commit d352e709567fd4306bd4011a5ebb0b604ce598aa
Author: Alexander "PapaTutuWawa <papatutuwawa@polynom.me>
Date:   Sat Dec 2 17:45:16 2023 +0100

    Initial commit

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..843aa8f
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+venv/
+**/__pycache__/
+*.egg-info/
\ No newline at end of file
diff --git a/lmm/__init__.py b/lmm/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/lmm/cli.py b/lmm/cli.py
new file mode 100644
index 0000000..7677667
--- /dev/null
+++ b/lmm/cli.py
@@ -0,0 +1,137 @@
+import os
+from typing import Optional
+
+from lmm.const import LMM_GAMES_PATH
+from lmm.games.config import load_game_configs
+from lmm.games.game import Game
+from lmm.games.bg3 import GAME_NAME as BG3
+from lmm.mods.bg3 import install_mod as bg3_install_mod
+
+import click
+
+def get_game_by_name(name: str) -> Optional[Game]:
+    games = load_game_configs()
+    for game in games:
+        if game.name == name:
+            return game
+    return None
+
+@click.group()
+@click.pass_context
+def cli(ctx):
+    if ctx.invoked_subcommand is None:
+        click.echo("Invoked without a subcommand")
+
+@cli.command()
+@click.option("-g", "--game", required=True)
+@click.option("-p", "--profile", required=True)
+def launch(game: str, profile: str):
+    game = get_game_by_name(game)
+    if game is None:
+        click.echo("Game not found")
+        return
+    
+    profile = game.get_profile_by_name(profile)
+    if profile is None:
+        click.echo("Profile not found")
+        return
+
+    runner = None 
+    if profile.runner is not None:
+        runner = profile.runner
+    elif game.default_runner is not None:
+        runner = game.default_runner
+    if runner is None:
+        click.echo("Cannot launch profile as no runner or default runner is configured")
+        return
+
+    # Prepare mounts
+    mounts_ok = True
+    mounts = game.prepare_overlays(profile)
+    for mount in mounts:
+        result = mount.mount()
+        if result is None:
+            click.echo("Mount failed")
+            mounts_ok = False
+            break
+
+        print(f"Mounted overlayfs at {result}")
+    
+    # Launch the game
+    if mounts_ok:
+        #runner.run()
+        #game.wait()
+        print(f"Stub runner: Would use {runner.__class__.__name__}")
+
+    # Unmount
+    for mount in mounts:
+        mount.unmount()
+
+@cli.command()
+@click.option("-g", "--game", required=True)
+@click.option("-P", "--path", required=True)
+def install(game: str, path: str):
+    install = {
+        BG3: bg3_install_mod,
+    }.get(game, None)
+    if install is None:
+        click.echo(f"Unknown game \"{game}\"")
+        return
+    
+    install(Path(path))
+
+@cli.command()
+@click.option("-g", "--game")
+def mods(game: Optional[str]):
+    if game is not None:
+        games = [game]
+    else:
+        games = [
+            item for item in os.listdir(LMM_GAMES_PATH) if (LMM_GAMES_PATH / item).is_dir()
+        ]
+
+    for idx, game_name in enumerate(games):
+        click.echo(f"Installed mods for {game_name}:")
+        for item in os.listdir(LMM_GAMES_PATH / game_name):
+            path = LMM_GAMES_PATH / game_name / item
+            if not path.is_dir():
+                continue
+
+            click.echo(f"- {item}")
+        
+        if idx < len(games) - 1:
+            click.echo()
+
+@cli.command
+def list():
+    games = load_game_configs()
+    for idx, game in enumerate(games):
+        if game.default_runner is not None:
+            default_runner_name = game.default_runner.__class__.__name__
+        else:
+            default_runner_name = "None"
+
+        click.echo(f"- {game.name}")
+        click.echo(f"  {game.installation_path}")
+        click.echo(f"  Can start: {game.can_start()}")
+        click.echo(f"  Default runner: {default_runner_name}")
+        click.echo("  Profiles:")
+        for profile in game.profiles:
+            mods = ", ".join(profile.get_mod_names())
+            if profile.runner is not None:
+                runner_name = profile.runner.__class__.__name__
+            else:
+                runner_name = "None"
+
+            click.echo(f"  - {profile.name}")
+            click.echo(f"    Runner: {runner_name}")
+            click.echo(f"    Mods: {mods}")
+        
+        if idx < len(games) - 1:
+            click.echo()
+
+def main():
+    cli()
+
+if __name__ == "__main__":
+    cli()
\ No newline at end of file
diff --git a/lmm/cmd.py b/lmm/cmd.py
new file mode 100644
index 0000000..7ca83ae
--- /dev/null
+++ b/lmm/cmd.py
@@ -0,0 +1,40 @@
