/* SVG Code Converter: upload SVG, view/clean code, copy and export.
   Everything is done client-side. */

(() => {
  const els = {
    dropzone: document.getElementById('dropzone'),
    fileInput: document.getElementById('fileInput'),
    uploadError: document.getElementById('uploadError'),
    preview: document.getElementById('preview'),
    svgMeta: document.getElementById('svgMeta'),
    codeOutput: document.getElementById('codeOutput'),
    copyBtn: document.getElementById('copyBtn'),
    minifyToggle: document.getElementById('minifyToggle'),
    stripComments: document.getElementById('stripComments'),
    stripMetadata: document.getElementById('stripMetadata'),
    prettyPrint: document.getElementById('prettyPrint'),
    keepViewBox: document.getElementById('keepViewBox'),
    downloadSvgBtn: document.getElementById('downloadSvgBtn'),
    downloadPngBtn: document.getElementById('downloadPngBtn'),
    themeToggle: document.getElementById('themeToggle'),
    themeIcon: document.getElementById('themeIcon'),
    codeInfo: document.getElementById('codeInfo'),
  };

  const state = {
    rawSvg: '',
    cleanSvg: '',
    fileName: 'image.svg',
    svgEl: null,
    dark: null,
  };

  // Theme handling
  const initTheme = () => {
    const stored = localStorage.getItem('theme');
    const prefersDark = window.matchMedia('(prefers-color-scheme: dark)').matches;
    state.dark = stored ? stored === 'dark' : prefersDark;
    document.documentElement.classList.toggle('dark', state.dark);
    setThemeIcon();
  };

  const setThemeIcon = () => {
    els.themeIcon.innerHTML = state.dark
      ? '<path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M20.354 15.354A9 9 0 018.646 3.646 9.003 9.003 0 0012 21a9.003 9.003 0 008.354-5.646z"/>'
      : '<path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M12 3v1m0 16v1m9-9h-1M4 12H3m15.364 6.364l-.707-.707M6.343 6.343l-.707-.707m12.728 0l-.707.707M6.343 17.657l-.707.707M16 12a4 4 0 11-8 0 4 4 0 018 0z"/>';
  };

  els.themeToggle.addEventListener('click', () => {
    state.dark = !state.dark;
    document.documentElement.classList.toggle('dark', state.dark);
    localStorage.setItem('theme', state.dark ? 'dark' : 'light');
    setThemeIcon();
  });

  // Utilities
  const showError = (msg) => {
    els.uploadError.textContent = msg;
    els.uploadError.classList.remove('hidden');
    setTimeout(() => els.uploadError.classList.add('hidden'), 5000);
  };

  const fmtBytes = (n) => {
    if (n < 1024) return `${n} B`;
    if (n < 1024 * 1024) return `${(n / 1024).toFixed(1)} KB`;
    return `${(n / (1024 * 1024)).toFixed(2)} MB`;
  };

  const decodeSvgText = (text) => {
    // Remove BOM and decode numeric entities robustly
    return text.replace(/^\uFEFF/, '').replace(/&nbsp;/g, ' ');
  };

  const stripComments = (str) => str.replace(/<!--([\s\S]*?)-->/g, '');

  const stripSvgMetadata = (str) => {
    // Remove sodipodi/inkscape metadata, editors' data, and XML processing instructions
    return str
      .replace(/<\?xml[\s\S]*?\?>/g, '')
      .replace(/<!DOCTYPE[\s\S]*?>/gi, '')
      .replace(/\s+(sodipodi:|inkscape:|xml:space)="[^"]*"/gi, '')
      .replace(/\s+(sodipodi:|inkscape:)[^=\s>]+/gi, '')
      .replace(/\s+data-name="[^"]*"/gi, '')
      .replace(/>\s+</g, '><')
      .trim();
  };

  const ensureViewBox = (svgString) => {
    // If viewBox is present, keep it; otherwise try to infer from width/height
    const hasViewBox = /viewBox\s*=/.test(svgString);
    if (hasViewBox) return svgString;

    const widthMatch = svgString.match(/\bwidth\s*=\s*["']?([0-9.]+)(px)?["']?/i);
    const heightMatch = svgString.match(/\bheight\s*=\s*["']?([0-9.]+)(px)?["']?/i);

    if (widthMatch && heightMatch) {
      const w = parseFloat(widthMatch[1]);
      const h = parseFloat(heightMatch[1]);
      if (isFinite(w) && isFinite(h) && w > 0 && h > 0) {
        // Insert or replace viewBox right after opening <svg ... >
        return svgString.replace(
          /<svg([^>]*?)>/i,
          `<svg$1 viewBox="0 0 ${w} ${h}">`
        );
      }
    }
    return svgString;
  };

  const cleanSvg = (raw, opts) => {
    let s = raw;

