Sync generate.py with Java version and add generateog.py

generate.py:
- Fix render_social_share to include category in share URLs
- Add ogImage token for per-pattern OG meta tags

generateog.py (new):
- Python equivalent of generateog.java
- Syntax-highlighted SVG+PNG cards (1200x630, 2x PNG)
- Same layout, palette, and dynamic font sizing as Java version
- Uses cairosvg for PNG conversion

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: brunoborges

html-generators/generate.py

@@ -367,9 +367,9 @@ def render_proof_section(data, strings):
     )
 
 
-def render_social_share(tpl, slug, title, strings):
+def render_social_share(tpl, category, slug, title, strings):
     """Render social share URLs."""
-    encoded_url = url_encode(f"{BASE_URL}/{slug}.html")
+    encoded_url = url_encode(f"{BASE_URL}/{category}/{slug}.html")
     encoded_text = url_encode(f"{title} \u2013 java.evolved")
     return replace_tokens(tpl, {
         "encodedUrl": encoded_url,
@@ -550,8 +550,9 @@ def generate_html(templates, data, all_snippets, extra_tokens, locale):
         "relatedCards": render_related_section(
             templates["related_card"], data, all_snippets, locale, extra_tokens
         ),
+        "ogImage": f"{BASE_URL}/og/{cat}/{slug}.png",
         "socialShare": render_social_share(
-            templates["social_share"], slug, data["title"], extra_tokens
+            templates["social_share"], cat, slug, data["title"], extra_tokens
         ),
     })
 

