import { on } from '../event'

const nodeList = []
const ctx = '@@clickoutsideContext'

let startClick
let seed = 0

on(document, 'mousedown', e => (startClick = e))

on(document, 'mouseup', e => {
  nodeList.forEach(node => node[ctx].documentHandler(e, startClick))
})

function createDocumentHandler (el, binding, vnode) {
  return function (mouseup = {}, mousedown = {}) {
    if (!vnode ||
      !vnode.context ||
      !mouseup.target ||
      !mousedown.target ||
      el.contains(mouseup.target) ||
      el.contains(mousedown.target) ||
      el === mouseup.target) return

    if (binding.expression &&
      el[ctx].methodName &&
      vnode.context[el[ctx].methodName]) {
      vnode.context[el[ctx].methodName]()
    } else {
      el[ctx].bindingFn && el[ctx].bindingFn()
    }
  }
}

export default {
  bind (el, binding, vnode) {
    nodeList.push(el)
    const id = seed++
    el[ctx] = {
      id,
      documentHandler: createDocumentHandler(el, binding, vnode),
      methodName: binding.expression,
      bindingFn: binding.value
    }
  },

  update (el, binding, vnode) {
    el[ctx].documentHandler = createDocumentHandler(el, binding, vnode)
    el[ctx].methodName = binding.expression
    el[ctx].bindingFn = binding.value
  },

  unbind (el) {
    const len = nodeList.length
    for (let i = 0; i < len; i++) {
      if (nodeList[i][ctx].id === el[ctx].id) {
        nodeList.splice(i, 1)
        break
      }
    }
    delete el[ctx]
  }
}
