import type { Dom } from '../dom'

export type ModifierKey = 'alt' | 'ctrl' | 'meta' | 'shift' | 'space'

export function parseModifierKey(modifiers: string | ModifierKey[]) {
  const or: ModifierKey[] = []
  const and: ModifierKey[] = []

  if (Array.isArray(modifiers)) {
    or.push(...modifiers)
  } else {
    modifiers.split('|').forEach((item) => {
      if (item.indexOf('&') === -1) {
        or.push(item as ModifierKey)
      } else {
        and.push(...(item.split('&') as ModifierKey[]))
      }
    })
  }

  return { or, and }
}

export function isModifierKeyEqual(
  modifiers1?: string | ModifierKey[] | null,
  modifiers2?: string | ModifierKey[] | null,
) {
  if (modifiers1 != null && modifiers2 != null) {
    const m1 = parseModifierKey(modifiers1)
    const m2 = parseModifierKey(modifiers2)
    const or1 = m1.or.sort()
    const or2 = m2.or.sort()
    const and1 = m1.and.sort()
    const and2 = m2.and.sort()

    const equal = (a1: ModifierKey[], a2: ModifierKey[]) => {
      return (
        a1.length === a2.length &&
        (a1.length === 0 || a1.every((a, i) => a === a2[i]))
      )
    }

    return equal(or1, or2) && equal(and1, and2)
  }

  if (modifiers1 == null && modifiers2 == null) {
    return true
  }

  return false
}

export function isModifierKeyMatch(
  e: Dom.EventObject | WheelEvent,
  modifiers?: string | ModifierKey[] | null,
  strict?: boolean,
) {
  if (
    modifiers == null ||
    (Array.isArray(modifiers) && modifiers.length === 0)
  ) {
    return strict
      ? e.altKey !== true &&
          e.ctrlKey !== true &&
          e.metaKey !== true &&
          e.shiftKey !== true
      : true
  }

  const { or, and } = parseModifierKey(modifiers)
  const match = (key: ModifierKey) => {
    const name = `${key.toLowerCase()}Key` as 'altKey'
    return e[name] === true
  }

  return or.some((key) => match(key)) && and.every((key) => match(key))
}