"""Alert 子域 Router。

外部系统限界上下文的告警事件管理 API，覆盖告警列表 / 详情 / 触发 /
确认 / 恢复 / 统计聚合 / 按链路查询 / 批量确认 / 批量恢复 / 告警上下文 /
通知状态。所有端点通过 ``create_use_cases_from_db`` 装配 use_cases，
经 ``alert_service`` 端口调用用例。

设计要点：

- ``list_alerts`` 支持 keyword / resource_type / resource_id / related_trace_id /
  dedup_key / 时间范围 多维过滤，结果携带 ``system_name`` / ``system_slug``（LEFT JOIN 填充）。
- ``get_alert_stats`` 支持 system_id / env_key / 时间范围 过滤，聚合按 status / severity /
  alert_type 分组与 Top 告警排行。
- ``list_alerts_by_trace`` 路径参数 ``trace_id`` 通过 ``Path(min_length=1, max_length=64)``
  约束，避免空串与超长输入。
- ``fire_alert`` 显式字段映射构造 ``FireAlertInput``，``triggered_by`` 由当前管理员 uid 填充；
  若 ``system_id`` 非空但系统不存在，Service 层抛 404；同一 ``dedup_key`` 在 firing 状态下去重更新。
- ``acknowledge_alert`` / ``resolve_alert`` 在告警不存在时返回 404，状态冲突时返回 409
  （由 Service 层区分并通过 unified_error_handler 自动映射）。
- Request Schema 与 Input DTO 不共享类，Router 内显式构造 DTO，确保 API 边界与用例边界解耦。
"""

from __future__ import annotations

from typing import Any, Literal

from fastapi import APIRouter, Body, Depends, Path, Query
from pydantic import BaseModel, ConfigDict, Field
from yuxi.external_systems.infrastructure.container import UseCases
from yuxi.external_systems.use_cases.dto.alert import (
    AcknowledgeAlertInput,
    AlertStatsInput,
    BatchAcknowledgeAlertsInput,
    BatchResolveAlertsInput,
    FireAlertInput,
    GetAlertContextInput,
    GetAlertInput,
    GetAlertNotificationsInput,
    ListAlertsByTraceInput,
    ListAlertsInput,
    ResolveAlertInput,
)
from yuxi.storage.postgres.models_business import User

from server.routers.external_systems import get_use_cases, parse_and_naive, validate_time_range
from server.utils.auth_middleware import get_admin_user, get_required_user

alert_router = APIRouter(prefix="/alerts", tags=["external-systems-alert"])


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


class FireAlertRequest(BaseModel):
    """触发告警请求体。字段对齐 ``FireAlertInput``。"""

    model_config = ConfigDict(frozen=True)

    system_id: int | None = Field(default=None, ge=1)
    alert_type: str = Field(..., min_length=1, max_length=64)
    title: str = Field(..., min_length=1, max_length=256)
    triggered_at: str
    env_key: str | None = Field(default=None, max_length=32)
    severity: Literal["info", "warning", "critical", "fatal"] = "warning"
    description: str | None = None
    detail: dict[str, Any] = Field(default_factory=dict)
    resource_type: str | None = Field(default=None, max_length=32)
    resource_id: str | None = Field(default=None, max_length=128)
    related_execution_id: str | None = Field(default=None, max_length=64)
    related_trace_id: str | None = Field(default=None, max_length=64)
    metric_snapshot: dict[str, Any] | None = None
    dedup_key: str | None = Field(default=None, max_length=256)


class AcknowledgeAlertRequest(BaseModel):
    """确认告警请求体。``acknowledged_by`` 由当前管理员填充，仅暴露 ``note``。"""

    model_config = ConfigDict(frozen=True)

    note: str | None = None


class ResolveAlertRequest(BaseModel):
    """恢复告警请求体。字段对齐 ``ResolveAlertInput``（不含 id / user）。"""

    model_config = ConfigDict(frozen=True)

    resolution_note: str | None = None


class BatchAcknowledgeAlertsRequest(BaseModel):
    """批量确认告警请求体。字段对齐 ``BatchAcknowledgeAlertsInput``（不含 acknowledged_by）。"""

    model_config = ConfigDict(frozen=True)

    alert_ids: list[int] = Field(..., min_length=1, max_length=100)
    note: str | None = None


class BatchResolveAlertsRequest(BaseModel):
    """批量恢复告警请求体。字段对齐 ``BatchResolveAlertsInput``（不含 user）。"""

    model_config = ConfigDict(frozen=True)

    alert_ids: list[int] = Field(..., min_length=1, max_length=100)
    resolution_note: str | None = None