html-generators/generateog.py

@@ -0,0 +1,334 @@
+#!/usr/bin/env python3
+"""
+Generate Open Graph SVG+PNG cards (1200×630) for each pattern.
+Light theme, side-by-side Old/Modern code, slug title at top.
+Python equivalent of generateog.java — produces identical output.
+
+Usage: python html-generators/generateog.py [category/slug]
+       No arguments → generate all patterns.
+
+Requires: cairosvg (pip install cairosvg)
+"""
+
+import json
+import os
+import re
+import sys
+import glob as glob_mod
+from collections import OrderedDict
+
+try:
+    import yaml
+except ImportError:
+    yaml = None
+
+try:
+    import cairosvg
+except ImportError:
+    cairosvg = None
+
+CONTENT_DIR = "content"
+OUTPUT_DIR = "site/og"
+CATEGORIES_FILE = "html-generators/categories.properties"
+
+# ── Light-theme palette ─────────────────────────────────────────────────
+BG         = "#ffffff"
+BORDER     = "#d8d8e0"
+TEXT       = "#1a1a2e"
+TEXT_MUTED = "#6b7280"
+OLD_BG     = "#fef2f2"
+MODERN_BG  = "#eff6ff"
+OLD_ACCENT = "#dc2626"
+GREEN      = "#059669"
+ACCENT     = "#6366f1"
+BADGE_BG   = "#f3f4f6"
+
+# ── Syntax highlight colors (VS Code light-inspired) ────────────────────
+SYN_KEYWORD    = "#7c3aed"
+SYN_TYPE       = "#0e7490"
+SYN_STRING     = "#059669"
+SYN_COMMENT    = "#6b7280"
+SYN_ANNOTATION = "#b45309"
+SYN_NUMBER     = "#c2410c"
+SYN_DEFAULT    = "#1a1a2e"
+
+JAVA_KEYWORDS = {
+    "abstract", "assert", "boolean", "break", "byte", "case", "catch", "char",
+    "class", "const", "continue", "default", "do", "double", "else", "enum",
+    "extends", "final", "finally", "float", "for", "goto", "if", "implements",
+    "import", "instanceof", "int", "interface", "long", "native", "new", "null",
+    "package", "private", "protected", "public", "record", "return", "sealed",
+    "short", "static", "strictfp", "super", "switch", "synchronized", "this",
+    "throw", "throws", "transient", "try", "var", "void", "volatile", "when",
+    "while", "with", "yield", "permits", "non-sealed", "module", "open", "opens",
+    "requires", "exports", "provides", "to", "uses", "transitive",
+    "true", "false",
+}
+
+SYN_PATTERN = re.compile(
+    r"(?P<comment>//.*)|"
+    r"(?P<blockcomment>/\*.*?\*/)|"
+    r"(?P<annotation>@\w+)|"
+    r'(?P<string>"""[\s\S]*?"""|"(?:[^"\\]|\\.)*"|\'(?:[^\'\\]|\\.)*\')|'
+    r"(?P<number>\b\d[\d_.]*[dDfFlL]?\b)|"
+    r"(?P<word>\b[A-Za-z_]\w*\b)|"
+    r"(?P<other>[^\s])"
+)
+
+# ── Dimensions ──────────────────────────────────────────────────────────
+W = 1200
+H = 630
+PAD = 40
+HEADER_H = 100
+FOOTER_H = 56
+CODE_TOP = HEADER_H
+CODE_H = H - HEADER_H - FOOTER_H
+COL_W = (W - PAD * 2 - 20) // 2
+CODE_PAD = 14
+LABEL_H = 32
+USABLE_W = COL_W - CODE_PAD * 2
+USABLE_H = CODE_H - LABEL_H - CODE_PAD
+CHAR_WIDTH_RATIO = 0.6
+LINE_HEIGHT_RATIO = 1.55
+MIN_CODE_FONT = 9
+MAX_CODE_FONT = 16
+
+
+# ── Helpers ─────────────────────────────────────────────────────────────
+
+def load_properties(path):
+    props = OrderedDict()
+    with open(path) as f:
+        for line in f:
+            line = line.strip()
+            if not line or line.startswith("#"):
+                continue
+            idx = line.find("=")
+            if idx > 0:
+                props[line[:idx].strip()] = line[idx + 1:].strip()
+    return props
+
+
+CATEGORY_DISPLAY = load_properties(CATEGORIES_FILE)
+
+
+def read_auto(path):
+    with open(path) as f:
+        if path.endswith((".yaml", ".yml")):
+            if yaml is None:
+                raise ImportError("PyYAML is required for YAML files: pip install pyyaml")
+            return yaml.safe_load(f)
+        return json.load(f)
+
+
+def xml_escape(s):
+    if s is None:
+        return ""
+    return (s.replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;")
+             .replace('"', "&quot;").replace("'", "&apos;"))
+
+
+def load_all_snippets():
+    snippets = OrderedDict()
+    for cat in CATEGORY_DISPLAY:
+        cat_dir = os.path.join(CONTENT_DIR, cat)
+        if not os.path.isdir(cat_dir):
+            continue
+        files = []
+        for ext in ("json", "yaml", "yml"):
+            files.extend(glob_mod.glob(os.path.join(cat_dir, f"*.{ext}")))
+        files.sort()
+        for path in files:
+            data = read_auto(path)
+            key = f"{data['category']}/{data['slug']}"
+            snippets[key] = data
+    return snippets
+
+
+# ── Syntax highlighting ─────────────────────────────────────────────────
+
+def highlight_line(line):
+    if line == "...":
+        return xml_escape(line)
+    result = []
+    last = 0
+    for m in SYN_PATTERN.finditer(line):
+        if m.start() > last:
+            result.append(xml_escape(line[last:m.start()]))
+        last = m.end()
+        token = m.group()
+        color = None
+        if m.group("comment") or m.group("blockcomment"):
+            color = SYN_COMMENT
+        elif m.group("annotation"):
+            color = SYN_ANNOTATION
+        elif m.group("string"):
+            color = SYN_STRING
+        elif m.group("number"):
+            color = SYN_NUMBER
+        elif m.group("word"):
+            if token in JAVA_KEYWORDS:
+                color = SYN_KEYWORD
+            elif token[0].isupper():
+                color = SYN_TYPE
+        if color:
+            result.append(f'<tspan fill="{color}">{xml_escape(token)}</tspan>')
+        else:
+            result.append(xml_escape(token))
+    if last < len(line):
+        result.append(xml_escape(line[last:]))
+    return "".join(result)
+
+
+# ── SVG rendering ───────────────────────────────────────────────────────
+
+def best_font_size(old_lines, modern_lines):
+    max_chars = max(
