440px;width:100%"></div>' +
        '</div>' +
      '</div>';
    }
    if (lang === 'kstock') {
      var ksRaw = trimmed.replace(/&amp;/g,'&').replace(/&lt;/g,'<').replace(/&gt;/g,'>').trim();
      var ksParts = ksRaw.split('|');
      var ksCode = ksParts[0].trim().replace(/\D/g,''); // 숫자만 (005930)
      var ksPeriod = (ksParts[1] || 'day').trim().toLowerCase();
      var ksPeriodMap = { '1d':'day','day':'day','1w':'week','week':'week','1m':'month','month':'month','3m':'3month','3month':'3month','1y':'year','year':'year','3y':'3year','3year':'3year' };
      var ksNaverPeriod = ksPeriodMap[ksPeriod] || 'day';
      var ksPeriodLabel = { day:'일봉', week:'주봉', month:'월봉', '3month':'3개월', year:'1년', '3year':'3년' }[ksNaverPeriod] || ksNaverPeriod;
      if (!ksCode) return '<pre class="md-code-block"><code>' + trimmed + '</code></pre>';
      var ksId = 'ks-' + Math.random().toString(36).slice(2, 9);
      var ksImgUrl = 'https://ssl.pstatic.net/imgfinance/chart/item/area/' + ksNaverPeriod + '/' + ksCode + '.png';
      var ksNaverUrl = 'https://finance.naver.com/item/main.naver?code=' + ksCode;
      return '<div class="music-widget" id="' + ksId + '">' +
        '<div class="music-widget-header">' +
          '<span class="music-widget-label">📈 ' + escHtml(ksCode) + ' · ' + escHtml(ksPeriodLabel) + ' · 네이버금융</span>' +
          '<div style="display:flex;gap:6px;align-items:center">' +
            '<a href="' + ksNaverUrl + '" target="_blank" style="font-size:12px;color:var(--muted);text-decoration:none">네이버금융 ↗</a>' +
            '<button onclick="toggleMusicWidget(\'' + ksId + '\')" style="background:none;border:none;cursor:pointer;font-size:14px;color:var(--muted);padding:2px 4px" title="접기/펼치기">▾</button>' +
            '<button onclick="closeMusicWidget(\'' + ksId + '\')" style="background:none;border:none;cursor:pointer;font-size:14px;color:var(--muted);padding:2px 4px" title="닫기">✕</button>' +
          '</div>' +
        '</div>' +
        '<div class="music-widget-body" style="padding:8px;text-align:center">' +
          '<img src="' + ksImgUrl + '" alt="' + escHtml(ksCode) + ' 차트" style="max-width:100%;border-radius:4px" onerror="this.parentNode.innerHTML=\'<span style=\\\"color:var(--muted);font-size:13px\\\">차트를 불러올 수 없습니다.</span>\'">' +
        '</div>' +
      '</div>';
    }
    if (lang === 'smiles') {
      // Also undo escHtml()'s backslash/backtick/$ escaping (not just the amp/lt/gt/quote
      // set the other widget blocks unescape) — SMILES cis/trans bond notation uses
      // backslash (e.g. C/C=C/C), which would otherwise stay mangled as &#92;.
      var smRaw = trimmed.replace(/&amp;/g,'&').replace(/&lt;/g,'<').replace(/&gt;/g,'>').replace(/&quot;/gi,'"').replace(/&#39;/g,"'").replace(/&#96;/g,'`').replace(/&#36;/g,'$').replace(/&#92;/g,'\\').trim();
      if (!smRaw) return '<pre class="md-code-block"><code>' + trimmed + '</code></pre>';
      // Textbook-style: no header/button chrome, auto-rendered by renderSmilesIn() right
      // after insertion (mirrors renderKatexIn — innerHTML doesn't run embedded <script>,
      // so *something* has to trigger the draw call after the SVG lands in the DOM).
      var smId = 'sm-' + Math.random().toString(36).slice(2, 9);
      var smSize = smilesSizeFor(smRaw);
      return '<span class="smiles-inline" data-smiles="' + escHtml(smRaw) + '">' +
        '<svg id="' + smId + '" width="' + smSize.width + '" height="' + smSize.height + '"></svg>' +
      '</span>';
    }
    return '<pre class="md-code-block"><code>' + trimmed + '</code></pre>';
    })();
    var phIdx = codeBlockPlaceholders.length;
    codeBlockPlaceholders.push(result);
    return '\x00CODEBLK' + phIdx + '\x00';
  });

