"""Quota 子域 Router。

外部系统限界上下文的配额管理 API，覆盖配额列表 / 详情 / 创建 / 更新 /
阈值查询 / 阈值设置 / 删除，以及扩展能力：按业务键查询 / 接近告警阈值列表 /
接近临界阈值列表 / 即将重置列表 / 统计聚合 / 重置窗口 / 批量调整 /
创建或更新 / 按系统批量删除。所有端点通过 ``create_use_cases_from_db`` 装配
use_cases，经 ``quota_service`` 端口调用用例。

Request Schema 与 Input DTO 不共享类，Router 内显式构造 DTO。

路径顺序约束：静态路径（``/thresholds`` / ``/by-key`` / ``/near-warning`` /
``/near-critical`` / ``/expiring`` / ``/stats`` / ``/batch-adjust`` /
``/upsert`` / ``/by-system/{system_id}``）必须在 ``/{quota_id}`` 前声明，
避免被路径参数捕获。
"""

from __future__ import annotations

from datetime import datetime
from typing import Any, Literal

from fastapi import APIRouter, Depends, Path, Query
from pydantic import BaseModel, ConfigDict, Field, model_validator
from sqlalchemy.ext.asyncio import AsyncSession
from yuxi.external_systems.infrastructure.container import create_use_cases_from_db
from yuxi.external_systems.use_cases.dto.quota import (
    BatchAdjustQuotaInput,
    BatchDeleteQuotaInput,
    CreateQuotaInput,
    DeleteQuotaInput,
    DeleteQuotasBySystemInput,
    GetQuotaByKeyInput,
    GetQuotaInput,
    GetQuotaStatsInput,
    GetQuotaThresholdInput,
    ListExpiringInput,
    ListNearCriticalInput,
    ListNearWarningInput,
    ListQuotasInput,
    QuotaAdjustmentItem,
    ResetQuotaInput,
    SetQuotaThresholdInput,
    UpdateQuotaInput,
    UpsertQuotaInput,
)
from yuxi.storage.postgres.models_business import User

from server.utils.auth_middleware import get_admin_user, get_db, get_required_user

quota_router = APIRouter(prefix="/quotas", tags=["external-systems-quota"])


# ---------------- Request Schemas ----------------

QuotaWindowType = Literal["daily", "hourly", "rolling_24h", "minute", "custom"]
SourceHeaderStrategy = Literal["remaining", "used", "limit", "fraction_used_limit"]


def _validate_thresholds(
    warning: int | None,
    critical: int | None,
) -> None:
    """校验告警阈值不变量：``warning_threshold <= critical_threshold``。

    仅在两者均显式传入时校验；部分更新场景（仅传其一）由 Service 层
    读取现有值后补全校验。
    """
    if warning is not None and critical is not None and warning > critical:
        raise ValueError(f"warning_threshold({warning}) 不能大于 critical_threshold({critical})")


class CreateQuotaRequest(BaseModel):
    """创建配额请求体。字段对齐 ``CreateQuotaInput``。

    字符串字段长度约束对齐 ``ExternalSystemQuotaUsage`` ORM 列定义，在边界层
    拦截非法输入；``window_start``/``window_end`` 使用 datetime 类型，由
    Pydantic 解析 ISO 8601 字符串；阈值字段约束 0-100，且
    ``warning_threshold <= critical_threshold``。
    """

    model_config = ConfigDict(frozen=True)

    system_id: int
    quota_key: str = Field(..., min_length=1, max_length=128)
    quota_name: str = Field(..., min_length=1, max_length=128)
    quota_window: QuotaWindowType = Field(..., description="窗口类型")
    env_key: str = Field(default="default", min_length=1, max_length=32)
    window_start: datetime | None = None
    window_end: datetime | None = None
    limit_value: int = Field(default=0, ge=0)
    used_value: int = Field(default=0, ge=0)
    unit: str = Field(default="calls", min_length=1, max_length=32)
    source: Literal["response_header", "manual", "config"] = Field(default="config")
    source_header_name: str | None = Field(default=None, max_length=128)
    source_header_strategy: SourceHeaderStrategy = Field(
        default="remaining",
        description="响应头解析策略：remaining/used/limit/fraction_used_limit",
    )
    warning_threshold: int = Field(default=80, ge=0, le=100)
    critical_threshold: int = Field(default=95, ge=0, le=100)