+import os
+import subprocess
+from typing import Optional
+from pathlib import Path
+
+def run_cmd(args: list[str], cd: Optional[Path] = None) -> int:
+    cmdline = " ".join(args)
+    if cd is not None:
+        print("Settings CWD to", cd)
+    print("Executing:", cmdline)
+
+    cwd = os.getcwd()
+    if cd is not None:
+        os.chdir(cd)
+    ret = subprocess.call(args, cwd=cd)
+    os.chdir(cwd)
+    return ret
+
+def run_sudo_cmd(args: list[str], cd: Optional[Path] = None) -> int:
+    return run_cmd(
+        [
+            "pkexec",
+            "--user", "root",
+            "--keep-cwd",
+            *args,
+        ],
+        cd=cd,
+    )
+
+def run_cmd_shell(cmd: str) -> None:
+    print("Executing:", cmd)
+    subprocess.run(
+        cmd,
+        shell=True,
+    )
+
+def run_cmd_nonblocking(args: list[str]) -> subprocess.Popen:
+    cmdline = " ".join(args)
+    print("Executing:", cmdline)
+    return subprocess.Popen(args)
diff --git a/lmm/const.py b/lmm/const.py
new file mode 100644
index 0000000..355bb3a
--- /dev/null
+++ b/lmm/const.py
@@ -0,0 +1,5 @@
+from pathlib import Path
+
+LMM_PATH: Path = Path.home() / ".local" / "share" / "lmm"
+
+LMM_GAMES_PATH: Path = LMM_PATH / "games"
\ No newline at end of file
diff --git a/lmm/games/bg3.py b/lmm/games/bg3.py
new file mode 100644
index 0000000..759d2a7
--- /dev/null
+++ b/lmm/games/bg3.py
@@ -0,0 +1,174 @@
+import os
+from pathlib import Path
+from enum import Enum, auto
+from dataclasses import dataclass
+from typing import Generator, Any
+
+from lmm.const import LMM_GAMES_PATH
+from lmm.profile import Profile
+from lmm.overlayfs import OverlayFSMount
+from lmm.games.game import ProtonGame, CannotStartReason, PathNotExistingReason
+from lmm.runners.base import runner_from_config
+
+GAME_NAME = "BaldursGate3"
+
+class BaldursGate3ModType(Enum):
+    # Override the game files
+    ROOT = 1
+
+    # Override the Paks in the compatdata prefix
+    PAK = 2
+
+@dataclass
+class BaldursGate3Mod:
+    # The directory name
+    name: str
+
+    # The type of mod
+    type: BaldursGate3ModType
+
+
+@dataclass
+class BaldursGate3Profile(Profile):
+    mods: list[BaldursGate3Mod]
+
+    def __init__(self, name: str, mods: list[BaldursGate3Mod], **kwargs):
+        super().__init__(GAME_NAME, name, **kwargs)
+        self.mods = mods
+
+    def get_mods(self, type: BaldursGate3ModType) -> Generator[BaldursGate3Mod, None, None]:
+        """Yields all mods of type @type"""
+        for mod in self.mods:
+            if not mod.type == type:
+                continue
+            
+            yield mod
+
+    def has_mods_of_type(self, type: BaldursGate3ModType) -> bool:
+        """Returns whether the profile has any mods of type @type"""
+        return any(self.get_mods(type))
+
+    def get_mod_names(self) -> list[str]:
+        return [mod.name for mod in self.mods]
+
+class BaldursGate3Game(ProtonGame):
+    def __init__(self, profiles: list[BaldursGate3Profile], **kwargs):
+        super().__init__(GAME_NAME, "1086940", profiles, **kwargs)
+
+    @property
+    def installation_path(self) -> Path:
+        return self.steam_library / "steamapps" / "common" / "Baldurs Gate 3"
+
+    @property
+    def compat_path(self) -> Path:
+        return self.steam_library / "steamapps" / "compatdata" / self.appid
+
+    @property
+    def user_mods_path(self) -> Path:
+        return self.compat_path / "pfx" / "drive_c" / "users" / "steamuser" / "AppData" / "Local" / "Larian Studios" / "Baldur's Gate 3" / "Mods"
+
+    def can_start(self) -> bool:
+        return self.user_mods_path.exists() and self.installation_path.exists()
+
+    def cannot_start_reasons(self) -> list[CannotStartReason]:
+        issues = []
+        if not self.user_mods_path.exists():
+            issues.append(
+                PathNotExistingReason(self.user_mods_path),
+            )
+        if not self.installation_path.exists():
+            issues.append(
+                PathNotExistingReason(self.installation_path),
+            )
+        return issues
+
+    def prepare_overlays(self, profile: BaldursGate3Profile) -> list[OverlayFSMount]:
+        overlays = []
+
+        if profile.has_mods_of_type(BaldursGate3ModType.ROOT):
+            mods = list(profile.get_mods(BaldursGate3ModType.ROOT))
+            mod_paths = [
+                LMM_GAMES_PATH / GAME_NAME / mod.name for mod in mods
+            ]
+            overlays.append(
+                OverlayFSMount(
+                    self.installation_path,
+                    mod_paths,
+                    mount=self.installation_path,
