import type { Ref } from 'vue'
import { computed, useSlots } from 'vue'
import classNames from 'classnames'
import type { ButtonDuotoneGradient, ButtonGradient, ButtonMonochromeGradient, ButtonSize, ButtonVariant } from './Button.vue'

const buttonColorClasses: Record<ButtonVariant, string> = {
  default: 'text-white bg-blue-700 hover:bg-blue-800 focus:ring-4 focus:ring-blue-300 font-medium rounded-lg dark:bg-blue-600 dark:hover:bg-blue-700 focus:outline-none dark:focus:ring-blue-800',
  alternative:
    'font-medium text-gray-900 focus:outline-none bg-white rounded-lg border border-gray-200 hover:bg-gray-100 hover:text-blue-700 focus:z-10 focus:ring-4 focus:ring-gray-200 dark:focus:ring-gray-700 dark:bg-gray-800 dark:text-gray-400 dark:border-gray-600 dark:hover:text-white dark:hover:bg-gray-700',
  dark: 'text-white bg-gray-800 hover:bg-gray-900 focus:outline-none focus:ring-4 focus:ring-gray-300 font-medium rounded-lg dark:bg-gray-800 dark:hover:bg-gray-700 dark:focus:ring-gray-700 dark:border-gray-700',
  light:
    'text-gray-900 bg-white border border-gray-300 focus:outline-none hover:bg-gray-100 focus:ring-4 focus:ring-gray-200 font-medium rounded-lg dark:bg-gray-800 dark:text-white dark:border-gray-600 dark:hover:bg-gray-700 dark:hover:border-gray-600 dark:focus:ring-gray-700',
  green: 'focus:outline-none text-white bg-green-700 hover:bg-green-800 focus:ring-4 focus:ring-green-300 font-medium rounded-lg dark:bg-green-600 dark:hover:bg-green-700 dark:focus:ring-green-800',
  red: 'focus:outline-none text-white bg-red-700 hover:bg-red-800 focus:ring-4 focus:ring-red-300 font-medium rounded-lg dark:bg-red-600 dark:hover:bg-red-700 dark:focus:ring-red-900',
  yellow: 'focus:outline-none text-white bg-yellow-400 hover:bg-yellow-500 focus:ring-4 focus:ring-yellow-300 font-medium rounded-lg dark:focus:ring-yellow-900',
  purple:
    'focus:outline-none text-white bg-purple-700 hover:bg-purple-800 focus:ring-4 focus:ring-purple-300 font-medium rounded-lg dark:bg-purple-600 dark:hover:bg-purple-700 dark:focus:ring-purple-900',
}

const buttonOutlineColorClasses: Record<Exclude<ButtonVariant, 'light' | 'alternative'>, string> = {
  dark: 'text-gray-900 hover:text-white border border-gray-800 hover:bg-gray-900 focus:ring-4 focus:outline-none focus:ring-gray-300 font-medium rounded-lg text-sm text-center dark:border-gray-600 dark:text-gray-400 dark:hover:text-white dark:hover:bg-gray-600 dark:focus:ring-gray-800',
  default:
    'text-blue-700 hover:text-white border border-blue-700 hover:bg-blue-800 focus:ring-4 focus:outline-none focus:ring-blue-300 font-medium rounded-lg text-sm text-center dark:border-blue-500 dark:text-blue-500 dark:hover:text-white dark:hover:bg-blue-600 dark:focus:ring-blue-800',
  green:
    'text-green-700 hover:text-white border border-green-700 hover:bg-green-800 focus:ring-4 focus:outline-none focus:ring-green-300 font-medium rounded-lg text-sm text-center dark:border-green-500 dark:text-green-500 dark:hover:text-white dark:hover:bg-green-600 dark:focus:ring-green-800',
  purple:
    'text-purple-700 hover:text-white border border-purple-700 hover:bg-purple-800 focus:ring-4 focus:outline-none focus:ring-purple-300 font-medium rounded-lg text-sm text-center dark:border-purple-400 dark:text-purple-400 dark:hover:text-white dark:hover:bg-purple-500 dark:focus:ring-purple-900',
  red: 'text-red-700 hover:text-white border border-red-700 hover:bg-red-800 focus:ring-4 focus:outline-none focus:ring-red-300 font-medium rounded-lg text-sm text-center dark:border-red-500 dark:text-red-500 dark:hover:text-white dark:hover:bg-red-600 dark:focus:ring-red-900',
  yellow:
    'text-yellow-400 hover:text-white border border-yellow-400 hover:bg-yellow-500 focus:ring-4 focus:outline-none focus:ring-yellow-300 font-medium rounded-lg text-sm text-center dark:border-yellow-300 dark:text-yellow-300 dark:hover:text-white dark:hover:bg-yellow-400 dark:focus:ring-yellow-900',
}