    @model_validator(mode="after")
    def _check_thresholds(self) -> CreateQuotaRequest:
        _validate_thresholds(self.warning_threshold, self.critical_threshold)
        return self


class SetQuotaThresholdRequest(BaseModel):
    """设置配额阈值请求体。字段对齐 ``SetQuotaThresholdInput``（不含 id）。

    仅透传客户端显式设置的字段。两者均传入时校验
    ``warning_threshold <= critical_threshold``；仅传其一由 Service 层
    读取现有值后补全校验。
    """

    model_config = ConfigDict(frozen=True)

    warning_threshold: int | None = Field(default=None, ge=0, le=100)
    critical_threshold: int | None = Field(default=None, ge=0, le=100)

    @model_validator(mode="after")
    def _check_thresholds(self) -> SetQuotaThresholdRequest:
        _validate_thresholds(self.warning_threshold, self.critical_threshold)
        return self


class UpdateQuotaRequest(BaseModel):
    """更新配额请求体。字段对齐 ``UpdateQuotaInput``（不含 id）。

    所有字段可选，支持部分更新；约束与 ``CreateQuotaRequest`` 保持一致，
    在边界层拦截非法输入。仅透传客户端显式设置的字段。两者均传入时校验
    ``warning_threshold <= critical_threshold``；仅传其一由 Service 层
    读取现有值后补全校验。
    """

    model_config = ConfigDict(frozen=True)

    quota_name: str | None = Field(default=None, min_length=1, max_length=128)
    quota_window: QuotaWindowType | None = Field(default=None, description="窗口类型")
    limit_value: int | None = Field(default=None, ge=0)
    used_value: int | None = Field(default=None, ge=0)
    unit: str | None = Field(default=None, min_length=1, max_length=32)
    source: Literal["response_header", "manual", "config"] | None = Field(default=None)
    source_header_name: str | None = Field(default=None, max_length=128)
    source_header_strategy: SourceHeaderStrategy | None = Field(
        default=None,
        description="响应头解析策略：remaining/used/limit/fraction_used_limit",
    )
    warning_threshold: int | None = Field(default=None, ge=0, le=100)
    critical_threshold: int | None = Field(default=None, ge=0, le=100)
    window_start: datetime | None = None
    window_end: datetime | None = None

    @model_validator(mode="after")
    def _check_thresholds(self) -> UpdateQuotaRequest:
        _validate_thresholds(self.warning_threshold, self.critical_threshold)
        return self


class ResetQuotaRequest(BaseModel):
    """重置配额窗口请求体。字段对齐 ``ResetQuotaInput``（不含 id）。

    允许仅重置 ``used_value``（如把用量清零但保持当前窗口），也允许同时更新
    窗口范围。传入窗口范围时校验 ``window_start < window_end``。
    """

    model_config = ConfigDict(frozen=True)

    window_start: datetime | None = None
    window_end: datetime | None = None
    used_value: int | None = Field(default=None, ge=0)

    @model_validator(mode="after")
    def _check_window_range(self) -> ResetQuotaRequest:
        if self.window_start is not None and self.window_end is not None and self.window_start >= self.window_end:
            raise ValueError("window_start 必须早于 window_end")
        return self


class QuotaAdjustmentItemRequest(BaseModel):
    """批量调整项请求体（对齐 ``QuotaAdjustmentItem`` DTO）。"""

    model_config = ConfigDict(frozen=True)

    quota_id: int = Field(..., ge=1)
    limit_value: int = Field(..., ge=0)
    reason: str | None = Field(default=None, max_length=500)


class BatchAdjustQuotaRequest(BaseModel):
    """批量调整配额限额请求体。"""

    model_config = ConfigDict(frozen=True)

    adjustments: list[QuotaAdjustmentItemRequest] = Field(..., min_length=1, max_length=100)


class BatchDeleteQuotaRequest(BaseModel):
    """批量删除配额请求体。"""

    model_config = ConfigDict(frozen=True)

    ids: list[int] = Field(..., min_length=1, max_length=100)


class UpsertQuotaRequest(BaseModel):
    """创建或更新配额请求体。字段对齐 ``UpsertQuotaInput``。"""

    model_config = ConfigDict(frozen=True)

    system_id: int
    quota_key: str = Field(..., min_length=1, max_length=128)
    quota_name: str = Field(..., min_length=1, max_length=128)
    quota_window: QuotaWindowType = Field(..., description="窗口类型")
    env_key: str = Field(default="default", min_length=1, max_length=32)
    window_start: datetime | None = None
    window_end: datetime | None = None
    limit_value: int = Field(default=0, ge=0)
    used_value: int = Field(default=0, ge=0)
    unit: str = Field(default="calls", min_length=1, max_length=32)
    source: Literal["response_header", "manual", "config"] = Field(default="config")
    source_header_name: str | None = Field(default=None, max_length=128)
    source_header_strategy: SourceHeaderStrategy = Field(
        default="remaining",
        description="响应头解析策略：remaining/used/limit/fraction_used_limit",
    )
    warning_threshold: int = Field(default=80, ge=0, le=100)
    critical_threshold: int = Field(default=95, ge=0, le=100)