+                ),
+            )
+
+            mod_names = ", ".join([mod.name for mod in mods])
+            print(f"Loaded root mods: {mod_names}")
+        if profile.has_mods_of_type(BaldursGate3ModType.PAK):
+            mods = list(profile.get_mods(BaldursGate3ModType.PAK))
+            mod_paths = [
+                os.path.join("./", mod.name) for mod in mods
+            ]
+
+            # Merge all mods
+            overlays.append(
+                OverlayFSMount(
+                    self.user_mods_path,
+                    mod_paths,
+                    self.user_mods_path,
+                    cd=LMM_GAMES_PATH / self.name,
+                ),
+            )
+
+            mod_names = ", ".join([mod.name for mod in mods])
+            print(f"Loaded PAK mods: {mod_names}")
+
+        return overlays
+
+    @property
+    def game_executable(self) -> Path:
+        return self.installation_path / "bin" / "bg3.exe"
+
+    def to_dict(self) -> dict[str, Any]:
+        return {
+            "profiles": [
+                {
+                    "name": profile.name,
+                    "mods": [
+                        {
+                            "name": mod.name,
+                            "type": mod.type.value,
+                        } for mod in profile.mods
+                    ]
+                } for profile in self.profiles
+            ]
+        }
+
+    @classmethod
+    def from_dict(cls, data: dict[str, Any]) -> "BaldursGate3Game":
+        profiles = []
+        for profile in data["profiles"]:
+            mods = []
+            for mod in profile["mods"]:
+                mods.append(
+                    BaldursGate3Mod(
+                        mod["name"],
+                        BaldursGate3ModType.ROOT if mod["type"] == 1 else BaldursGate3ModType.PAK,
+                    ),
+                )
+
+            if "runner" in profile:
+                runner = runner_from_config(profile["runner"])
+            else:
+                runner = None
+
+            profiles.append(
+                BaldursGate3Profile(
+                    profile["name"],
+                    mods,
+                    runner=runner,
+                ),
+            )
+        
+        if "default_runner" in data:
+            default_runner = runner_from_config(data["default_runner"])
+        else:
+            default_runner = None
+
+        return BaldursGate3Game(profiles, default_runner=default_runner)
\ No newline at end of file
diff --git a/lmm/games/config.py b/lmm/games/config.py
new file mode 100644
index 0000000..a6723ca
--- /dev/null
+++ b/lmm/games/config.py
@@ -0,0 +1,50 @@
+import json
+import os
+
+from lmm.const import LMM_GAMES_PATH
+from lmm.games.game import Game
+from lmm.games.bg3 import (
+    GAME_NAME as BG3,
+    BaldursGate3Game,
+)
+from lmm.games.pdmm import (
+    GAME_NAME as PDMM,
+    ProjectDivaMegaMixGame,
+)
+from lmm.games.ron import (
+    GAME_NAME as RON,
+    ReadyOrNotGame,
+)
+
+import yaml
+
+
+def load_game_configs() -> list[Game]:
+    games = []
+    for item in os.listdir(LMM_GAMES_PATH):
+        path = LMM_GAMES_PATH / item
+        if not path.is_dir():
+            continue
+
+        config = path / "config.yaml"
+        if not config.exists():
+            continue
+
+        game_cls = {
+            BG3: BaldursGate3Game,
+            PDMM: ProjectDivaMegaMixGame,
+            RON: ReadyOrNotGame,
+        }.get(item, None)
+        if game_cls is None:
+            print(f"Unknown game {item}")
+            continue
+
+        with open(config, "r") as f:
+            try:
+                config_data = yaml.load(f, Loader=yaml.CLoader)
+                games.append(
+                    game_cls.from_dict(config_data),
+                )
+            except Exception as ex:
+                print(f"Failed to load game {item}: {ex}")
+    return games
\ No newline at end of file
diff --git a/lmm/games/game.py b/lmm/games/game.py
new file mode 100644
index 0000000..995910e
--- /dev/null
+++ b/lmm/games/game.py
@@ -0,0 +1,125 @@
+import abc
+import os
+from pathlib import Path
+import time
+from typing import Optional, Any
+from dataclasses import dataclass
+
+from lmm.overlayfs import OverlayFSMount
+from lmm.profile import Profile
+from lmm.steam import find_library_folder_for_game
+
+class CannotStartReason:
+    pass
+
+@dataclass
+class PathNotExistingReason(CannotStartReason):
+    # The path that is not existing
+    path: Path
+
+    def __str__(self) -> str:
+        return f"Path {self.path} does not exist"
+
+class Game(abc.ABC):
+    # The name of the game.
