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

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

  async getEntries(view: string, date: string) {
    const { start, end } = this.parseRange(view, date);

    const videos = await this.prisma.video.findMany({
      where: {
        OR: [
          { scheduledAt: { gte: start, lte: end } },
          { publishedAt: { gte: start, lte: end } },
        ],
      },
      include: {
        template: { select: { id: true, name: true } },
      },
      orderBy: { scheduledAt: 'asc' },
    });

    const allCollabIds = [...new Set(videos.flatMap((v) => (v.collaboratorIds as string[]) ?? []))];
    const collabs = allCollabIds.length > 0
      ? await this.prisma.collaborator.findMany({
          where: { id: { in: allCollabIds } },
          select: { id: true, name: true, youtubeLink: true },
        })
      : [];
    const collabMap = new Map(collabs.map((c) => [c.id, c]));

    return videos.map((v) => ({
      videoId: v.id,
      title: v.title,
      date: v.scheduledAt ?? v.publishedAt,
      templateName: v.template?.name,
      collaborators: ((v.collaboratorIds as string[]) ?? []).map((id) => collabMap.get(id)).filter(Boolean),
      lintStatus: v.lintStatus,
      channelId: v.channelId,
      privacyStatus: v.privacyStatus,
    }));
  }

  private parseRange(view: string, date: string): { start: Date; end: Date } {
    const [year, month] = date.split('-').map(Number);

    if (view === 'month') {
      const start = new Date(year, month - 1, 1);
      const end = new Date(year, month, 0, 23, 59, 59);
      return { start, end };
    }

    if (view === 'week') {
      const base = new Date(year, month - 1, 1);
      const start = new Date(base);
      start.setDate(base.getDate() - base.getDay());
      const end = new Date(start);
      end.setDate(start.getDate() + 6);
      end.setHours(23, 59, 59);
      return { start, end };
    }

    // agenda: next 30 days from date
    const start = new Date(date);
    const end = new Date(start);
    end.setDate(start.getDate() + 30);
    return { start, end };
  }
}