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


@alert_router.get("", response_model=dict)
async def list_alerts(
    limit: int = Query(100, ge=1, le=500),
    offset: int = Query(0, ge=0),
    system_id: int | None = Query(None, ge=1),
    env_key: str | None = Query(None, max_length=32),
    alert_type: str | None = Query(None, max_length=64),
    severity: Literal["info", "warning", "critical", "fatal"] | None = Query(
        None, description="严重度：info/warning/critical/fatal"
    ),
    status: Literal["firing", "acknowledged", "resolved", "suppressed"] | None = Query(
        None, description="告警状态：firing/acknowledged/resolved/suppressed"
    ),
    start_time: str | None = Query(None, description="开始时间（ISO 8601）"),
    end_time: str | None = Query(None, description="结束时间（ISO 8601）"),
    keyword: str | None = Query(
        None, max_length=128, description="关键词搜索（title/description/alert_type/system name/slug）"
    ),
    # 新增查询参数
    resource_type: str | None = Query(None, max_length=32),
    resource_id: str | None = Query(None, max_length=128),
    related_trace_id: str | None = Query(None, max_length=64),
    dedup_key: str | None = Query(None, max_length=256),
    use_cases: UseCases = Depends(get_use_cases),
    current_user: User = Depends(get_required_user),
) -> dict[str, Any]:
    """分页列出告警事件（支持 keyword / resource_type / resource_id / related_trace_id / dedup_key 过滤）。

    时间范围校验：若 ``start_time`` 晚于 ``end_time``，抛 ``DomainValidationError``
    （由全局 ``unified_error_handler`` 统一映射为 400 + 项目统一错误格式）。
    列表结果包含 ``system_name`` / ``system_slug``（由 LEFT JOIN 填充）。
    """
    start_dt = parse_and_naive("start_time", start_time)
    end_dt = parse_and_naive("end_time", end_time)
    validate_time_range(start_dt, end_dt)
    input_dto = ListAlertsInput(
        limit=limit,
        offset=offset,
        system_id=system_id,
        env_key=env_key,
        alert_type=alert_type,
        severity=severity,
        status=status,
        start_at=start_dt,
        end_at=end_dt,
        keyword=keyword,
        resource_type=resource_type,
        resource_id=resource_id,
        related_trace_id=related_trace_id,
        dedup_key=dedup_key,
    )
    output = await use_cases.alert_service.list_alerts(input_dto)
    return {"success": True, "data": output.model_dump()}


@alert_router.get("/stats", response_model=dict)
async def get_alert_stats(
    system_id: int | None = Query(None, ge=1),
    env_key: str | None = Query(None, max_length=32),
    start_time: str | None = Query(None, description="开始时间（ISO 8601）"),
    end_time: str | None = Query(None, description="结束时间（ISO 8601）"),
    use_cases: UseCases = Depends(get_use_cases),
    current_user: User = Depends(get_required_user),
) -> dict[str, Any]:
    """查询告警统计聚合（支持 system_id / env_key / 时间范围过滤）。

    时间范围基于 ``triggered_at`` 字段，若 ``start_time`` 晚于 ``end_time`` 抛
    ``DomainValidationError``（由全局 ``unified_error_handler`` 统一映射为 400）。
    """
    start_dt = parse_and_naive("start_time", start_time)
    end_dt = parse_and_naive("end_time", end_time)
    validate_time_range(start_dt, end_dt)
    input_dto = AlertStatsInput(
        system_id=system_id,
        env_key=env_key,
        start_at=start_dt,
        end_at=end_dt,
    )
    output = await use_cases.alert_service.get_alert_stats(input_dto)
    return {"success": True, "data": output.model_dump()}


@alert_router.get("/by-trace/{trace_id}", response_model=dict)
async def list_alerts_by_trace(
    trace_id: str = Path(..., min_length=1, max_length=64, description="链路 ID"),
    limit: int = Query(100, ge=1, le=500),
    offset: int = Query(0, ge=0),
    use_cases: UseCases = Depends(get_use_cases),
    current_user: User = Depends(get_required_user),
) -> dict[str, Any]:
    """按链路 ID 查询告警（通过 related_trace_id 关联，支持分页）。"""
    input_dto = ListAlertsByTraceInput(
        trace_id=trace_id,
        limit=limit,
        offset=offset,
    )
    output = await use_cases.alert_service.list_alerts_by_trace(input_dto)
    return {"success": True, "data": output.model_dump()}


@alert_router.post("/batch-acknowledge", response_model=dict)
async def batch_acknowledge_alerts(
    payload: BatchAcknowledgeAlertsRequest,
    use_cases: UseCases = Depends(get_use_cases),
    current_user: User = Depends(get_admin_user),
) -> dict[str, Any]:
    """批量确认告警。``acknowledged_by`` 由当前管理员填充。"""
    input_dto = BatchAcknowledgeAlertsInput(
        alert_ids=payload.alert_ids,
        note=payload.note,
        acknowledged_by=current_user.uid,
    )
    output = await use_cases.alert_service.batch_acknowledge_alerts(input_dto)
    return {"success": True, "data": output.model_dump()}


