refactor: split the emulator page renderer

generate_emulator_page carried a 228-line loop body rendering one file
row from thirty-odd optional fields, which put its complexity at 141,
more than twice the next function in the repository. The row renderer
and its badge strip are now their own functions and the page function
sits at 68.

_forge_sources went from 18 to 32 when it learned to pair each
repository with its own revision; the pairing is now its own function
and the caller is back under the threshold.

Verified by regenerating the site and diffing: all 505 pages are
identical apart from their generation timestamps.

scripts/generate_site.py

@@ -65,6 +65,49 @@ ICON_CACHE_PATH = Path(".cache") / "system_icons.json"
 _icon_available: dict[str, bool] = {}
 
 
+def _by_mode(value, mode: str) -> str:
+    """Read a profile field that may be keyed by build mode."""
+    if isinstance(value, dict):
+        return str(value.get(mode) or "") if mode else ""
+    return str(value or "")
+
+
+def _repo_pins(profile: dict, field: str, label: str) -> list[tuple[str, str, str]]:
+    """Pair each declared repository URL with its own revision.
+
+    A profile whose builds live in separate repositories keys both the URL
+    and the revision by build mode. Reading them apart would pin a libretro
+    fork to the standalone revision and produce a permalink into a tree that
+    never held the cited line. Each tuple is (url, pin, source_commit
+    fallback for that same mode).
+    """
+    raw = profile.get(field, "")
+    pin_field = profile.get(f"{field}_commit") or ""
+    source_field = profile.get("source_commit") or ""
+
+    if not isinstance(raw, dict):
+        if not raw:
+            return []
+        return [
+            (
+                str(raw),
+                _by_mode(pin_field, label),
+                _by_mode(source_field, label),
+            )
+        ]
+
+    # The requested build mode first, so it wins when several repositories
+    # would otherwise be equally good candidates.
+    ordered = ([label] if label and label in raw else []) + [
+        key for key in raw if key != label
+    ]
+    return [
+        (str(raw[key]), _by_mode(pin_field, key), _by_mode(source_field, key))
+        for key in ordered
+        if raw.get(key)
+    ]
+
+
 def _forge_sources(profile: dict, label: str = "") -> list[tuple[upstream.Repo, str]]:
     """Supported source repositories and immutable revisions for a profile."""
     candidates: list[tuple[upstream.Repo, str]] = []
@@ -72,42 +115,7 @@ def _forge_sources(profile: dict, label: str = "") -> list[tuple[upstream.Repo,
     source_repos: set[tuple[str, str]] = set()
 
     for field in ("source", "upstream"):
-        raw = profile.get(field, "")
-        raw_pin = profile.get(f"{field}_commit") or ""
-        source_pin = profile.get("source_commit") or ""
-
-        # A profile whose builds live in separate repositories keys both the
-        # URL and the revision by build mode. The two have to be read as
-        # pairs: pinning a libretro fork to the standalone revision would
-        # produce a permalink into the wrong tree.
-        pairs: list[tuple[str, str]] = []
-        if isinstance(raw, dict):
-            ordered = ([label] if label and label in raw else []) + [
-                key for key in raw if key != label
-            ]
-            for key in ordered:
-                value = raw.get(key)
-                if not value:
-                    continue
-                pin = raw_pin.get(key, "") if isinstance(raw_pin, dict) else raw_pin
-                fallback = (
-                    source_pin.get(key, "")
-                    if isinstance(source_pin, dict)
-                    else source_pin
-                )
-                pairs.append((str(value), str(pin or ""), str(fallback or "")))
-        elif raw:
-            pin = raw_pin.get(label, "") if isinstance(raw_pin, dict) and label else (
-                "" if isinstance(raw_pin, dict) else raw_pin
-            )
-            fallback = (
-                source_pin.get(label, "")
-                if isinstance(source_pin, dict) and label
-                else ("" if isinstance(source_pin, dict) else source_pin)
-            )
-            pairs.append((str(raw), str(pin or ""), str(fallback or "")))
-
-        for value, pin, fallback in pairs:
+        for value, pin, fallback in _repo_pins(profile, field, label):
             repo = upstream.parse_repo(value)
             if repo is None:
                 continue
@@ -2109,6 +2117,271 @@ def generate_emulators_index(profiles: dict) -> str:
     return "\n".join(lines) + "\n"
 