+        max((len(l) for l in old_lines), default=1),
+        max((len(l) for l in modern_lines), default=1),
+    )
+    max_lines = max(len(old_lines), len(modern_lines))
+    by_width = int(USABLE_W / (max_chars * CHAR_WIDTH_RATIO))
+    by_height = int(USABLE_H / (max_lines * LINE_HEIGHT_RATIO))
+    return max(MIN_CODE_FONT, min(MAX_CODE_FONT, min(by_width, by_height)))
+
+
+def fit_lines(lines, font_size):
+    line_h = int(font_size * LINE_HEIGHT_RATIO)
+    max_lines = USABLE_H // line_h
+    if len(lines) <= max_lines:
+        return lines
+    truncated = list(lines[:max_lines - 1])
+    truncated.append("...")
+    return truncated
+
+
+def render_code_block(lines, x, y, line_h):
+    parts = []
+    for i, line in enumerate(lines):
+        parts.append(
+            f'    <text x="{x}" y="{y + i * line_h}" class="code" xml:space="preserve">'
+            f'{highlight_line(line)}</text>\n'
+        )
+    return "".join(parts)
+
+
+def generate_svg(data):
+    left_x = PAD
+    right_x = PAD + COL_W + 20
+    label_y = CODE_TOP + 26
+    code_y = CODE_TOP + 52
+
+    old_lines = data["oldCode"].split("\n")
+    modern_lines = data["modernCode"].split("\n")
+
+    font_size = best_font_size(old_lines, modern_lines)
+    line_h = int(font_size * LINE_HEIGHT_RATIO)
+
+    old_lines = fit_lines(old_lines, font_size)
+    modern_lines = fit_lines(modern_lines, font_size)
+
+    cat_display = CATEGORY_DISPLAY.get(data["category"], data["category"])
+    badge_width = len(cat_display) * 8 + 16
+
+    old_code_svg = render_code_block(old_lines, left_x + 14, code_y, line_h)
+    modern_code_svg = render_code_block(modern_lines, right_x + 14, code_y, line_h)
+
+    return f"""<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg" width="{W}" height="{H}" viewBox="0 0 {W} {H}">
+  <defs>
+    <style>
+      .title    {{ font: 700 24px/1 'Inter', sans-serif; fill: {TEXT}; }}
+      .category {{ font: 600 13px/1 'Inter', sans-serif; fill: {TEXT_MUTED}; }}
+      .label    {{ font: 600 11px/1 'Inter', sans-serif; text-transform: uppercase; letter-spacing: 0.05em; }}
+      .code     {{ font: 400 {font_size}px/1 'JetBrains Mono', monospace; fill: {TEXT}; }}
+      .footer   {{ font: 500 13px/1 'Inter', sans-serif; fill: {TEXT_MUTED}; }}
+      .brand    {{ font: 700 14px/1 'Inter', sans-serif; fill: {ACCENT}; }}
+    </style>
+    <clipPath id="clip-left">
+      <rect x="{left_x}" y="{CODE_TOP}" width="{COL_W}" height="{CODE_H}" rx="8"/>
+    </clipPath>
+    <clipPath id="clip-right">
+      <rect x="{right_x}" y="{CODE_TOP}" width="{COL_W}" height="{CODE_H}" rx="8"/>
+    </clipPath>
+  </defs>
+
+  <!-- Background -->
+  <rect width="{W}" height="{H}" rx="16" fill="{BG}"/>
+  <rect x="0.5" y="0.5" width="{W - 1}" height="{H - 1}" rx="16" fill="none" stroke="{BORDER}" stroke-width="1"/>
+
+  <!-- Header: category badge + title -->
+  <rect x="{PAD}" y="28" width="{badge_width}" height="22" rx="6" fill="{BADGE_BG}"/>
+  <text x="{PAD + 8}" y="43" class="category">{xml_escape(cat_display)}</text>
+  <text x="{PAD}" y="76" class="title">{xml_escape(data['title'])}</text>
+
+  <!-- Left panel: Old code -->
+  <rect x="{left_x}" y="{CODE_TOP}" width="{COL_W}" height="{CODE_H}" rx="8" fill="{OLD_BG}"/>
+  <rect x="{left_x}" y="{CODE_TOP}" width="{COL_W}" height="{CODE_H}" rx="8" fill="none" stroke="{BORDER}" stroke-width="0.5"/>
+  <text x="{left_x + 14}" y="{label_y}" class="label" fill="{OLD_ACCENT}">\u2717  {xml_escape(data['oldLabel'])}</text>
+  <g clip-path="url(#clip-left)">
+{old_code_svg}  </g>
+
+  <!-- Right panel: Modern code -->
+  <rect x="{right_x}" y="{CODE_TOP}" width="{COL_W}" height="{CODE_H}" rx="8" fill="{MODERN_BG}"/>
+  <rect x="{right_x}" y="{CODE_TOP}" width="{COL_W}" height="{CODE_H}" rx="8" fill="none" stroke="{BORDER}" stroke-width="0.5"/>
+  <text x="{right_x + 14}" y="{label_y}" class="label" fill="{GREEN}">\u2713  {xml_escape(data['modernLabel'])}</text>
+  <g clip-path="url(#clip-right)">
+{modern_code_svg}  </g>
+
+  <!-- Footer -->
+  <text x="{PAD}" y="{H - 22}" class="footer">JDK {data['jdkVersion']}+</text>
+  <text x="{W - PAD}" y="{H - 22}" class="brand" text-anchor="end">javaevolved.github.io</text>
+</svg>
+"""
+
+
+def svg_to_png(svg_content, png_path):
+    if cairosvg is None:
+        raise ImportError("cairosvg is required for PNG generation: pip install cairosvg")
+    cairosvg.svg2png(
+        bytestring=svg_content.encode("utf-8"),
+        write_to=png_path,
+        output_width=W * 2,
+        output_height=H * 2,
+    )
+
+
+# ── Main ────────────────────────────────────────────────────────────────
+
+def main():
+    all_snippets = load_all_snippets()
+    print(f"Loaded {len(all_snippets)} snippets")
+
+    # Filter to a single slug if provided
+    if len(sys.argv) > 1:
+        key = sys.argv[1]
+        if key not in all_snippets:
+            print(f"Unknown pattern: {key}")
+            print(f"Available: {', '.join(all_snippets.keys())}")
+            sys.exit(1)
+        targets = {key: all_snippets[key]}
+    else:
+        targets = all_snippets
+
+    count = 0
+    for key, data in targets.items():
+        cat = data["category"]
+        slug = data["slug"]
+        out_dir = os.path.join(OUTPUT_DIR, cat)
+        os.makedirs(out_dir, exist_ok=True)
+
+        svg = generate_svg(data)
+        svg_path = os.path.join(out_dir, f"{slug}.svg")
+        with open(svg_path, "w") as f:
+            f.write(svg)
+
+        png_path = os.path.join(out_dir, f"{slug}.png")
+        svg_to_png(svg, png_path)
+        count += 1
+
+    print(f"Generated {count} SVG+PNG card(s) in {OUTPUT_DIR}/")
+
+
+if __name__ == "__main__":
+    main()