# -*- coding: utf-8 -*-
"""接口层依赖：数据库句柄与当前登录用户（JWT + RBAC，全异步）。

``Database`` 实例由 ``main.py`` 在启动时创建并挂在 ``app.state.db`` 上，
路由通过 ``Depends(get_db)`` 取用；测试时可替换为临时目录实例。
"""
from __future__ import annotations

import asyncio
import contextlib

from fastapi import Depends, HTTPException, Request

from .. import config
from ..infrastructure.repositories import Database
from ..jwt import decode_access_token

BEARER_PREFIX = "Bearer "


def extract_bearer_token(request: Request) -> str:
    """从 Authorization 头提取 Bearer token，没有则返回空串。"""
    auth_header = request.headers.get("Authorization", "")
    if auth_header.startswith(BEARER_PREFIX):
        return auth_header[len(BEARER_PREFIX):].strip()
    return ""


async def get_db():
    """每请求一个独立 Database/AsyncSession（绑定共享引擎）。

    之前直接返回 app.state.db（单例 AsyncSession）被并发请求复用，会间歇报
    ``sqlalchemy.exc.InvalidRequestError: concurrent operations are not permitted``。
    改为每请求各建一个 Database 并在请求结束关闭，根除该竞态。
    """
    db = Database()
    try:
        yield db
    finally:
        try:
            await db.close()
        except asyncio.CancelledError:
            # 请求任务已被取消（客户端断开 / 超时 / 服务关闭）：取消上下文中
            # 的 await 会立即抛 CancelledError，SQLAlchemy 的 rollback 会被
            # asyncmy 打断并报 "Cancelled during execution"，导致 session 关不掉、
            # 连接无法归还连接池（随后被 GC 回收时产生 non-checked-in 警告）。
            # 用 shield 把 close 移到独立任务执行，确保连接一定归还。
            with contextlib.suppress(BaseException):
                await asyncio.shield(db.close())
            raise


async def _compute_capabilities(db: Database, user: dict) -> list[str]:
    """叠加制能力集合（身份不互斥）：
    - opc_member：所有账号的基础能力；
    - operator：运营端角色；
    - carrier：园区端角色 或 已绑定园区管理员（organization_members.role=admin + org.type=carrier，或旧表 park_members.admin / park_tenants.operator_user_id）；
    - enterprise：已绑定企业管理员（organization_members.role=admin + org.type=enterprise，或旧表 company_members.is_admin）。

    优先查统一的 organization_members 表，回退查旧表（park_members/company_members），保持兼容。
    """
    from ..infrastructure.models import CompanyMember, Organization, OrganizationMember, ParkMember, ParkTenant
    from sqlalchemy import select

    role = user.get("role", "")
    caps = ["opc_member"]
    if role in ("operator", "operator_internal", "op_admin", "op_super_admin", "superadmin", "admin"):
        caps.append("operator")
    if role in ("carrier", "park", "park_staff", "carrier_staff"):
        caps.append("carrier")
    else:
        # 优先查统一表：organization_members.role=admin + org.type=carrier
        admin_orgs = (await db.session.scalars(
            select(Organization.id).join(
                OrganizationMember, OrganizationMember.org_id == Organization.id
            ).where(
                OrganizationMember.user_id == user.get("id", ""),
                OrganizationMember.role == "admin",
                OrganizationMember.status == "active",
                Organization.type == "carrier",
            )
        )).all()
        if admin_orgs:
            caps.append("carrier")
        else:
            # 回退查旧表
            bound = await db.session.scalar(select(ParkMember).where(
                ParkMember.user_id == user.get("id", ""), ParkMember.park_id != "",
                ParkMember.member_type == "admin", ParkMember.status == "active").limit(1))
            if not bound:
                bound = await db.session.scalar(select(ParkTenant).where(
                    ParkTenant.operator_user_id == user.get("id", "")).limit(1))
            if bound:
                caps.append("carrier")

    # enterprise 能力：优先查统一表，回退查旧表
    ent_orgs = (await db.session.scalars(
        select(Organization.id).join(
            OrganizationMember, OrganizationMember.org_id == Organization.id
        ).where(
            OrganizationMember.user_id == user.get("id", ""),
            OrganizationMember.role == "admin",
            OrganizationMember.status == "active",
            Organization.type == "enterprise",
        )
    )).all()
    if ent_orgs:
        caps.append("enterprise")
    else:
        ent = await db.session.scalar(select(CompanyMember).where(
            CompanyMember.user_id == user.get("id", ""), CompanyMember.is_admin.is_(True),
            CompanyMember.status == "active").limit(1))
        if ent:
            caps.append("enterprise")
    return caps


async def get_user_organizations(db: Database, user_id: str) -> list[dict]:
    """查询用户绑定的所有组织（优先 organization_members，回退 users.org_id）。

