# =============================================================================
# 企微IT智能服务台 — 独立审批队列 API（Tier1 新增）
# =============================================================================
# 说明：独立审批队列接口，管理超出会话上下文的待审批提案。
#   1. GET /queued — 获取队列中的提案列表
#   2. GET /queued/stats — 获取队列统计
#   3. POST /queued/{id}/dequeue-approve — 队列中审批通过提案
#
# D7 硬约束：
#   - 提案默认 status=pending，不自动 applied
#   - 未处理的进入独立队列（queued）
#   - 72 小时超时 → expired
# =============================================================================

import logging
from typing import Optional

from fastapi import APIRouter, Depends, Query
from sqlalchemy import select, func
from sqlalchemy.ext.asyncio import AsyncSession

from app.database import get_db
from app.dependencies import get_current_user, require_admin, UserInfo
from app.models.knowledge_suggestion import KnowledgeSuggestion
from app.schemas.knowledge_suggestion import KnowledgeSuggestionResponse
from app.schemas.enums import SuggestionStatusEnum
from app.services.knowledge_iteration_service import (
    KnowledgeIterationService,
    dep_knowledge_iteration_service,
)
from app.services.neo4j_client import get_neo4j_client

logger = logging.getLogger(__name__)

router = APIRouter()


# -----------------------------------------------------------------------------
# 获取独立队列列表（Tier1 新增）
# -----------------------------------------------------------------------------
# GET /api/admin/approval-queue/queued
@router.get("/queued")
@require_admin
async def list_queued_suggestions(
    status: Optional[str] = Query(
        default=None,
        description="筛选状态：pending/queued（不传则返回 pending+queued）",
    ),
    audience: Optional[str] = Query(
        default=None,
        description="筛选受众：employee_quick_reply/engineer_workguide",
    ),
    page: int = Query(default=1, ge=1, description="页码"),
    page_size: int = Query(default=20, ge=1, le=100, description="每页数量"),
    current_user: UserInfo = Depends(get_current_user),
    db: AsyncSession = Depends(get_db),
):
    """获取独立队列中的提案列表。

    默认返回 status=pending 和 status=queued 的提案。
    支持按 audience 筛选和分页。

    - **status**: 筛选状态（pending/queued）
    - **audience**: 按受众类型筛选
    - **page**: 页码
    - **page_size**: 每页数量

    **需要管理员权限。**
    """
    # 构建查询：pending 或 queued 状态的提案
    target_statuses = [status] if status else [
        SuggestionStatusEnum.pending.value,
        SuggestionStatusEnum.queued.value,
    ]

    stmt = (
        select(KnowledgeSuggestion)
        .where(KnowledgeSuggestion.status.in_(target_statuses))
        .order_by(
            # 按入队时间降序（queued 的提案在前），然后按创建时间
            KnowledgeSuggestion.queued_at.desc().nullslast(),
            KnowledgeSuggestion.created_at.desc(),
        )
    )

    if audience:
        stmt = stmt.where(KnowledgeSuggestion.audience == audience)

    # 分页
    offset = (page - 1) * page_size
    stmt = stmt.offset(offset).limit(page_size)

    result = await db.execute(stmt)
    suggestions = result.scalars().all()

    # 统计总数
    count_stmt = (
        select(func.count())
        .select_from(KnowledgeSuggestion)
        .where(KnowledgeSuggestion.status.in_(target_statuses))
    )
    if audience:
        count_stmt = count_stmt.where(KnowledgeSuggestion.audience == audience)

    total_result = await db.execute(count_stmt)
    total = total_result.scalar()

    return {
        "code": 0,
        "message": "success",
        "data": {
            "total": total,
            "items": [
                KnowledgeSuggestionResponse.model_validate(s) for s in suggestions
            ],
        },
    }


# -----------------------------------------------------------------------------
# 获取队列统计（Tier1 新增）
# -----------------------------------------------------------------------------
# GET /api/admin/approval-queue/queued/stats
@router.get("/queued/stats")
@require_admin
async def get_queue_stats(
    current_user: UserInfo = Depends(get_current_user),
    db: AsyncSession = Depends(get_db),
    service: KnowledgeIterationService = Depends(dep_knowledge_iteration_service),
):
    """获取独立审批队列统计信息。

    返回：
    - queued_total: 队列中提案数
    - pending_total: 待审核提案数
    - by_audience: 按受众分组统计
    - by_source_type: 按来源分组统计

    **需要管理员权限。**
    """
    stats = await service.get_queue_stats(db)

    # 补充按来源分组统计
    source_stats_stmt = (
        select(
            KnowledgeSuggestion.source_type,
            func.count(),
        )
        .where(
            KnowledgeSuggestion.status.in_([
                SuggestionStatusEnum.pending.value,
                SuggestionStatusEnum.queued.value,
            ])
        )
        .group_by(KnowledgeSuggestion.source_type)
    )
    source_result = await db.execute(source_stats_stmt)
    by_source_type = {row[0]: row[1] for row in source_result.fetchall()}

    stats["by_source_type"] = by_source_type

    return {
        "code": 0,
        "message": "success",
        "data": stats,
    }


# -----------------------------------------------------------------------------
# 队列中审批通过（Tier1 新增）
# -----------------------------------------------------------------------------
# POST /api/admin/approval-queue/queued/{id}/dequeue-approve
@router.post("/queued/{suggestion_id}/dequeue-approve")
@require_admin
async def dequeue_approve(
    suggestion_id: str,
    current_user: UserInfo = Depends(get_current_user),
    db: AsyncSession = Depends(get_db),
    service: KnowledgeIterationService = Depends(dep_knowledge_iteration_service),
):
    """从独立队列中审批通过提案。

    流程：queued → approved → applied → graph_synced（同 approve_suggestion）。

    - **suggestion_id**: 建议ID

    **需要管理员权限。**
    """
    logger.info(
        f"管理员 {current_user.name} 从独立队列审批通过: {suggestion_id}"
    )

    neo4j_client = await get_neo4j_client()

    suggestion = await service.dequeue_approve(
        db, suggestion_id, current_user.employee_id,
        neo4j_client=neo4j_client,
    )

    if not suggestion:
        return {"code": 404, "message": "建议不存在或状态转换无效", "data": None}

    return {
        "code": 0,
        "message": "队列审批通过，已应用到知识库并同步至知识图谱",
        "data": KnowledgeSuggestionResponse.model_validate(suggestion),
    }