import selectorParser from 'postcss-selector-parser'
import escapeCommas from './escapeCommas'
import { withAlphaValue } from './withAlphaVariable'
import isKeyframeRule from './isKeyframeRule'
import { parseColor } from './color'

export function applyPseudoToMarker(selector, marker, state, join) {
  let states = [state]

  let markerIdx = selector.indexOf(marker + ':')

  if (markerIdx !== -1) {
    let existingMarker = selector.slice(markerIdx, selector.indexOf(' ', markerIdx))

    states = states.concat(
      selector.slice(markerIdx + marker.length + 1, existingMarker.length).split(':')
    )

    selector = selector.replace(existingMarker, '')
  }

  return join(`${[marker, ...states].join(':')}`, selector)
}

export function updateAllClasses(selectors, updateClass) {
  let parser = selectorParser((selectors) => {
    selectors.walkClasses((sel) => {
      let updatedClass = updateClass(sel.value, {
        withPseudo(className, pseudo) {
          sel.parent.insertAfter(sel, selectorParser.pseudo({ value: `${pseudo}` }))
          return className
        },
      })
      sel.value = updatedClass
      if (sel.raws && sel.raws.value) {
        sel.raws.value = escapeCommas(sel.raws.value)
      }
    })
  })

  let result = parser.processSync(selectors)

  return result
}

export function updateLastClasses(selectors, updateClass) {
  let parser = selectorParser((selectors) => {
    selectors.each((sel) => {
      let lastClass = sel.filter(({ type }) => type === 'class').pop()

      if (lastClass === undefined) {
        return
      }

      let updatedClass = updateClass(lastClass.value, {
        withPseudo(className, pseudo) {
          lastClass.parent.insertAfter(lastClass, selectorParser.pseudo({ value: `${pseudo}` }))
          return className
        },
      })
      lastClass.value = updatedClass
      if (lastClass.raws && lastClass.raws.value) {
        lastClass.raws.value = escapeCommas(lastClass.raws.value)
      }
    })
  })
  let result = parser.processSync(selectors)

  return result
}

function splitByNotEscapedCommas(str) {
  let chunks = []
  let currentChunk = ''
  for (let i = 0; i < str.length; i++) {
    if (str[i] === ',' && str[i - 1] !== '\\') {
      chunks.push(currentChunk)
      currentChunk = ''
    } else {
      currentChunk += str[i]
    }
  }
  chunks.push(currentChunk)
  return chunks
}

export function transformAllSelectors(transformSelector, { wrap, withRule } = {}) {
  return ({ container }) => {
    container.walkRules((rule) => {
      if (isKeyframeRule(rule)) {
        return rule
      }
      let transformed = splitByNotEscapedCommas(rule.selector).map(transformSelector).join(',')
      rule.selector = transformed
      if (withRule) {
        withRule(rule)
      }
      return rule
    })

    if (wrap) {
      let wrapper = wrap()
      let nodes = container.nodes
      container.removeAll()
      wrapper.append(nodes)
      container.append(wrapper)
    }
  }
}

export function transformAllClasses(transformClass, { wrap, withRule } = {}) {
  return ({ container }) => {
    container.walkRules((rule) => {
      let selector = rule.selector
      let variantSelector = updateAllClasses(selector, transformClass)
      rule.selector = variantSelector
      if (withRule) {
        withRule(rule)
      }
      return rule
    })

    if (wrap) {
      let wrapper = wrap()
      let nodes = container.nodes
      container.removeAll()
      wrapper.append(nodes)
      container.append(wrapper)
    }
  }
}

export function transformLastClasses(transformClass, { wrap, withRule } = {}) {
  return ({ container }) => {
    container.walkRules((rule) => {
      let selector = rule.selector
      let variantSelector = updateLastClasses(selector, transformClass)
      rule.selector = variantSelector
      if (withRule) {
        withRule(rule)
      }
      return rule
    })

    if (wrap) {
      let wrapper = wrap()
      let nodes = container.nodes
      container.removeAll()
      wrapper.append(nodes)
      container.append(wrapper)
    }
  }
}

export function asValue(modifier, lookup = {}, { validate = () => true } = {}) {
  let value = lookup[modifier]

  if (value !== undefined) {
    return value
  }

  if (modifier[0] !== '[' || modifier[modifier.length - 1] !== ']') {
    return undefined
  }

  value = modifier.slice(1, -1)

  if (!validate(value)) {
    return undefined
  }

  // convert `_` to ` `, escept for escaped underscores `\_`
  value = value
    .replace(/([^\\])_/g, '$1 ')
    .replace(/^_/g, ' ')
    .replace(/\\_/g, '_')