const buttonGradientClasses: Record<ButtonGradient, string> = {
  'cyan-blue': 'text-white bg-gradient-to-r from-cyan-500 to-blue-500 hover:bg-gradient-to-bl focus:ring-4 focus:outline-none focus:ring-cyan-300 dark:focus:ring-cyan-800 font-medium rounded-lg',
  'green-blue': 'text-white bg-gradient-to-br from-green-400 to-blue-600 hover:bg-gradient-to-bl focus:ring-4 focus:outline-none focus:ring-green-200 dark:focus:ring-green-800 font-medium rounded-lg',
  'pink-orange': 'text-white bg-gradient-to-br from-pink-500 to-orange-400 hover:bg-gradient-to-bl focus:ring-4 focus:outline-none focus:ring-pink-200 dark:focus:ring-pink-800 font-medium rounded-lg',
  'purple-blue': 'text-white bg-gradient-to-br from-purple-600 to-blue-500 hover:bg-gradient-to-bl focus:ring-4 focus:outline-none focus:ring-blue-300 dark:focus:ring-blue-800 font-medium rounded-lg',
  'purple-pink':
    'text-white bg-gradient-to-r from-purple-500 to-pink-500 hover:bg-gradient-to-l focus:ring-4 focus:outline-none focus:ring-purple-200 dark:focus:ring-purple-800 font-medium rounded-lg',
  'red-yellow':
    'text-gray-900 bg-gradient-to-r from-red-200 via-red-300 to-yellow-200 hover:bg-gradient-to-bl focus:ring-4 focus:outline-none focus:ring-red-100 dark:focus:ring-red-400 font-medium rounded-lg',
  'teal-lime':
    'text-gray-900 bg-gradient-to-r from-teal-200 to-lime-200 hover:bg-gradient-to-l hover:from-teal-200 hover:to-lime-200 focus:ring-4 focus:outline-none focus:ring-lime-200 dark:focus:ring-teal-700 font-medium rounded-lg',
  blue: 'text-white bg-gradient-to-r from-blue-500 via-blue-600 to-blue-700 hover:bg-gradient-to-br focus:ring-4 focus:outline-none focus:ring-blue-300 dark:focus:ring-blue-800 rounded-lg',
  cyan: 'text-white bg-gradient-to-r from-cyan-500 via-cyan-600 to-cyan-700 hover:bg-gradient-to-br focus:ring-4 focus:outline-none focus:ring-cyan-300 dark:focus:ring-cyan-800 rounded-lg',
  green: 'text-white bg-gradient-to-r from-green-500 via-green-600 to-green-700 hover:bg-gradient-to-br focus:ring-4 focus:outline-none focus:ring-green-300 dark:focus:ring-green-800 rounded-lg',
  lime: 'text-gray-900 bg-gradient-to-r from-lime-500 via-lime-600 to-lime-700 hover:bg-gradient-to-br focus:ring-4 focus:outline-none focus:ring-lime-300 dark:focus:ring-lime-800 rounded-lg',
  pink: 'text-white bg-gradient-to-r from-pink-500 via-pink-600 to-pink-700 hover:bg-gradient-to-br focus:ring-4 focus:outline-none focus:ring-pink-300 dark:focus:ring-pink-800 rounded-lg',
  purple:
    'text-white bg-gradient-to-r from-purple-500 via-purple-600 to-purple-700 hover:bg-gradient-to-br focus:ring-4 focus:outline-none focus:ring-purple-300 dark:focus:ring-purple-800 rounded-lg',
  red: 'text-white bg-gradient-to-r from-red-500 via-red-600 to-red-700 hover:bg-gradient-to-br focus:ring-4 focus:outline-none focus:ring-red-300 dark:focus:ring-red-800 rounded-lg',
  teal: 'text-white bg-gradient-to-r from-teal-500 via-teal-600 to-teal-700 hover:bg-gradient-to-br focus:ring-4 focus:outline-none focus:ring-teal-300 dark:focus:ring-teal-800 rounded-lg',
}

