feat: add knulli, amberelec and emuelec platforms

Each OS publishes Batocera's systems dict (knulli-systems, and
batocera-systems at AmberELEC's newest prerelease commit and EmuELEC v4.8),
read with the shared parser. Cores come from each OS's own ES list.
AmberELEC and EmuELEC declare neogeo/ and ports/ beside bios/ from
/storage/roms, so their packs extract there and core_destination puts
core files under bios/.

scripts/scraper/emuelec_scraper.py

@@ -0,0 +1,148 @@
+#!/usr/bin/env python3
+"""Scraper for EmuELEC's batocera-systems.
+
+Source: packages/sx05re/emuelec/bin/batocera/batocera-systems
+Format: Python source, Batocera's `systems` dict, parsed by batocera_scraper
+Hash: MD5
+
+`naomi` and `Dinothawr` are written twice in the dict. Python keeps the later
+value of a repeated key when the script runs, and so does the parser: naomi
+is the entry at line 461 (naomi_boot.bin and naomi.zip, line 444 naming
+naomi.zip alone), Dinothawr the one at line 776 (dinothawr.game, line 494
+naming level_3-3.tmx).
+
+Verification (batocera-systems at the release tag):
+- checkBios (lines 817-833): md5sum() of the file at /storage/roms/<file>
+  against the declared md5, an empty md5 meaning presence only. It never
+  reads zippedFile: the FM Towns entries that name a member hash the whole
+  archive against the member's md5. There is no emulator or core gate.
+- Run with no argument by EmulationStation's BIOS screen
+  (EmuELEC/emuelec-emulationstation 09356d0d, es-app/src/ApiSystem.cpp:
+  645-655, `--filter <system>` for one system), and with `--strictfilter
+  <platform>` by ee_check_bios after a failed launch
+  (packages/sx05re/emuelec/profile.d/99-emuelec.conf:261, called from
+  emuelecRunEmu.sh:605).
+"""
+
+from __future__ import annotations
+
+import re
+import urllib.error
+import urllib.request
+
+from .base_scraper import BaseScraper, BiosRequirement, fetch_github_latest_version
+from .batocera_scraper import (
+    SYSTEM_SLUG_MAP as BATOCERA_SLUGS,
+)
+from .batocera_scraper import (
+    extract_systems_dict,
+    platform_systems,
+    requirements_from_systems,
+)
+from .es_emulators import es_cores, json_emulators
+
+PLATFORM_NAME = "emuelec"
+
+REPO = "EmuELEC/EmuELEC"
+_RAW = "https://raw.githubusercontent.com/EmuELEC/EmuELEC/{ref}/"
+SOURCE_TEMPLATE = _RAW + "packages/sx05re/emuelec/bin/batocera/batocera-systems"
+ES_SYSTEMS_TEMPLATE = _RAW + "packages/sx05re/emuelec-emulationstation/config/es_systems.json"
+
+# Batocera's names, plus the keys EmuELEC writes that Batocera does not:
+# console keys under the slug the other scrapers give them, and each port
+# under the system of the profile of the engine its name gives
+# (devilutionx, prboom, opentyrian, cannonball, nxengine, tyrquake,
+# reminiscence, xrick, vvvvvv, eduke32, sonic2013, sonic-mania, dinothawr).
+SYSTEM_SLUG_MAP = {
+    **BATOCERA_SLUGS,
+    "atari7800": "atari-7800",
+    "atarilynx": "atari-lynx",
+    "n64": "nintendo-64",
+    "o2em": "magnavox-odyssey2",
+    "Diablo": "diablo",
+    "Hellfire": "diablo",
+    "Dinothawr": "dinothawr",
+    "Quake": "quake",
+    "VVVVVV": "vvvvvv",
+    "DOOM1": "doom",
+    "DOOM2": "doom",
+    "OpenTyrian": "tyrian",
+    "Cannonball": "sega-outrun",
+    "CaveStory": "cave-story",
+    "REminiscence": "flashback",
+    "RickDangerous": "xrick",
+    "eduke32": "duke3d",
+    "sonic1": "sonic-1-2013",
+    "sonic2": "sonic-2-2013",
+    "sonicmania": "sonic-mania",
+}
+
+# es_systems.json names libretro cores under `libretro`, and `retrorun`
+# loads the libretro core it lists.
+RUNNERS: dict[str, str | None] = {"libretro": None, "retrorun": None}
+# packages/sx05re/emulators/PPSSPPSDL builds PPSSPP's SDL front end.
+RENAMED = {"PPSSPPSDL": "ppsspp"}
+
+
+class Scraper(BaseScraper):
+    """Scraper for EmuELEC's batocera-systems."""
+
+    def __init__(self, url: str | None = None) -> None:
+        self.tag = "" if url else fetch_github_latest_version(REPO)
+        super().__init__(url=url or SOURCE_TEMPLATE.format(ref=self.tag))
+
+    def _fetch_text(self, url: str) -> str:
+        req = urllib.request.Request(url, headers={"User-Agent": "retrobios-scraper/1.0"})
+        try:
+            with urllib.request.urlopen(req, timeout=30) as resp:
+                return resp.read().decode("utf-8")
+        except urllib.error.URLError as e:
+            raise ConnectionError(f"Failed to fetch {url}: {e}") from e
+
+    def validate_format(self, raw_data: str) -> bool:
+        has_dict = re.search(r"^systems\s*=\s*\{", raw_data, re.MULTILINE) is not None
+        return has_dict and "def checkBios" in raw_data and '"biosFiles"' in raw_data
+
+    def fetch_requirements(self) -> list[BiosRequirement]:
+        raw = self._fetch_raw()
+        if not self.validate_format(raw):
+            raise ValueError("batocera-systems format validation failed")
+        # Paths are relative to /storage/roms (`prefix`, lines 859-865): the
+        # list names neogeo/ and ports/ beside bios/.
+        return requirements_from_systems(extract_systems_dict(raw), SYSTEM_SLUG_MAP, strip="")
+
+    def generate_platform_yaml(self) -> dict:
+        systems = platform_systems(
+            self.fetch_requirements(), extract_systems_dict(self._fetch_raw()), SYSTEM_SLUG_MAP
+        )
+        cores, standalone, dual = es_cores(
+            json_emulators(self._fetch_text(ES_SYSTEMS_TEMPLATE.format(ref=self.tag))),
+            RUNNERS,
+            RENAMED,
+        )
+        return {
+            "platform": "EmuELEC",
+            "version": self.tag.removeprefix("v"),
+            "homepage": "https://emuelec.org",
+            "source": self.url,
+            "base_destination": "",
+            # RetroArch's system_directory is /storage/roms/bios
+            # (packages/sx05re/libretro_base/retroarch/package.mk:117).
+            "core_destination": "bios",
+            "hash_type": "md5",
+            "verification_mode": "md5",
+            "cores": cores,
+            "standalone_cores": standalone,
+            "dual_mode_cores": dual,
+            "systems": systems,
+        }
+
+
+def main() -> None:
+    from .base_scraper import scraper_cli
+
+    scraper_cli(Scraper, "Scrape EmuELEC BIOS requirements")
+
+
+if __name__ == "__main__":
+    main()