    // Normalize newlines and decode
    s = decodeSvgText(s.replace(/\r\n?/g, '\n'));

    if (opts.stripComments) s = stripComments(s);
    if (opts.stripMetadata) s = stripSvgMetadata(s);

    if (opts.minify) {
      // Minify: remove unnecessary whitespace between tags, collapse spaces between attributes
      s = s
        .replace(/>\s+</g, '><')
        .replace(/\s{2,}/g, ' ')
        .replace(/\s*=\s*/g, '=')
        .replace(/\s*([<>"'])\s*/g, '$1')
        .trim();
    } else if (opts.pretty) {
      s = prettyXml(s);
    }

    if (opts.keepViewBox) {
      s = ensureViewBox(s);
    }

    return s;
  };

  const prettyXml = (xml) => {
    // Simple pretty printer for XML/SVG
    try {
      const PADDING = '  ';
      const reg = /(>)(<)(\/*)/g;
      let xmlStr = xml.replace(reg, '$1\r\n$2$3');
      let pad = 0;
      return xmlStr.split('\r\n').map((line) => {
        if (line.match(/.+<\/\w[^>]*>$/)) {
          // Single line
          return (PADDING.repeat(pad)) + line;
        }
        if (line.match(/^<\/\w/)) {
          // Closing tag
          pad = Math.max(pad - 1, 0);
          return (PADDING.repeat(pad)) + line;
        }
        if (line.match(/^<\w[^>]*[^\/]>.*$/)) {
          // Opening tag
          const out = (PADDING.repeat(pad)) + line;
          pad += 1;
          return out;
        }
        return (PADDING.repeat(pad)) + line;
      }).join('\n');
    } catch {
      return xml;
    }
  };

  const updateCodeInfo = () => {
    const text = els.codeOutput.value;
    const lines = (text.match(/\n/g) || []).length + 1;
    const chars = text.length.toLocaleString();
    els.codeInfo.textContent = `${lines} lines • ${chars} chars`;
  };

  const renderPreview = (svgString) => {
    els.preview.innerHTML = '';
    if (!svgString) {
      const div = document.createElement('div');
      div.className = 'text-center text-gray-500';
      div.innerHTML = '<svg xmlns="http://www.w3.org/2000/svg" class="mx-auto w-10 h-10 mb-2 text-gray-400" viewBox="0 0 24 24" fill="none" stroke="currentColor"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M4 16l4.586-4.586a2 2 0 012.828 0L16 16m-2-2l1.586-1.586a2 2 0 012.828 0L20 14m-6-6h.01M6 20h12a2 2 0 002-2V6a2 2 0 00-2-2H6a2 2 0 00-2 2v12a2 2 0 002 2z"/></svg><p>SVG preview will appear here</p>';
      els.preview.appendChild(div);
      return;
    }
    const wrapper = document.createElement('div');
    wrapper.className = 'w-full h-full flex items-center justify-center overflow-auto';
    // Parse and insert safely
    const parser = new DOMParser();
    const doc = parser.parseFromString(svgString, 'image/svg+xml');
    const parseError = doc.querySelector('parsererror');
    if (parseError) {
      const err = document.createElement('div');
      err.className = 'text-red-600 text-sm';
      err.textContent = 'Invalid SVG: ' + parseError.textContent;
      els.preview.appendChild(err);
      return;
    }
    const svg = doc.documentElement;
    svg.classList.remove('hidden');
    svg.removeAttribute('width');
    svg.removeAttribute('height');
    svg.setAttribute('preserveAspectRatio', 'xMidYMid meet');
    svg.style.maxWidth = '100%';
    svg.style.maxHeight = '100%';
    wrapper.appendChild(svg);
    els.preview.appendChild(wrapper);
    state.svgEl = svg;
  };

  const updateAll = () => {
    const opts = {
      minify: els.minifyToggle.checked,
      stripComments: els.stripComments.checked,
      stripMetadata: els.stripMetadata.checked,
      pretty: els.prettyPrint.checked && !els.minifyToggle.checked,
      keepViewBox: els.keepViewBox.checked,
    };
    const cleaned = cleanSvg(state.rawSvg, opts);
    state.cleanSvg = cleaned;
    els.codeOutput.value = cleaned;
    updateCodeInfo();
    renderPreview(cleaned);
    els.downloadSvgBtn.disabled = !cleaned;
    els.downloadPngBtn.disabled = !cleaned;
  };

  const handleFile = (file) => {
    if (!file) return;
    if (!/\.svg$/i.test(file.name) && file.type !== 'image/svg+xml') {
      showError('Please select a valid SVG file.');
      return;
    }
    const maxSize = 5 * 1024 * 1024;
    if (file.size > maxSize) {
      showError('File is too large. Max 5 MB.');
      return;
    }
    state.fileName = file.name.endsWith('.svg') ? file.name : (file.name.replace(/\.[^.]+$/, '') + '.svg');
    const reader = new FileReader();
    reader.onload = () => {
      state.rawSvg = String(reader.result || '');
      updateAll();
      els.svgMeta.textContent = `${file.name} • ${fmtBytes(file.size)}`;
    };
    reader.onerror = () => showError('Failed to read the file.');
    reader.readAsText(file);
  };