const buttonOutlineGradientClasses: Record<ButtonDuotoneGradient, string> = {
  'cyan-blue':
    'relative inline-flex items-center justify-center overflow-hidden font-medium text-gray-900 rounded-lg group bg-gradient-to-br from-cyan-500 to-blue-500 group-hover:from-cyan-500 group-hover:to-blue-500 hover:text-white dark:text-white focus:ring-4 focus:outline-none focus:ring-cyan-200 dark:focus:ring-cyan-800',
  'green-blue':
    'relative inline-flex items-center justify-center overflow-hidden font-medium text-gray-900 rounded-lg group bg-gradient-to-br from-green-400 to-blue-600 group-hover:from-green-400 group-hover:to-blue-600 hover:text-white dark:text-white focus:ring-4 focus:outline-none focus:ring-green-200 dark:focus:ring-green-800',
  'pink-orange':
    'relative inline-flex items-center justify-center overflow-hidden font-medium text-gray-900 rounded-lg group bg-gradient-to-br from-pink-500 to-orange-400 group-hover:from-pink-500 group-hover:to-orange-400 hover:text-white dark:text-white focus:ring-4 focus:outline-none focus:ring-pink-200 dark:focus:ring-pink-800',
  'purple-blue':
    'relative inline-flex items-center justify-center overflow-hidden font-medium text-gray-900 rounded-lg group bg-gradient-to-br from-purple-600 to-blue-500 group-hover:from-purple-600 group-hover:to-blue-500 hover:text-white dark:text-white focus:ring-4 focus:outline-none focus:ring-blue-300 dark:focus:ring-blue-800',
  'purple-pink':
    'relative inline-flex items-center justify-center overflow-hidden font-medium text-gray-900 rounded-lg group bg-gradient-to-br from-purple-500 to-pink-500 group-hover:from-purple-500 group-hover:to-pink-500 hover:text-white dark:text-white focus:ring-4 focus:outline-none focus:ring-purple-200 dark:focus:ring-purple-800',
  'red-yellow':
    'relative inline-flex items-center justify-center overflow-hidden font-medium text-gray-900 rounded-lg group bg-gradient-to-br from-red-200 via-red-300 to-yellow-200 group-hover:from-red-200 group-hover:via-red-300 group-hover:to-yellow-200 dark:text-white dark:hover:text-gray-900 focus:ring-4 focus:outline-none focus:ring-red-100 dark:focus:ring-red-400',
  'teal-lime':
    'relative inline-flex items-center justify-center overflow-hidden font-medium text-gray-900 rounded-lg group bg-gradient-to-br from-teal-300 to-lime-300 group-hover:from-teal-300 group-hover:to-lime-300 dark:text-white dark:hover:text-gray-900 focus:ring-4 focus:outline-none focus:ring-lime-200 dark:focus:ring-lime-800',
}

const buttonSizeClasses: Record<ButtonSize, string> = {
  xs: 'text-xs px-2 py-1',
  sm: 'text-sm px-3 py-1.5',
  md: 'text-sm px-4 py-2',
  lg: 'text-base px-5 py-2.5',
  xl: 'text-base px-6 py-3',
}

const buttonSquareSizeClasses: Record<ButtonSize, string> = {
  xs: 'text-xs p-1',
  sm: 'text-sm p-1.5',
  md: 'text-sm p-2',
  lg: 'text-base p-2.5',
  xl: 'text-base p-3',
}

