"""
Core Configuration - ServiceManagerWeb

Configuración centralizada usando Pydantic Settings v2
"""

from functools import lru_cache
from typing import List, Optional
from pydantic_settings import BaseSettings
from pydantic import field_validator, Field
import os


class Settings(BaseSettings):
    """Configuración de la aplicación."""
    
    model_config = {
        "env_file": ".env",
        "env_file_encoding": "utf-8",
        "case_sensitive": False
    }
    
    # ===================================
    # GENERAL
    # ===================================
    ENVIRONMENT: str = Field(default="development")
    DEBUG: bool = Field(default=False)
    SECRET_KEY: str = Field(...)
    API_VERSION: str = Field(default="v1")
    
    # ===================================
    # DATABASE
    # ===================================
    DATABASE_URL: str = Field(...)
    
    # ===================================
    # REDIS
    # ===================================
    REDIS_URL: str = Field(...)
    
    # ===================================
    # JWT AUTHENTICATION
    # ===================================
    JWT_SECRET_KEY: str = Field(...)
    JWT_ALGORITHM: str = Field(default="HS256")
    ACCESS_TOKEN_EXPIRE_MINUTES: int = Field(default=60)
    REFRESH_TOKEN_EXPIRE_DAYS: int = Field(default=7)
    
    # ===================================
    # CORS
    # ===================================
    CORS_ORIGINS: str = Field(
        default="http://localhost:3000,http://localhost:3001"
    )
    
    # ===================================
    # EMAIL
    # ===================================
    SMTP_HOST: str = Field(default="localhost")
    SMTP_PORT: int = Field(default=587)
    SMTP_USER: Optional[str] = Field(default=None)
    SMTP_PASSWORD: Optional[str] = Field(default=None)
    SMTP_USE_TLS: bool = Field(default=True)
    SMTP_USE_SSL: bool = Field(default=False)
    
    DEFAULT_FROM_EMAIL: str = Field(default="noreply@servicemanager.local")
    DEFAULT_FROM_NAME: str = Field(default="ServiceManager")
    
    # ===================================
    # FILE UPLOADS
    # ===================================
    MAX_UPLOAD_SIZE_MB: int = Field(default=10)
    ALLOWED_FILE_EXTENSIONS_STR: str = Field(
        default="pdf,jpg,jpeg,png,doc,docx,xls,xlsx,txt",
        alias="ALLOWED_FILE_EXTENSIONS"
    )
    UPLOAD_PATH: str = Field(default="/app/uploads")
    
    @property
    def ALLOWED_FILE_EXTENSIONS(self) -> List[str]:
        """Parse the comma-separated file extensions."""
        return [ext.strip().lower() for ext in self.ALLOWED_FILE_EXTENSIONS_STR.split(",")]
    
    # ===================================
    # SECURITY
    # ===================================
    RATE_LIMIT_ENABLED: bool = Field(default=True)
    PASSWORD_MIN_LENGTH: int = Field(default=8)
    
    # Argon2 settings
    ARGON2_TIME_COST: int = Field(default=3)
    ARGON2_MEMORY_COST: int = Field(default=65536)
    ARGON2_PARALLELISM: int = Field(default=4)
    
    # ===================================
    # LOGGING
    # ===================================
    LOG_LEVEL: str = Field(default="INFO")
    LOG_FORMAT: str = Field(default="json")
    LOG_FILE: Optional[str] = Field(default=None)
    
    # ===================================
    # FRONTEND URLS
    # ===================================
    CLIENT_FRONTEND_URL: str = Field(default="http://localhost:3000")
    INTERNAL_FRONTEND_URL: str = Field(default="http://localhost:3001")
    
    # ===================================
    # HEALTH CHECKS
    # ===================================
    HEALTH_CHECK_TIMEOUT: int = Field(default=30)
    
    # ===================================
    # CELERY
    # ===================================
    CELERY_BROKER_URL: str = Field(...)
    CELERY_RESULT_BACKEND: str = Field(...)
    
    def is_production(self) -> bool:
        """Check if environment is production."""
        return self.ENVIRONMENT.lower() == "production"
    
    def is_development(self) -> bool:
        """Check if environment is development."""
        return self.ENVIRONMENT.lower() == "development"
    
    def is_testing(self) -> bool:
        """Check if environment is testing."""
        return self.ENVIRONMENT.lower() == "testing"


@lru_cache()
def get_settings() -> Settings:
    """
    Get cached settings instance.
    
    Using lru_cache to create a singleton pattern for settings.
    """
    return Settings()