+    name: str
+
+    # List of profiles.
+    profiles: list[Profile]
+
+    # The default runner to use when launching the game.
+    default_runner: Optional["Runner"]
+
+    def __init__(self, name: str, profiles: list[Profile], default_runner: Optional["Runner"]):
+        self.name = name
+        self.profiles = profiles
+        self.default_runner = default_runner
+
+    def get_profile_by_name(self, name: str) -> Optional[Profile]:
+        for profile in self.profiles:
+            if profile.name == name:
+                return profile
+        return None
+
+    @classmethod
+    def from_dict(cls, data: dict[str, Any]) -> "Game":
+        raise NotImplementedError()
+
+    def to_dict(self) -> dict[str, Any]:
+        raise NotImplementedError()
+
+    def installation_path(self) -> Path:
+        raise NotImplementedError()
+
+    def prepare_overlays(self, profile: Profile) -> list[OverlayFSMount]:
+        raise NotImplementedError()
+
+    def can_start(self) -> bool:
+        return True
+
+    def cannot_start_reasons(self) -> list[CannotStartReason]:
+        return []
+
+    def wait(self):
+        return None
+
+class ProtonGame(Game, abc.ABC):
+    # The appid of the game in Steam.
+    appid: str
+
+    # The PID of the game.
+    _pid: Optional[str]
+
+    def __init__(self, name: str, appid: str, profiles: list[Profile], default_runner: Optional["Runner"]):
+        super().__init__(name, profiles, default_runner)
+        self._pid = None
+        self.appid = appid
+
+    def compat_path(self) -> Path:
+        raise NotImplementedError()
+
+    @property
+    def game_executable(self) -> Path:
+        raise NotImplementedError()
+
+    @property
+    def steam_library(self) -> Optional[Path]:
+        return find_library_folder_for_game(self.appid)
+
+    def wait(self):
+        # Wait until we started the game.
+        proc = Path("/proc")
+        windows_path = str(self.game_executable).replace("/", "\\")
+        wine_exe_path = f"Z:{windows_path}"
+        print(wine_exe_path)
+        print("Polling for game process...")
+        while True:
+            for dir in os.listdir(proc):
+                if not dir.isnumeric():
+                    continue
+
+                proc_path = proc / dir / "cmdline"
+                try:
+                    with open(proc_path, "r") as f:
+                        cmdline = f.read()
+
+                    # Workaround for games like Baldur's Gate 3 that have a relative path in the cmdline.
+                    # Note that the cmdline contains null bytes that we have to remove.
+                    abs_cmdline = os.path.abspath(cmdline).replace("\x00", "")
+                    if cmdline.startswith(wine_exe_path) or abs_cmdline == str(self.game_executable):
+                        self._pid = dir
+                        break
+                except:
+                    pass
+            if self._pid is not None:
+                print(f"Found {self.name} at PID {self._pid}")
+                break
+            print(".")
+            time.sleep(2)
+        print()
+
+        # Poll until the game quits.
+        print(f"Polling {self._pid}")
+        pid_path = proc / self._pid
+        while pid_path.exists():
+            time.sleep(2)
diff --git a/lmm/games/pdmm.py b/lmm/games/pdmm.py
new file mode 100644
index 0000000..ea17f1c
--- /dev/null
+++ b/lmm/games/pdmm.py
@@ -0,0 +1,86 @@
+from pathlib import Path
+from typing import Any
+
+from lmm.games.game import ProtonGame
+from lmm.profile import Profile
+from lmm.overlayfs import OverlayFSMount
+from lmm.const import LMM_GAMES_PATH
+from lmm.runners.base import runner_from_config
+
+GAME_NAME = "ProjectDivaMegaMix"
+
+class ProjectDivaMegaMixProfile(Profile):
+    # The names of the directories the the mods directory.
