src/core/config/config.py

# src/core/config.py
import os
from urllib.parse import quote_plus
from pydantic_settings import BaseSettings
from pydantic import Field, computed_field
from typing import List, Optional
from functools import lru_cache
from dotenv import load_dotenv, find_dotenv

_ = load_dotenv(find_dotenv())

class Settings(BaseSettings):
    """
    Application settings.
    
    Values can come from:
    1. Environment variables
    2. .env file
    3. Default values in this class
    
    Priority: Environment variables > .env file > defaults
    """
    
    # ===== APP SETTINGS =====
    APP_NAME: str = "Agentic Chatbot"
    DEBUG: bool = False
    ENVIRONMENT: str = "development"  # development, staging, production
    
    # ===== SERVER SETTINGS =====
    HOST: str = "0.0.0.0"
    PORT: int = 8000
    WORKERS: int = 4
    
    # ===== DATABASE (Supabase PostgreSQL) =====
    # Individual DB components for proper URL encoding
    DB_USER: str = Field(default="", description="Database username")
    DB_PASSWORD: str = Field(default="", description="Database password (will be URL encoded)")
    DB_HOST: str = Field(default="", description="Database host")
    DB_PORT: int = Field(default=6543, description="Database port")
    DB_NAME: str = Field(default="postgres", description="Database name")
    
    # Raw DATABASE_URL (fallback if components not provided)
    DATABASE_URL_RAW: str = Field(
        default="",
        alias="DATABASE_URL",
        description="Raw DATABASE_URL (use DB_* components instead for special chars)"
    )
    
    @computed_field
    @property
    def DATABASE_URL(self) -> str:
        """Build DATABASE_URL with properly encoded password."""
        # If individual components are provided, build URL from them
        if self.DB_USER and self.DB_PASSWORD and self.DB_HOST:
            encoded_password = quote_plus(self.DB_PASSWORD)
            return f"postgresql+asyncpg://{self.DB_USER}:{encoded_password}@{self.DB_HOST}:{self.DB_PORT}/{self.DB_NAME}"
        # Fallback to raw DATABASE_URL
        return self.DATABASE_URL_RAW
    
    # ===== SUPABASE =====
    SUPABASE_URL: str = Field(default="https://hsmtojoigweyexzczjap.supabase.co", description="Supabase project URL")
    SUPABASE_API_KEY: str = Field(default="sb_publishable_BD9CDK3YcHSUmC0gXRUSdw_V2G5cwIW", description="Supabase anon/public API key")
    
    # ===== REDIS =====
    REDIS_URL: str = Field(default=os.getenv("REDIS_URL", "redis://localhost:6379/0"), description="Redis connection string")
    
    # ===== SECURITY =====
    SECRET_KEY: str = Field(default=os.getenv("SECRET_KEY", "your-super-secret-key-at-least-32-characters-long"), description="JWT secret key")
    JWT_ALGORITHM: str = "HS256"
    ACCESS_TOKEN_EXPIRE_MINUTES: int = 30
    
    # ===== OPTIONAL SETTINGS =====
    CORS_ORIGINS: List[str] = Field(default=["http://localhost:3000", "http://localhost:8080"], description="CORS allowed origins")
    LOG_LEVEL: str = "INFO"
    
    class Config:
        # Tell Pydantic to read from .env file
        env_file = ".env"
        env_file_encoding = "utf-8"
        # Make field names case-sensitive
        case_sensitive = True
        # Allow extra fields from .env without raising validation error
        extra = "ignore"

# CACHE THE SETTINGS
# lru_cache means "only create this once, then reuse"
@lru_cache()
def get_settings() -> Settings:
    """
    Get cached settings instance.
    
    Why cache? Settings are read from files/environment,
    which is slow. We only need to do it once.
    """
    return Settings()

# For easy import
settings = get_settings()