from dataclasses import dataclass, field
from urllib.parse import urlsplit

import config


@dataclass(frozen=True)
class GatewaySettings:
    base_url: str
    bearer: str = field(repr=False)
    file_base_url: str = ""
    upload_path: str = "ai-agent/ventilation"
    timeout: float = 30
    max_file_bytes: int = 50 * 1024 * 1024

    def __post_init__(self):
        for value in (self.base_url, self.file_base_url):
            if value:
                parts = urlsplit(value)
                if parts.scheme not in {"http", "https"} or not parts.netloc or parts.username or parts.password or parts.query or parts.fragment:
                    raise ValueError("网关及文件系统地址必须为不含凭证或查询串的 HTTP(S) 根地址")
        if not self.base_url or not self.bearer.strip():
            raise ValueError("启用网关需要 SHANXI_GATEWAY_URL 和 SHANXI_GATEWAY_TOKEN")
        if self.timeout <= 0 or self.max_file_bytes <= 0:
            raise ValueError("网关超时及文件大小上限必须大于零")

    @classmethod
    def from_config(cls):
        return cls(config.get_str("SHANXI_GATEWAY_URL").rstrip("/"),
                   config.get_str("SHANXI_GATEWAY_TOKEN"),
                   config.get_str("SHANXI_FILE_BASE_URL").rstrip("/"),
                   config.get_str("SHANXI_UPLOAD_PATH", "ai-agent/ventilation"),
                   config.get_float("SHANXI_HTTP_TIMEOUT", 30),
                   config.get_int("SHANXI_MAX_FILE_MB", 50) * 1024 * 1024)