+    mods: list[str]
+
+    def __init__(self, name: str, mods: list[str], **kwargs):
+        super().__init__(GAME_NAME, name, **kwargs)
+
+        self.mods = mods
+
+    def get_mod_names(self) -> list[str]:
+        return self.mods
+
+class ProjectDivaMegaMixGame(ProtonGame):
+    def __init__(self, profiles: list[ProjectDivaMegaMixProfile], **kwargs):
+        super().__init__(GAME_NAME, "1761390", profiles, **kwargs)
+
+    @property
+    def installation_path(self) -> Path:
+        return self.steam_library / "steamapps/common/Hatsune Miku Project DIVA Mega Mix Plus"
+
+    @property
+    def game_executable(self) -> Path:
+        return self.installation_path / "DivaMegaMix.exe"
+
+    def prepare_overlays(self, profile: ProjectDivaMegaMixProfile) -> list[OverlayFSMount]:
+        return [
+            OverlayFSMount(
+                upper=self.installation_path,
+                lower=profile.mods,
+                mount=self.installation_path,
+                cd=LMM_GAMES_PATH / self.name,
+            ),
+        ]
+
+    def to_dict(self) -> dict[str, Any]:
+        return {
+            "profiles": [
+                {
+                    "name": profile.name,
+                    "mods": [
+                        {
+                            "name": mod,
+                        } for mod in profile.mods
+                    ]
+                } for profile in self.profiles
+            ]
+        }
+
+    @classmethod
+    def from_dict(cls, data: dict[str, Any]) -> "ProjectDivaMegaMixGame":
+        profiles = []
+        for profile in data["profiles"]:
+            mods = [
+                mod["name"] for mod in profile["mods"]
+            ]
+
+            if "runner" in profile:
+                runner = runner_from_config(profile["runner"])
+            else:
+                runner = None
+
+            profiles.append(
+                ProjectDivaMegaMixProfile(
+                    profile["name"],
+                    mods,
+                    runner=runner,
+                ),
+            )
+
+        if "default_runner" in data:
+            default_runner = runner_from_config(data["default_runner"])
+        else:
+            default_runner = None
+
+        return ProjectDivaMegaMixGame(profiles, default_runner=default_runner)
\ No newline at end of file
diff --git a/lmm/games/ron.py b/lmm/games/ron.py
new file mode 100644
index 0000000..a5e093e
--- /dev/null
+++ b/lmm/games/ron.py
@@ -0,0 +1,90 @@
+from pathlib import Path
+from typing import Any
+
+from lmm.profile import Profile
+from lmm.overlayfs import OverlayFSMount
+from lmm.games.game import ProtonGame
+
+GAME_NAME = "ReadyOrNot"
+
+class ReadyOrNotProfile(Profile):
+    # Names of directories inside the game's mods directory.
