from collections.abc import Awaitable, Callable
from typing import Any

from fastapi import APIRouter, Depends, Header, Path, Query, Response
from pydantic import BaseModel
from sqlalchemy.ext.asyncio import AsyncSession

from app.api.dependencies.auth import build_request_context
from app.api.dependencies.database import get_session
from app.api.dependencies.rate_limit import enforce_rate_limit
from app.api.schemas.admin import (
    EmptyPayload,
    EndpointPayload,
    HandoverAssignPayload,
    HandoverCancelPayload,
    HandoverClosePayload,
    HandoverResolvePayload,
    HandoverStatus,
    IntentPayload,
    ItemPayload,
    NegativePayload,
    PromptPayload,
    ReleasePayload,
    ReplyPayload,
    ReviewPayload,
    RoutingPayload,
)
from app.api.views.envelope import envelope as _envelope
from app.core.contracts import RequestContext
from app.core.profile_governance_contracts import ProfileDriftReviewRequest
from app.service.admin_service import AdminService
from app.service.api_transaction_service import ApiTransactionService
from app.service.customer_profile_candidate_service import CustomerProfileCandidateService
from app.service.customer_service_handover_action_service import (
    CustomerServiceHandoverActionService,
)
from app.service.customer_service_handover_admin_service import CustomerServiceHandoverAdminService
from app.service.profile_governance_service import ProfileGovernanceService

router = APIRouter(
    prefix="/api/v1/admin", tags=["platform-admin"], dependencies=[Depends(enforce_rate_limit)]
)


@router.get("/advisor/profile-tags")
async def list_profile_tags(
    customer_id: int = Query(gt=0),
    context: RequestContext = Depends(build_request_context),  # noqa: B008
) -> dict[str, object]:
    return await ProfileGovernanceService().tags(customer_id, context)


@router.get("/advisor/profile-drift-reviews")
async def list_profile_drift_reviews(
    context: RequestContext = Depends(build_request_context),  # noqa: B008
) -> dict[str, object]:
    return await ProfileGovernanceService().pending_reviews(context)


@router.post("/advisor/profile-drift-reviews/{review_id}/reviews")
async def review_profile_drift(
    payload: ProfileDriftReviewRequest,
    review_id: int = Path(gt=0),
    context: RequestContext = Depends(build_request_context),  # noqa: B008
    key: str | None = Header(default=None, alias="Idempotency-Key"),
) -> dict[str, object]:
    return await ProfileGovernanceService().review(review_id, payload, context, key)


def register_resource(
    resource: str,
    schema: type[BaseModel],
    id_name: str,
    *,
    scoped: bool = False,
    update: bool = True,
    detail: bool = True,
) -> None:
    prefix = f"/config-releases/{{release_id}}/{resource}" if scoped else f"/{resource}"

    async def create(
        payload: BaseModel,
        response: Response,
        release_id: int | None = None,
        context: RequestContext = Depends(build_request_context),  # noqa: B008
        key: str | None = Header(default=None, alias="Idempotency-Key"),
    ) -> dict[str, Any]:
        result = await AdminService().mutate(
            resource, context, payload.model_dump(mode="json"), key, None, release_id=release_id
        )
        response.headers["ETag"] = f'"{result["meta"]["etag"]}"'
        return result

    create.__annotations__["payload"] = schema
    router.add_api_route(
        prefix, create, methods=["POST"], status_code=201, operation_id=f"create_{resource}"
    )

    async def list_rows(
        release_id: int | None = None,
        limit: int = Query(default=20, ge=1, le=100),
        cursor: str | None = Query(default=None),
        context: RequestContext = Depends(build_request_context),  # noqa: B008
    ) -> dict[str, Any]:
        """列表查询（文档 §3.8 统一游标）。游标校验在 Service 的权限闸门之后进行。"""
        return await AdminService().query(
            resource, context, release_id=release_id, limit=limit, cursor=cursor
        )

    router.add_api_route(prefix, list_rows, methods=["GET"], operation_id=f"list_{resource}")