  // Drag & drop
  const preventDefaults = (e) => { e.preventDefault(); e.stopPropagation(); };
  ['dragenter', 'dragover', 'dragleave', 'drop'].forEach((evt) => {
    els.dropzone.addEventListener(evt, preventDefaults, false);
  });
  els.dropzone.addEventListener('dragover', () => {
    els.dropzone.classList.add('border-primary-400');
  });
  els.dropzone.addEventListener('dragleave', () => {
    els.dropzone.classList.remove('border-primary-400');
  });
  els.dropzone.addEventListener('drop', (e) => {
    els.dropzone.classList.remove('border-primary-400');
    const file = e.dataTransfer.files?.[0];
    handleFile(file);
  });
  els.dropzone.addEventListener('click', () => els.fileInput.click());
  els.fileInput.addEventListener('change', () => handleFile(els.fileInput.files?.[0]));

  // Controls
  els.copyBtn.addEventListener('click', async () => {
    try {
      await navigator.clipboard.writeText(els.codeOutput.value);
      const original = els.copyBtn.textContent;
      els.copyBtn.textContent = 'Copied!';
      setTimeout(() => (els.copyBtn.textContent = original), 1200);
    } catch {
      showError('Clipboard write failed. Select the code and copy manually.');
    }
  });

  [els.minifyToggle, els.stripComments, els.stripMetadata, els.prettyPrint, els.keepViewBox].forEach((el) => {
    el.addEventListener('change', updateAll);
  });

  els.downloadSvgBtn.addEventListener('click', () => {
    if (!state.cleanSvg) return;
    const blob = new Blob([state.cleanSvg], { type: 'image/svg+xml;charset=utf-8' });
    const a = document.createElement('a');
    a.href = URL.createObjectURL(blob);
    a.download = state.fileName || 'image.svg';
    document.body.appendChild(a);
    a.click();
    a.remove();
    setTimeout(() => URL.revokeObjectURL(a.href), 2000);
  });

  els.downloadPngBtn.addEventListener('click', async () => {
    if (!state.cleanSvg) return;
    try {
      const { image, width, height } = await rasterizeSvg(state.cleanSvg, 2); // 2x scale
      const a = document.createElement('a');
      a.href = image.src;
      a.download = (state.fileName || 'image').replace(/\.svg$/i, '') + '.png';
      document.body.appendChild(a);
      a.click();
      a.remove();
    } catch (err) {
      console.error(err);
      showError('Failed to export PNG.');
    }
  });

  const rasterizeSvg = (svgString, scale = 1) => {
    return new Promise((resolve, reject) => {
      const svgBlob = new Blob([svgString], { type: 'image/svg+xml;charset=utf-8' });
      const url = URL.createObjectURL(svgBlob);
      const img = new Image();
      img.onload = () => {
        // Determine final dimensions
        const width = Math.max(1, Math.ceil(img.naturalWidth * scale) || 1024);
        const height = Math.max(1, Math.ceil(img.naturalHeight * scale) || 1024);
        const canvas = document.createElement('canvas');
        canvas.width = width;
        canvas.height = height;
        const ctx = canvas.getContext('2d');
        // Optional: white background for non-opaque exports
        ctx.fillStyle = 'white';
        ctx.fillRect(0, 0, width, height);
        ctx.drawImage(img, 0, 0, width, height);
        canvas.toBlob((blob) => {
          if (!blob) {
            URL.revokeObjectURL(url);
            reject(new Error('Canvas toBlob failed'));
            return;
          }
          const image = new Image();
          image.onload = () => {
            URL.revokeObjectURL(url);
            resolve({ image, width, height });
          };
          image.onerror = () => {
            URL.revokeObjectURL(url);
            reject(new Error('Image load failed'));
          };
          image.src = URL.createObjectURL(blob);
        }, 'image/png');
      };
      img.onerror = () => {
        URL.revokeObjectURL(url);
        reject(new Error('Invalid SVG'));
      };
      img.src = url;
    });
  };

  // Initialize
  initTheme();
  updateAll();
})();