+    mods: list[str]
+
+    def __init__(self, name: str, mods: list[str], **kwargs):
+        super().__init__(GAME_NAME, name, **kwargs)
+        self.mods = mods
+
+    def get_mod_names(self) -> list[str]:
+        return self.mods
+
+class ReadyOrNotGame(ProtonGame):
+    def __init__(self, profiles: list[ReadyOrNotProfile], **kwargs):
+        super().__init__(GAME_NAME, "1144200", profiles, **kwargs)
+
+    @property
+    def installation_path(self) -> Path:
+        return self.steam_library / "steamapps" / "common" / "Ready Or Not"
+
+    @property
+    def compat_path(self) -> Path:
+        return self.steam_library / "steamapps" / "compatdata" / self.appid
+
+    def can_start(self) -> bool:
+        return self.steam_library is not None
+
+    def prepare_overlays(self, profile: Profile) -> list[OverlayFSMount]:
+        return [
+            OverlayFSMount(
+                self.installation_path,
+                profile.mod_paths,
+                mount=self.installation_path,
+                workdir=profile.workdir,
+            ),
+        ]
+
+    @property
+    def game_executable(self) -> Path:
+        return self.installation_path / "ReadyOrNot.exe"
+
+    def to_dict(self) -> dict[str, Any]:
+        return {
+            "profiles": [
+                {
+                    "name": profile.name,
+                    "mods": [
+                        {
+                            "name": mod,
+                        } for mod in profile.mods
+                    ]
+                } for profile in self.profiles
+            ]
+        }
+
+    @classmethod
+    def from_dict(cls, data: dict[str, Any]) -> "ReadyOrNotGame":
+        profiles = []
+        for profile in data["profiles"]:
+            mods = [
+                mod["name"] for mod in profile["mods"]
+            ]
+
+            if "runner" in profile:
+                runner = runner_from_config(profile["runner"])
+            else:
+                runner = None
+
+            profiles.append(
+                ReadyOrNotProfile(
+                    profile["name"],
+                    mods,
+                    runner=runner,
+                ),
+            )
+
+        if "default_runner" in data:
+            default_runner = runner_from_config(data["default_runner"])
+        else:
+            default_runner = None
+
+        return ReadyOrNotGame(profiles, default_runner=default_runner)
\ No newline at end of file
diff --git a/lmm/mods/bg3.py b/lmm/mods/bg3.py
new file mode 100644
index 0000000..cfdf22e
--- /dev/null
+++ b/lmm/mods/bg3.py
@@ -0,0 +1,61 @@
+import json
+from pathlib import Path
+import zipfile
+
+from lmm.const import LMM_GAMES_PATH
+from lmm.games.bg3 import GAME_NAME
+
+def install_mod(mod: Path):
+    match mod.suffix:
+        case ".zip":
+            install_zip_mod(mod)
+        case _:
+            print("Unknown mod")
+
+def install_zip_mod(mod: Path):
+    # Inspect the archive to see if it's a PAK mod
+    with zipfile.ZipFile(mod, "r") as f:
+        paks = []
+        info_json = None
+        for member in f.infolist():
+            if member.filename.endswith(".pak"):
+                paks.append(member)
+            elif member.filename == "info.json":
+                info_json = member
+
+        if not paks:
+            print("Automatic installation of non-PAK mods not supported yet")
+            pass
+
+        # This mod is a PAK only mod
+        if info_json is not None:
+            with f.open("info.json", "r") as info:
+                data = json.load(info)
+            name = data["Mods"][0]["Name"].replace(" ", "")
+        elif len(paks) == 1:
+            print("Guessing name from PAK file")
+            name = paks[0].filename.replace(".pak", "").replace(" ", "")
+        else:
+            print("Cannot deduce mod name!")
+            try:
+                name = input("Mod name: ")
+            except InterruptedError:
+                print("Not installing mod")
+                return
+            except EOFError:
+                print("Not installing mod")
+                return
+
+        # Check if we can install the mod
+        installed_mod_path = LMM_GAMES_PATH / GAME_NAME / name
+        if installed_mod_path.exists():
+            print(f"Mod already exists: {name}")
+            return
+
+        # Install the mod
+        installed_mod_path.mkdir(parents=True)
+        for pak in paks:
+            print(f"Extracting {pak.filename}...")
+            f.extract(pak, installed_mod_path)
+
+        print(f"Installed mod as {name}")
diff --git a/lmm/overlayfs.py b/lmm/overlayfs.py
new file mode 100644
index 0000000..b0e9b7b
--- /dev/null
+++ b/lmm/overlayfs.py
@@ -0,0 +1,106 @@
