import { DateTimeUtils } from '../common/utils/datetime.utils'

import { Injectable, Logger } from '@nestjs/common'
import { PrismaService } from 'src/Prisma/prisma.service'

import { AppConfigService } from 'src/AppConfig/appconfig.service'
import {
  PreviewScheduleType,
  ScheduleConfigType,
  ScheduleConfigTypeForCenter,
  ScheduleSlotType,
} from './schedule.d'
import { Config, Schedule, ScheduleDate } from '@prisma/client'
import { DateTime, Settings, Zone } from 'luxon'
import * as _ from 'lodash'
import { ScheduleDateInput } from './schedule'

@Injectable()
export class ScheduleService {
  constructor(
    private readonly prisma: PrismaService,
    private readonly appConfigService: AppConfigService,
  ) {}

  async createSchedulePreviewForSingleDay(
    scheduleConfig: ScheduleConfigType,
  ): Promise<PreviewScheduleType> {
    // generate Slot By config
    const slots = this.generateSlots(scheduleConfig)

    return {
      totalSlots: slots.length,
      slots: slots,
    }
  }

  // create preview for center require scheduleConfigInput: { startDate: "2024-11-02T00:00:00.000Z", endDate: "2024-11-22T00:00:00.000Z", slots: [1, 3], days: [2, 5] }
  async createSchedulePreviewForCenter(
    scheduleConfig: ScheduleConfigTypeForCenter,
  ): Promise<PreviewScheduleType> {
    const config: ScheduleConfigType = (
      await this.appConfigService.getVisibleConfigs()
    ).reduce((acc, curr) => {
      // @ts-ignore
      acc[curr.key] = curr.value
      return acc
    }, {} as ScheduleConfigType)
    const slots = this.generateSlotsPreviewForCenter(scheduleConfig, config)
    return {
      totalSlots: slots.length,
      slots: slots,
    }
  }

  async generateScheduleDates(schedule: Schedule): Promise<ScheduleDate[]> {
    // generate schedule dates based on data and config
    const config: ScheduleConfigType = (
      await this.appConfigService.getVisibleConfigs()
    ).reduce((acc, curr) => {
      // @ts-ignore
      acc[curr.key] = curr.value
      return acc
    }, {} as ScheduleConfigType)

    const daysOfWeeks = schedule.daysOfWeek
    const slots = schedule.slots
    const scheduleStart = DateTime.fromJSDate(schedule.scheduleStart)
    const scheduleEnd = DateTime.fromJSDate(schedule.scheduleEnd)
    const slotDuration = parseInt(config.slotDuration)
    const slotBreakDuration = parseInt(config.slotBreakDuration)
    // add participants to schedule dates
    const scheduleDates: ScheduleDateInput[] = []

    // loop each day from scheduleStart to scheduleEnd
    for (
      let date = scheduleStart;
      date <= scheduleEnd;
      date = date.plus({ days: 1 })
    ) {
      // Check if the current date matches one of the specified days of the week
      if (daysOfWeeks.includes(date.weekday)) {
        // loop through slots
        for (const slot of slots) {
          const { startTime, endTime } = this.getSlotStartAndEndTime(
            slot,
            slotDuration.toString(),
            slotBreakDuration.toString(),
            DateTimeUtils.getATimeWithDateB(
              DateTime.fromISO(config.dayStartTime),
              date,
            ).toISO() ?? '',
          )
          scheduleDates.push({
            scheduleId: schedule.id,
            start: startTime.toISO() ?? '',
            end: endTime.toISO() ?? '',
            dayOfWeek: date.weekday,
            slot: slot,
            participantIds: [],
            serviceId: schedule.managedServiceId,
            orderId: schedule.orderId,
          })
        }
      }
    }
    const scheduleDatesCreated =
      await this.prisma.scheduleDate.createManyAndReturn({
        data: scheduleDates,
      })

    return scheduleDatesCreated
  }

  /*
  example query:
query CenterPreviewSchedule {
    centerPreviewSchedule(
        scheduleConfigInput: { days: [3,5], endDate: "2024-11-22T00:00:00.000Z", slots: [2,6], startDate: "2024-11-02T00:00:00.000Z" }
    ) {
        totalSlots
        slots {
            dayOfWeek
            end
            slot
            start
        }
    }
}
  */

