"""
Configuration module for MIDI-to-Hue application.
Handles loading, creating and validating configuration.
"""
import os
import json
from typing import Dict, Any, Optional

# Default config file path
DEFAULT_CONFIG_FILE = 'midi_hue_config.json'

# Default MIDI-to-Hue mapping if no config file exists
DEFAULT_CONFIG = {
    "midi_device": 1,  # Index of MIDI device to use (from available inputs list)
    "update_interval_ms": 50,  # Throttling interval in milliseconds
    "bridge_ip": "192.168.178.35",  # Default Bridge IP
    "mappings": [
        {
            "midi_channel": 5,
            "midi_control": 1,
            "light_name": "Zimmer Decke",
            "parameter": "bri",
            "value_transform": "value * 2"  # MIDI range 0-127 to Hue brightness 0-254
        },
        {
            "midi_channel": 6,
            "midi_control": 1,
            "light_name": "Fernseher links",
            "parameter": "bri",
            "value_transform": "value * 2"  # MIDI range 0-127 to Hue brightness 0-254
        },
    ]
}

class ConfigManager:
    """Manages configuration loading, validation and access."""
    
    def __init__(self, config_file: str = DEFAULT_CONFIG_FILE):
        """Initialize the config manager with a specific config file."""
        self.config_file = config_file
        self.config = self._load_or_create_config()
        
    def _load_or_create_config(self) -> Dict[str, Any]:
        """Load config from file or create with defaults if it doesn't exist."""
        try:
            if os.path.exists(self.config_file):
                with open(self.config_file, 'r') as f:
                    config = json.load(f)
                    print(f"Loaded configuration from {self.config_file}")
                    return config
        except Exception as e:
            print(f"Error loading config file: {e}")
        
        # If we get here, either the file doesn't exist or there was an error
        # Create the default config file
        with open(self.config_file, 'w') as f:
            json.dump(DEFAULT_CONFIG, f, indent=4)
            print(f"Created default configuration file at {self.config_file}")
        
        return DEFAULT_CONFIG

    def get(self, key: str, default: Any = None) -> Any:
        """Get a configuration value by key with a default fallback."""
        return self.config.get(key, default)
    
    def get_mappings(self) -> list:
        """Get all mappings from the configuration."""
        return self.config.get("mappings", [])
    
    def get_bridge_ip(self) -> str:
        """Get the Bridge IP address."""
        return self.config.get("bridge_ip", "192.168.178.35")
    
    def get_update_interval_sec(self) -> float:
        """Get the update interval in seconds."""
        update_interval_ms = self.config.get("update_interval_ms", 50)
        return update_interval_ms / 1000  # Convert to seconds
    
    def get_midi_device_index(self) -> int:
        """Get the MIDI device index."""
        return self.config.get("midi_device", 1)