+from pathlib import Path
+import tempfile
+from typing import Optional
+
+from lmm.cmd import run_sudo_cmd
+
+def compute_workdirs_location(mount: Path) -> Path:
+    with open("/proc/mounts", "r") as f:
+        mounts = f.read().split("\n")
+
+    mounted_dirs = [
+        m for line in mounts if line != "" and (m := line.strip().split(" ")[1]) != "/"
+    ]
+    mounted_dirs.sort()
+
+    closest_mount = None
+    for m in mounted_dirs:
+        if str(mount).startswith(m) and len(m) > len(closest_mount or ""):
+            closest_mount = m
+            continue
+    
+    return Path("/tmp") if closest_mount is None else Path(closest_mount) / ".temp"
+
+
+class OverlayFSMount:
+    upper: Optional[Path]
+
+    lower: list[Path | str]
+
+    workdir: Optional[tempfile.TemporaryDirectory]
+
+    mount_path: Path
+
+    _mounted: bool
+
+    cd: Optional[Path]
+
+    def __init__(self, upper: Optional[Path], lower: list[Path | str], mount: Path, cd: Optional[Path] = None):
+        self.upper = upper
+        self.lower = lower
+        self.mount_path = mount
+        self._mounted = False
+        self.cd = cd
+
+        assert len(lower) < 500, "overlayfs only supports up-to 500 lower directories"
+
+    def create_workdir(self) -> Path:
+        # Ensure the temporary directory for workdirs exists
+        workdir_location = compute_workdirs_location(self.mount_path)
+        if not workdir_location.exists():
+            workdir_location.mkdir(parents=True, exist_ok=True)
+
+        # Create the workdir
+        self.workdir = tempfile.TemporaryDirectory(
+            dir=workdir_location,
+        )
+        print(f"Temporary workdir {self.workdir.name} created")
+        return Path(self.workdir.name)
+
+    def mount(self) -> Optional[Path]:
+        lower = ":".join([
+            str(l) for l in self.lower
+        ])
+        options = f"lowerdir={lower}"
+        if self.upper is not None:
+            workdir = self.create_workdir()
+            options += f",upperdir={self.upper},workdir={workdir}"
+
+        result = run_sudo_cmd(
+            [
+                "mount",
+                "-t", "overlay", "overlay",
+                "-o", options,
+                str(self.mount_path),
+            ],
+            cd=self.cd,
+        )
+        print("Mount result:", result)
+        if not result == 0:
+            return None
+
+        self._mounted = True
+        return self.mount_path
+
+    def unmount(self):
+        if self._mounted:
+            print("Unmounting...")
+            
+            # Remove the mount
+            run_sudo_cmd([
+                "umount",
+                str(self.mount_path),
+            ])
+
+            # Remove the temporary workdir
+            if self.workdir is not None:
+                try:
+                    # TODO: This fails because the workdir is owned by root
+                    self.workdir.cleanup()
+                except PermissionError:
+                    print(f"Failed to clean temporary directory {self.workdir.name}")
+
+            self._mounted = False
+
+    def __del__(self):
+        self.unmount()
diff --git a/lmm/profile.py b/lmm/profile.py
new file mode 100644
index 0000000..af69ba8
--- /dev/null
+++ b/lmm/profile.py
@@ -0,0 +1,22 @@
+from pathlib import Path
+from typing import Optional
+
+from lmm.const import LMM_GAMES_PATH
+
+class Profile:
+    # The name of the game.
+    game: str
+
+    # The name of the profile.
+    name: str
+
+    # The runner to use for the profile.
+    runner: Optional["Runner"]
+
+    def __init__(self, game: str, name: str, runner: Optional["Runner"]):
+        self.game = game
+        self.name = name
+        self.runner = runner
+
+    def get_mod_names(self) -> list[str]:
+        raise NotImplementedError()
\ No newline at end of file
diff --git a/lmm/runners/base.py b/lmm/runners/base.py
new file mode 100644
index 0000000..9e94f83
--- /dev/null
+++ b/lmm/runners/base.py
@@ -0,0 +1,15 @@
+import abc
+from pathlib import Path
+from typing import Any, Optional
+
+from lmm.cmd import run_cmd_nonblocking
+from lmm.games.game import Game, ProtonGame
+from lmm.runners.runner import Runner
+from lmm.runners.steam import SteamFlatpakAppIdRunner
+
+def runner_from_config(data: dict[str, Any]) -> Optional[Runner]:
+    match data["type"]:
+        case "steam.flatpak":
+            return SteamFlatpakAppIdRunner()
+        case _:
+            return None
diff --git a/lmm/runners/runner.py b/lmm/runners/runner.py
new file mode 100644
index 0000000..ebe90c1
--- /dev/null
+++ b/lmm/runners/runner.py
@@ -0,0 +1,13 @@
+import abc
+
+from lmm.games.game import Game
+
+class Runner(abc.ABC):
+    # Type identifier of the runner.