  // Keep raw strings if it starts with `url(`
  if (value.startsWith('url(')) return value

  // add spaces around operators inside calc() that do not follow an operator or (
  return value.replace(
    /(-?\d*\.?\d(?!\b-.+[,)](?![^+\-/*])\D)(?:%|[a-z]+)?|\))([+\-/*])/g,
    '$1 $2 '
  )
}

export function asUnit(modifier, units, lookup = {}) {
  return asValue(modifier, lookup, {
    validate: (value) => {
      let unitsPattern = `(?:${units.join('|')})`
      return (
        new RegExp(`${unitsPattern}$`).test(value) ||
        new RegExp(`^calc\\(.+?${unitsPattern}`).test(value)
      )
    },
  })
}

function isArbitraryValue(input) {
  return input.startsWith('[') && input.endsWith(']')
}

function splitAlpha(modifier) {
  let slashIdx = modifier.lastIndexOf('/')

  if (slashIdx === -1 || slashIdx === modifier.length - 1) {
    return [modifier]
  }

  return [modifier.slice(0, slashIdx), modifier.slice(slashIdx + 1)]
}

export function asColor(modifier, lookup = {}, tailwindConfig = {}) {
  if (lookup[modifier] !== undefined) {
    return lookup[modifier]
  }

  let [color, alpha] = splitAlpha(modifier)

  if (lookup[color] !== undefined) {
    if (isArbitraryValue(alpha)) {
      return withAlphaValue(lookup[color], alpha.slice(1, -1))
    }

    if (tailwindConfig.theme?.opacity?.[alpha] === undefined) {
      return undefined
    }

    return withAlphaValue(lookup[color], tailwindConfig.theme.opacity[alpha])
  }

  return asValue(modifier, lookup, {
    validate: (value) => parseColor(value) !== null,
  })
}

export function asAngle(modifier, lookup = {}) {
  return asUnit(modifier, ['deg', 'grad', 'rad', 'turn'], lookup)
}

export function asURL(modifier, lookup = {}) {
  return asValue(modifier, lookup, {
    validate: (value) => value.startsWith('url('),
  })
}

export function asLength(modifier, lookup = {}) {
  return asUnit(
    modifier,
    [
      'cm',
      'mm',
      'Q',
      'in',
      'pc',
      'pt',
      'px',
      'em',
      'ex',
      'ch',
      'rem',
      'lh',
      'vw',
      'vh',
      'vmin',
      'vmax',
      '%',
    ],
    lookup
  )
}

export function asLookupValue(modifier, lookup = {}) {
  return lookup[modifier]
}

let typeMap = {
  any: asValue,
  color: asColor,
  angle: asAngle,
  length: asLength,
  url: asURL,
  lookup: asLookupValue,
}

function splitAtFirst(input, delim) {
  return (([first, ...rest]) => [first, rest.join(delim)])(input.split(delim))
}

export function coerceValue(type, modifier, values, tailwindConfig) {
  let [scaleType, arbitraryType = scaleType] = [].concat(type)

  if (isArbitraryValue(modifier)) {
    let [explicitType, value] = splitAtFirst(modifier.slice(1, -1), ':')

    if (value.length > 0 && Object.keys(typeMap).includes(explicitType)) {
      return [asValue(`[${value}]`, values, tailwindConfig), explicitType]
    }

    return [typeMap[arbitraryType](modifier, values, tailwindConfig), arbitraryType]
  }

  return [typeMap[scaleType](modifier, values, tailwindConfig), scaleType]
}