"""
Configuration Manager for the application.
Handles loading and saving of application settings to a JSON file.
"""

import json
from pathlib import Path
from typing import Dict, Any, Optional, List

from . import logger
from ..core.export_profiles import ExportProfile, ExportField

log = logger.get_logger(__name__)


class ConfigManager:
    """Manages loading and saving configuration from/to a JSON file."""

    def __init__(self, config_path: Path):
        self.config_path: Path = config_path
        self.config: Dict[str, Any] = self._get_default_config()
        self.export_profiles: List[ExportProfile] = []

    @staticmethod
    def _get_default_config() -> Dict[str, Any]:
        """Provides the default configuration structure."""
        default_profile = ExportProfile(
            name="Default",
            fields=[
                ExportField(column_name="batch_id", data_path="batch_id"),
                ExportField(
                    column_name="timetag",
                    data_path="main_header.ge_header.signal_descr.ttag",
                ),
                ExportField(
                    column_name="file_batch_counter",
                    data_path="main_header.ge_header.signal_descr.batch_counter",
                ),
            ],
        )
        return {
            "last_opened_out_file": "",
            "last_opened_rec_file": "",
            "last_out_output_dir": "",
            "last_rec_output_dir": "",
            "active_out_export_profile_name": "Default",
            "active_rec_csv_profile_name": "Default",
            "active_rec_json_profile_name": "Default",
            "export_profiles": [default_profile.to_dict()],
        }

    def load_config(self) -> None:
        """Loads the main application configuration from the JSON file."""
        log.info(f"Attempting to load configuration from: {self.config_path}")
        if self.config_path.is_file():
            try:
                with open(self.config_path, "r", encoding="utf-8") as f:
                    loaded_data = json.load(f)

                default_conf = self._get_default_config()
                for key in default_conf:
                    self.config[key] = loaded_data.get(key, default_conf[key])

                profiles_data = loaded_data.get("export_profiles", [])
                self.export_profiles = [
                    ExportProfile.from_dict(p_data) for p_data in profiles_data
                ]

                if not self.export_profiles:
                    log.warning("No export profiles found in config, loading defaults.")
                    self._load_default_profiles()

                log.info(
                    f"Configuration loaded successfully. Found {len(self.export_profiles)} export profiles."
                )

            except (json.JSONDecodeError, IOError, KeyError) as e:
                log.error(f"Failed to load or parse config file: {e}. Using defaults.")
                self._load_defaults()
        else:
            log.warning("Configuration file not found. Using default settings.")
            self._load_defaults()

    def _load_defaults(self):
        """Loads all default settings into the manager."""
        self.config = self._get_default_config()
        self._load_default_profiles()

    def _load_default_profiles(self):
        """Loads just the default profiles from the default config."""
        default_conf = self._get_default_config()
        profiles_data = default_conf.get("export_profiles", [])
        self.export_profiles = [
            ExportProfile.from_dict(p_data) for p_data in profiles_data
        ]

    def save_config(self) -> None:
        """Saves the current configuration to the JSON file."""
        log.info(f"Saving configuration to: {self.config_path}")

        data_to_save = self.config.copy()
        data_to_save["export_profiles"] = [
            profile.to_dict() for profile in self.export_profiles
        ]

        try:
            self.config_path.parent.mkdir(parents=True, exist_ok=True)
            with open(self.config_path, "w", encoding="utf-8") as f:
                json.dump(data_to_save, f, indent=4)
            log.info("Configuration saved successfully.")
        except IOError as e:
            log.error(f"Failed to save configuration file: {e}")

    def get(self, key: str, default: Optional[Any] = None) -> Any:
        """Gets a value from the configuration."""
        return self.config.get(key, default)

    def set(self, key: str, value: Any) -> None:
        """Sets a value in the configuration."""
        self.config[key] = value

    def get_export_profiles(self) -> List[ExportProfile]:
        """Returns the list of loaded export profiles."""
        return self.export_profiles

    def save_export_profiles(self, profiles: List[ExportProfile]):
        """Updates the list of export profiles and saves the config."""
        self.export_profiles = profiles
        self.save_config()