+    runner_type: str
+
+    def __init__(self, runner_type: str):
+        self.runner_type = runner_type
+
+    def run(self, game: Game):
+        raise NotImplementedError()
\ No newline at end of file
diff --git a/lmm/runners/steam.py b/lmm/runners/steam.py
new file mode 100644
index 0000000..c9e48d3
--- /dev/null
+++ b/lmm/runners/steam.py
@@ -0,0 +1,105 @@
+import abc
+from pathlib import Path
+
+from lmm.runners.runner import Runner
+from lmm.games.game import Game
+
+class SteamRuntime(abc.ABC):
+    def get_run_script(self) -> Path:
+        raise NotImplementedError()
+
+class SteamSniperRuntime(SteamRuntime):
+    library: Path
+
+    def __init__(self, library: Path):
+        self.library = library
+
+    def get_run_script(self) -> Path:
+        return self.library / "steamapps" / "common" / "SteamLinuxRuntime_sniper" / "run-in-sniper"
+
+
+class SteamSoldierRuntime(SteamRuntime):
+    library: Path
+
+    def __init__(self, library: Path):
+        self.library = library
+
+    def get_run_script(self) -> Path:
+        return self.library / "steamapps" / "common" / "SteamLinuxRuntime_soldier" / "run-in-soldier"
+
+class SteamFlatpakAppIdRunner(Runner):
+    def __init__(self):
+        super().__init__("steam.flatpak")
+
+    def run(self, game: Game):
+        assert isinstance(game, ProtonGame)
+
+        run_cmd_nonblocking([
+            "flatpak",
+            "run",
+            "com.valvesoftware.Steam",
+            f"steam://launch/{game.appid}/",
+        ])
+
+class SteamFlatpakProtonRunner(Runner):
+    # Path to the Proton prefix
+    compat_data: Path
+
+    proton_version: str
+
+    runtime: SteamRuntime
+
+    game: str
+
+    # Launchmode as passed to Proton.
+    # "waitforexitandrun" | "run"
+    launchmode: str
+
+    def __init__(self, compat_data: Path, runtime: SteamRuntime, proton_version: str, game: str, launchmode: str = "waitforexitandrun"):
+        self.compat_data = compat_data
+        self.runtime = runtime
+        self.game = game
+        self.proton_version = proton_version
+
+        self.launchmode = launchmode
+
+    @property
+    def _steam_install_path(self) -> Path:
+        return Path.home() / ".steam" / "steam"
+
+    def _build_environ(self) -> list[str]:
+        proton = self._proton_path
+        return [
+            f"--env=STEAM_COMPAT_CLIENT_INSTALL_PATH={self._steam_install_path}",
+            f"--env=STEAM_COMPAT_DATA_PATH={self.compat_data}",
+            #f"--env=WINEDLLPATH={proton}/files/lib64/wine:{proton}/files/lib/wine",
+            #f"--env=WINEPREFIX={self.compat_data}/pfx",
+            #f"--env=SteamGameId=1144200",
+            #"--env=WINEDLLOVERRIDES=steam.exe=b"
+            #f"--env=WINEDEBUG=-all",
+        ]
+
+    @property
+    def _proton_path(self) -> Path:
+        return Path.home() / "data" / "Steam" / "compatibilitytools.d" / self.proton_version
+
+    def _build_launch_command(self) -> str:
+        command = [
+            str(self.runtime.get_run_script()),
+            str(self._proton_path / "proton"),
+            self.launchmode,
+            f"'{self.game}'",
+        ]
+        commandline = " ".join(command)
+        return commandline
+
+    def run(self):
+        run_cmd_shell(" ".join([
+            "flatpak",
+            "run",
+            "--command=bash",
+            *self._build_environ(),
+            "com.valvesoftware.Steam",
+            "-c",
+            f'"{self._build_launch_command()}"',
+        ]))
diff --git a/lmm/steam.py b/lmm/steam.py
new file mode 100644
index 0000000..afeaac9
--- /dev/null
+++ b/lmm/steam.py
@@ -0,0 +1,31 @@
+from typing import Optional
+from pathlib import Path
+
+import vdf
+
+STEAM_PATHS = [
+    Path.home() / ".var/app/com.valvesoftware.Steam/data/Steam",
+]
+
+def find_library_folder_for_game(appid: str) -> Optional[Path]:
+    for steam_path in STEAM_PATHS:
+        if not steam_path.exists():
+            continue
+
+        library_folders_vdf = steam_path / "steamapps/libraryfolders.vdf"
+        if not library_folders_vdf.exists():
+            continue
+
+        with open(library_folders_vdf, "r") as f:
+            content = vdf.load(f)
+        
+        for index in content["libraryfolders"]:
+            library = content["libraryfolders"][index]
+
+            if not Path(library["path"]).exists():
+                continue
+
+            if appid in library["apps"]:
+                return Path(library["path"])
+
+    return None
\ No newline at end of file
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..f986791
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,11 @@
+[project]
+name = "lmm"
+version = "0.1.0"
+requires-python = ">= 3.10"
+dependencies = [
+    "vdf",
+    "pyyaml"
+]
+
+[project.scripts]
+lmm = "lmm.cli:main"
\ No newline at end of file