    @model_validator(mode="after")
    def _check_thresholds(self) -> UpsertQuotaRequest:
        _validate_thresholds(self.warning_threshold, self.critical_threshold)
        return self


# ---------------- Endpoints ----------------


# ---- 静态路径端点（必须在 /{quota_id} 之前声明） ----


@quota_router.get("/thresholds", response_model=dict)
async def get_quota_threshold(
    system_id: int = Query(...),
    env_key: str | None = Query(None, max_length=32),
    quota_key: str | None = Query(None, max_length=128),
    limit: int = Query(100, ge=1, le=500, description="返回记录数上限"),
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_required_user),
) -> dict[str, Any]:
    """获取达到告警阈值的配额列表（含临界）。

    ``system_id`` 为必填过滤维度，对齐 ``GetQuotaThresholdInput`` 契约。
    """
    use_cases = create_use_cases_from_db(db)
    input_dto = GetQuotaThresholdInput(
        system_id=system_id,
        env_key=env_key,
        quota_key=quota_key,
        limit=limit,
    )
    output = await use_cases.quota_service.get_quota_threshold(input_dto)
    return {"success": True, "data": output.model_dump()}


@quota_router.get("/by-key", response_model=dict)
async def get_quota_by_key(
    system_id: int = Query(...),
    env_key: str = Query("default", max_length=32),
    quota_key: str = Query(..., max_length=128),
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_required_user),
) -> dict[str, Any]:
    """按业务键查询配额。无数据返回 null。

    探测性查询语义：配额可能尚未配置，调用方需自行处理 null。与按 ID
    查询（``GET /{quota_id}``，不存在抛 404）的语义不同。
    """
    use_cases = create_use_cases_from_db(db)
    input_dto = GetQuotaByKeyInput(
        system_id=system_id,
        env_key=env_key,
        quota_key=quota_key,
    )
    output = await use_cases.quota_service.get_quota_by_key(input_dto)
    return {"success": True, "data": output.model_dump() if output else None}


@quota_router.get("/near-warning", response_model=dict)
async def list_near_warning(
    limit: int = Query(100, ge=1, le=500, description="返回记录数上限"),
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_required_user),
) -> dict[str, Any]:
    """列出接近告警阈值的配额（全局，含临界）。

    与 ``GET /thresholds`` 的区别：本端点为全局查询（无 ``system_id``
    过滤），用于跨系统告警大盘。
    """
    use_cases = create_use_cases_from_db(db)
    input_dto = ListNearWarningInput(limit=limit)
    output = await use_cases.quota_service.list_near_warning(input_dto)
    return {"success": True, "data": output.model_dump()}


@quota_router.get("/near-critical", response_model=dict)
async def list_near_critical(
    limit: int = Query(100, ge=1, le=500, description="返回记录数上限"),
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_required_user),
) -> dict[str, Any]:
    """列出接近临界阈值的配额（全局，无 ``system_id`` 过滤）。"""
    use_cases = create_use_cases_from_db(db)
    input_dto = ListNearCriticalInput(limit=limit)
    output = await use_cases.quota_service.list_near_critical(input_dto)
    return {"success": True, "data": output.model_dump()}


@quota_router.get("/expiring", response_model=dict)
async def list_expiring(
    before: datetime = Query(..., description="ISO8601 截止时间，返回 window_end <= before 的配额"),
    system_id: int | None = Query(None, description="按系统过滤（可选）"),
    limit: int = Query(100, ge=1, le=500, description="返回记录数上限"),
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_required_user),
) -> dict[str, Any]:
    """列出即将重置的配额（``window_end <= before``）。"""
    use_cases = create_use_cases_from_db(db)
    input_dto = ListExpiringInput(
        before=before,
        system_id=system_id,
        limit=limit,
    )
    output = await use_cases.quota_service.list_expiring(input_dto)
    return {"success": True, "data": output.model_dump()}


@quota_router.get("/stats", response_model=dict)
async def get_quota_stats(
    system_id: int | None = Query(None, description="按系统过滤（可选，不传则全局聚合）"),
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_required_user),
) -> dict[str, Any]:
    """配额统计聚合。