    async def get(
        response: Response,
        row_id: int = Path(alias=id_name, gt=0),
        context: RequestContext = Depends(build_request_context),  # noqa: B008
    ) -> dict[str, Any]:
        result = await AdminService().query(resource, context, row_id=row_id)
        response.headers["ETag"] = f'"{result["meta"]["etag"]}"'
        return result

    if detail:
        router.add_api_route(
            f"{prefix}/{{{id_name}}}", get, methods=["GET"], operation_id=f"get_{resource}"
        )

    async def put(
        payload: BaseModel,
        response: Response,
        row_id: int = Path(alias=id_name, gt=0),
        release_id: int | None = None,
        context: RequestContext = Depends(build_request_context),  # noqa: B008
        key: str | None = Header(default=None, alias="Idempotency-Key"),
        if_match: str | None = Header(default=None, alias="If-Match"),
    ) -> dict[str, Any]:
        result = await AdminService().mutate(
            resource,
            context,
            payload.model_dump(mode="json"),
            key,
            if_match,
            row_id=row_id,
            release_id=release_id,
        )
        response.headers["ETag"] = f'"{result["meta"]["etag"]}"'
        return result

    put.__annotations__["payload"] = schema
    if update:
        router.add_api_route(
            f"{prefix}/{{{id_name}}}", put, methods=["PUT"], operation_id=f"update_{resource}"
        )


def register_transition(resource: str, id_name: str, action: str) -> None:
    async def transition(
        payload: BaseModel,
        response: Response,
        row_id: int = Path(alias=id_name, gt=0),
        context: RequestContext = Depends(build_request_context),  # noqa: B008
        key: str | None = Header(default=None, alias="Idempotency-Key"),
        if_match: str | None = Header(default=None, alias="If-Match"),
    ) -> dict[str, Any]:
        result = await AdminService().mutate(
            resource,
            context,
            payload.model_dump(mode="json"),
            key,
            if_match,
            row_id=row_id,
            action=action,
        )
        response.headers["ETag"] = f'"{result["meta"]["etag"]}"'
        return result

    transition.__annotations__["payload"] = ReviewPayload if action == "reviews" else EmptyPayload
    router.add_api_route(
        f"/{resource}/{{{id_name}}}/{action}",
        transition,
        methods=["POST"],
        status_code=201 if action == "rollbacks" else 200,
        operation_id=f"{action}_{resource}",
    )


register_resource("config-releases", ReleasePayload, "release_id", update=False)
# ⚠️ `platform-config-items` 与 `model-routing-rules` 必须是 `detail=True`：
# 它们的更新端点（PUT）**硬性要求 `If-Match`**，而校验用的是**该行内容的 digest**
# （`admin_service.mutate`：`if_match is None or if_match != digest(existing) → 409`）。
# 此前 `detail=False` 意味着**没有任何端点能返回这个 digest** —— 列表的 `meta` 只有
# trace_id、也没有详情端点，于是**首次编辑必然 409**：乐观并发成了死锁，
# 编辑功能实际不可用（2026-09-13 前端等价测试发现）。
register_resource("platform-config-items", ItemPayload, "item_id", scoped=True, detail=True)
register_resource("model-endpoints", EndpointPayload, "endpoint_id")
register_resource("model-routing-rules", RoutingPayload, "rule_id", scoped=True, detail=True)
register_resource("prompt-templates", PromptPayload, "prompt_id", update=False)
register_resource("agent-intent-configs", IntentPayload, "config_id")
register_resource("reply-templates", ReplyPayload, "template_id", detail=False)
register_resource("negative-word-rules", NegativePayload, "rule_id", detail=False)
for action in ("validations", "reviews", "activations", "rollbacks"):
    register_transition("config-releases", "release_id", action)
for action in ("reviews", "activations", "disablements"):
    register_transition("model-endpoints", "endpoint_id", action)
# 意图配置沿用同一套"审核 → 生效 → 归档"流转；归档落 `archived`
# （该表 CHECK 约束只允许 draft/approved/active/archived，没有 disabled）。
for action in ("reviews", "activations", "archivals"):
    register_transition("agent-intent-configs", "config_id", action)


