/* eslint-disable @typescript-eslint/naming-convention */
import { getClientWithToken } from '../apollo/client';
import { ERRORS as SHARED_ERRORS } from '../constants/errors';
import * as GQL from '../types';
import { BaseService } from './base';
import { ServicesService } from './services';
import { type VariablesOf } from '@graphql-typed-document-node/core';
import { getMinutes, isBeforeNow } from '@repo/utils/datetime-format';
import dayjs from 'dayjs';

export const ERRORS = {
  INACTIVE_MASTER: 'Пользователь не является активным или мастером',
  INVALID_TIME: 'Некорректное время',
  MISSING_DATETIME_END: 'Не указана дата окончания',
  MISSING_DATETIME_START: 'Не указана дата начала',
  MISSING_SERVICES_IDS: 'Не указаны услуги',
  NO_PAST_SLOT: 'Нельзя создать слот в прошлом',
  NOT_FOUND_MASTER: 'Мастер не найден',
  NOT_FOUND_SERVICE: 'Сервис не найден',
  NOT_FOUND_SLOT: 'Слот не найден',
  OVERLAPPING_TIME: 'Время пересекается с другими слотами',
  SLOT_HAS_ORDERS: 'Слот имеет активные заказы',
};

export class SlotsService extends BaseService {
  async createSlot(variables: VariablesOf<typeof GQL.CreateSlotDocument>) {
    await this.checkIsBanned();

    await this.checkBeforeCreate(variables);

    const { customer } = await this._getUser();

    const { mutate } = await getClientWithToken();

    const mutationResult = await mutate({
      mutation: GQL.CreateSlotDocument,
      variables: {
        ...variables,
        input: {
          ...variables.input,
          master: customer?.documentId,
        },
      },
    });

    const error = mutationResult.errors?.at(0);
    if (error) throw new Error(error.message);

    return mutationResult.data;
  }

  async deleteSlot(variables: VariablesOf<typeof GQL.DeleteSlotDocument>) {
    await this.checkIsBanned();

    await this.checkPermission(variables);

    const { slot } = await this.getSlot({ documentId: variables.documentId });

    if (slot?.orders?.length) {
      throw new Error(ERRORS.SLOT_HAS_ORDERS);
    }

    const { mutate } = await getClientWithToken();

    const mutationResult = await mutate({
      mutation: GQL.DeleteSlotDocument,
      variables,
    });

    const error = mutationResult.errors?.at(0);
    if (error) throw new Error(error.message);

    return mutationResult.data;
  }

  async getAvailableTimeSlots(
    variables: VariablesOf<typeof GQL.GetSlotsDocument>,
    context: { services: string[] },
  ) {
    await this.checkIsBanned();

    if (!variables.filters?.datetime_start) throw new Error(ERRORS.MISSING_DATETIME_START);
    if (!context?.services?.length) throw new Error(ERRORS.MISSING_SERVICES_IDS);

    const servicesService = new ServicesService(this._user);

    // Получаем все услуги по массиву id`
    const services: Array<{ duration: string }> = [];
    for (const serviceId of context.services) {
      const { service } = await servicesService.getService({
        documentId: serviceId,
      });

      if (!service) throw new Error(ERRORS.NOT_FOUND_SERVICE);

      services.push(service);
    }

    // Суммируем длительности всех услуг
    const totalServiceDuration = services.reduce(
      (sum, service) => sum + getMinutes(service.duration),
      0,
    );

    const { query } = await getClientWithToken();

    const getSlotsResult = await query({
      query: GQL.GetSlotsOrdersDocument,
      variables: {
        filters: {
          ...variables.filters,
          state: { eq: GQL.Enum_Slot_State.Open },
        },
      },
    });

    if (getSlotsResult.error) throw new Error(getSlotsResult.error.message);

    const slots = getSlotsResult.data.slots;

    const times: Array<{ slotId: string; time: string }> = [];

    const now = dayjs();

    for (const slot of slots) {
      if (!slot?.datetime_start || !slot?.datetime_end) continue;

      let datetimeStart = dayjs(slot.datetime_start);
      const datetimeEnd = dayjs(slot.datetime_end).subtract(totalServiceDuration, 'minutes');

      while (datetimeStart.valueOf() <= datetimeEnd.valueOf()) {
        const slotStartTime = datetimeStart;
        const potentialDatetimeEnd = datetimeStart.add(totalServiceDuration, 'minutes');

        const hasConflict = slot.orders.some(
          (order) =>
            order?.state &&
            ![GQL.Enum_Order_State.Cancelled].includes(order.state) &&
            slotStartTime.isBefore(dayjs(order.datetime_end)) &&
            potentialDatetimeEnd.isAfter(dayjs(order.datetime_start)),
        );

        if (!hasConflict && datetimeStart.isAfter(now, 'minute')) {
          times.push({ slotId: slot.documentId, time: datetimeStart.toISOString() });
        }