@alert_router.post("/batch-resolve", response_model=dict)
async def batch_resolve_alerts(
    payload: BatchResolveAlertsRequest,
    use_cases: UseCases = Depends(get_use_cases),
    current_user: User = Depends(get_admin_user),
) -> dict[str, Any]:
    """批量恢复告警。``user`` 由当前管理员填充，确保审计可追溯。"""
    input_dto = BatchResolveAlertsInput(
        alert_ids=payload.alert_ids,
        user=current_user.uid,
        resolution_note=payload.resolution_note,
    )
    output = await use_cases.alert_service.batch_resolve_alerts(input_dto)
    return {"success": True, "data": output.model_dump()}


@alert_router.get("/{alert_id}", response_model=dict)
async def get_alert(
    alert_id: int = Path(ge=1),
    use_cases: UseCases = Depends(get_use_cases),
    current_user: User = Depends(get_required_user),
) -> dict[str, Any]:
    """获取告警详情。"""
    input_dto = GetAlertInput(id=alert_id)
    output = await use_cases.alert_service.get_alert(input_dto)
    return {"success": True, "data": output.model_dump()}


@alert_router.post("", response_model=dict)
async def fire_alert(
    payload: FireAlertRequest,
    use_cases: UseCases = Depends(get_use_cases),
    current_user: User = Depends(get_admin_user),
) -> dict[str, Any]:
    """触发告警事件（含去重与自动通知派发）。

    ``triggered_by`` 由当前管理员 uid 填充，确保审计可追溯。
    若 ``system_id`` 非空但对应系统不存在，Service 层抛 404。
    同一 ``dedup_key`` 在 ``firing`` 状态下重复触发时更新已有记录。
    """
    input_dto = FireAlertInput(
        system_id=payload.system_id,
        alert_type=payload.alert_type,
        title=payload.title,
        triggered_at=parse_and_naive("triggered_at", payload.triggered_at),
        env_key=payload.env_key,
        severity=payload.severity,
        description=payload.description,
        detail=payload.detail,
        resource_type=payload.resource_type,
        resource_id=payload.resource_id,
        related_execution_id=payload.related_execution_id,
        related_trace_id=payload.related_trace_id,
        metric_snapshot=payload.metric_snapshot,
        dedup_key=payload.dedup_key,
        triggered_by=current_user.uid,
    )
    output = await use_cases.alert_service.fire_alert(input_dto)
    return {"success": True, "data": output.model_dump()}


@alert_router.post("/{alert_id}/acknowledge", response_model=dict)
async def acknowledge_alert(
    alert_id: int = Path(ge=1),
    payload: AcknowledgeAlertRequest = Body(...),
    use_cases: UseCases = Depends(get_use_cases),
    current_user: User = Depends(get_admin_user),
) -> dict[str, Any]:
    """确认告警。``acknowledged_by`` 由当前管理员 uid 填充，``note`` 可选。"""
    input_dto = AcknowledgeAlertInput(
        id=alert_id,
        acknowledged_by=current_user.uid,
        note=payload.note,
    )
    output = await use_cases.alert_service.acknowledge_alert(input_dto)
    return {"success": True, "data": output.model_dump()}


@alert_router.post("/{alert_id}/resolve", response_model=dict)
async def resolve_alert(
    alert_id: int = Path(ge=1),
    payload: ResolveAlertRequest = Body(...),
    use_cases: UseCases = Depends(get_use_cases),
    current_user: User = Depends(get_admin_user),
) -> dict[str, Any]:
    """恢复告警。``user`` 由当前管理员 uid 填充，确保审计可追溯。"""
    input_dto = ResolveAlertInput(
        id=alert_id,
        user=current_user.uid,
        resolution_note=payload.resolution_note,
    )
    output = await use_cases.alert_service.resolve_alert(input_dto)
    return {"success": True, "data": output.model_dump()}


@alert_router.get("/{alert_id}/context", response_model=dict)
async def get_alert_context(
    alert_id: int = Path(ge=1),
    use_cases: UseCases = Depends(get_use_cases),
    current_user: User = Depends(get_required_user),
) -> dict[str, Any]:
    """查询告警上下文（含执行记录 + 指标快照）。"""
    input_dto = GetAlertContextInput(alert_id=alert_id)
    output = await use_cases.alert_service.get_alert_context(input_dto)
    return {"success": True, "data": output.model_dump()}


@alert_router.get("/{alert_id}/notifications", response_model=dict)
async def get_alert_notifications(
    alert_id: int = Path(ge=1),
    use_cases: UseCases = Depends(get_use_cases),
    current_user: User = Depends(get_required_user),
) -> dict[str, Any]:
    """查询告警通知状态。"""
    input_dto = GetAlertNotificationsInput(alert_id=alert_id)
    output = await use_cases.alert_service.get_alert_notifications(input_dto)
    return {"success": True, "data": output.model_dump()}