@router.get("/audit-records")
async def audit_records(
    limit: int = Query(default=20, ge=1, le=100),
    cursor: str | None = Query(default=None),
    context: RequestContext = Depends(build_request_context),  # noqa: B008
) -> dict[str, Any]:
    """审计查询（文档 §9.6 支持游标过滤）。游标非法时返回 `400 INVALID_CURSOR`。"""
    return await AdminService().query("audit-records", context, limit=limit, cursor=cursor)


@router.get("/customer-service/handover-tickets")
async def list_customer_service_handover_tickets(
    limit: int = Query(default=20, ge=1, le=100),
    cursor: str | None = Query(default=None),
    status: HandoverStatus | None = Query(default=None),  # noqa: B008
    context: RequestContext = Depends(build_request_context),  # noqa: B008
) -> dict[str, Any]:
    """只读查看客服转人工队列；不暴露原始会话。可按状态筛。

    处置动作在下面五个端点里，需要 `handover:write`（本端点只需 `handover:read`）。
    """
    return await CustomerServiceHandoverAdminService().list_tickets(
        context, limit=limit, cursor=cursor, status=status
    )


@router.get("/customer-service/handover-tickets/{ticket_no}")
async def get_customer_service_handover_ticket(
    ticket_no: str,
    context: RequestContext = Depends(build_request_context),  # noqa: B008
) -> dict[str, Any]:
    """只读查看单个工单的脱敏转接摘要与流转状态。"""
    return await CustomerServiceHandoverAdminService().get_ticket(ticket_no, context)


# ---- 转人工工单处置（分配 / 接单 / 解决 / 关闭 / 取消）----
#
# 状态机与权限口径见 `docs/02` §7.2 与 `app/service/customer_service_handover_action_service.py`：
#   pending -> assigned -> processing -> resolved -> closed，未解决可 cancelled。
# 五个端点都要求 `handover:write` + admin 角色，并且都要求 `Idempotency-Key`
# （重复提交直接回放上次结果，不会二次推进状态机）。


@router.post("/customer-service/handover-tickets/{ticket_no}/assignments")
async def assign_customer_service_handover_ticket(
    payload: HandoverAssignPayload,
    ticket_no: str = Path(min_length=1, max_length=64, pattern=r"^[A-Za-z0-9_-]+$"),
    context: RequestContext = Depends(build_request_context),  # noqa: B008
    session: AsyncSession = Depends(get_session),  # noqa: B008
    key: str | None = Header(default=None, alias="Idempotency-Key"),
) -> dict[str, Any]:
    """把待处理工单分配给一个坐席（`pending -> assigned`）。"""
    return await _handover_action(
        session,
        context,
        key,
        f"POST /api/v1/admin/customer-service/handover-tickets/{ticket_no}/assignments",
        payload.model_dump(),
        lambda inner: CustomerServiceHandoverActionService(inner).assign(
            ticket_no, payload.assignee_id, context
        ),
    )


@router.post("/customer-service/handover-tickets/{ticket_no}/acceptances")
async def accept_customer_service_handover_ticket(
    ticket_no: str = Path(min_length=1, max_length=64, pattern=r"^[A-Za-z0-9_-]+$"),
    context: RequestContext = Depends(build_request_context),  # noqa: B008
    session: AsyncSession = Depends(get_session),  # noqa: B008
    key: str | None = Header(default=None, alias="Idempotency-Key"),
) -> dict[str, Any]:
    """坐席接单（`pending` 自助接管 / `assigned -> processing`）。"""
    return await _handover_action(
        session,
        context,
        key,
        f"POST /api/v1/admin/customer-service/handover-tickets/{ticket_no}/acceptances",
        {},
        lambda inner: CustomerServiceHandoverActionService(inner).accept(ticket_no, context),
    )