        datetimeStart = datetimeStart.add(15, 'minutes');
      }
    }

    return { slots, times };
  }

  async getSlot(variables: VariablesOf<typeof GQL.GetSlotDocument>) {
    await this.checkIsBanned();

    const { query } = await getClientWithToken();

    const result = await query({
      query: GQL.GetSlotDocument,
      variables,
    });

    return result.data;
  }

  async getSlots(variables: VariablesOf<typeof GQL.GetSlotsDocument>) {
    await this.checkIsBanned();

    const { query } = await getClientWithToken();

    const result = await query({
      query: GQL.GetSlotsDocument,
      variables,
    });

    return result.data;
  }

  async updateSlot(variables: VariablesOf<typeof GQL.UpdateSlotDocument>) {
    await this.checkIsBanned();

    await this.checkPermission(variables);
    await this.checkBeforeUpdateDatetime(variables);

    const { mutate } = await getClientWithToken();

    const mutationResult = await mutate({
      mutation: GQL.UpdateSlotDocument,
      variables,
    });

    const error = mutationResult.errors?.at(0);
    if (error) throw new Error(error.message);

    return mutationResult.data;
  }

  private async checkBeforeCreate(variables: VariablesOf<typeof GQL.CreateSlotDocument>) {
    const { datetime_end, datetime_start } = variables.input;

    if (!datetime_start) throw new Error(ERRORS.MISSING_DATETIME_START);
    if (!datetime_end) throw new Error(ERRORS.MISSING_DATETIME_END);

    // Проверка, что мастер существует и активен
    const { customer: masterEntity } = await this._getUser();

    if (!masterEntity) throw new Error(ERRORS.NOT_FOUND_MASTER);

    if (!masterEntity?.active) {
      throw new Error(ERRORS.INACTIVE_MASTER);
    }

    // Проверка, что слот не создаётся в прошлом
    if (datetime_start && isBeforeNow(datetime_start)) {
      throw new Error(ERRORS.NO_PAST_SLOT);
    }

    // Проверка валидности времени
    if (!datetime_start || !datetime_end) {
      throw new Error(ERRORS.INVALID_TIME);
    }

    if (new Date(datetime_end) <= new Date(datetime_start)) {
      throw new Error(ERRORS.INVALID_TIME);
    }

    const overlappingEntities = await this.getSlots({
      filters: {
        datetime_end: { gt: datetime_start },
        datetime_start: { lt: datetime_end },
        master: { telegramId: { eq: this._user.telegramId } },
      },
    });

    if (overlappingEntities?.slots?.length) {
      throw new Error(ERRORS.OVERLAPPING_TIME);
    }
  }

  private async checkBeforeUpdateDatetime(variables: VariablesOf<typeof GQL.UpdateSlotDocument>) {
    const { slot } = await this.getSlot({ documentId: variables.documentId });

    if (!slot) throw new Error(ERRORS.NOT_FOUND_SLOT);

    const { datetime_end, datetime_start } = variables.data;

    const isTimeChanging = datetime_start || datetime_end;

    if (!isTimeChanging) return;

    if (!datetime_start) throw new Error(ERRORS.MISSING_DATETIME_START);
    if (!datetime_end) throw new Error(ERRORS.MISSING_DATETIME_END);

    // Проверка валидности времени
    if (new Date(datetime_end) <= new Date(datetime_start)) {
      throw new Error(ERRORS.INVALID_TIME);
    }

    const orders = slot?.orders;

    if (
      orders?.length &&
      orders?.some(
        (order) =>
          order?.state &&
          [
            GQL.Enum_Order_State.Approved,
            GQL.Enum_Order_State.Cancelled,
            GQL.Enum_Order_State.Completed,
            GQL.Enum_Order_State.Scheduled,
          ].includes(order.state),
      )
    ) {
      throw new Error(ERRORS.SLOT_HAS_ORDERS);
    }

    const { documentId } = slot;

    const overlappingEntities = await this.getSlots({
      filters: {
        datetime_end: { gt: datetime_start },
        datetime_start: { lt: datetime_end },
        documentId: { not: { eq: documentId } },
        master: { telegramId: { eq: this._user.telegramId } },
      },
    });

    if (overlappingEntities?.slots?.length) {
      throw new Error(ERRORS.OVERLAPPING_TIME);
    }
  }

  private async checkPermission(
    variables: Pick<VariablesOf<typeof GQL.GetSlotDocument>, 'documentId'>,
  ) {
    const { customer } = await this._getUser();

    const { slot } = await this.getSlot({ documentId: variables.documentId });

    if (!slot) throw new Error(ERRORS.NOT_FOUND_SLOT);

    if (slot?.master?.documentId !== customer?.documentId)
      throw new Error(SHARED_ERRORS.NO_PERMISSION);
  }
}