from pydantic_settings import BaseSettings
from typing import List, Optional
from pathlib import Path

class Settings(BaseSettings):
    # SECURITY: Must be set via .env file. No default for production safety.
    SECRET_KEY: str  # Required - generate with: openssl rand -base64 32
    ALGORITHM: str = "HS256"
    ACCESS_TOKEN_EXPIRE_MINUTES: int = 60 * 24

    # MongoDB Atlas configuration
    # Example: mongodb+srv://user:pass@cluster.mongodb.net/
    # NOTE: Credentials present here only for legacy/dev; MUST be overridden in environment (.env)
    # Recommendation: remove secrets before committing publicly.
    # IMPORTANT: Provide via environment (.env). Default points to localhost for safety.
    MONGODB_URI: str = "mongodb://localhost:27017"  # Override in .env for Atlas or remote
    MONGODB_DB_NAME: str = "atriumchain"
    # SECURITY: Explicit allowed origins only - no wildcard "*" for production
    # Add production domains here when deploying (e.g., "https://yourdomain.com")
    CORS_ORIGINS: List[str] = [
        "http://localhost:5173", 
        "http://127.0.0.1:5173", 
        "http://localhost:5174", 
        "http://127.0.0.1:5174", 
        "http://localhost:5175", 
        "http://127.0.0.1:5175",
        # Production domains
        "https://atriumchain.web.app",
        "https://atriumchain.firebaseapp.com",
        "https://jainish1808-atriumchain-api.hf.space",
        "https://huggingface.co"
    ]
    ALLOWED_ORIGINS: Optional[str] = None  # comma-separated override list; if set replaces CORS_ORIGINS

    XRPL_NETWORK: str = "testnet"  # testnet only
    ISSUER_SEED: str | None = None  # DEPRECATED: Use admin wallet instead (kept for backward compatibility)
    
    # TOKEN MODEL: IOU for fractional real estate ownership
    # Uses XRPL issued currencies for fungible property tokens
    XRPL_TOKEN_MODEL: str = "IOU"  # Fixed to IOU - the correct model for fractional ownership

    # Blockchain integration is mandatory for production
    XRPL_LEDGER_PURCHASE_ENABLED: bool = True

    # Configurable AED to XRP demo conversion rate (used only for displaying estimated costs
    # and in IOU path cost calculation). Previously hard-coded to 1e-6.
    # NOTE: This should be replaced with real-time oracle in production
    XRPL_RATE_AED_TO_XRP: float = 0.000001

    # Unified explorer base (avoid hard-coded duplicates elsewhere)
    XRPL_EXPLORER_BASE: str = "https://testnet.xrpl.org/transactions/"
    # Unified RPC URL (replace ad-hoc constants in services)
    XRPL_RPC_URL: str = "https://s.altnet.rippletest.net:51234/"

    # Optional encryption key (32 byte raw, hex, or Fernet base64). If absent seeds remain legacy/base64.
    ENCRYPTION_KEY: str | None = None

    # Security Configuration
    RATE_LIMIT_ENABLED: bool = True
    MAX_LOGIN_ATTEMPTS: int = 5
    LOGIN_LOCKOUT_MINUTES: int = 15
    REQUIRE_STRONG_PASSWORDS: bool = True
    MIN_PASSWORD_LENGTH: int = 8
    
    # Session Configuration
    SESSION_TIMEOUT_MINUTES: int = 60
    REFRESH_TOKEN_EXPIRE_DAYS: int = 7

    # IPFS Configuration for Decentralized Document Storage
    WEB3_STORAGE_API_TOKEN: str | None = None  # Get free token from https://web3.storage
    PINATA_API_KEY: str | None = None  # Get free API key from https://pinata.cloud
    PINATA_SECRET_KEY: str | None = None  # Secret key from Pinata dashboard
    IPFS_GATEWAY: str = "ipfs.io"  # Default public IPFS gateway
    IPFS_BACKUP_GATEWAY: str = "cloudflare-ipfs.com"  # Backup gateway
    IPFS_PROVIDER: str = "local_simulation"  # Options: "pinata", "web3storage", "local_simulation"

    # Monitoring and Logging Configuration
    LOG_LEVEL: str = "INFO"  # DEBUG, INFO, WARNING, ERROR, CRITICAL
    LOG_FILE_ENABLED: bool = True
    LOG_FILE_PATH: str = "logs/app.log"
    LOG_FILE_MAX_SIZE: int = 10485760  # 10MB in bytes
    LOG_FILE_BACKUP_COUNT: int = 5
    
    # Performance Monitoring
    ENABLE_PERFORMANCE_MONITORING: bool = True
    SLOW_QUERY_THRESHOLD: float = 1.0  # Log queries taking longer than 1 second
    
    # Transaction Monitoring
    ENABLE_TRANSACTION_MONITORING: bool = True
    BLOCKCHAIN_TIMEOUT_SECONDS: int = 30
    
    # Environment-specific settings
    ENVIRONMENT: str = "development"  # development, staging, production
    DEBUG_MODE: bool = True  # Set to False in production

    def encryption_enabled(self) -> bool:
        return bool(self.ENCRYPTION_KEY)
    
    def is_production(self) -> bool:
        return self.ENVIRONMENT.lower() == "production"
    
    def is_development(self) -> bool:
        return self.ENVIRONMENT.lower() == "development"

    def validate_configuration(self):  # renamed from validate_issuer_seed for clarity
        """Validate configuration settings and log important information"""
        
        # Validate IOU token configuration
        if not self.ISSUER_SEED:
            print("[CONFIG][INFO] ISSUER_SEED not set – using admin wallet for token issuance (recommended).")
            
        # Configure CORS origins
        if self.ALLOWED_ORIGINS:
            self.CORS_ORIGINS = [o.strip() for o in self.ALLOWED_ORIGINS.split(',') if o.strip()]
            
        # Validate environment-specific settings
        if self.is_production():
            # CRITICAL: Validate production security requirements
            if self.DEBUG_MODE:
                print("[CONFIG][ERROR] DEBUG_MODE is enabled in production environment!")
                print("[CONFIG][ERROR] Set DEBUG_MODE=false in .env file immediately!")
                raise ValueError("DEBUG_MODE must be disabled in production environment")
            
            # H1/H3: Enforce encryption key in production for wallet seed security
            if not self.ENCRYPTION_KEY:
                print("[CONFIG][ERROR] ENCRYPTION_KEY not set in production environment!")
                print("[CONFIG][ERROR] Wallet seeds will not be encrypted. This is a security risk.")
                print("[CONFIG][INFO] Generate key: python -c \"from cryptography.fernet import Fernet; print(Fernet.generate_key().decode())\"")
                raise ValueError("ENCRYPTION_KEY is required in production environment")
            else:
                print("[CONFIG][INFO] ✅ Encryption enabled for wallet seeds.")
        else:
            # Development environment warnings
            if not self.ENCRYPTION_KEY:
                print("[CONFIG][WARNING] ENCRYPTION_KEY not set – wallet seeds stored with legacy obfuscation.")
                print("[CONFIG][WARNING] For production, generate with: python -c \"from cryptography.fernet import Fernet; print(Fernet.generate_key().decode())\"")
            else:
                print("[CONFIG][INFO] ✅ Encryption enabled for wallet seeds.")
                
        # Log monitoring configuration
        print(f"[CONFIG][INFO] Logging level: {self.LOG_LEVEL}")
        print(f"[CONFIG][INFO] Environment: {self.ENVIRONMENT}")
        print(f"[CONFIG][INFO] Performance monitoring: {'Enabled' if self.ENABLE_PERFORMANCE_MONITORING else 'Disabled'}")
        print(f"[CONFIG][INFO] Transaction monitoring: {'Enabled' if self.ENABLE_TRANSACTION_MONITORING else 'Disabled'}")

    class Config:
        env_file = Path(__file__).parent / ".env"

settings = Settings()
settings.validate_configuration()