    返回列表，每项包含：org_id, name, type, role, is_admin
    """
    from ..infrastructure.models import Organization, OrganizationMember
    from sqlalchemy import select

    orgs = []
    # 优先查统一表
    members = (await db.session.scalars(
        select(OrganizationMember).where(
            OrganizationMember.user_id == user_id,
            OrganizationMember.status == "active",
        )
    )).all()
    for m in members:
        org = await db.session.get(Organization, m.org_id)
        if org:
            orgs.append({
                "org_id": org.id, "name": org.name, "type": org.type,
                "role": m.role, "is_admin": m.is_admin,
            })
    # 回退：users.org_id
    if not orgs:
        user = await db.users.get_by_id(user_id)
        if user and user.get("org_id"):
            org = await db.session.get(Organization, user["org_id"])
            if org:
                orgs.append({
                    "org_id": org.id, "name": org.name, "type": org.type,
                    "role": "admin", "is_admin": True,
                })
    return orgs


async def get_user_primary_org(db: Database, user: dict, org_type: str | None = None) -> dict | None:
    """获取用户的主组织（优先 organization_members 中的管理员，可按类型过滤）。"""
    orgs = await get_user_organizations(db, user.get("id", ""))
    if org_type:
        orgs = [o for o in orgs if o["type"] == org_type]
    # 优先管理员
    admins = [o for o in orgs if o.get("is_admin")]
    return admins[0] if admins else (orgs[0] if orgs else None)


async def _resolve_identity(user: dict, db: Database, payload: dict | None = None) -> dict:
    """叠加制能力模型：role 为基础角色，capabilities 为绑定叠加出的能力集合。

    capabilities 优先从 JWT payload 读取（登录时已计算并写入），避免每次请求查库；
    若 JWT 中无 capabilities（旧 token），则回退到实时计算。
    """
    from ..domain.account_types import account_type, permission_role
    atype = account_type(user.get("role"))
    user["role"] = atype  # 归一化为三种账号类型之一
    user["permissions"] = await db.roles.permissions_for(permission_role(atype), None)
    user["scope_region_ids"] = await db.regions.visible_region_ids(user.get("region_id"))
    user["scope_level"] = await db.regions.level(user.get("region_id"))
    if payload and payload.get("capabilities"):
        user["capabilities"] = payload["capabilities"]
    else:
        user["capabilities"] = await _compute_capabilities(db, user)
    return user


async def get_current_user(
    request: Request,
    db: Database = Depends(get_db),
) -> dict:
    """校验调用方 JWT，返回当前用户记录（含 role/权限/数据范围）。"""
    token = extract_bearer_token(request)
    if not token:
        raise HTTPException(status_code=401, detail="No token provided")

    payload = decode_access_token(token)
    if payload is None:
        raise HTTPException(status_code=401, detail="Invalid or expired token")

    user_id = payload.get("sub")
    if not await db.tokens.session_valid(
        payload.get("jti", ""),
        user_id,
        payload.get("ver", 0),
    ):
        raise HTTPException(status_code=401, detail="Invalid or expired token")

    user = await db.users.get_by_id(user_id)
    if user is None or user.get("status") != "active":
        raise HTTPException(status_code=401, detail="Invalid or expired token")

    return await _resolve_identity(user, db, payload)


async def optional_current_user(
    request: Request,
    db: Database = Depends(get_db),
) -> dict | None:
    """可选登录：有有效 JWT 则返回用户，否则返回 None（不报错）。"""
    token = extract_bearer_token(request)
    if not token:
        return None
    payload = decode_access_token(token)
    if payload is None:
        return None
    if not await db.tokens.session_valid(
        payload.get("jti", ""), payload.get("sub", ""), payload.get("ver", 0),
    ):
        return None
    user = await db.users.get_by_id(payload.get("sub"))
    if user is None or user.get("status") != "active":
        return None
    return await _resolve_identity(user, db, payload)


def require_port(user: dict = Depends(get_current_user)) -> dict:
    """按端口隔离的资源（如智能体）—— 单角色后不再按端口隔离，仅要求已登录。

    账号唯一角色：智能体不再按端口隔离，统一归到该账号（port=""）。为兼容
    既有 AgentRepository 的 port 过滤，这里补一个恒定空串。
    """
    user.setdefault("port", "")
    return user