@router.post("/customer-service/handover-tickets/{ticket_no}/resolutions")
async def resolve_customer_service_handover_ticket(
    payload: HandoverResolvePayload,
    ticket_no: str = Path(min_length=1, max_length=64, pattern=r"^[A-Za-z0-9_-]+$"),
    context: RequestContext = Depends(build_request_context),  # noqa: B008
    session: AsyncSession = Depends(get_session),  # noqa: B008
    key: str | None = Header(default=None, alias="Idempotency-Key"),
) -> dict[str, Any]:
    """给出解决结论（`processing -> resolved`）。"""
    return await _handover_action(
        session,
        context,
        key,
        f"POST /api/v1/admin/customer-service/handover-tickets/{ticket_no}/resolutions",
        payload.model_dump(),
        lambda inner: CustomerServiceHandoverActionService(inner).resolve(
            ticket_no, payload.resolution, context
        ),
    )


@router.post("/customer-service/handover-tickets/{ticket_no}/closures")
async def close_customer_service_handover_ticket(
    ticket_no: str = Path(min_length=1, max_length=64, pattern=r"^[A-Za-z0-9_-]+$"),
    payload: HandoverClosePayload | None = None,
    context: RequestContext = Depends(build_request_context),  # noqa: B008
    session: AsyncSession = Depends(get_session),  # noqa: B008
    key: str | None = Header(default=None, alias="Idempotency-Key"),
) -> dict[str, Any]:
    """归档关闭（`resolved -> closed`）；可选补一条说明。"""
    note = payload.note if payload is not None else ""
    return await _handover_action(
        session,
        context,
        key,
        f"POST /api/v1/admin/customer-service/handover-tickets/{ticket_no}/closures",
        {"note": note},
        lambda inner: CustomerServiceHandoverActionService(inner).close(
            ticket_no, note, context
        ),
    )


@router.post("/customer-service/handover-tickets/{ticket_no}/cancellations")
async def cancel_customer_service_handover_ticket(
    payload: HandoverCancelPayload,
    ticket_no: str = Path(min_length=1, max_length=64, pattern=r"^[A-Za-z0-9_-]+$"),
    context: RequestContext = Depends(build_request_context),  # noqa: B008
    session: AsyncSession = Depends(get_session),  # noqa: B008
    key: str | None = Header(default=None, alias="Idempotency-Key"),
) -> dict[str, Any]:
    """取消未解决的工单（`pending|assigned|processing -> cancelled`）。"""
    return await _handover_action(
        session,
        context,
        key,
        f"POST /api/v1/admin/customer-service/handover-tickets/{ticket_no}/cancellations",
        payload.model_dump(),
        lambda inner: CustomerServiceHandoverActionService(inner).cancel(
            ticket_no, payload.reason, context
        ),
    )


async def _handover_action(
    session: AsyncSession,
    context: RequestContext,
    key: str | None,
    scope: str,
    body: dict[str, Any],
    action: Callable[[AsyncSession], Awaitable[dict[str, Any]]],
) -> dict[str, Any]:
    """工单处置的统一外壳：幂等 + 统一信封。

    幂等记录与业务写入**同事务**（`ApiTransactionService.execute_in`），
    重复请求直接回放 `response_json`，不会二次驱动状态机。
    幂等范围含路径参数 —— 同一个键用在两张不同工单上会被当成两次不同操作
    （与风控处置同一口径：把路径参数折成模板会让不同资源互相回放）。
    """
    data = await ApiTransactionService().execute_in(
        session, context, scope, key, body, action
    )
    return _envelope(data, context)


@router.get("/customer-profile-candidates")
async def list_customer_profile_candidates(
    limit: int = Query(default=20, ge=1, le=100),
    context: RequestContext = Depends(build_request_context),  # noqa: B008
) -> dict[str, Any]:
    """管理员查看待确认或待审核的画像候选。"""
    return await CustomerProfileCandidateService().list_for_admin(context, limit=limit)


@router.post("/customer-profile-candidates/{candidate_id}/reviews", status_code=200)
async def review_customer_profile_candidate(
    candidate_id: int,
    payload: ReviewPayload,
    context: RequestContext = Depends(build_request_context),  # noqa: B008
) -> dict[str, Any]:
    """管理员批准或驳回候选；批准会处理同键旧正式记忆。"""
    return await CustomerProfileCandidateService().review_by_admin(
        candidate_id, payload.decision, context, comment=payload.comment
    )