 
+def _file_badges(f: dict, in_repo: bool) -> list[str]:
+    """The status chips shown beside a file name.
+
+    Fourteen independent optional fields, each contributing at most one
+    chip. Kept apart from the rest of the row so the field-by-field
+    rendering stays readable.
+    """
+    required = f.get("required", False)
+    hle = f.get("hle_fallback", False)
+    mode = f.get("mode", "")
+    category = f.get("category", "")
+    region = f.get("region", "")
+    storage = f.get("storage", "")
+    bundled = f.get("bundled", False)
+    embedded = f.get("embedded", False)
+    has_builtin = f.get("has_builtin", False)
+    archive = f.get("archive", "")
+    ftype = f.get("type", "")
+    badges = []
+    if required:
+        badges.append(
+            '<span class="rb-badge rb-badge-danger">required</span>'
+        )
+    else:
+        badges.append(
+            '<span class="rb-badge rb-badge-muted">optional</span>'
+        )
+    if not in_repo:
+        badges.append(
+            '<span class="rb-badge rb-badge-warning">missing</span>'
+        )
+    elif in_repo:
+        badges.append(
+            '<span class="rb-badge rb-badge-success">in repo</span>'
+        )
+    if hle:
+        badges.append(
+            '<span class="rb-badge rb-badge-info">HLE fallback</span>'
+        )
+    if mode:
+        badges.append(
+            f'<span class="rb-badge rb-badge-muted">{mode}</span>'
+        )
+    if category and category != "bios":
+        badges.append(
+            f'<span class="rb-badge rb-badge-info">{category}</span>'
+        )
+    if region:
+        region_str = (
+            ", ".join(region) if isinstance(region, list) else str(region)
+        )
+        badges.append(
+            f'<span class="rb-badge rb-badge-muted">{region_str}</span>'
+        )
+    if storage and storage != "embedded":
+        badges.append(
+            f'<span class="rb-badge rb-badge-muted">{storage}</span>'
+        )
+    if bundled:
+        badges.append(
+            '<span class="rb-badge rb-badge-muted">bundled</span>'
+        )
+    if embedded:
+        badges.append(
+            '<span class="rb-badge rb-badge-muted">embedded</span>'
+        )
+    if has_builtin:
+        badges.append(
+            '<span class="rb-badge rb-badge-info">built-in fallback</span>'
+        )
+    if archive:
+        badges.append(
+            f'<span class="rb-badge rb-badge-muted">in {archive}</span>'
+        )
+    if ftype and ftype != "bios":
+        badges.append(
+            f'<span class="rb-badge rb-badge-muted">{ftype}</span>'
+        )
+
+    return badges
+
+
+def _render_emulator_file(
+    f: dict,
+    profile: dict,
+    platform_files: dict | None,
+    files: list,
+    _file_available,
+) -> list[str]:
+    """Render one row of an emulator profile's file table.
+
+    Split out of generate_emulator_page, where it was a 228-line loop body
+    carrying most of that function's branching: thirty-odd optional fields,
+    each with its own badge, hash line or note.
+    """
+    lines: list[str] = []
+    fname = f.get("name", "")
+    required = f.get("required", False)
+    in_repo = _file_available(f)
+    source_ref = f.get("source_ref", "")
+    mode = f.get("mode", "")
+    hle = f.get("hle_fallback", False)
+    aliases = f.get("aliases", [])
+    category = f.get("category", "")
+    validation = f.get("validation", [])
+    size = f.get("size")
+    fnote = f.get("note", f.get("notes", ""))
+    storage = f.get("storage", "")
+    fmd5 = f.get("md5", "")
+    fsha1 = f.get("sha1", "")
+    fcrc32 = f.get("crc32", "")
+    fsha256 = f.get("sha256", "")
+    fadler32 = f.get("known_hash_adler32", "")
+    fmin = f.get("min_size")
+    fmax = f.get("max_size")
+    desc = f.get("description", "")
+    region = f.get("region", "")
+    archive = f.get("archive", "")
+    fpath = f.get("path", "")
+    fsystem = f.get("system", "")
+    priority = f.get("priority")
+    fast_boot = f.get("fast_boot")
+    bundled = f.get("bundled", False)
+    embedded = f.get("embedded", False)
+    has_builtin = f.get("has_builtin", False)
+    contents = f.get("contents", [])
+    config_key = f.get("config_key", "")
+    dest = f.get("dest", f.get("destination", ""))
+    ftype = f.get("type", "")
+    fpattern = f.get("pattern", "")
+    region_check = f.get("region_check")
+    size_note = f.get("size_note", "")
+    size_options = f.get("size_options", [])
+    size_range = f.get("size_range", "")
+
+    badges = _file_badges(f, in_repo)