  generateSlotsPreviewForCenter(
    _scheduleConfig: ScheduleConfigTypeForCenter,
    _config: ScheduleConfigType,
  ): ScheduleSlotType[] {
    const slots: ScheduleSlotType[] = []
    const daysOfWeeks = _scheduleConfig.days
    const scheduleStart = DateTime.fromISO(_scheduleConfig.startDate)
    const scheduleEnd = DateTime.fromISO(_scheduleConfig.endDate)
    // loop each day from scheduleStart to scheduleEnd
    for (
      let date = scheduleStart;
      date <= scheduleEnd;
      date = date.plus({ days: 1 })
    ) {
      // Check if the current date matches one of the specified days of the week
      if (daysOfWeeks.includes(date.weekday)) {
        // loop through slots
        for (const slot of _scheduleConfig.slots) {
          // get slot start and end time
          const { startTime, endTime } = this.getSlotStartAndEndTime(
            slot,
            _config.slotDuration,
            _config.slotBreakDuration,
            DateTimeUtils.getATimeWithDateB(
              DateTime.fromISO(_config.dayStartTime),
              date,
            ).toISO() ?? '',
          )
          // if the slot is not overlapping with mid day break time, add it to the slots
          if (
            !DateTimeUtils.isOverlap(
              startTime,
              endTime,
              DateTimeUtils.fromIsoString(_config.midDayBreakTimeStart),
              DateTimeUtils.fromIsoString(_config.midDayBreakTimeEnd),
            )
          ) {
            slots.push({
              slot: slot.toString(),
              start: startTime.toString(),
              end: endTime.toString(),
              dayOfWeek: date.weekday,
            })
          }
        }
      }
    }
    return slots
  }

  generateSlots(scheduleConfig: ScheduleConfigType): ScheduleSlotType[] {
    const slots: ScheduleSlotType[] = []
    const numberOfSlots = this.calculateNumberOfSlots(
      scheduleConfig.dayStartTime,
      scheduleConfig.dayEndTime,
      scheduleConfig.slotDuration,
      scheduleConfig.slotBreakDuration,
    )
    for (let i = 1; i <= numberOfSlots; i++) {
      const { startTime, endTime } = this.getSlotStartAndEndTime(
        i,
        scheduleConfig.slotDuration,
        scheduleConfig.slotBreakDuration,
        scheduleConfig.dayStartTime,
      )
      // if the slot is not overlapping with mid day break time, add it to the slots
      if (
        !DateTimeUtils.isOverlap(
          startTime,
          endTime,
          DateTimeUtils.fromIsoString(scheduleConfig.midDayBreakTimeStart),
          DateTimeUtils.fromIsoString(scheduleConfig.midDayBreakTimeEnd),
        )
      ) {
        slots.push({
          slot: i.toString(),
          start: startTime.toString(),
          end: endTime.toString(),
          dayOfWeek: startTime.weekday,
        })
      }
    }
    return slots
  }

  isOverLapping(
    startTime1: DateTime,
    endTime1: DateTime,
    startTime2: DateTime,
    endTime2: DateTime,
  ) {
    return (
      Math.max(startTime1.toMillis(), startTime2.toMillis()) <
      Math.min(endTime1.toMillis(), endTime2.toMillis())
    )
  }

  calculateNumberOfSlots(
    startTime: string,
    endTime: string,
    slotDuration: string,
    slotBreakDuration: string,
  ) {
    const _startTime = DateTimeUtils.toTime(startTime)
    const _endTime = DateTimeUtils.toTime(endTime)
    const _slotDuration = parseInt(slotDuration) // minutes
    const _slotBreakDuration = parseInt(slotBreakDuration) // minutes

    const startDate = DateTime.fromObject({
      hour: _startTime.hour,
      minute: _startTime.minute,
      second: _startTime.second,
    })
    const endDate = DateTime.fromObject({
      hour: _endTime.hour,
      minute: _endTime.minute,
      second: _endTime.second,
    })

    const totalMinutes =
      (endDate.toMillis() - startDate.toMillis()) / (60 * 1000)
    const numberOfSlots = Math.floor(
      totalMinutes / (_slotDuration + _slotBreakDuration),
    )
    return numberOfSlots
  }

  getSlotStartAndEndTime(
    slotNumber: number,
    slotDuration: string,
    slotBreakDuration: string,
    dayStartTime: string,
  ) {
    const durationInMinutes = parseInt(slotDuration)
    const breakDurationInMinutes = parseInt(slotBreakDuration)
    const initialStartTime = DateTime.fromISO(dayStartTime)

    const startTime = initialStartTime.plus({
      minutes: (slotNumber - 1) * (durationInMinutes + breakDurationInMinutes),
    })

    const endTime = startTime.plus({ minutes: durationInMinutes })
    return {
      startTime: startTime,
      endTime: endTime,
    }
  }
}