  // Inline code — same escHtml()-escapes-backticks issue as the fenced code blocks above.
  // Content may still contain other entities (&amp;, &lt;, ...), so only exclude another
  // &#96; sequence rather than excluding every '&' (which would truncate on those entities).
  html = html.replace(/&#96;((?:(?!&#96;)[\s\S])+?)&#96;/g, '<code class="md-inline-code">$1</code>');

  // Images: ![alt](url)
  html = html.replace(/!\[([^\]]*)\]\(([^)]+)\)/g, function(_, alt, url) {
    var safeAlt = alt.replace(/"/g, '&quot;');
    var errAlt = (alt || '이미지').replace(/'/g, '&#39;').replace(/</g, '&lt;');
    var onerr = "this.onerror=null;this.style.display='none';this.insertAdjacentHTML('afterend','<span class=&quot;md-img-err&quot;>&#x2716; " + errAlt + "를 불러올 수 없습니다.</span>')";
    return '<img class="md-img" src="' + url + '" alt="' + safeAlt + '" loading="lazy" onclick="openImageZoom(this.src)" onerror="' + onerr + '" />';
  });

  // Links: [text](url) — render download links for file types as buttons, PPTX gets preview
  html = html.replace(/\[([^\]]+)\]\(([^)]+)\)/g, function(_, text, url) {
    return _renderLinkButton(text, url, opts);
  });

  // Bare /api/files/... URLs — auto-convert to download buttons even without markdown syntax
  html = html.replace(/(\s|^)(\/api\/files\/[^\s<"]+)/g, function(_, space, url) {
    return space + _renderLinkButton(decodeURIComponent(url.split('/').pop() || 'download'), url, opts);
  });

  // YouTube URLs on their own line → inline iframe
  html = html.replace(/((?:^|\n)[ \t]*)(https?:\/\/(?:(?:www\.|m\.)?youtube\.com\/(?:watch|shorts|embed)|youtu\.be\/)[^\s<>")\n]*)([ \t]*)(?=\n|$)/gim, function(m, pre, url, post) {
    var embedUrl = youtubeToEmbedUrl(url);
    if (!embedUrl) return m;
    var safeEmbed = embedUrl.replace(/"/g, '&quot;');
    var safeOrig = url.replace(/"/g, '&quot;');
    return pre + '<div class="yt-embed-wrap"><iframe class="yt-embed" src="' + safeEmbed + '" allowfullscreen allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" loading="lazy"></iframe><div class="map-embed-link"><a href="' + safeOrig + '" target="_blank" rel="noopener">YouTube에서 열기 ↗</a></div></div>' + post;
  });

  // Google Maps URLs on their own line → inline iframe
  html = html.replace(/((?:^|\n)[ \t]*)(https?:\/\/(?:www\.google\.com\/maps|maps\.google\.com|goo\.gl\/maps)[^\s<>")\n]*)([ \t]*)(?=\n|$)/gim, function(m, pre, url, post) {
    var embedUrl = mapsToEmbedUrl(url);
    if (!embedUrl) return m;
    var safeEmbed = embedUrl.replace(/"/g, '&quot;');
    var safeOrig = url.replace(/"/g, '&quot;');
    return pre + '<div class="map-embed-wrap"><iframe class="map-embed" src="' + safeEmbed + '" allowfullscreen loading="lazy" referrerpolicy="no-referrer-when-downgrade"></iframe><div class="map-embed-link"><a href="' + safeOrig + '" target="_blank" rel="noopener">Google 지도에서 열기 ↗</a></div></div>' + post;
  });

  // Windy URLs in <img src="..."> (model used ![alt](url) syntax) → inline iframe  [must run first]
  html = html.replace(/<img\s[^>]*src="(https?:\/\/(?:embed\.windy\.com|(?:www\.)?windy\.com)[^"]*)"[^>]*\/?>/gi, function(m, url) {
    var embedUrl = windyToEmbedUrl(url);
    if (!embedUrl) return m;
    var safeEmbed = embedUrl.replace(/"/g, '&quot;');
    var safeOrig = url.replace(/"/g, '&quot;');
    return '<div class="windy-embed-wrap"><iframe class="windy-embed" src="' + safeEmbed + '" allowfullscreen loading="lazy"></iframe><div class="map-embed-link"><a href="' + safeOrig + '" target="_blank" rel="noopener">Windy에서 열기 ↗</a></div></div>';
  });

