import { tripRepo } from "@/server/repositories/trip.repo";
import { participantRepo } from "@/server/repositories/participant.repo";
import { LIMITS } from "@/lib/limits";
import { utcStartOfDay, isTripDepartureDayPast } from "@/lib/trip-dates";

interface CreateTripInput {
  title: string;
  description?: string;
  mountain: string;
  location: string;
  date: Date;
  endDate?: Date;
  maxParticipants: number;
  price: number;
  organizerId: string;
  imageUrls?: string[];
}

export const tripService = {
  async getOpenTrips(filters?: { q?: string; from?: string; to?: string }) {
    return tripRepo.findOpen(filters);
  },

  async getAllTrips() {
    return tripRepo.findAll();
  },

  async getTripById(id: string) {
    const trip = await tripRepo.findById(id);
    if (!trip) {
      throw new Error("Trip tidak ditemukan");
    }
    return trip;
  },

  async createTrip(input: CreateTripInput) {
    const since = utcStartOfDay(new Date());
    const todayCount = await tripRepo.countByOrganizerSince(
      input.organizerId,
      since
    );
    if (todayCount >= LIMITS.MAX_TRIPS_PER_ORGANIZER_PER_DAY) {
      throw new Error(
        `Batas harian: maksimal ${LIMITS.MAX_TRIPS_PER_ORGANIZER_PER_DAY} trip per hari (UTC). Coba lagi besok.`
      );
    }

    if (isTripDepartureDayPast(input.date)) {
      throw new Error("Tanggal berangkat tidak boleh di masa lalu");
    }

    if (input.endDate && input.endDate.getTime() < input.date.getTime()) {
      throw new Error("Tanggal pulang tidak boleh sebelum tanggal berangkat");
    }

    const images = input.imageUrls?.length
      ? {
          create: input.imageUrls.map((url, i) => ({ url, order: i })),
        }
      : undefined;

    return tripRepo.create({
      title: input.title,
      description: input.description,
      mountain: input.mountain,
      location: input.location,
      date: input.date,
      endDate: input.endDate,
      maxParticipants: input.maxParticipants,
      price: input.price,
      organizer: { connect: { id: input.organizerId } },
      images,
    });
  },

  async joinTrip(tripId: string, userId: string) {
    const trip = await tripRepo.findById(tripId);
    if (!trip) {
      throw new Error("Trip tidak ditemukan");
    }

    if (trip.status !== "OPEN") {
      throw new Error("Trip tidak tersedia untuk pendaftaran");
    }

    if (isTripDepartureDayPast(trip.date)) {
      throw new Error(
        "Trip sudah melewati tanggal berangkat, tidak bisa mendaftar"
      );
    }

    if (trip.organizerId === userId) {
      throw new Error("Organizer tidak bisa join trip sendiri");
    }

    const existing = await participantRepo.findByTripAndUser(tripId, userId);
    if (existing && existing.status !== "CANCELLED") {
      throw new Error("Kamu sudah terdaftar di trip ini");
    }

    const participantCount = await participantRepo.countByTrip(tripId);
    if (participantCount >= trip.maxParticipants) {
      await tripRepo.updateStatus(tripId, "FULL");
      throw new Error("Trip sudah penuh");
    }

    const participant =
      existing?.status === "CANCELLED"
        ? await participantRepo.reactivate(tripId, userId)
        : await participantRepo.create(tripId, userId);

    const newCount = await participantRepo.countByTrip(tripId);
    if (newCount >= trip.maxParticipants) {
      await tripRepo.updateStatus(tripId, "FULL");
    }

    return participant;
  },

  async cancelJoin(tripId: string, userId: string) {
    const trip = await tripRepo.findById(tripId);
    if (!trip) {
      throw new Error("Trip tidak ditemukan");
    }

    if (isTripDepartureDayPast(trip.date)) {
      throw new Error(
        "Tanggal berangkat trip sudah lewat — pendaftaran tidak bisa dibatalkan. Jika trip sudah selesai, gunakan bagian ulasan."
      );
    }

    const existing = await participantRepo.findByTripAndUser(tripId, userId);
    if (!existing || existing.status === "CANCELLED") {
      throw new Error("Kamu tidak terdaftar di trip ini");
    }

    const result = await participantRepo.cancel(tripId, userId);

    if (trip.status === "FULL") {
      const count = await participantRepo.countByTrip(tripId);
      if (count < trip.maxParticipants) {
        await tripRepo.updateStatus(tripId, "OPEN");
      }
    }

    return result;
  },
};