<template>
  <div class="w-full py-2">
    <div class="flex">
      <div class="w-28 h-8 rounded-tl-md shadow-md relative border border-black-200 flex items-center justify-center cursor-pointer hover:text-white" :class="!showAdvancedView ? 'text-gray-200 bg-primary hover:bg-opacity-60' : 'text-gray-400 bg-bg hover:bg-primary hover:bg-opacity-20'" @click="showAdvancedView = false">
        <p class="text-sm">Cron Builder</p>
      </div>
      <div class="w-28 h-8 rounded-tr-md shadow-md relative border border-black-200 flex items-center justify-center -ml-px cursor-pointer hover:text-white" :class="showAdvancedView ? 'text-gray-200 bg-primary hover:bg-opacity-60' : 'text-gray-400 bg-bg hover:bg-primary hover:bg-opacity-20'" @click="showAdvancedView = true">
        <p class="text-sm">Advanced</p>
      </div>
    </div>
    <div class="p-4 border border-black-200 rounded-b-md rounded-tr-md -mt-px" style="min-height: 200px">
      <template v-if="!showAdvancedView">
        <ui-multi-select-dropdown v-model="selectedWeekdays" @input="updateCron" label="Weekdays to run" :items="weekdays" />

        <div v-show="selectedWeekdays.length" class="flex items-center py-2">
          <ui-text-input-with-label v-model="selectedHour" @input="updateCron" @blur="hourBlur" type="number" label="Hour" class="max-w-20" />
          <p class="text-xl px-2 mt-4">:</p>
          <ui-text-input-with-label v-model="selectedMinute" @input="updateCron" @blur="minuteBlur" type="number" label="Minute" class="max-w-20" />
        </div>

        <div v-if="description" class="w-full bg-primary bg-opacity-75 rounded-xl p-4 text-center mt-2">
          <p class="text-lg text-gray-200" v-html="description" />
        </div>
      </template>
      <template v-else>
        <p class="px-1 text-sm font-semibold">Cron Expression</p>
        <ui-text-input v-model="customCronExpression" @blur="cronExpressionBlur" label="Cron Expression" :padding-y="2" text-center class="w-full text-4xl -tracking-widest mb-4 font-mono" />

        <div class="flex items-center justify-center">
          <widgets-loading-spinner v-if="isValidating" class="mr-2" />
          <span v-else class="material-icons-outlined mr-2" :class="isValid ? 'text-success' : 'text-error'">{{ isValid ? 'check_circle_outline' : 'error_outline' }}</span>
          <p v-if="isValidating" class="text-gray-300 text-lg text-center">Checking cron...</p>
          <p v-else-if="customCronError" class="text-error text-lg text-center">{{ customCronError }}</p>
          <p v-else class="text-success text-lg text-center">Valid cron expression</p>
        </div>
      </template>
    </div>
  </div>
</template>

<script>
export default {
  props: {
    value: {
      type: String,
      default: null
    }
  },
  data() {
    return {
      showAdvancedView: false,
      selectedHour: 0,
      selectedMinute: 0,
      selectedWeekdays: [],
      cronExpression: '0 0 * * *',
      customCronExpression: '0 0 * * *',
      customCronError: '',
      isValidating: false,
      validatedCron: null,
      isValid: true
    }
  },
  computed: {
    minuteIsValid() {
      return !(isNaN(this.selectedMinute) || this.selectedMinute === '' || this.selectedMinute < 0 || this.selectedMinute > 59)
    },
    hourIsValid() {
      return !(isNaN(this.selectedHour) || this.selectedHour === '' || this.selectedHour < 0 || this.selectedHour > 23)
    },
    description() {
      if (!this.selectedWeekdays.length) return ''

      if (!this.hourIsValid) {
        return `<span class="text-error">Invalid hour must be 0-23 | ${this.selectedHour < 0 || this.selectedHour > 23}</span>`
      }
      if (!this.minuteIsValid) {
        return `<span class="text-error">Invalid minute must be 0-59</span>`
      }

      var description = 'Run every '
      const weekdayTexts =
        this.selectedWeekdays.length === 7
          ? 'day'
          : this.selectedWeekdays
              .map((weekday) => {
                return this.weekdays.find((w) => w.value === weekday).text
              })
              .join(', ')
      description += `<span class="font-bold text-white">${weekdayTexts}</span>`

