Implement Retroarch Importer

I'm quite rusty with Python, so please let me know if there are any (or many) grave mistakes!

data/gtk/preferences.blp

@@ -226,6 +226,20 @@ template $PreferencesWindow : Adw.PreferencesWindow {
         }
       }
 
+      Adw.ExpanderRow retroarch_expander_row {
+        title: _("Retroarch");
+        show-enable-switch: true;
+
+        Adw.ActionRow retroarch_config_action_row {
+          title: _("Install Location");
+
+          Button retroarch_config_file_chooser_button {
+            icon-name: "folder-symbolic";
+            valign: center;
+          }
+        }
+      }
+
       Adw.ExpanderRow flatpak_expander_row {
         title: _("Flatpak");
         show-enable-switch: true;

data/hu.kramo.Cartridges.gschema.xml.in

@@ -64,6 +64,12 @@
     <key name="legendary-location" type="s">
       <default>"~/.config/legendary/"</default>
     </key>
+    <key name="retroarch" type="b">
+      <default>true</default>
+    </key>
+    <key name="retroarch-location" type="s">
+      <default>"~/.var/app/org.libretro.RetroArch/config/retroarch/"</default>
+    </key>
     <key name="flatpak" type="b">
       <default>true</default>
     </key>
@@ -110,4 +116,4 @@
       <default>"[]"</default>
     </key>
   </schema>
-</schemalist>
+</schemalist>

flatpak/hu.kramo.Cartridges.Devel.json

@@ -17,6 +17,7 @@
         "--filesystem=~/.var/app/com.heroicgameslauncher.hgl/config/heroic/:ro",
         "--filesystem=~/.var/app/com.usebottles.bottles/data/bottles/:ro",
         "--filesystem=~/.var/app/io.itch.itch/config/itch/:ro",
+        "--filesystem=~/.var/app/org.libretro.RetroArch/config/retroarch/:ro",
         "--filesystem=/var/lib/flatpak:ro"
     ],
     "cleanup" : [

src/importer/sources/retroarch_source.py

@@ -0,0 +1,119 @@
+# retroarch_source.py
+#
+# Copyright 2023 Rilic
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from pathlib import Path
+from time import time
+
+import json
+import os
+import logging
+from json import JSONDecodeError
+
+from src import shared
+from src.game import Game
+from src.importer.sources.location import Location
+from src.importer.sources.source import (
+    SourceIterationResult,
+    SourceIterator,
+    Source
+)
+
+
+class RetroarchSourceIterator(SourceIterator):
+    source: "RetroarchSource"
+
+    def generator_builder(self) -> SourceIterationResult:
+        playlist_files = []
+        for file in os.listdir(self.source.config_location["playlists"]):
+            if file.endswith('.lpl'):
+                playlist_files.append(file)
+
+        playlist_items = []
+        for playlist_file in playlist_files:
+            open_file = open(str(self.source.config_location["playlists"]) + "/" + playlist_file)
+            try:
+                playlist_json = json.load(open_file)
+            except (JSONDecodeError, OSError, KeyError):
+                logging.warning("Cannot read playlist file: %s", str(playlist_file))
+                continue
+
+            for item in playlist_json["items"]:
+                # Select the core. Try the content's core first, then the playlist's
+                # default core.
+                core_path = item["core_path"]
+                if core_path == "DETECT":
+                    default_core = playlist_json["default_core_path"]
+                    if default_core:
+                        core_path = default_core
+                    else:
+                        logging.warning("Cannot find core for: %s", str(item["path"]))
+                        continue
+
+                # Build game
+                game_title = item["label"].split("(", 1)[0]
+                values = {
+                    "source": self.source.id,
+                    "added": int(time()),
+                    "name": game_title,
+                    "game_id": self.source.game_id_format.format(game_id=item["crc32"][:8]),
+                    "executable": self.source.executable_format.format(
+                        rom_path = item["path"],
+                        core_path = core_path,
+                    )
+                }
+
+                game = Game(values)
+                additional_data = {}
+
+                # Get boxart
+                boxart_image_name = item["label"].split(".", 1)[0] + ".png"
+                boxart_folder_name = playlist_file.split(".", 1)[0]
+                image_path = self.source.config_location["thumbnails"] / boxart_folder_name / "Named_Boxarts" / boxart_image_name
+                additional_data = {"local_image_path": image_path}
+
+                yield(game, additional_data)
+
+
+class RetroarchSource(Source):
+    args = ' -L "{core_path}" "{rom_path}"'
+
+    name = "Retroarch"
+    available_on = {"linux"}
+    iterator_class = RetroarchSourceIterator
+    executable_format = 'retroarch' + args
+
+    config_location = Location(
+        schema_key="retroarch-location",
+        candidates=(
+            shared.flatpak_dir / "org.libretro.RetroArch" / "config" / "retroarch",
+            shared.config_dir / "retroarch",
+            shared.home / ".config" / "retroarch",
+        ),
+        paths={
+            "playlists": (True, "playlists"),
+            "thumbnails": (True, "thumbnails"),
+        },
+    )
+
+    # Check if installation is flatpak'd.
+    # TODO: There's probably a MUCH better way of doing this.
+    # There's *is* a URI format, but it doesn't seem to work on the flatpak
+    # version of Retroarch. https://github.com/libretro/RetroArch/pull/13563
+    if str(shared.flatpak_dir) in str(config_location["playlists"]):
+        executable_format = 'flatpak run org.libretro.RetroArch' + args

