<template lang="html">
  <label>
    <input type="checkbox" :checked="shouldBeChecked" :value="value" @change="updateInput">
    {{ label }}
  </label>
</template>
<script>
export default {
  model: {
    prop: 'modelValue',
    event: 'change'
  },
  props: {
    value: {
      type: String
    },
    modelValue: {
      default: false
    },
    label: {
      type: String,
      required: true
    },
    trueValue: {
      default: true
    },
    falseValue: {
      default: false
    }
  },
  computed: {
    shouldBeChecked () {
      if (this.modelValue instanceof Array) {
        return this.modelValue.includes(this.value)
      }
      return this.modelValue === this.trueValue
    }
  },
  methods: {
    updateInput (event) {
      let isChecked = event.target.checked

      if (this.modelValue instanceof Array) {
        let newValue = [...this.modelValue]

        if (isChecked) {
          newValue.push(this.value)
        } else {
          newValue.splice(newValue.indexOf(this.value), 1)
        }

        this.$emit('change', newValue)
      } else {
        this.$emit('change', isChecked ? this.trueValue : this.falseValue)
      }
    }
  }
}
</script>