      const hourString = this.selectedHour.toString()
      const minuteString = this.selectedMinute.toString().padStart(2, '0')
      description += ` at <span class="font-bold text-white">${hourString}:${minuteString}</span>`
      return description
    },
    weekdays() {
      return [
        {
          text: 'Sunday',
          value: 0
        },
        {
          text: 'Monday',
          value: 1
        },
        {
          text: 'Tuesday',
          value: 2
        },
        {
          text: 'Wednesday',
          value: 3
        },
        {
          text: 'Thursday',
          value: 4
        },
        {
          text: 'Friday',
          value: 5
        },
        {
          text: 'Saturday',
          value: 6
        }
      ]
    }
  },
  methods: {
    updateCron() {
      if (!this.minuteIsValid || !this.hourIsValid || !this.selectedWeekdays.length) {
        this.cronExpression = null
        return
      }
      this.selectedWeekdays.sort()
      this.cronExpression = `${this.selectedMinute} ${this.selectedHour} * * ${this.selectedWeekdays.join(',')}`
      this.customCronExpression = this.cronExpression
      this.validatedCron = this.cronExpression
      this.isValid = true
      this.customCronError = ''
      this.$emit('input', this.cronExpression)
    },
    minuteBlur() {
      const v = this.selectedMinute
      if (v === '' || v === null || isNaN(v) || v < 0) {
        this.selectedMinute = 0
      } else if (v > 59) {
        this.selectedMinute = 59
      } else {
        this.selectedMinute = Number(v)
      }
      this.updateCron()
    },
    hourBlur() {
      const v = this.selectedHour
      if (v === '' || v === null || isNaN(v) || v < 0) {
        this.selectedHour = 0
      } else if (v > 23) {
        this.selectedHour = 23
      } else {
        this.selectedHour = Number(v)
      }
      this.updateCron()
    },
    async cronExpressionBlur() {
      this.customCronError = ''
      if (!this.customCronExpression || this.customCronExpression.split(' ').length !== 5) {
        this.customCronError = 'Invalid cron expression'
        this.isValid = false
        return
      } else if (this.customCronExpression.split(' ')[0] === '*') {
        this.customCronError = 'Cannot use * in minutes position'
        this.isValid = false
        return
      }

      if (this.customCronExpression !== this.cronExpression) {
        this.selectedWeekdays = []
        this.selectedHour = 0
        this.selectedMinute = 0
        this.cronExpression = this.customCronExpression
      }

      if (!this.validatedCron || this.validatedCron !== this.cronExpression) {
        const validationPayload = await this.validateCron()
        this.isValid = validationPayload.isValid
        this.validatedCron = this.cronExpression
        this.customCronError = validationPayload.error || ''
      }

      if (this.isValid) {
        this.$emit('input', this.cronExpression)
      }
    },
    validateCron() {
      this.isValidating = true
      return this.$axios
        .$post('/api/validate-cron', { expression: this.customCronExpression })
        .then(() => {
          this.isValidating = false
          return {
            isValid: true
          }
        })
        .catch((error) => {
          console.error('Invalid cron', error)
          var errMsg = error.response ? error.response.data || '' : ''
          this.isValidating = false
          return {
            isValid: false,
            error: errMsg || 'Invalid cron expression'
          }
        })
    },
    init() {
      if (!this.value) return
      // TODO: parse
      const pieces = this.value.split(' ')
      if (pieces.length !== 5) {
        console.error('Invalid cron expression input', this.value)
        return
      }

      var isCustomCron = false
      if (isNaN(pieces[0]) || isNaN(pieces[1])) {
        isCustomCron = true
      } else if (pieces[2] !== '*' || pieces[3] !== '*') {
        isCustomCron = true
      } else if (pieces[4].split(',').some((num) => isNaN(num))) {
        isCustomCron = true
      }

      if (isCustomCron) {
        this.showAdvancedView = true
      } else {
        this.selectedWeekdays = pieces[4].split(',').map((num) => Number(num))
        this.selectedHour = pieces[1]
        this.selectedMinute = pieces[0]
      }
      this.cronExpression = this.value
      this.customCronExpression = this.value
    }
  },
  mounted() {
    this.init()
  }
}
</script>