    所有字段均为精确值，统一复用仓储 ``count`` 方法（支持 ``system_id``
    过滤）：``total`` / ``by_window`` / ``near_warning_count`` /
    ``near_critical_count`` / ``expiring_count``（窗口已结束，需重置）。
    """
    use_cases = create_use_cases_from_db(db)
    input_dto = GetQuotaStatsInput(system_id=system_id)
    output = await use_cases.quota_service.get_quota_stats(input_dto)
    return {"success": True, "data": output.model_dump()}


@quota_router.post("/batch-adjust", response_model=dict)
async def batch_adjust_quotas(
    payload: BatchAdjustQuotaRequest,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_admin_user),
) -> dict[str, Any]:
    """批量调整配额限额。``updated_by`` 由 ``current_user.uid`` 填充
    （对齐 ``batch_enable_environments``，批量更新操作使用 ``updated_by``）。"""
    use_cases = create_use_cases_from_db(db)
    input_dto = BatchAdjustQuotaInput(
        adjustments=[
            QuotaAdjustmentItem(
                quota_id=item.quota_id,
                limit_value=item.limit_value,
                reason=item.reason,
            )
            for item in payload.adjustments
        ],
        updated_by=current_user.uid,
    )
    output = await use_cases.quota_service.batch_adjust_quotas(input_dto)
    return {"success": True, "data": output.model_dump()}


@quota_router.delete("/batch", response_model=dict)
async def batch_delete_quotas(
    payload: BatchDeleteQuotaRequest,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_admin_user),
) -> dict[str, Any]:
    """批量删除配额。``user`` 由 ``current_user.uid`` 填充。

    部分成功语义：信封 ``success`` 固定为 ``True``（表示请求已处理），
    操作级结果（``deleted_count`` / ``failed_count`` / ``failures``）在
    ``data`` 内返回，对齐 ``batch_adjust_quotas`` 及其他批量端点约定。
    """
    use_cases = create_use_cases_from_db(db)
    input_dto = BatchDeleteQuotaInput(
        ids=payload.ids,
        user=current_user.uid,
    )
    output = await use_cases.quota_service.batch_delete_quotas(input_dto)
    return {"success": True, "data": output.model_dump()}


@quota_router.post("/upsert", response_model=dict)
async def upsert_quota(
    payload: UpsertQuotaRequest,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_admin_user),
) -> dict[str, Any]:
    """创建或更新配额（基于 ``system_id+env_key+quota_key`` 冲突时更新）。

    ``created_by`` / ``updated_by`` 均由 ``current_user.uid`` 填充：
    - 新建场景：``created_by`` 生效，``updated_by`` 同步填充以便首次审计完整。
    - 更新场景：``updated_by`` 生效，``created_by`` 由仓储层忽略原值保持不变。
    """
    use_cases = create_use_cases_from_db(db)
    input_dto = UpsertQuotaInput(
        **payload.model_dump(),
        created_by=current_user.uid,
        updated_by=current_user.uid,
    )
    output = await use_cases.quota_service.upsert_quota(input_dto)
    return {"success": True, "data": output.model_dump()}


@quota_router.delete("/by-system/{system_id}", response_model=dict)
async def delete_quotas_by_system(
    system_id: int = Path(ge=1),
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_admin_user),
) -> dict[str, Any]:
    """按系统批量软删除配额。"""
    use_cases = create_use_cases_from_db(db)
    input_dto = DeleteQuotasBySystemInput(system_id=system_id, user=current_user.uid)
    output = await use_cases.quota_service.delete_quotas_by_system(input_dto)
    return {"success": True, "data": output.model_dump()}


