# P2P Network Communication - Configuration Module
"""
配置模块，包含服务器和客户端的配置参数
"""

import os
from dataclasses import dataclass
from typing import Optional


@dataclass
class ServerConfig:
    """服务器配置"""
    host: str = "0.0.0.0"
    port: int = 8888
    max_connections: int = 1000
    heartbeat_interval: int = 30  # seconds
    offline_message_ttl: int = 7 * 24 * 3600  # 7 days in seconds
    
    # Database configuration
    db_host: str = "localhost"
    db_port: int = 3306
    db_name: str = "p2p_chat"
    db_user: str = "root"
    db_password: str = ""
    db_pool_size: int = 10


@dataclass
class ClientConfig:
    """客户端配置"""
    server_host: str = "113.45.148.222"
    server_port: int = 8888
    
    # LAN discovery
    lan_broadcast_port: int = 8889
    lan_discovery_timeout: float = 2.0  # seconds
    
    # Connection settings
    connection_timeout: float = 10.0  # seconds
    reconnect_attempts: int = 3
    reconnect_delay: float = 1.0  # seconds (will be multiplied: 1s, 2s, 4s)
    heartbeat_interval: int = 30  # seconds
    
    # File transfer
    chunk_size: int = 64 * 1024  # 64KB per chunk
    max_file_size: int = 2 * 1024 * 1024 * 1024  # 2GB max
    
    # Voice chat
    audio_sample_rate: int = 16000
    audio_channels: int = 1
    audio_chunk_duration: float = 0.02  # 20ms per chunk
    max_voice_latency: float = 0.3  # 300ms max latency
    
    # UI settings
    window_width: int = 1024
    window_height: int = 768
    thumbnail_size: tuple = (200, 200)
    
    # Local storage
    data_dir: str = "data"
    cache_dir: str = "cache"


@dataclass
class SecurityConfig:
    """安全配置"""
    use_tls: bool = True
    cert_file: Optional[str] = None
    key_file: Optional[str] = None
    
    # Encryption
    encryption_algorithm: str = "AES-256-GCM"
    key_derivation: str = "PBKDF2"
    key_iterations: int = 100000


def load_server_config() -> ServerConfig:
    """从环境变量加载服务器配置"""
    return ServerConfig(
        host=os.getenv("P2P_SERVER_HOST", "0.0.0.0"),
        port=int(os.getenv("P2P_SERVER_PORT", "8888")),
        max_connections=int(os.getenv("P2P_MAX_CONNECTIONS", "1000")),
        db_host=os.getenv("P2P_DB_HOST", "localhost"),
        db_port=int(os.getenv("P2P_DB_PORT", "3306")),
        db_name=os.getenv("P2P_DB_NAME", "p2p_chat"),
        db_user=os.getenv("P2P_DB_USER", "root"),
        db_password=os.getenv("P2P_DB_PASSWORD", ""),
    )


def load_client_config() -> ClientConfig:
    """从环境变量加载客户端配置"""
    return ClientConfig(
        server_host=os.getenv("P2P_SERVER_HOST", "127.0.0.1"),
        server_port=int(os.getenv("P2P_SERVER_PORT", "8888")),
    )


def load_security_config() -> SecurityConfig:
    """从环境变量加载安全配置"""
    return SecurityConfig(
        use_tls=os.getenv("P2P_USE_TLS", "true").lower() == "true",
        cert_file=os.getenv("P2P_CERT_FILE"),
        key_file=os.getenv("P2P_KEY_FILE"),
    )