import { Injectable } from '@nestjs/common';
import { PrismaService } from '../prisma/prisma.service';

export type CalendarEventType =
  | 'TASK'
  | 'INSPECTION'
  | 'TREATMENT'
  | 'FEEDING'
  | 'HARVEST'
  | 'QUEEN_ASSIGNMENT';

export interface CalendarEvent {
  id: string;
  type: CalendarEventType;
  date: Date;
  title: string;
  relatedType: string;
  relatedId: string;
}

export interface CalendarQuery {
  from: Date;
  to: Date;
  apiaryId?: string;
}

@Injectable()
export class CalendarService {
  constructor(private readonly prisma: PrismaService) {}

  async getEvents(query: CalendarQuery): Promise<CalendarEvent[]> {
    const { from, to, apiaryId } = query;
    const colonyFilter = apiaryId ? { colony: { apiaryId } } : {};

    const [
      tasks,
      inspections,
      treatments,
      feedings,
      harvests,
      queenAssignments,
    ] = await Promise.all([
      this.prisma.task.findMany({
        where: { dueDate: { gte: from, lte: to } },
      }),
      this.prisma.inspection.findMany({
        where: { date: { gte: from, lte: to }, ...colonyFilter },
        include: { colony: true },
      }),
      this.prisma.treatment.findMany({
        where: { date: { gte: from, lte: to }, ...colonyFilter },
        include: { colony: true },
      }),
      this.prisma.feeding.findMany({
        where: { date: { gte: from, lte: to }, ...colonyFilter },
        include: { colony: true },
      }),
      this.prisma.harvest.findMany({
        where: {
          date: { gte: from, lte: to },
          ...(apiaryId ? { apiaryId } : {}),
        },
      }),
      this.prisma.queenColonyHistory.findMany({
        where: { startDate: { gte: from, lte: to }, ...colonyFilter },
        include: { colony: true, queen: true },
      }),
    ]);

    const events: CalendarEvent[] = [
      ...tasks
        .filter((task) => task.dueDate !== null)
        .map((task) => ({
          id: task.id,
          type: 'TASK' as const,
          date: task.dueDate!,
          title: task.title,
          relatedType: 'Task',
          relatedId: task.id,
        })),
      ...inspections.map((inspection) => ({
        id: inspection.id,
        type: 'INSPECTION' as const,
        date: inspection.date,
        title: `Durchsicht ${inspection.colony.code}`,
        relatedType: 'Colony',
        relatedId: inspection.colonyId,
      })),
      ...treatments.map((treatment) => ({
        id: treatment.id,
        type: 'TREATMENT' as const,
        date: treatment.date,
        title: `Behandlung ${treatment.colony.code} · ${treatment.product}`,
        relatedType: 'Colony',
        relatedId: treatment.colonyId,
      })),
      ...feedings.map((feeding) => ({
        id: feeding.id,
        type: 'FEEDING' as const,
        date: feeding.date,
        title: `Fütterung ${feeding.colony.code}`,
        relatedType: 'Colony',
        relatedId: feeding.colonyId,
      })),
      ...harvests.map((harvest) => ({
        id: harvest.id,
        type: 'HARVEST' as const,
        date: harvest.date,
        title: 'Ernte',
        relatedType: 'Apiary',
        relatedId: harvest.apiaryId,
      })),
      ...queenAssignments.map((assignment) => ({
        id: assignment.id,
        type: 'QUEEN_ASSIGNMENT' as const,
        date: assignment.startDate,
        title: `Königin ${assignment.queen.code} → ${assignment.colony.code}`,
        relatedType: 'Queen',
        relatedId: assignment.queenId,
      })),
    ];

    return events.sort((a, b) => a.date.getTime() - b.date.getTime());
  }
}