"""门户跳转集成配置：全部从环境变量（.env）读取。

对接对端门户系统时，优先只改 .env（provider=http 的声明式对接）；
形态特殊时改 portal_provider.py 中的一个函数（见该文件内模板）。
本模块在每次请求时读取环境变量，改 .env 后重启进程生效。
"""

from __future__ import annotations

import os
from dataclasses import dataclass


ALLOWED_PROVIDERS = {"", "mock", "http", "custom"}
ALLOWED_LOCAL_FIELDS = {"externalId", "username", "realName", "orgName"}


class PortalConfigError(Exception):
    """门户配置缺失或非法（服务端 .env 问题，非用户输入问题）。"""


@dataclass(frozen=True)
class PortalConfig:
    provider: str  # ""=关闭 / mock / http / custom
    token_param: str
    # ---- http provider：验签 ----
    verify_url: str
    verify_method: str  # GET / POST
    verify_token_in: str  # header / body / query
    verify_header: str
    verify_header_template: str  # 内含 {token} 占位
    verify_success_field: str
    verify_success_value: str
    verify_user_field: str  # 验签响应中用户信息对象所在字段路径（如 data）
    # ---- http provider：独立的用户信息接口（可空=验签已含用户信息）----
    userinfo_url: str
    userinfo_uid_param: str
    # ---- 用户信息字段映射：local -> remote ----
    field_map: dict[str, str]
    # ---- 新用户落库默认值 ----
    default_org_id: int | None
    # ---- 其他 ----
    http_timeout_seconds: int

    @property
    def enabled(self) -> bool:
        return bool(self.provider)


def _env(name: str, default: str = "") -> str:
    return os.environ.get(name, default).strip()


def _parse_field_map(raw: str) -> dict[str, str]:
    """解析 ``local:remote,local:remote`` 形式的字段映射。"""
    field_map: dict[str, str] = {}
    for chunk in raw.split(","):
        chunk = chunk.strip()
        if not chunk:
            continue
        local, sep, remote = chunk.partition(":")
        local = local.strip()
        remote = remote.strip()
        if not sep or local not in ALLOWED_LOCAL_FIELDS or not remote:
            raise PortalConfigError(
                f"DMS_PORTAL_FIELD_MAP格式非法（{chunk}），"
                f"合法local字段：{sorted(ALLOWED_LOCAL_FIELDS)}"
            )
        field_map[local] = remote
    return field_map


def load_portal_config() -> PortalConfig:
    provider = _env("DMS_PORTAL_PROVIDER").lower()
    if provider not in ALLOWED_PROVIDERS:
        raise PortalConfigError(
            "DMS_PORTAL_PROVIDER必须是 mock/http/custom 之一，留空表示关闭门户登录"
        )

    field_map = _parse_field_map(
        _env(
            "DMS_PORTAL_FIELD_MAP",
            "externalId:userId,username:loginName,realName:realName,orgName:orgName",
        )
    )
    if "externalId" not in field_map:
        raise PortalConfigError("DMS_PORTAL_FIELD_MAP必须包含externalId映射")

    raw_org_id = _env("DMS_PORTAL_DEFAULT_ORG_ID")
    try:
        default_org_id = int(raw_org_id) if raw_org_id else None
    except ValueError as exc:
        raise PortalConfigError("DMS_PORTAL_DEFAULT_ORG_ID必须是整数") from exc

    timeout_raw = _env("DMS_PORTAL_HTTP_TIMEOUT_SECONDS", "10")
    try:
        timeout_seconds = int(timeout_raw) if timeout_raw else 10
    except ValueError as exc:
        raise PortalConfigError("DMS_PORTAL_HTTP_TIMEOUT_SECONDS必须是整数") from exc

    token_in = _env("DMS_PORTAL_VERIFY_TOKEN_IN", "header").lower()
    if token_in not in {"header", "body", "query"}:
        raise PortalConfigError("DMS_PORTAL_VERIFY_TOKEN_IN必须是header/body/query")

    return PortalConfig(
        provider=provider,
        token_param=_env("DMS_PORTAL_TOKEN_PARAM", "token"),
        verify_url=_env("DMS_PORTAL_VERIFY_URL"),
        verify_method=_env("DMS_PORTAL_VERIFY_METHOD", "POST").upper(),
        verify_token_in=token_in,
        verify_header=_env("DMS_PORTAL_VERIFY_HEADER", "Authorization"),
        verify_header_template=_env("DMS_PORTAL_VERIFY_HEADER_TEMPLATE", "Bearer {token}"),
        verify_success_field=_env("DMS_PORTAL_VERIFY_SUCCESS_FIELD", "code"),
        verify_success_value=_env("DMS_PORTAL_VERIFY_SUCCESS_VALUE", "0"),
        verify_user_field=_env("DMS_PORTAL_VERIFY_USER_FIELD", "data"),
        userinfo_url=_env("DMS_PORTAL_USERINFO_URL"),
        userinfo_uid_param=_env("DMS_PORTAL_USERINFO_UID_PARAM", "userId"),
        field_map=field_map,
        default_org_id=default_org_id,
        http_timeout_seconds=timeout_seconds,
    )