import * as mongoose from 'mongoose'
import { v4 as uuidv4 } from 'uuid'
import {
  dateFormatBackend,
  getDays,
  nowInTz,
  dateParseBackend,
} from '../helpers/date'
import { createCalendarEvent, deleteCalendarEvent } from '../lib/googlecalendar'

import { Bill } from './bill'
import { BOOKING_STATUS, VALIDATION_ERRORS } from './enums'

export type Booking = {
  uuid: string
  name: string
  email: string
  phone: string
  street: string
  zip: string
  city: string
  bill?: Bill
  // format YYYY-MM-DD
  startDate: string
  // format YYYY-MM-DD
  endDate: string
  status?: BOOKING_STATUS
  purpose?: string
  org?: string
  destination?: string
  days?: string[]
  calendarEventId: string
}

export type BookingDocument = Booking &
  mongoose.Document &
  mongoose.SchemaTimestampsConfig

export type BookingModel = mongoose.Model<BookingDocument> & {
  findBookedDays(uuidsToIngore?: string[]): Promise<string[]>
}

const BookingSchema = new mongoose.Schema<BookingDocument>(
  {
    // need a seperate uuid to be able to target a booking anonimously
    uuid: {
      type: String,
      default: uuidv4,
      index: true,
    },
    name: { type: String, required: true },
    email: { type: String, required: true, minlength: 5 },
    phone: { type: String, required: false },
    street: { type: String, required: true },
    zip: { type: String, required: true },
    city: { type: String, required: true },
    bill: {
      type: mongoose.Schema.Types.ObjectId,
      ref: 'Bill',
      required: false,
    },
    startDate: {
      type: String,
      required: true,
      validator: function (value: string): boolean {
        return !!dateParseBackend(value)
      },
    },
    endDate: {
      type: String,
      required: true,
      validator: function (value: string): boolean {
        return !!dateParseBackend(value)
      },
    },
    days: {
      type: [String],
      required: true,
      validate: {
        validator: async function (days: string[]): Promise<boolean> {
          const booking = this as Booking
          const uuid = booking.uuid && [booking.uuid]
          const bookedDays = await BookingModel.findBookedDays(uuid)

          const doubleBookedDays = days.filter((day: string): boolean =>
            bookedDays.includes(day)
          )
          return doubleBookedDays.length === 0
        },
        message: (props: { value: string[] }): string =>
          `At least one day is of ${props.value.join(',')} is already booked`,
        type: VALIDATION_ERRORS.AT_LEAST_ONE_DAY_BOOKED,
      },
    },
    status: {
      type: String,
      enum: Object.values(BOOKING_STATUS),
      required: true,
      default: BOOKING_STATUS.REQUESTED,
    },
    purpose: { type: String, required: false },
    org: { type: String, required: false },
    destination: { type: String, required: false },
    calendarEventId: { type: String, required: false },
  },
  {
    timestamps: true,
    toJSON: { virtuals: true, getters: true },
    toObject: { virtuals: true, getters: true },
  }
)

BookingSchema.pre('validate', function (next: () => void): void {
  const booking = this as BookingDocument
  booking.days = getDays({
    startDate: new Date(booking.startDate),
    endDate: new Date(booking.endDate),
  })
  next()
})

BookingSchema.pre('save', async function (next: () => void): Promise<void> {
  const booking = this as BookingDocument

  if (!booking.calendarEventId) {
    // create calendar event before saving to database
    await createCalendarEvent(booking)
  } else if (
    [BOOKING_STATUS.CANCELED, BOOKING_STATUS.REJECTED].includes(booking.status)
  ) {
    // event has been canceled or rejected, delete calendar event again to free up the slot
    await deleteCalendarEvent(booking)
  }

  next()
})

BookingSchema.static(
  'findBookedDays',
  async function (uuidsToIngore: string[] = []): Promise<string[]> {
    const model = this as BookingModel
    const now = nowInTz()
    const bookedDays = await model
      .find(
        {
          status: { $in: [BOOKING_STATUS.REQUESTED, BOOKING_STATUS.CONFIRMED] },
          uuid: { $nin: uuidsToIngore },
          // dateFormatBackend uses YYYY-MM-DD, which is startOfDay anyway
          endDate: { $gt: dateFormatBackend(now) },
        },
        'days'
      )
      .exec()

    return bookedDays
      .map((b) => b.days)
      .flat()
      .sort()
  }
)

const BookingModel = (mongoose.models.Booking ||
  mongoose.model<BookingDocument, BookingModel>(
    'Booking',
    BookingSchema
  )) as BookingModel

export default BookingModel