  // Windy URLs inside anchor tags (markdown links) → inline iframe  [must run BEFORE bare-URL regex]
  html = html.replace(/<a\s[^>]*href="(https?:\/\/(?:embed\.windy\.com|(?:www\.)?windy\.com)[^"]*)"[^>]*>[^<]*<\/a>/gi, function(m, url) {
    var embedUrl = windyToEmbedUrl(url);
    if (!embedUrl) return m;
    var safeEmbed = embedUrl.replace(/"/g, '&quot;');
    var safeOrig = url.replace(/"/g, '&quot;');
    return '<div class="windy-embed-wrap"><iframe class="windy-embed" src="' + safeEmbed + '" allowfullscreen loading="lazy"></iframe><div class="map-embed-link"><a href="' + safeOrig + '" target="_blank" rel="noopener">Windy에서 열기 ↗</a></div></div>';
  });

  // Windy URLs on their own line → inline iframe  [runs after anchor regex to avoid double-render]
  html = html.replace(/((?:^|\n)[ \t]*)(https?:\/\/(?:embed\.windy\.com|(?:www\.)?windy\.com)[^\s<>")\n]*)([ \t]*)(?=\n|$)/gim, function(m, pre, url, post) {
    var embedUrl = windyToEmbedUrl(url);
    if (!embedUrl) return m;
    var safeEmbed = embedUrl.replace(/"/g, '&quot;');
    var safeOrig = url.replace(/"/g, '&quot;');
    return pre + '<div class="windy-embed-wrap"><iframe class="windy-embed" src="' + safeEmbed + '" allowfullscreen loading="lazy"></iframe><div class="map-embed-link"><a href="' + safeOrig + '" target="_blank" rel="noopener">Windy에서 열기 ↗</a></div></div>' + post;
  });

  // Bare image URLs on their own line → inline image
  html = html.replace(/((?:^|\n)[ \t]*)(https?:\/\/[^\s<>"()\n#?]+\.(?:jpe?g|png|gif|webp|svg|bmp|avif|tiff)(?:[?#][^\s<>"()\n]*)?)([ \t]*)(?=\n|$)/gim, function(m, pre, url, post) {
    var onerr = "this.onerror=null;this.style.display='none';this.insertAdjacentHTML('afterend','<span class=&quot;md-img-err&quot;>&#x2716; 이미지를 불러올 수 없습니다.</span>')";
    return pre + '<img class="md-img" src="' + url + '" alt="" loading="lazy" onclick="openImageZoom(this.src)" onerror="' + onerr + '" />' + post;
  });

  // Bold
  html = html.replace(/\*\*([^*]+)\*\*/g, '<strong>$1</strong>');

  // Italic
  html = html.replace(/(?<!\*)\*([^*]+)\*(?!\*)/g, '<em>$1</em>');

  // Markdown tables → HTML (line-by-line, O(n), must run BEFORE \n → <br>)
  (function() {
    var lines = html.split('\n');
    var out = [];
    var parseRow = function(line) {
      var cells = line.trim().split('|');
      if (cells.length && cells[0].trim() === '') cells.shift();
      if (cells.length && cells[cells.length - 1].trim() === '') cells.pop();
      return cells.map(function(c) { return c.trim(); });
    };
    var isSep = function(line) { return /^\|[\s|:\-]+\|[ \t]*$/.test(line.trim()); };
    var isRow = function(line) { return /^\|.+\|[ \t]*$/.test(line.trim()); };
    var i = 0;
    while (i < lines.length) {
      var line = lines[i];
      if (isRow(line) && i + 1 < lines.length && isSep(lines[i + 1])) {
        var tbl = [line, lines[i + 1]];
        var j = i + 2;
        while (j < lines.length && isRow(lines[j])) { tbl.push(lines[j]); j++; }
        var headers = parseRow(tbl[0]);
        var thead = '<thead><tr>' + headers.map(function(h) { return '<th>' + h + '</th>'; }).join('') + '</tr></thead>';
        var tbody = '<tbody>' + tbl.slice(2).map(function(row) {
          return '<tr>' + parseRow(row).map(function(c) { return '<td>' + c + '</td>'; }).join('') + '</tr>';
        }).join('') + '</tbody>';
        out.push('<div class="md-table-wrap"><table class="md-table">' + thead + tbody + '</table></div>');
        i = j;
        continue;
      }
      out.push(line);
      i++;
    }
    html = out.join('\n');
  })();

  // Restore widget HTML stashed before the link/image/bold/table passes above.
  codeBlockPlaceholders.forEach(function(blockHtml, i) {
    html = html.replace('\x00CODEBLK' + i + '\x00', function() { return blockHtml; });
  });

  // Line breaks
  html = html.replace(/\n/g, '<br>');

  return html;
}