+    badge_str = " ".join(badges)
+    border_cls = (
+        "rb-file-entry-required" if required else "rb-file-entry-optional"
+    )
+    lines.append(
+        f'<div class="rb-file-entry {border_cls}" markdown>'
+    )
+    lines.append("")
+    lines.append(f"**`{fname}`** {badge_str}")
+    if desc:
+        lines.append(f"<br>{desc}")
+    lines.append("")
+
+    details = []
+    if fpath and fpath != fname:
+        details.append(f"Path: `{fpath}`")
+    if fsystem:
+        details.append(f"System: {_system_link(fsystem, '../')}")
+    if size:
+        if isinstance(size, list):
+            size_str = " / ".join(_fmt_size(s) for s in size)
+        else:
+            size_str = _fmt_size(size)
+        if fmin or fmax:
+            bounds = []
+            if fmin:
+                bounds.append(f"min {_fmt_size(fmin)}")
+            if fmax:
+                bounds.append(f"max {_fmt_size(fmax)}")
+            size_str += f" ({', '.join(bounds)})"
+        details.append(f"Size: {size_str}")
+    elif fmin or fmax:
+        bounds = []
+        if fmin:
+            bounds.append(f"min {_fmt_size(fmin)}")
+        if fmax:
+            bounds.append(f"max {_fmt_size(fmax)}")
+        details.append(f"Size: {', '.join(bounds)}")
+    if fsha1:
+        s = fsha1[:12]
+        details.append(
+            f'SHA1: <span class="rb-hash" title="{fsha1}">'
+            f"`{s}...`</span>"
+        )
+    if fmd5:
+        s = fmd5[:12]
+        details.append(
+            f'MD5: <span class="rb-hash" title="{fmd5}">'
+            f"`{s}...`</span>"
+        )
+    if fcrc32:
+        details.append(f"CRC32: `{fcrc32}`")
+    if fsha256:
+        s = fsha256[:12]
+        details.append(
+            f'SHA256: <span class="rb-hash" title="{fsha256}">'
+            f"`{s}...`</span>"
+        )
+    if fadler32:
+        details.append(f"Adler32: `{fadler32}`")
+    if aliases:
+        details.append(f"Aliases: {', '.join(f'`{a}`' for a in aliases)}")
+    if priority is not None:
+        details.append(f"Priority: {priority}")
+    if fast_boot is not None:
+        details.append(f"Fast boot: {'yes' if fast_boot else 'no'}")
+    if validation:
+        if isinstance(validation, list):
+            details.append(f"Validation: {', '.join(validation)}")
+        elif isinstance(validation, dict):
+            for scope, checks in validation.items():
+                details.append(f"Validation ({scope}): {', '.join(checks)}")
+    if source_ref:
+        details.append(
+            f"Source: {_source_ref_markdown(profile, source_ref)}"
+        )
+    if platform_files:
+        plats = sorted(
+            p for p, names in platform_files.items() if fname in names
+        )
+        if plats:
+            plat_links = [_platform_link(p, p, "../") for p in plats]
+            details.append(f"Platforms: {', '.join(plat_links)}")
+
+    if dest and dest != fname and dest != fpath:
+        details.append(f"Destination: `{dest}`")
+    if config_key:
+        details.append(f"Config key: `{config_key}`")
+    if fpattern:
+        details.append(f"Pattern: `{fpattern}`")
+    if region_check is not None:
+        details.append(f"Region check: {'yes' if region_check else 'no'}")
+    if size_note:
+        details.append(f"Size note: {size_note}")
+    if size_options:
+        details.append(
+            f"Size options: {', '.join(_fmt_size(s) for s in size_options)}"
+        )
+    if size_range:
+        details.append(f"Size range: {size_range}")
+
+    if details:
+        for d in details:
+            lines.append(f"- {d}")
+    if fnote:
+        lines.append(f"- {fnote}")
+    if contents:
+        lines.append(f"- Contents ({len(contents)} entries):")
+        for c in contents[:10]:
+            if isinstance(c, dict):
+                cname = c.get("name", "")
+                cdesc = c.get("description", "")
+                csize = c.get("size", "")
+                parts = [f"`{cname}`"]
+                if cdesc:
+                    parts.append(cdesc)
+                if csize:
+                    parts.append(_fmt_size(csize))
+                lines.append(f"    - {' -'.join(parts)}")
+            else:
+                lines.append(f"    - {c}")
+        if len(contents) > 10:
+            lines.append(f"    - ... and {len(contents) - 10} more")
+    lines.append("")
+    lines.append("</div>")
+    lines.append("")
+    return lines
+
+
 def generate_emulator_page(
     name: str,
     profile: dict,
@@ -2369,233 +2642,11 @@ def generate_emulator_page(
 
