import DateTime from '../utils/DateTime'
import Dimensions from './dimensions/Dimensions'
import Graphics from './Graphics'
import Utils from '../utils/Utils'

const MINUTES_IN_DAY = 24 * 60
const SECONDS_IN_DAY = MINUTES_IN_DAY * 60
const MIN_ZOOM_DAYS = 10 / SECONDS_IN_DAY

/**
 * ApexCharts TimeScale Class for generating time ticks for x-axis.
 *
 * @module TimeScale
 **/

class TimeScale {
  constructor(ctx) {
    this.ctx = ctx
    this.w = ctx.w
    this.timeScaleArray = []
    this.utc = this.w.config.xaxis.labels.datetimeUTC
  }

  calculateTimeScaleTicks(minX, maxX) {
    let w = this.w

    // null check when no series to show
    if (w.globals.allSeriesCollapsed) {
      w.globals.labels = []
      w.globals.timescaleLabels = []
      return []
    }

    let dt = new DateTime(this.ctx)

    const daysDiff = (maxX - minX) / (1000 * SECONDS_IN_DAY)
    this.determineInterval(daysDiff)

    w.globals.disableZoomIn = false
    w.globals.disableZoomOut = false

    if (daysDiff < MIN_ZOOM_DAYS) {
      w.globals.disableZoomIn = true
    } else if (daysDiff > 50000) {
      w.globals.disableZoomOut = true
    }

    const timeIntervals = dt.getTimeUnitsfromTimestamp(minX, maxX, this.utc)

    const daysWidthOnXAxis = w.globals.gridWidth / daysDiff
    const hoursWidthOnXAxis = daysWidthOnXAxis / 24
    const minutesWidthOnXAxis = hoursWidthOnXAxis / 60
    const secondsWidthOnXAxis = minutesWidthOnXAxis / 60

    let numberOfHours = Math.floor(daysDiff * 24)
    let numberOfMinutes = Math.floor(daysDiff * MINUTES_IN_DAY)
    let numberOfSeconds = Math.floor(daysDiff * SECONDS_IN_DAY)
    let numberOfDays = Math.floor(daysDiff)
    let numberOfMonths = Math.floor(daysDiff / 30)
    let numberOfYears = Math.floor(daysDiff / 365)

    const firstVal = {
      minMillisecond: timeIntervals.minMillisecond,
      minSecond: timeIntervals.minSecond,
      minMinute: timeIntervals.minMinute,
      minHour: timeIntervals.minHour,
      minDate: timeIntervals.minDate,
      minMonth: timeIntervals.minMonth,
      minYear: timeIntervals.minYear
    }

    let currentMillisecond = firstVal.minMillisecond
    let currentSecond = firstVal.minSecond
    let currentMinute = firstVal.minMinute
    let currentHour = firstVal.minHour
    let currentMonthDate = firstVal.minDate
    let currentDate = firstVal.minDate
    let currentMonth = firstVal.minMonth
    let currentYear = firstVal.minYear

    const params = {
      firstVal,
      currentMillisecond,
      currentSecond,
      currentMinute,
      currentHour,
      currentMonthDate,
      currentDate,
      currentMonth,
      currentYear,
      daysWidthOnXAxis,
      hoursWidthOnXAxis,
      minutesWidthOnXAxis,
      secondsWidthOnXAxis,
      numberOfSeconds,
      numberOfMinutes,
      numberOfHours,
      numberOfDays,
      numberOfMonths,
      numberOfYears
    }

    switch (this.tickInterval) {
      case 'years': {
        this.generateYearScale(params)
        break
      }
      case 'months':
      case 'half_year': {
        this.generateMonthScale(params)
        break
      }
      case 'months_days':
      case 'months_fortnight':
      case 'days':
      case 'week_days': {
        this.generateDayScale(params)
        break
      }
      case 'hours': {
        this.generateHourScale(params)
        break
      }
      case 'minutes_fives':
      case 'minutes':
        this.generateMinuteScale(params)
        break
      case 'seconds_tens':
      case 'seconds_fives':
      case 'seconds':
        this.generateSecondScale(params)
        break
    }

    // first, we will adjust the month values index
    // as in the upper function, it is starting from 0
    // we will start them from 1
    const adjustedMonthInTimeScaleArray = this.timeScaleArray.map((ts) => {
      let defaultReturn = {
        position: ts.position,
        unit: ts.unit,
        year: ts.year,
        day: ts.day ? ts.day : 1,
        hour: ts.hour ? ts.hour : 0,
        month: ts.month + 1
      }
      if (ts.unit === 'month') {
        return {
          ...defaultReturn,
          day: 1,
          value: ts.value + 1
        }
      } else if (ts.unit === 'day' || ts.unit === 'hour') {
        return {
          ...defaultReturn,
          value: ts.value
        }
      } else if (ts.unit === 'minute') {
        return {
          ...defaultReturn,
          value: ts.value,
          minute: ts.value
        }
      } else if (ts.unit === 'second') {
        return {
          ...defaultReturn,
          value: ts.value,
          minute: ts.minute,
          second: ts.second
        }
      }

      return ts
    })

    const filteredTimeScale = adjustedMonthInTimeScaleArray.filter((ts) => {
      let modulo = 1
      let ticks = Math.ceil(w.globals.gridWidth / 120)
      let value = ts.value
      if (w.config.xaxis.tickAmount !== undefined) {
        ticks = w.config.xaxis.tickAmount
      }
      if (adjustedMonthInTimeScaleArray.length > ticks) {
        modulo = Math.floor(adjustedMonthInTimeScaleArray.length / ticks)
      }

      let shouldNotSkipUnit = false // there is a big change in unit i.e days to months
      let shouldNotPrint = false // should skip these values

      switch (this.tickInterval) {
        case 'years':
          // make years label denser
          if (ts.unit === 'year') {
            shouldNotSkipUnit = true
          }
          break
        case 'half_year':
          modulo = 7
          if (ts.unit === 'year') {
            shouldNotSkipUnit = true
          }
          break
        case 'months':
          modulo = 1
          if (ts.unit === 'year') {
            shouldNotSkipUnit = true
          }
          break
        case 'months_fortnight':
          modulo = 15
          if (ts.unit === 'year' || ts.unit === 'month') {
            shouldNotSkipUnit = true
          }
          if (value === 30) {
            shouldNotPrint = true
          }
          break
        case 'months_days':
          modulo = 10
          if (ts.unit === 'month') {
            shouldNotSkipUnit = true
          }
          if (value === 30) {
            shouldNotPrint = true
          }
          break
        case 'week_days':
          modulo = 8
          if (ts.unit === 'month') {
            shouldNotSkipUnit = true
          }
          break
        case 'days':
          modulo = 1
          if (ts.unit === 'month') {
            shouldNotSkipUnit = true
          }
          break
        case 'hours':
          if (ts.unit === 'day') {
            shouldNotSkipUnit = true
          }
          break
        case 'minutes_fives':
          if (value % 5 !== 0) {
            shouldNotPrint = true
          }
          break
        case 'seconds_tens':
          if (value % 10 !== 0) {
            shouldNotPrint = true
          }
          break
        case 'seconds_fives':
          if (value % 5 !== 0) {
            shouldNotPrint = true
          }
          break
      }

      if (
        this.tickInterval === 'hours' ||
        this.tickInterval === 'minutes_fives' ||
        this.tickInterval === 'seconds_tens' ||
        this.tickInterval === 'seconds_fives'
      ) {
        if (!shouldNotPrint) {
          return true
        }
      } else {
        if ((value % modulo === 0 || shouldNotSkipUnit) && !shouldNotPrint) {
          return true
        }
      }
    })

    return filteredTimeScale
  }

  recalcDimensionsBasedOnFormat(filteredTimeScale, inverted) {
    const w = this.w
    const reformattedTimescaleArray = this.formatDates(filteredTimeScale)

    const removedOverlappingTS = this.removeOverlappingTS(
      reformattedTimescaleArray
    )

    w.globals.timescaleLabels = removedOverlappingTS.slice()

    // at this stage, we need to re-calculate coords of the grid as timeline labels may have altered the xaxis labels coords
    // The reason we can't do this prior to this stage is because timeline labels depends on gridWidth, and as the ticks are calculated based on available gridWidth, there can be unknown number of ticks generated for different minX and maxX
    // Dependency on Dimensions(), need to refactor correctly
    // TODO - find an alternate way to avoid calling this Heavy method twice
    let dimensions = new Dimensions(this.ctx)
    dimensions.plotCoords()
  }

  determineInterval(daysDiff) {
    const yearsDiff = daysDiff / 365
    const hoursDiff = daysDiff * 24
    const minutesDiff = hoursDiff * 60
    const secondsDiff = minutesDiff * 60
    switch (true) {
      case yearsDiff > 5:
        this.tickInterval = 'years'
        break
      case daysDiff > 800:
        this.tickInterval = 'half_year'
        break
      case daysDiff > 180:
        this.tickInterval = 'months'
        break
      case daysDiff > 90:
        this.tickInterval = 'months_fortnight'
        break
      case daysDiff > 60:
        this.tickInterval = 'months_days'
        break
      case daysDiff > 30:
        this.tickInterval = 'week_days'
        break
      case daysDiff > 2:
        this.tickInterval = 'days'
        break
      case hoursDiff > 2.4:
        this.tickInterval = 'hours'
        break
      case minutesDiff > 15:
        this.tickInterval = 'minutes_fives'
        break
      case minutesDiff > 5:
        this.tickInterval = 'minutes'
        break
      case minutesDiff > 1:
        this.tickInterval = 'seconds_tens'
        break
      case secondsDiff > 20:
        this.tickInterval = 'seconds_fives'
        break
      default:
        this.tickInterval = 'seconds'
        break
    }
  }

  generateYearScale({
    firstVal,
    currentMonth,
    currentYear,
    daysWidthOnXAxis,
    numberOfYears
  }) {
    let firstTickValue = firstVal.minYear
    let firstTickPosition = 0
    const dt = new DateTime(this.ctx)

    let unit = 'year'

    if (firstVal.minDate > 1 || firstVal.minMonth > 0) {
      let remainingDays = dt.determineRemainingDaysOfYear(
        firstVal.minYear,
        firstVal.minMonth,
        firstVal.minDate
      )

      // remainingDaysofFirstMonth is used to reacht the 2nd tick position
      let remainingDaysOfFirstYear =
        dt.determineDaysOfYear(firstVal.minYear) - remainingDays + 1

      // calculate the first tick position
      firstTickPosition = remainingDaysOfFirstYear * daysWidthOnXAxis
      firstTickValue = firstVal.minYear + 1
      // push the first tick in the array
      this.timeScaleArray.push({
        position: firstTickPosition,
        value: firstTickValue,
        unit,
        year: firstTickValue,
        month: Utils.monthMod(currentMonth + 1)
      })
    } else if (firstVal.minDate === 1 && firstVal.minMonth === 0) {
      // push the first tick in the array
      this.timeScaleArray.push({
        position: firstTickPosition,
        value: firstTickValue,
        unit,
        year: currentYear,
        month: Utils.monthMod(currentMonth + 1)
      })
    }

    let year = firstTickValue
    let pos = firstTickPosition

    // keep drawing rest of the ticks
    for (let i = 0; i < numberOfYears; i++) {
      year++
      pos = dt.determineDaysOfYear(year - 1) * daysWidthOnXAxis + pos
      this.timeScaleArray.push({
        position: pos,
        value: year,
        unit,
        year,
        month: 1
      })
    }
  }

  generateMonthScale({
    firstVal,
    currentMonthDate,
    currentMonth,
    currentYear,
    daysWidthOnXAxis,
    numberOfMonths
  }) {
    let firstTickValue = currentMonth
    let firstTickPosition = 0
    const dt = new DateTime(this.ctx)
    let unit = 'month'
    let yrCounter = 0

    if (firstVal.minDate > 1) {
      // remainingDaysofFirstMonth is used to reacht the 2nd tick position
      let remainingDaysOfFirstMonth =
        dt.determineDaysOfMonths(currentMonth + 1, firstVal.minYear) -
        currentMonthDate +
        1

      // calculate the first tick position
      firstTickPosition = remainingDaysOfFirstMonth * daysWidthOnXAxis
      firstTickValue = Utils.monthMod(currentMonth + 1)

      let year = currentYear + yrCounter
      let month = Utils.monthMod(firstTickValue)
      let value = firstTickValue
      // it's Jan, so update the year
      if (firstTickValue === 0) {
        unit = 'year'
        value = year
        month = 1
        yrCounter += 1
        year = year + yrCounter
      }

      // push the first tick in the array
      this.timeScaleArray.push({
        position: firstTickPosition,
        value,
        unit,
        year,
        month
      })
    } else {
      // push the first tick in the array
      this.timeScaleArray.push({
        position: firstTickPosition,
        value: firstTickValue,
        unit,
        year: currentYear,
        month: Utils.monthMod(currentMonth)
      })
    }

    let month = firstTickValue + 1
    let pos = firstTickPosition

    // keep drawing rest of the ticks
    for (let i = 0, j = 1; i < numberOfMonths; i++, j++) {
      month = Utils.monthMod(month)

      if (month === 0) {
        unit = 'year'
        yrCounter += 1
      } else {
        unit = 'month'
      }
      let year = this._getYear(currentYear, month, yrCounter)

      pos = dt.determineDaysOfMonths(month, year) * daysWidthOnXAxis + pos
      let monthVal = month === 0 ? year : month
      this.timeScaleArray.push({
        position: pos,
        value: monthVal,
        unit,
        year,
        month: month === 0 ? 1 : month
      })
      month++
    }
  }

  generateDayScale({
    firstVal,
    currentMonth,
    currentYear,
    hoursWidthOnXAxis,
    numberOfDays
  }) {
    const dt = new DateTime(this.ctx)
    let unit = 'day'
    let firstTickValue = firstVal.minDate + 1
    let date = firstTickValue

    const changeMonth = (dateVal, month, year) => {
      let monthdays = dt.determineDaysOfMonths(month + 1, year)

      if (dateVal > monthdays) {
        month = month + 1
        date = 1
        unit = 'month'
        val = month
        return month
      }

      return month
    }

    let remainingHours = 24 - firstVal.minHour
    let yrCounter = 0

    // calculate the first tick position
    let firstTickPosition = remainingHours * hoursWidthOnXAxis

    let val = firstTickValue
    let month = changeMonth(date, currentMonth, currentYear)

    if (firstVal.minHour === 0 && firstVal.minDate === 1) {
      // the first value is the first day of month
      firstTickPosition = 0
      val = Utils.monthMod(firstVal.minMonth)
      unit = 'month'
      date = firstVal.minDate
      numberOfDays++
    } else if (
      firstVal.minDate !== 1 &&
      firstVal.minHour === 0 &&
      firstVal.minMinute === 0
    ) {
      // fixes apexcharts/apexcharts.js/issues/1730
      firstTickPosition = 0
      firstTickValue = firstVal.minDate
      date = firstTickValue
      val = firstTickValue
      // in case it's the last date of month, we need to check it
      month = changeMonth(date, currentMonth, currentYear)
    }

    // push the first tick in the array
    this.timeScaleArray.push({
      position: firstTickPosition,
      value: val,
      unit,
      year: this._getYear(currentYear, month, yrCounter),
      month: Utils.monthMod(month),
      day: date
    })

    let pos = firstTickPosition
    // keep drawing rest of the ticks
    for (let i = 0; i < numberOfDays; i++) {
      date += 1
      unit = 'day'
      month = changeMonth(
        date,
        month,
        this._getYear(currentYear, month, yrCounter)
      )

      let year = this._getYear(currentYear, month, yrCounter)

      pos = 24 * hoursWidthOnXAxis + pos
      let value = date === 1 ? Utils.monthMod(month) : date
      this.timeScaleArray.push({
        position: pos,
        value,
        unit,
        year,
        month: Utils.monthMod(month),
        day: value
      })
    }
  }

  generateHourScale({
    firstVal,
    currentDate,
    currentMonth,
    currentYear,
    minutesWidthOnXAxis,
    numberOfHours
  }) {
    const dt = new DateTime(this.ctx)

    let yrCounter = 0
    let unit = 'hour'

    const changeDate = (dateVal, month) => {
      let monthdays = dt.determineDaysOfMonths(month + 1, currentYear)
      if (dateVal > monthdays) {
        date = 1
        month = month + 1
      }
      return { month, date }
    }

    const changeMonth = (dateVal, month) => {
      let monthdays = dt.determineDaysOfMonths(month + 1, currentYear)
      if (dateVal > monthdays) {
        month = month + 1
        return month
      }

      return month
    }

    // factor in minSeconds as well
    let remainingMins = 60 - (firstVal.minMinute + firstVal.minSecond / 60.0)

    let firstTickPosition = remainingMins * minutesWidthOnXAxis
    let firstTickValue = firstVal.minHour + 1
    let hour = firstTickValue + 1

    if (remainingMins === 60) {
      firstTickPosition = 0
      firstTickValue = firstVal.minHour
      hour = firstTickValue + 1
    }

    let date = currentDate

    let month = changeMonth(date, currentMonth)

    // push the first tick in the array
    this.timeScaleArray.push({
      position: firstTickPosition,
      value: firstTickValue,
      unit,
      day: date,
      hour,
      year: currentYear,
      month: Utils.monthMod(month)
    })

    let pos = firstTickPosition
    // keep drawing rest of the ticks
    for (let i = 0; i < numberOfHours; i++) {
      unit = 'hour'

      if (hour >= 24) {
        hour = 0
        date += 1
        unit = 'day'

        const checkNextMonth = changeDate(date, month)

        month = checkNextMonth.month
        month = changeMonth(date, month)
      }

      let year = this._getYear(currentYear, month, yrCounter)
      pos =
        hour === 0 && i === 0
          ? remainingMins * minutesWidthOnXAxis
          : 60 * minutesWidthOnXAxis + pos
      let val = hour === 0 ? date : hour
      this.timeScaleArray.push({
        position: pos,
        value: val,
        unit,
        hour,
        day: date,
        year,
        month: Utils.monthMod(month)
      })

      hour++
    }
  }

  generateMinuteScale({
    currentMillisecond,
    currentSecond,
    currentMinute,
    currentHour,
    currentDate,
    currentMonth,
    currentYear,
    minutesWidthOnXAxis,
    secondsWidthOnXAxis,
    numberOfMinutes
  }) {
    let yrCounter = 0
    let unit = 'minute'

    let remainingSecs = 60 - currentSecond
    let firstTickPosition =
      (remainingSecs - currentMillisecond / 1000) * secondsWidthOnXAxis
    let minute = currentMinute + 1

    let date = currentDate
    let month = currentMonth
    let year = currentYear
    let hour = currentHour

    let pos = firstTickPosition
    for (let i = 0; i < numberOfMinutes; i++) {
      if (minute >= 60) {
        minute = 0
        hour += 1
        if (hour === 24) {
          hour = 0
        }
      }

      this.timeScaleArray.push({
        position: pos,
        value: minute,
        unit,
        hour,
        minute,
        day: date,
        year: this._getYear(year, month, yrCounter),
        month: Utils.monthMod(month)
      })

      pos += minutesWidthOnXAxis
      minute++
    }
  }

  generateSecondScale({
    currentMillisecond,
    currentSecond,
    currentMinute,
    currentHour,
    currentDate,
    currentMonth,
    currentYear,
    secondsWidthOnXAxis,
    numberOfSeconds
  }) {
    let yrCounter = 0
    let unit = 'second'

    const remainingMillisecs = 1000 - currentMillisecond
    let firstTickPosition = (remainingMillisecs / 1000) * secondsWidthOnXAxis

    let second = currentSecond + 1
    let minute = currentMinute
    let date = currentDate
    let month = currentMonth
    let year = currentYear
    let hour = currentHour

    let pos = firstTickPosition
    for (let i = 0; i < numberOfSeconds; i++) {
      if (second >= 60) {
        minute++
        second = 0
        if (minute >= 60) {
          hour++
          minute = 0
          if (hour === 24) {
            hour = 0
          }
        }
      }

      this.timeScaleArray.push({
        position: pos,
        value: second,
        unit,
        hour,
        minute,
        second,
        day: date,
        year: this._getYear(year, month, yrCounter),
        month: Utils.monthMod(month)
      })

      pos += secondsWidthOnXAxis
      second++
    }
  }

  createRawDateString(ts, value) {
    let raw = ts.year

    if (ts.month === 0) {
      // invalid month, correct it
      ts.month = 1
    }
    raw += '-' + ('0' + ts.month.toString()).slice(-2)

