"""Per-user game data and XDG support paths used by the installer."""

from __future__ import annotations

from dataclasses import dataclass
import os
from pathlib import Path
from typing import Mapping


APP_DIRECTORY_NAME = "pristontale-eu"
DEFAULT_INSTALL_DIRECTORY_NAME = "PristontaleEU"
INSTALL_DIRECTORY_VARIABLE = "PTLINUX_INSTALL_DIR"
GAME_RELATIVE_PATH = Path("drive_c/Program Files (x86)/Pristontale EU")


def _xdg_path(
	environment: Mapping[str, str],
	variable: str,
	fallback: Path,
) -> Path:
	value = environment.get(variable)
	if not value:
		return fallback
	path = Path(value).expanduser()
	# The XDG Base Directory specification requires absolute paths. Ignoring an
	# invalid relative value keeps settings anchored to HOME instead of making
	# their location depend on the launcher's current working directory.
	return path if path.is_absolute() else fallback


@dataclass(frozen=True)
class AppPaths:
	"""All persistent paths for one user's installation."""

	data: Path
	config: Path
	state: Path
	cache: Path

	@classmethod
	def from_environment(
		cls,
		environment: Mapping[str, str] | None = None,
	) -> AppPaths:
		env = os.environ if environment is None else environment
		home_value = env.get("HOME")
		if not home_value:
			raise RuntimeError("HOME is not set")
		home = Path(home_value).expanduser()
		config_home = _xdg_path(env, "XDG_CONFIG_HOME", home / ".config")
		state_home = _xdg_path(env, "XDG_STATE_HOME", home / ".local/state")
		cache_home = _xdg_path(env, "XDG_CACHE_HOME", home / ".cache")
		install_value = env.get(INSTALL_DIRECTORY_VARIABLE)
		if install_value:
			data = Path(install_value).expanduser()
			if not data.is_absolute():
				raise RuntimeError(
					f"{INSTALL_DIRECTORY_VARIABLE} must be an absolute path"
				)
		else:
			data = home / "Games" / DEFAULT_INSTALL_DIRECTORY_NAME
		return cls(
			data=data.resolve(),
			config=(config_home / APP_DIRECTORY_NAME).resolve(),
			state=(state_home / APP_DIRECTORY_NAME).resolve(),
			cache=(cache_home / APP_DIRECTORY_NAME).resolve(),
		)

	@property
	def downloads(self) -> Path:
		return self.cache / "downloads"

	@property
	def app_home(self) -> Path:
		"""Stable home containing versioned native-launcher releases."""

		return self.data / "app"

	@property
	def launcher_releases(self) -> Path:
		return self.app_home / "releases"

	@property
	def launcher_current(self) -> Path:
		return self.app_home / "current"

	@property
	def launcher_previous(self) -> Path:
		return self.app_home / "previous"

	@property
	def launcher_update_state(self) -> Path:
		return self.state / "launcher-update.json"

	@property
	def launcher_update_lock(self) -> Path:
		return self.state / "launcher-update.lock"

	@property
	def launcher_update_check_cache(self) -> Path:
		"""Display-only cache of the last authenticated update check."""

		return self.cache / "launcher-update-check.json"

	def launcher_update_archive(self, version: str) -> Path:
		return self.downloads / f"pristontale-eu-linux-update-v{version}.tar.gz"

	@property
	def launcher_pristine(self) -> Path:
		return self.downloads / "Pristontale EU Launcher.exe"

	@property
	def launcher_patched(self) -> Path:
		return self.data / "launcher" / "Pristontale EU Launcher.exe"

	@property
	def launcher_metadata(self) -> Path:
		return self.state / "launcher-download.json"

	@property
	def launcher_prefix(self) -> Path:
		return self.data / "launcher-prefix"

	@property
	def launcher_prefix_marker(self) -> Path:
		return self.state / "launcher-prefix.json"

	@property
	def launcher_operation_lock(self) -> Path:
		return self.state / "launcher-operation.lock"

	@property
	def game_runtime_marker(self) -> Path:
		"""Verified Proton/D3D preparation state for the game prefix."""

		return self.state / "game-runtime.json"

	@property
	def source_game(self) -> Path:
		return self.launcher_prefix / GAME_RELATIVE_PATH

	@property
	def game_import_manifest(self) -> Path:
		return self.state / "game-import.json"

	@property
	def native_depot_state(self) -> Path:
		"""Last completed native depot synchronization."""

		return self.state / "native-depot.json"

	@property
	def news_cache(self) -> Path:
		return self.cache / "news.json"

	@property
	def broadcast_cache(self) -> Path:
		"""Cached latest announcement from the broadcast service."""

		return self.cache / "broadcast.json"

	@property
	def news_image_cache(self) -> Path:
		"""Cached official PNG thumbnails used by the native news cards."""

		return self.cache / "news-images"

	@property
	def logo_cache(self) -> Path:
		"""Cached PNG asset for the official PristonTale EU logo."""

		return self.cache / "logo-small.png"

	@property
	def runtime_view(self) -> Path:
		return self.data / "runtime-view"

	@property
	def runtime_manifest(self) -> Path:
		return self.state / "runtime-view.json"

	@property
	def game_user_data(self) -> Path:
		"""Writable game-created data kept outside the replaceable runtime view."""

		return self.data / "user-data"

	@property
	def game_save(self) -> Path:
		return self.game_user_data / "save"

	@property
	def compatibility_binaries(self) -> Path:
		return self.data / "compatibility-binaries"

	@property
	def compatibility_manifest(self) -> Path:
		return self.state / "compatibility-binaries.json"

	@property
	def runtime_patch_directory(self) -> Path:
		"""Retired 0.5.8 disk-patch cache; never selected for play."""

		return self.data / "runtime-patches" / "v21-post-auth-reclaim"

	@property
	def runtime_patch_dll(self) -> Path:
		"""Retired 0.5.8 DLL retained only so diagnostics can identify it."""

		return self.runtime_patch_directory / "game.dll"

	@property
	def runtime_patch_manifest(self) -> Path:
		return self.state / "runtime-patch.json"

	@property
	def retired_runtime_patch_dll(self) -> Path:
		"""The pre-0.5.7 all-session patch, retained only for diagnostics."""

		return self.data / "runtime-patches" / "v21-texture-reclaim" / "game.dll"

	@property
	def compat_data(self) -> Path:
		return self.data / "game-compat"

	@property
	def proton_prefix(self) -> Path:
		return self.compat_data / "pfx"

	@property
	def umu_prefix(self) -> Path:
		return self.data / "umu-prefix"

	@property
	def dxvk_cache(self) -> Path:
		return self.cache / "dxvk-state"

	@property
	def logs(self) -> Path:
		return self.state / "logs"

	@property
	def settings_file(self) -> Path:
		return self.config / "settings.json"

	@property
	def settings_lock(self) -> Path:
		return self.config / "settings.lock"

	def create_base_directories(self) -> None:
		for path in (
			self.data,
			self.config,
			self.state,
			self.cache,
			self.downloads,
			self.logs,
			self.dxvk_cache,
		):
			path.mkdir(parents=True, exist_ok=True)