         # File table
         for f in files:
-            fname = f.get("name", "")
-            required = f.get("required", False)
-            in_repo = _file_available(f)
-            source_ref = f.get("source_ref", "")
-            mode = f.get("mode", "")
-            hle = f.get("hle_fallback", False)
-            aliases = f.get("aliases", [])
-            category = f.get("category", "")
-            validation = f.get("validation", [])
-            size = f.get("size")
-            fnote = f.get("note", f.get("notes", ""))
-            storage = f.get("storage", "")
-            fmd5 = f.get("md5", "")
-            fsha1 = f.get("sha1", "")
-            fcrc32 = f.get("crc32", "")
-            fsha256 = f.get("sha256", "")
-            fadler32 = f.get("known_hash_adler32", "")
-            fmin = f.get("min_size")
-            fmax = f.get("max_size")
-            desc = f.get("description", "")
-            region = f.get("region", "")
-            archive = f.get("archive", "")
-            fpath = f.get("path", "")
-            fsystem = f.get("system", "")
-            priority = f.get("priority")
-            fast_boot = f.get("fast_boot")
-            bundled = f.get("bundled", False)
-            embedded = f.get("embedded", False)
-            has_builtin = f.get("has_builtin", False)
-            contents = f.get("contents", [])
-            config_key = f.get("config_key", "")
-            dest = f.get("dest", f.get("destination", ""))
-            ftype = f.get("type", "")
-            fpattern = f.get("pattern", "")
-            region_check = f.get("region_check")
-            size_note = f.get("size_note", "")
-            size_options = f.get("size_options", [])
-            size_range = f.get("size_range", "")
-
-            # Status badges (HTML)
-            badges = []
-            if required:
-                badges.append(
-                    '<span class="rb-badge rb-badge-danger">required</span>'
+            lines.extend(
+                _render_emulator_file(
+                    f, profile, platform_files, files, _file_available
                 )
-            else:
-                badges.append(
-                    '<span class="rb-badge rb-badge-muted">optional</span>'
-                )
-            if not in_repo:
-                badges.append(
-                    '<span class="rb-badge rb-badge-warning">missing</span>'
-                )
-            elif in_repo:
-                badges.append(
-                    '<span class="rb-badge rb-badge-success">in repo</span>'
-                )
-            if hle:
-                badges.append(
-                    '<span class="rb-badge rb-badge-info">HLE fallback</span>'
-                )
-            if mode:
-                badges.append(
-                    f'<span class="rb-badge rb-badge-muted">{mode}</span>'
-                )
-            if category and category != "bios":
-                badges.append(
-                    f'<span class="rb-badge rb-badge-info">{category}</span>'
-                )
-            if region:
-                region_str = (
-                    ", ".join(region) if isinstance(region, list) else str(region)
-                )
-                badges.append(
-                    f'<span class="rb-badge rb-badge-muted">{region_str}</span>'
-                )
-            if storage and storage != "embedded":
-                badges.append(
-                    f'<span class="rb-badge rb-badge-muted">{storage}</span>'
-                )
-            if bundled:
-                badges.append(
-                    '<span class="rb-badge rb-badge-muted">bundled</span>'
-                )
-            if embedded:
-                badges.append(
-                    '<span class="rb-badge rb-badge-muted">embedded</span>'
-                )
-            if has_builtin:
-                badges.append(
-                    '<span class="rb-badge rb-badge-info">built-in fallback</span>'
-                )
-            if archive:
-                badges.append(
-                    f'<span class="rb-badge rb-badge-muted">in {archive}</span>'
-                )
-            if ftype and ftype != "bios":
-                badges.append(
-                    f'<span class="rb-badge rb-badge-muted">{ftype}</span>'
-                )
-
-            badge_str = " ".join(badges)
-            border_cls = (
-                "rb-file-entry-required" if required else "rb-file-entry-optional"
             )
-            lines.append(
-                f'<div class="rb-file-entry {border_cls}" markdown>'
-            )
-            lines.append("")
-            lines.append(f"**`{fname}`** {badge_str}")
-            if desc:
-                lines.append(f"<br>{desc}")
-            lines.append("")
-
-            details = []
-            if fpath and fpath != fname:
-                details.append(f"Path: `{fpath}`")
-            if fsystem:
-                details.append(f"System: {_system_link(fsystem, '../')}")
-            if size:
-                if isinstance(size, list):
-                    size_str = " / ".join(_fmt_size(s) for s in size)
-                else:
-                    size_str = _fmt_size(size)
-                if fmin or fmax:
-                    bounds = []
-                    if fmin:
-                        bounds.append(f"min {_fmt_size(fmin)}")
-                    if fmax:
-                        bounds.append(f"max {_fmt_size(fmax)}")
-                    size_str += f" ({', '.join(bounds)})"
-                details.append(f"Size: {size_str}")
-            elif fmin or fmax:
-                bounds = []
-                if fmin:
-                    bounds.append(f"min {_fmt_size(fmin)}")
-                if fmax:
-                    bounds.append(f"max {_fmt_size(fmax)}")
-                details.append(f"Size: {', '.join(bounds)}")
-            if fsha1:
-                s = fsha1[:12]
-                details.append(
-                    f'SHA1: <span class="rb-hash" title="{fsha1}">'
-                    f"`{s}...`</span>"
-                )
-            if fmd5:
-                s = fmd5[:12]
-                details.append(
-                    f'MD5: <span class="rb-hash" title="{fmd5}">'
-                    f"`{s}...`</span>"
-                )
-            if fcrc32:
-                details.append(f"CRC32: `{fcrc32}`")
-            if fsha256:
-                s = fsha256[:12]
-                details.append(
-                    f'SHA256: <span class="rb-hash" title="{fsha256}">'
-                    f"`{s}...`</span>"
-                )
-            if fadler32:
-                details.append(f"Adler32: `{fadler32}`")
-            if aliases:
-                details.append(f"Aliases: {', '.join(f'`{a}`' for a in aliases)}")
-            if priority is not None:
-                details.append(f"Priority: {priority}")
-            if fast_boot is not None:
-                details.append(f"Fast boot: {'yes' if fast_boot else 'no'}")
-            if validation:
-                if isinstance(validation, list):
-                    details.append(f"Validation: {', '.join(validation)}")
-                elif isinstance(validation, dict):
-                    for scope, checks in validation.items():
-                        details.append(f"Validation ({scope}): {', '.join(checks)}")
-            if source_ref:
-                details.append(
-                    f"Source: {_source_ref_markdown(profile, source_ref)}"
-                )
-            if platform_files:
-                plats = sorted(
-                    p for p, names in platform_files.items() if fname in names
-                )
-                if plats:
-                    plat_links = [_platform_link(p, p, "../") for p in plats]
-                    details.append(f"Platforms: {', '.join(plat_links)}")
-
-            if dest and dest != fname and dest != fpath:
-                details.append(f"Destination: `{dest}`")
-            if config_key:
-                details.append(f"Config key: `{config_key}`")
-            if fpattern:
-                details.append(f"Pattern: `{fpattern}`")
-            if region_check is not None:
-                details.append(f"Region check: {'yes' if region_check else 'no'}")
-            if size_note:
-                details.append(f"Size note: {size_note}")
-            if size_options:
-                details.append(
-                    f"Size options: {', '.join(_fmt_size(s) for s in size_options)}"
-                )
-            if size_range:
-                details.append(f"Size range: {size_range}")
-
-            if details:
-                for d in details:
-                    lines.append(f"- {d}")
-            if fnote:
-                lines.append(f"- {fnote}")
-            if contents:
-                lines.append(f"- Contents ({len(contents)} entries):")
-                for c in contents[:10]:
-                    if isinstance(c, dict):
-                        cname = c.get("name", "")
-                        cdesc = c.get("description", "")
-                        csize = c.get("size", "")
-                        parts = [f"`{cname}`"]
-                        if cdesc:
-                            parts.append(cdesc)
-                        if csize:
-                            parts.append(_fmt_size(csize))
-                        lines.append(f"    - {' -'.join(parts)}")
-                    else:
-                        lines.append(f"    - {c}")
-                if len(contents) > 10:
-                    lines.append(f"    - ... and {len(contents) - 10} more")
-            lines.append("")
-            lines.append("</div>")
-            lines.append("")
 
     # Data directories
     if data_dirs: