"""Konfigurationsmanagement - Singleton fuer Settings und Presets"""
import os
import logging
import yaml
from pathlib import Path
from typing import Optional
from logging.handlers import TimedRotatingFileHandler, RotatingFileHandler


class Config:
    """Laedt und verwaltet settings.yaml und presets.yaml"""
    _instance: Optional['Config'] = None

    def __new__(cls) -> 'Config':
        if cls._instance is None:
            cls._instance = super().__new__(cls)
            cls._instance._initialized = False
        return cls._instance

    def __init__(self) -> None:
        if self._initialized:
            return
        self._initialized = True

        self._base_path = Path(__file__).parent
        self._cfg_path = self._base_path / "cfg"
        self._log_path = self._base_path.parent / "logs"
        self._data_path = self._base_path.parent / "data"

        # Verzeichnisse sicherstellen
        self._log_path.mkdir(parents=True, exist_ok=True)
        self._data_path.mkdir(parents=True, exist_ok=True)

        self.settings: dict = {}
        self.presets: dict = {}
        self._load_settings()
        self._load_presets()
        self._apply_env_overrides()

    def _load_settings(self) -> None:
        """Laedt settings.yaml"""
        settings_file = self._cfg_path / "settings.yaml"
        try:
            with open(settings_file, "r", encoding="utf-8") as f:
                self.settings = yaml.safe_load(f) or {}
            logging.info(f"Settings geladen: {settings_file}")
        except FileNotFoundError:
            logging.error(f"Settings nicht gefunden: {settings_file}")
            self.settings = {}

    def _load_presets(self) -> None:
        """Laedt presets.yaml"""
        presets_file = self._cfg_path / "presets.yaml"
        try:
            with open(presets_file, "r", encoding="utf-8") as f:
                self.presets = yaml.safe_load(f) or {}
            logging.info(f"Presets geladen: {presets_file}")
        except FileNotFoundError:
            logging.error(f"Presets nicht gefunden: {presets_file}")
            self.presets = {}

    def _apply_env_overrides(self) -> None:
        """Umgebungsvariablen ueberschreiben Settings"""
        env_mode = os.environ.get("VIDEO_KONVERTER_MODE")
        if env_mode and env_mode in ("cpu", "gpu", "auto"):
            self.settings.setdefault("encoding", {})["mode"] = env_mode
            logging.info(f"Encoding-Modus per Umgebungsvariable: {env_mode}")

    def save_settings(self) -> None:
        """Schreibt aktuelle Settings zurueck in settings.yaml"""
        settings_file = self._cfg_path / "settings.yaml"
        try:
            with open(settings_file, "w", encoding="utf-8") as f:
                yaml.dump(self.settings, f, default_flow_style=False,
                          indent=2, allow_unicode=True)
            logging.info("Settings gespeichert")
        except Exception as e:
            logging.error(f"Settings speichern fehlgeschlagen: {e}")

    def save_presets(self) -> None:
        """Schreibt Presets zurueck in presets.yaml"""
        presets_file = self._cfg_path / "presets.yaml"
        try:
            with open(presets_file, "w", encoding="utf-8") as f:
                yaml.dump(self.presets, f, default_flow_style=False,
                          indent=2, allow_unicode=True)
            logging.info("Presets gespeichert")
        except Exception as e:
            logging.error(f"Presets speichern fehlgeschlagen: {e}")

    def setup_logging(self) -> None:
        """Konfiguriert Logging mit Rotation"""
        log_cfg = self.settings.get("logging", {})
        log_level = log_cfg.get("level", "INFO")
        log_file = log_cfg.get("file", "server.log")
        log_mode = log_cfg.get("rotation", "time")
        backup_count = log_cfg.get("backup_count", 7)

        log_path = self._log_path / log_file
        handlers = [logging.StreamHandler()]

        if log_mode == "time":
            file_handler = TimedRotatingFileHandler(
                str(log_path), when="midnight", interval=1,
                backupCount=backup_count, encoding="utf-8"
            )
        else:
            max_bytes = log_cfg.get("max_size_mb", 10) * 1024 * 1024
            file_handler = RotatingFileHandler(
                str(log_path), maxBytes=max_bytes,
                backupCount=backup_count, encoding="utf-8"
            )

        handlers.append(file_handler)

        # force=True weil Config.__init__ logging aufruft bevor setup_logging()
        logging.basicConfig(
            level=getattr(logging, log_level, logging.INFO),
            format="%(asctime)s - %(levelname)s - %(message)s",
            handlers=handlers,
            force=True,
        )

    # --- Properties fuer haeufig benoetigte Werte ---

    @property
    def encoding_mode(self) -> str:
        return self.settings.get("encoding", {}).get("mode", "cpu")

    @property
    def gpu_device(self) -> str:
        return self.settings.get("encoding", {}).get("gpu_device", "/dev/dri/renderD128")

    @property
    def max_parallel_jobs(self) -> int:
        return self.settings.get("encoding", {}).get("max_parallel_jobs", 1)

    @property
    def target_container(self) -> str:
        return self.settings.get("files", {}).get("target_container", "webm")

    @property
    def default_preset_name(self) -> str:
        return self.settings.get("encoding", {}).get("default_preset", "cpu_av1")

    @property
    def default_preset(self) -> dict:
        name = self.default_preset_name
        return self.presets.get(name, {})

    @property
    def data_path(self) -> Path:
        return self._data_path

    @property
    def audio_config(self) -> dict:
        return self.settings.get("audio", {})

    @property
    def subtitle_config(self) -> dict:
        return self.settings.get("subtitle", {})

    @property
    def files_config(self) -> dict:
        return self.settings.get("files", {})

    @property
    def cleanup_config(self) -> dict:
        return self.settings.get("cleanup", {})

    @property
    def server_config(self) -> dict:
        return self.settings.get("server", {})