"""Dashboard 统计服务"""
from datetime import datetime
from sqlalchemy import select, func
from sqlalchemy.ext.asyncio import AsyncSession
from pydantic import BaseModel


class DashboardStats(BaseModel):
    # 产品
    products_total: int
    products_pending: int
    products_in_progress: int
    products_completed: int
    # 任务
    tasks_total: int
    tasks_pending: int
    tasks_in_progress: int
    tasks_completed: int
    tasks_rejected: int
    tasks_rework: int
    # 通知 + 留言
    unread_notifications: int = 0
    unread_messages: int = 0


class WipTask(BaseModel):
    """在制品 — 当前卡在手里的任务"""
    task_id: str
    task_name: str
    assignee: str        # 中文姓名
    product_sn: str
    status: str          # PENDING / WIP
    received_at: str     # 接收时间
    duration_hours: float  # 已滞留小时数


async def get_dashboard_stats(db: AsyncSession) -> DashboardStats:
    from app.models.product import Product
    from app.models.task import (
        Task, TASK_STATUS_PENDING, TASK_STATUS_WIP, TASK_STATUS_COMPLETED,
        TASK_STATUS_REJECTED,
    )
    from app.models.notification import Notification
    from app.models.message import ProductMessage

    p_total = await db.scalar(select(func.count(Product.id)))
    p_pending = await db.scalar(select(func.count(Product.id)).where(Product.status == "pending"))
    p_progress = await db.scalar(select(func.count(Product.id)).where(Product.status == "in_progress"))
    p_done = await db.scalar(select(func.count(Product.id)).where(Product.status == "completed"))

    t_total = await db.scalar(select(func.count(Task.id)))
    t_pending = await db.scalar(select(func.count(Task.id)).where(Task.status == TASK_STATUS_PENDING))
    t_progress = await db.scalar(select(func.count(Task.id)).where(Task.status == TASK_STATUS_WIP))
    t_done = await db.scalar(select(func.count(Task.id)).where(Task.status == TASK_STATUS_COMPLETED))
    t_rejected = await db.scalar(select(func.count(Task.id)).where(Task.status == TASK_STATUS_REJECTED))
    t_rework = await db.scalar(select(func.count(Task.id)).where(Task.is_rework.is_(True)))

    unread_notif = await db.scalar(
        select(func.count(Notification.id)).where(Notification.is_read.is_(False))
    )
    # 留言板未读数 — 全局（所有产品下的留言总数）
    unread_msg = await db.scalar(select(func.count(ProductMessage.id)))

    return DashboardStats(
        products_total=p_total or 0,
        products_pending=p_pending or 0,
        products_in_progress=p_progress or 0,
        products_completed=p_done or 0,
        tasks_total=t_total or 0,
        tasks_pending=t_pending or 0,
        tasks_in_progress=t_progress or 0,
        tasks_completed=t_done or 0,
        tasks_rejected=t_rejected or 0,
        tasks_rework=t_rework or 0,
        unread_notifications=unread_notif or 0,
        unread_messages=unread_msg or 0,
    )


async def get_wip_tasks(db: AsyncSession, limit: int = 20) -> list[WipTask]:
    """
    在制品看板 — 当前所有 PENDING/WIP 状态的任务，
    按接收时间升序（最早接收的排最前 = 滞留最久）。
    """
    from app.models.task import (
        Task, TASK_STATUS_PENDING, TASK_STATUS_WIP,
    )
    from app.models.product import Product
    from app.core.time_utils import get_beijing_time, BEIJING_TZ

    stmt = (
        select(Task, Product.serial_number)
        .join(Product, Task.product_id == Product.id)
        .where(Task.status.in_([TASK_STATUS_PENDING, TASK_STATUS_WIP]))
        .order_by(Task.received_at.asc().nulls_first(), Task.created_at.asc())
        .limit(limit)
    )
    result = await db.execute(stmt)
    rows = result.all()

    # 收集 assignee_id 批量翻译中文姓名
    raw_ids = list({t.assignee_id for t, _ in rows if t.assignee_id})
    name_map: dict[str, str] = {}
    if raw_ids:
        from app.services.mom_cache import get_display_names
        name_map = get_display_names(raw_ids)

    now = get_beijing_time()
    wip_list: list[WipTask] = []
    for task, product_sn in rows:
        # 计算滞留时长
        start = task.received_at or task.created_at
        if start:
            if start.tzinfo is None:
                start = start.replace(tzinfo=BEIJING_TZ)
            else:
                start = start.astimezone(BEIJING_TZ)
            hours = round((now - start).total_seconds() / 3600, 1)
            recv_str = start.strftime("%m-%d %H:%M")
        else:
            hours = 0
            recv_str = ""

        wip_list.append(WipTask(
            task_id=str(task.id),
            task_name=task.task_name,
            assignee=name_map.get(task.assignee_id or "", task.assignee_id or "未分配"),
            product_sn=product_sn or "",
            status=task.status,
            received_at=recv_str,
            duration_hours=hours,
        ))
    return wip_list


def _action_label(action_type: str) -> str:
    labels = {
        "create": "创建任务", "receive": "确认接收", "complete": "完成任务",
        "transfer": "完工转交", "reject": "品质驳回", "end": "结束分支",
        "recall": "撤回转交",
    }
    return labels.get(action_type, action_type)