    // unit is day
    if (ts.unit === 'day') {
      raw += ts.unit === 'day' ? '-' + ('0' + value).slice(-2) : '-01'
    } else {
      raw += '-' + ('0' + (ts.day ? ts.day : '1')).slice(-2)
    }

    // unit is hour
    if (ts.unit === 'hour') {
      raw += ts.unit === 'hour' ? 'T' + ('0' + value).slice(-2) : 'T00'
    } else {
      raw += 'T' + ('0' + (ts.hour ? ts.hour : '0')).slice(-2)
    }

    if (ts.unit === 'minute') {
      raw += ':' + ('0' + value).slice(-2)
    } else {
      raw += ':' + (ts.minute ? ('0' + ts.minute).slice(-2) : '00')
    }

    if (ts.unit === 'second') {
      raw += ':' + ('0' + value).slice(-2)
    } else {
      raw += ':00'
    }

    if (this.utc) {
      raw += '.000Z'
    }
    return raw
  }

  formatDates(filteredTimeScale) {
    const w = this.w

    const reformattedTimescaleArray = filteredTimeScale.map((ts) => {
      let value = ts.value.toString()

      let dt = new DateTime(this.ctx)

      const raw = this.createRawDateString(ts, value)

      let dateToFormat = dt.getDate(dt.parseDate(raw))
      if (!this.utc) {
        // Fixes #1726, #1544, #1485, #1255
        dateToFormat = dt.getDate(dt.parseDateWithTimezone(raw))
      }

      if (w.config.xaxis.labels.format === undefined) {
        let customFormat = 'dd MMM'
        const dtFormatter = w.config.xaxis.labels.datetimeFormatter
        if (ts.unit === 'year') customFormat = dtFormatter.year
        if (ts.unit === 'month') customFormat = dtFormatter.month
        if (ts.unit === 'day') customFormat = dtFormatter.day
        if (ts.unit === 'hour') customFormat = dtFormatter.hour
        if (ts.unit === 'minute') customFormat = dtFormatter.minute
        if (ts.unit === 'second') customFormat = dtFormatter.second

        value = dt.formatDate(dateToFormat, customFormat)
      } else {
        value = dt.formatDate(dateToFormat, w.config.xaxis.labels.format)
      }

      return {
        dateString: raw,
        position: ts.position,
        value,
        unit: ts.unit,
        year: ts.year,
        month: ts.month
      }
    })

    return reformattedTimescaleArray
  }

  removeOverlappingTS(arr) {
    const graphics = new Graphics(this.ctx)

    let equalLabelLengthFlag = false // These labels got same length?
    let constantLabelWidth // If true, what is the constant length to use
    if (
      arr.length > 0 && // check arr length
      arr[0].value && // check arr[0] contains value
      arr.every((lb) => lb.value.length === arr[0].value.length) // check every arr label value is the same as the first one
    ) {
      equalLabelLengthFlag = true // These labels got same length
      constantLabelWidth = graphics.getTextRects(arr[0].value).width // The constant label width to use
    }

    let lastDrawnIndex = 0

    let filteredArray = arr.map((item, index) => {
      if (index > 0 && this.w.config.xaxis.labels.hideOverlappingLabels) {
        const prevLabelWidth = !equalLabelLengthFlag // if vary in label length
          ? graphics.getTextRects(arr[lastDrawnIndex].value).width // get individual length
          : constantLabelWidth // else: use constant length
        const prevPos = arr[lastDrawnIndex].position
        const pos = item.position

        if (pos > prevPos + prevLabelWidth + 10) {
          lastDrawnIndex = index
          return item
        } else {
          return null
        }
      } else {
        return item
      }
    })

    filteredArray = filteredArray.filter((f) => f !== null)

    return filteredArray
  }

  _getYear(currentYear, month, yrCounter) {
    return currentYear + Math.floor(month / 12) + yrCounter
  }
}

export default TimeScale
