"""
通知服務
"""
from datetime import datetime
from typing import Optional, List

from sqlalchemy.orm import Session

from app.models.notification import Notification, NotificationPreference
from app.models.employee import Employee
from app.models.kpi_sheet import KPISheet


class NotifyService:
    """通知服務"""

    def __init__(self, db: Session):
        self.db = db

    def create(
        self,
        recipient_id: int,
        type: str,
        title: str,
        content: Optional[str] = None,
        related_sheet_id: Optional[int] = None,
    ) -> Notification:
        """建立通知"""
        notification = Notification(
            recipient_id=recipient_id,
            type=type,
            title=title,
            content=content,
            related_sheet_id=related_sheet_id,
        )
        self.db.add(notification)
        self.db.commit()
        self.db.refresh(notification)
        return notification

    def get_by_recipient(
        self, recipient_id: int, skip: int = 0, limit: int = 50
    ) -> List[Notification]:
        """取得通知列表"""
        return (
            self.db.query(Notification)
            .filter(Notification.recipient_id == recipient_id)
            .order_by(Notification.created_at.desc())
            .offset(skip)
            .limit(limit)
            .all()
        )

    def get_unread_count(self, recipient_id: int) -> int:
        """取得未讀數量"""
        return (
            self.db.query(Notification)
            .filter(
                Notification.recipient_id == recipient_id,
                Notification.is_read == False,
            )
            .count()
        )

    def mark_as_read(self, notification_id: int, recipient_id: int) -> bool:
        """標記已讀"""
        notification = (
            self.db.query(Notification)
            .filter(
                Notification.id == notification_id,
                Notification.recipient_id == recipient_id,
            )
            .first()
        )

        if not notification:
            return False

        notification.is_read = True
        notification.read_at = datetime.utcnow()
        self.db.commit()
        return True

    def mark_all_as_read(self, recipient_id: int) -> int:
        """全部標記已讀"""
        result = (
            self.db.query(Notification)
            .filter(
                Notification.recipient_id == recipient_id,
                Notification.is_read == False,
            )
            .update({"is_read": True, "read_at": datetime.utcnow()})
        )
        self.db.commit()
        return result

    def get_preferences(self, employee_id: int) -> Optional[NotificationPreference]:
        """取得通知偏好"""
        return (
            self.db.query(NotificationPreference)
            .filter(NotificationPreference.employee_id == employee_id)
            .first()
        )

    def update_preferences(
        self,
        employee_id: int,
        email_enabled: Optional[bool] = None,
        in_app_enabled: Optional[bool] = None,
        reminder_days_before: Optional[int] = None,
    ) -> NotificationPreference:
        """更新通知偏好"""
        pref = self.get_preferences(employee_id)

        if not pref:
            pref = NotificationPreference(employee_id=employee_id)
            self.db.add(pref)

        if email_enabled is not None:
            pref.email_enabled = email_enabled
        if in_app_enabled is not None:
            pref.in_app_enabled = in_app_enabled
        if reminder_days_before is not None:
            pref.reminder_days_before = reminder_days_before

        self.db.commit()
        self.db.refresh(pref)
        return pref

    # ==================== 事件通知 ====================

    def notify_kpi_submitted(self, sheet: KPISheet) -> None:
        """通知 KPI 已提交"""
        employee = sheet.employee
        if not employee.manager_id:
            return

        self.create(
            recipient_id=employee.manager_id,
            type="kpi_submitted",
            title="KPI 待審核",
            content=f"{employee.name} 的 {sheet.period.code} KPI 已提交，請審核。",
            related_sheet_id=sheet.id,
        )

    def notify_kpi_approved(self, sheet: KPISheet) -> None:
        """通知 KPI 已核准"""
        self.create(
            recipient_id=sheet.employee_id,
            type="kpi_approved",
            title="KPI 已核准",
            content=f"您的 {sheet.period.code} KPI 已審核通過。",
            related_sheet_id=sheet.id,
        )

    def notify_kpi_rejected(self, sheet: KPISheet, reason: str) -> None:
        """通知 KPI 已退回"""
        self.create(
            recipient_id=sheet.employee_id,
            type="kpi_rejected",
            title="KPI 已退回",
            content=f"您的 {sheet.period.code} KPI 已退回，原因：{reason}",
            related_sheet_id=sheet.id,
        )

    def notify_self_eval_completed(self, sheet: KPISheet) -> None:
        """通知自評已完成"""
        employee = sheet.employee
        if not employee.manager_id:
            return

        self.create(
            recipient_id=employee.manager_id,
            type="self_eval_completed",
            title="員工自評已完成",
            content=f"{employee.name} 的 {sheet.period.code} 自評已完成，請進行覆核。",
            related_sheet_id=sheet.id,
        )

    def notify_manager_eval_completed(self, sheet: KPISheet) -> None:
        """通知主管評核已完成"""
        self.create(
            recipient_id=sheet.employee_id,
            type="manager_eval_completed",
            title="KPI 評核已完成",
            content=f"您的 {sheet.period.code} KPI 評核已完成，獎金月數：{sheet.total_score}。",
            related_sheet_id=sheet.id,
        )