src/main.py

@@ -33,6 +33,7 @@ from src import shared
 from src.details_window import DetailsWindow
 from src.game import Game
 from src.importer.importer import Importer
+from src.importer.sources.retroarch_source import RetroarchSource
 from src.importer.sources.bottles_source import BottlesSource
 from src.importer.sources.flatpak_source import FlatpakSource
 from src.importer.sources.heroic_source import HeroicSource
@@ -230,6 +231,9 @@ class CartridgesApplication(Adw.Application):
         if shared.schema.get_boolean("legendary"):
             importer.add_source(LegendarySource())
 
+        if shared.schema.get_boolean("retroarch"):
+            importer.add_source(RetroarchSource())
+
         importer.run()
 
     def on_remove_game_action(self, *_args):

src/preferences.py

@@ -30,6 +30,7 @@ from src.importer.sources.flatpak_source import FlatpakSource
 from src.importer.sources.heroic_source import HeroicSource
 from src.importer.sources.itch_source import ItchSource
 from src.importer.sources.legendary_source import LegendarySource
+from src.importer.sources.retroarch_source import RetroarchSource
 from src.importer.sources.location import UnresolvableLocationError
 from src.importer.sources.lutris_source import LutrisSource
 from src.importer.sources.source import Source
@@ -82,6 +83,9 @@ class PreferencesWindow(Adw.PreferencesWindow):
     legendary_config_action_row = Gtk.Template.Child()
     legendary_config_file_chooser_button = Gtk.Template.Child()
 
+    retroarch_expander_row = Gtk.Template.Child()
+    retroarch_config_file_chooser_button = Gtk.Template.Child()
+
     flatpak_expander_row = Gtk.Template.Child()
     flatpak_data_action_row = Gtk.Template.Child()
     flatpak_data_file_chooser_button = Gtk.Template.Child()
@@ -138,6 +142,7 @@ class PreferencesWindow(Adw.PreferencesWindow):
             ItchSource,
             LegendarySource,
             LutrisSource,
+            RetroarchSource,
             SteamSource,
         ):
             source = source_class()
@@ -385,3 +390,4 @@ class PreferencesWindow(Adw.PreferencesWindow):
         # Set the source row subtitles
         self.resolve_locations(source)
         self.update_source_action_row_paths(source)
+