feat: list recalbox cores per board

Recalbox builds seven board images with different emulators. The new
target scraper reads each board's defconfig against the package every
system.ini core names. The names that reached no profile are mapped to
the projects Recalbox builds or profiled from their source, and the
mupen64plus video plugins are set aside.

scripts/scraper/recalbox_scraper.py

@@ -117,18 +117,14 @@ BLOBS_QUERY = (
 BLOBS_PER_QUERY = 50
 
 
-def system_ini_cores(text: str) -> tuple[set[str], set[str]]:
-    """The cores one Recalbox system.ini offers, and those run standalone.
+def _ini_sections(text: str) -> dict[str, dict[str, str]]:
+    """Sections and their key = value lines of one Recalbox system.ini.
 
-    Each ``[core.N]`` section (or its board override ``[core.N.<board>]``)
-    names an ``emulator`` and a ``core``: ``libretro`` with the core's name,
-    or a standalone emulator. es_bios.xml only names the cores that need a
-    BIOS, so read alone it left most of Recalbox's cores outside the pack.
+    Recalbox's .ini files are not strict INI (a value can run on a bare
+    line), so only sections and key = value lines are read.
     """
     import re
 
-    # Recalbox's .ini files are not strict INI (a value can run on a bare
-    # line), so only sections and key = value lines are read.
     sections: dict[str, dict[str, str]] = {}
     current: dict[str, str] | None = None
     for raw in text.splitlines():
@@ -142,25 +138,64 @@ def system_ini_cores(text: str) -> tuple[set[str], set[str]]:
         if current is not None and "=" in line:
             key, value = line.split("=", 1)
             current[key.strip()] = value.strip().strip('"')
+    return sections
+
+
+def _core_names(values: dict[str, str]) -> tuple[set[str], set[str]]:
+    """(cores, standalone) one [core.N] section names."""
+    emulator = values.get("emulator", "")
+    core = values.get("core", "")
+    if emulator == "libretro":
+        return ({core} if core else set()), set()
+    if not emulator:
+        return set(), set()
+    names = {emulator} | ({core} if core and core != emulator else set())
+    return names, set(names)
+
+
+def system_ini_cores(text: str) -> tuple[set[str], set[str]]:
+    """The cores one Recalbox system.ini offers, and those run standalone.
+
+    Each ``[core.N]`` section (or its board override ``[core.N.<board>]``)
+    names an ``emulator`` and a ``core``: ``libretro`` with the core's name,
+    or a standalone emulator. es_bios.xml only names the cores that need a
+    BIOS, so read alone it left most of Recalbox's cores outside the pack.
+    """
+    import re
+
     cores: set[str] = set()
     standalone: set[str] = set()
-    for section, values in sections.items():
+    for section, values in _ini_sections(text).items():
         if not re.fullmatch(r"core\.\d+(\.[\w-]+)?", section):
             continue
-        emulator = values.get("emulator", "")
-        core = values.get("core", "")
-        if emulator == "libretro":
-            if core:
-                cores.add(core)
-        elif emulator:
-            cores.add(emulator)
-            standalone.add(emulator)
-            if core and core != emulator:
-                cores.add(core)
-                standalone.add(core)
+        found, alone = _core_names(values)
+        cores |= found
+        standalone |= alone
     return cores, standalone
 
 
+def board_cores(text: str, board: str, enabled: set[str]) -> set[str]:
+    """The cores of one system.ini a board's image builds.
+
+    A core is built when the Buildroot package its section names is enabled
+    in the board's defconfig. ``[core.N.<board>]`` replaces the section on
+    that board and ``package.<board>`` its package.
+    """
+    import re
+
+    sections = _ini_sections(text)
+    cores: set[str] = set()
+    for section, values in sections.items():
+        match = re.fullmatch(r"core\.(\d+)", section)
+        if not match:
+            continue
+        values = sections.get(f"{section}.{board}", values)
+        package = values.get(f"package.{board}", values.get("package", ""))
+        if package in enabled:
+            cores |= _core_names(values)[0]
+    return cores
+
+
 class Scraper(BaseScraper):
     """Scraper for Recalbox es_bios.xml."""