"""
性能配置汇总模块

集中管理所有性能相关配置，使用 Pydantic Settings 实现：
- 支持从环境变量读取配置
- 支持从 .env 文件读取配置
- 使用 lru_cache 缓存配置实例

需求引用: 10.1, 10.2, 10.3, 10.4
"""
from functools import lru_cache
from typing import Optional
from pydantic_settings import BaseSettings
from pydantic import Field


class PerformanceSettings(BaseSettings):
    """性能相关配置
    
    所有配置项都有合理的默认值，可通过环境变量或 .env 文件覆盖。
    """
    
    # ============================================
    # 数据库连接池配置 (需求 10.1)
    # ============================================
    db_host: str = Field(default="localhost", description="数据库主机地址")
    db_port: int = Field(default=5432, description="数据库端口")
    db_user: str = Field(default="postgres", description="数据库用户名")
    db_password: str = Field(default="", description="数据库密码")
    db_name: str = Field(default="model_square", description="数据库名称")
    db_pool_size: int = Field(default=20, description="连接池大小")
    db_max_overflow: int = Field(default=40, description="连接池最大溢出数")
    db_pool_timeout: int = Field(default=30, description="连接池获取超时时间(秒)")
    db_pool_recycle: int = Field(default=1800, description="连接回收时间(秒)")
    
    # ============================================
    # Redis 配置 (需求 10.2)
    # ============================================
    redis_url: str = Field(default="redis://localhost:6379", description="Redis 连接地址")
    redis_password: str = Field(default="", description="Redis 密码")
    redis_pool_size: int = Field(default=50, description="Redis 连接池大小")
    cache_default_ttl: int = Field(default=300, description="缓存默认过期时间(秒)")
    
    # ============================================
    # 限流配置 (需求 10.3)
    # ============================================
    rate_limit_default: int = Field(default=100, description="默认限流阈值(次/窗口)")
    rate_limit_window: int = Field(default=60, description="限流时间窗口(秒)")
    
    # ============================================
    # Gunicorn/应用配置 (需求 10.4)
    # ============================================
    gunicorn_workers: int = Field(default=4, description="Gunicorn Worker 数量")
    app_host: str = Field(default="0.0.0.0", description="应用监听地址")
    app_port: int = Field(default=8010, description="应用监听端口")
    log_level: str = Field(default="info", description="日志级别")
    
    # ============================================
    # 慢查询配置 (需求 7.4)
    # ============================================
    slow_query_threshold_ms: int = Field(default=1000, description="慢查询阈值(毫秒)")
    
    # ============================================
    # 调试配置
    # ============================================
    debug: bool = Field(default=False, description="调试模式")

    # ============================================
    # 爬虫同步配置
    # ============================================
    crawler_base_url: str = Field(default="http://localhost:8000", description="爬虫系统地址")
    crawler_referer: str = Field(default="aigcspace.com", description="请求爬虫时的 Referer 域名")
    apikey_encrypt_key: str = Field(default="", description="爬虫 API Key 解密密钥")

    model_config = {
        "env_file": ".env",
        "env_file_encoding": "utf-8",
        "extra": "ignore"  # 忽略未定义的环境变量
    }
    
    @property
    def async_database_url(self) -> str:
        """构建异步数据库连接 URL"""
        return f"postgresql+asyncpg://{self.db_user}:{self.db_password}@{self.db_host}:{self.db_port}/{self.db_name}"
    
    @property
    def sync_database_url(self) -> str:
        """构建同步数据库连接 URL"""
        return f"postgresql://{self.db_user}:{self.db_password}@{self.db_host}:{self.db_port}/{self.db_name}"


@lru_cache()
def get_performance_settings() -> PerformanceSettings:
    """获取性能配置单例
    
    使用 lru_cache 确保配置只加载一次，
    后续调用直接返回缓存的实例。
    
    Returns:
        PerformanceSettings: 性能配置实例
    """
    return PerformanceSettings()


# 导出配置实例，方便直接导入使用
settings = get_performance_settings()