"""
Configuration management for Calejo Control Adapter.
"""

from pydantic_settings import BaseSettings
from typing import Optional, List
from pydantic import validator
import os


class Settings(BaseSettings):
    """Application settings loaded from environment variables."""
    
    # Database configuration
    db_host: str = "localhost"
    db_port: int = 5432
    db_name: str = "calejo"
    db_user: str = "control_reader"
    db_password: str = "secure_password"
    db_min_connections: int = 2
    db_max_connections: int = 10
    
    # Station filter (optional)
    station_filter: Optional[str] = None
    
    # Security
    api_key: str = "your_api_key_here"
    tls_enabled: bool = True
    tls_cert_path: Optional[str] = None
    tls_key_path: Optional[str] = None
    
    # OPC UA
    opcua_enabled: bool = True
    opcua_host: str = "localhost"
    opcua_port: int = 4840
    opcua_security_mode: str = "SignAndEncrypt"
    opcua_cert_path: Optional[str] = None
    opcua_key_path: Optional[str] = None
    
    # Modbus TCP
    modbus_enabled: bool = True
    modbus_host: str = "localhost"
    modbus_port: int = 502
    modbus_unit_id: int = 1
    
    # REST API
    rest_api_enabled: bool = True
    rest_api_host: str = "localhost"
    rest_api_port: int = 8080
    rest_api_cors_enabled: bool = True
    
    # Safety - Watchdog
    watchdog_enabled: bool = True
    watchdog_timeout_seconds: int = 1200  # 20 minutes
    watchdog_check_interval_seconds: int = 60  # Check every minute
    
    # Auto-Discovery
    auto_discovery_enabled: bool = True
    auto_discovery_refresh_minutes: int = 60
    
    # Alerts - Email
    alert_email_enabled: bool = True
    alert_email_from: str = "calejo-control@example.com"
    alert_email_recipients: List[str] = ["operator1@utility.it", "operator2@utility.it"]
    smtp_host: str = "smtp.gmail.com"
    smtp_port: int = 587
    smtp_username: str = "calejo-control@example.com"
    smtp_password: str = "smtp_password"
    smtp_use_tls: bool = True
    
    # Alerts - SMS
    alert_sms_enabled: bool = True
    alert_sms_recipients: List[str] = ["+393401234567", "+393407654321"]
    twilio_account_sid: str = "your_twilio_account_sid"
    twilio_auth_token: str = "your_twilio_auth_token"
    twilio_phone_number: str = "+15551234567"
    
    # Alerts - Webhook
    alert_webhook_enabled: bool = True
    alert_webhook_url: str = "https://utility-monitoring.example.com/webhook"
    alert_webhook_token: str = "webhook_bearer_token"
    
    # Alerts - SCADA
    alert_scada_enabled: bool = True
    
    # Logging
    log_level: str = "INFO"
    log_format: str = "json"
    audit_log_enabled: bool = True
    
    # Application
    app_name: str = "Calejo Control Adapter"
    app_version: str = "2.0.0"
    environment: str = "development"
    
    # Auto-discovery settings
    auto_discovery_enabled: bool = True
    auto_discovery_refresh_minutes: int = 60
    
    # Optimization plan management settings
    optimization_monitoring_enabled: bool = True
    optimization_refresh_seconds: int = 30
    
    @property
    def database_url(self) -> str:
        """Generate database URL from components."""
        return f"postgresql://{self.db_user}:{self.db_password}@{self.db_host}:{self.db_port}/{self.db_name}"
    
    @validator('db_port')
    def validate_db_port(cls, v):
        if not 1 <= v <= 65535:
            raise ValueError('Database port must be between 1 and 65535')
        return v
    
    @validator('opcua_port')
    def validate_opcua_port(cls, v):
        if not 1 <= v <= 65535:
            raise ValueError('OPC UA port must be between 1 and 65535')
        return v
    
    @validator('modbus_port')
    def validate_modbus_port(cls, v):
        if not 1 <= v <= 65535:
            raise ValueError('Modbus port must be between 1 and 65535')
        return v
    
    @validator('rest_api_port')
    def validate_rest_api_port(cls, v):
        if not 1 <= v <= 65535:
            raise ValueError('REST API port must be between 1 and 65535')
        return v
    
    @validator('log_level')
    def validate_log_level(cls, v):
        valid_levels = ['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL']
        if v.upper() not in valid_levels:
            raise ValueError(f'Log level must be one of: {valid_levels}')
        return v.upper()
    
    @validator('alert_email_recipients', 'alert_sms_recipients', pre=True)
    def parse_recipients(cls, v):
        if isinstance(v, str):
            return [recipient.strip() for recipient in v.split(',')]
        return v
    
    def get_sensitive_fields(self) -> List[str]:
        """Get list of sensitive fields for logging/masking."""
        return [
            'db_password',
            'api_key',
            'smtp_password',
            'twilio_auth_token',
            'alert_webhook_token'
        ]
    
    def get_safe_dict(self) -> dict:
        """Get settings dictionary with sensitive fields masked."""
        settings_dict = self.dict()
        for field in self.get_sensitive_fields():
            if field in settings_dict and settings_dict[field]:
                settings_dict[field] = '***MASKED***'
        return settings_dict
    
    class Config:
        env_file = ".env"
        env_file_encoding = "utf-8"
        case_sensitive = False


# Global settings instance
settings = Settings()