const buttonShadowClasses: Record<ButtonMonochromeGradient, string> = {
  blue: 'shadow-lg shadow-blue-500/50 dark:shadow-lg dark:shadow-blue-800/80',
  cyan: 'shadow-lg shadow-cyan-500/50 dark:shadow-lg dark:shadow-cyan-800/80',
  green: 'shadow-lg shadow-green-500/50 dark:shadow-lg dark:shadow-green-800/80',
  lime: 'shadow-lg shadow-lime-500/50 dark:shadow-lg dark:shadow-lime-800/80',
  pink: 'shadow-lg shadow-pink-500/50 dark:shadow-lg dark:shadow-pink-800/80',
  purple: 'shadow-lg shadow-purple-500/50 dark:shadow-lg dark:shadow-purple-800/80',
  red: 'shadow-lg shadow-red-500/50 dark:shadow-lg dark:shadow-red-800/80',
  teal: 'shadow-lg shadow-teal-500/50 dark:shadow-lg dark:shadow-teal-800/80',
}

export type UseButtonClassesProps = {
  pill: boolean
  disabled: boolean
  loading: boolean
  outline: boolean
  size: ButtonSize
  square: boolean
  color: ButtonVariant
  gradient: ButtonGradient | null
  shadow: ButtonMonochromeGradient | '' | null
}

const simpleColors = ['blue', 'green', 'cyan', 'teal', 'lime', 'red', 'pink', 'purple']

export function useButtonClasses(props: UseButtonClassesProps): { wrapperClasses: Ref<string>, spanClasses: Ref<string> } {
  const slots = useSlots()

  const sizeClasses = computed(() => {
    if (props.square) return buttonSquareSizeClasses[props.size]
    return buttonSizeClasses[props.size]
  })

  const bindClasses = computed(() => {
    const isGradient = !!props.gradient
    const isColor = !!props.color
    const isOutline = props.outline

    let backgroundClass = ''

    if (isGradient && isOutline) {
      if (simpleColors.includes(props.gradient!)) {
        // invalid gradients for outline
        backgroundClass = buttonGradientClasses[props.gradient!]
      } else {
        backgroundClass = buttonOutlineGradientClasses[props.gradient as unknown as keyof typeof buttonOutlineGradientClasses]
      }
    } else if (isGradient) {
      backgroundClass = buttonGradientClasses[props.gradient!]
    } else if (isColor && isOutline) {
      if (['alternative', 'light'].includes(props.color)) {
        // invalid colors for outline
        backgroundClass = buttonColorClasses[props.color]
      } else {
        backgroundClass = buttonOutlineColorClasses[props.color as unknown as keyof typeof buttonOutlineColorClasses]
      }
    } else {
      backgroundClass = buttonColorClasses[props.color]
    }

    let shadowClass = ''
    if (props.shadow === '') {
      // if shadow prop passed without value - try to find color for shadow by gradient
      if (props.gradient && simpleColors.includes(props.gradient)) {
        shadowClass = buttonShadowClasses[props.gradient as unknown as keyof typeof buttonShadowClasses]
      }
    } else if (typeof props.shadow === 'string') {
      // if provided color for shadow - use it
      if (simpleColors.includes(props.shadow)) {
        shadowClass = buttonShadowClasses[props.shadow as unknown as keyof typeof buttonShadowClasses]
      }
    }

    return classNames(
      backgroundClass,
      shadowClass,
      props.pill ? '!rounded-full' : '',
      props.disabled ? 'cursor-not-allowed' : '',
      isGradient && isOutline ? 'p-0.5' : sizeClasses.value,
      (slots.prefix || slots.suffix || props.loading) ? 'inline-flex items-center' : '',
    )
  })

  const spanClasses = computed(() => {
    if (!!props.gradient && props.outline) return classNames('relative transition-all ease-in duration-75 bg-white dark:bg-gray-900 rounded-md group-hover:bg-opacity-0', sizeClasses.value)
    return ''
  })

  return {
    wrapperClasses: bindClasses,
    spanClasses,
  }
}