# ---- 根路径端点 ----


@quota_router.get("", response_model=dict)
async def list_quotas(
    limit: int = Query(100, ge=1, le=500, description="返回记录数上限"),
    offset: int = Query(0, ge=0, description="偏移量（与 limit 配合分页）"),
    system_id: int | None = Query(None, description="按系统过滤"),
    env_key: str | None = Query(None, max_length=32, description="按环境键过滤"),
    quota_key: str | None = Query(None, max_length=128, description="按配额键过滤"),
    quota_window: Literal["daily", "hourly", "rolling_24h", "minute", "custom"] | None = Query(
        None, description="窗口类型：daily/hourly/rolling_24h/minute/custom"
    ),
    source: Literal["response_header", "manual", "config"] | None = Query(
        None, description="配额来源：response_header/manual/config"
    ),
    near_warning: bool = Query(False, description="仅返回接近告警阈值的配额"),
    near_critical: bool = Query(False, description="仅返回接近临界阈值的配额"),
    expiring_before: datetime | None = Query(None, description="仅返回 window_end <= 该时间的配额"),
    keyword: str | None = Query(None, max_length=128, description="按 quota_name / quota_key 模糊匹配"),
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_required_user),
) -> dict[str, Any]:
    """分页列出配额。支持多维度过滤。"""
    use_cases = create_use_cases_from_db(db)
    input_dto = ListQuotasInput(
        limit=limit,
        offset=offset,
        system_id=system_id,
        env_key=env_key,
        quota_key=quota_key,
        quota_window=quota_window,
        source=source,
        near_warning=near_warning,
        near_critical=near_critical,
        expiring_before=expiring_before,
        keyword=keyword,
    )
    output = await use_cases.quota_service.list_quotas(input_dto)
    return {"success": True, "data": output.model_dump()}


@quota_router.post("", response_model=dict)
async def create_quota(
    payload: CreateQuotaRequest,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_admin_user),
) -> dict[str, Any]:
    """创建配额。``created_by`` 由 ``current_user.uid`` 填充。"""
    use_cases = create_use_cases_from_db(db)
    input_dto = CreateQuotaInput(**payload.model_dump(), created_by=current_user.uid)
    output = await use_cases.quota_service.create_quota(input_dto)
    return {"success": True, "data": output.model_dump()}


# ---- 动态路径端点 /{quota_id} ----


@quota_router.get("/{quota_id}", response_model=dict)
async def get_quota(
    quota_id: int = Path(ge=1),
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_required_user),
) -> dict[str, Any]:
    """获取配额详情。"""
    use_cases = create_use_cases_from_db(db)
    input_dto = GetQuotaInput(id=quota_id)
    output = await use_cases.quota_service.get_quota(input_dto)
    return {"success": True, "data": output.model_dump()}


@quota_router.put("/{quota_id}", response_model=dict)
async def update_quota(
    payload: UpdateQuotaRequest,
    quota_id: int = Path(ge=1),
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_admin_user),
) -> dict[str, Any]:
    """更新配额（部分更新）。仅透传显式设置的字段。``updated_by`` 由 ``current_user.uid`` 填充。"""
    use_cases = create_use_cases_from_db(db)
    input_dto = UpdateQuotaInput(
        id=quota_id,
        **payload.model_dump(exclude_unset=True),
        updated_by=current_user.uid,
    )
    output = await use_cases.quota_service.update_quota(input_dto)
    return {"success": True, "data": output.model_dump()}


@quota_router.patch("/{quota_id}/threshold", response_model=dict)
async def set_quota_threshold(
    payload: SetQuotaThresholdRequest,
    quota_id: int = Path(ge=1),
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_admin_user),
) -> dict[str, Any]:
    """设置配额阈值。仅透传显式设置的字段。``updated_by`` 由 ``current_user.uid`` 填充。"""
    use_cases = create_use_cases_from_db(db)
    input_dto = SetQuotaThresholdInput(
        id=quota_id,
        **payload.model_dump(exclude_unset=True),
        updated_by=current_user.uid,
    )
    output = await use_cases.quota_service.set_quota_threshold(input_dto)
    return {"success": True, "data": output.model_dump()}


@quota_router.post("/{quota_id}/reset", response_model=dict)
async def reset_quota(
    payload: ResetQuotaRequest,
    quota_id: int = Path(ge=1),
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_admin_user),
) -> dict[str, Any]:
    """重置配额窗口。仅透传显式设置的字段。``updated_by`` 由 ``current_user.uid`` 填充。"""
    use_cases = create_use_cases_from_db(db)
    input_dto = ResetQuotaInput(
        id=quota_id,
        **payload.model_dump(exclude_unset=True),
        updated_by=current_user.uid,
    )
    output = await use_cases.quota_service.reset_quota(input_dto)
    return {"success": True, "data": output.model_dump()}


@quota_router.delete("/{quota_id}", response_model=dict)
async def delete_quota(
    quota_id: int = Path(ge=1),
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_admin_user),
) -> dict[str, Any]:
    """删除配额。``user`` 由 ``current_user.uid`` 填充。"""
    use_cases = create_use_cases_from_db(db)
    input_dto = DeleteQuotaInput(id=quota_id, user=current_user.uid)
    output = await use_cases.quota_service.delete_quota(input_dto)
    return {"success": True, "data": output.model_dump()}