from pydantic_settings import BaseSettings
from typing import Optional, List
from pydantic import field_validator, ConfigDict
import json


class Settings(BaseSettings):
    # Database
    database_url: str = "sqlite+aiosqlite:///./mockapi.db"
    
    # Application
    debug: bool = False
    title: str = "Mock API Server"
    version: str = "1.0.0"
    log_level: str = "INFO"
    host: str = "0.0.0.0"
    port: int = 8000
    
    # Admin authentication
    admin_username: str = "admin"
    admin_password: str = "admin123"
    secret_key: str = "your-secret-key-here-change-me"
    
    # Security
    session_cookie_name: str = "mockapi_session"
    session_max_age: int = 24 * 60 * 60  # 24 hours
    
    # OAuth2 Settings
    oauth2_issuer: str = "http://localhost:8000"  # Used for discovery
    oauth2_access_token_expire_minutes: int = 30
    oauth2_refresh_token_expire_days: int = 7
    oauth2_authorization_code_expire_minutes: int = 10
    oauth2_supported_grant_types: List[str] = ["authorization_code", "client_credentials", "refresh_token"]
    oauth2_supported_scopes: List[str] = ["openid", "profile", "email", "api:read", "api:write"]
    oauth2_pkce_required: bool = False  # Future enhancement
    
    @field_validator('admin_password')
    def validate_admin_password(cls, v, info):
        if not info.data.get('debug', True) and v == "admin123":
            raise ValueError(
                'admin_password must be set via environment variable in production (debug=False)'
            )
        return v
    
    @field_validator('secret_key')
    def validate_secret_key(cls, v, info):
        if not info.data.get('debug', True) and v == "your-secret-key-here-change-me":
            raise ValueError(
                'secret_key must be set via environment variable in production (debug=False)'
            )
        return v
    
    @field_validator('oauth2_supported_scopes', 'oauth2_supported_grant_types', mode='before')
    @classmethod
    def parse_list_from_string(cls, v):
        """Parse list from either JSON string or space/comma-separated string."""
        if isinstance(v, list):
            return v
        if isinstance(v, str):
            # Try to parse as JSON first
            try:
                return json.loads(v)
            except json.JSONDecodeError:
                # If not JSON, try comma-separated or space-separated
                # Remove quotes and split by commas or spaces
                v = v.strip()
                if ',' in v:
                    # Comma-separated
                    items = [item.strip().strip('"\'') for item in v.split(',')]
                else:
                    # Space-separated
                    items = [item.strip().strip('"\'') for item in v.split()]
                # Filter out empty strings
                return [item for item in items if item]
        # Return as-is for other types (should be list)
        return v
    
    model_config = ConfigDict(env_file=".env", extra="allow")


settings = Settings()