<template>
    <div>
        <div>
            <div class="layoutJSON">
                Displayed as <code>[x, y, w, h]</code>:
                <div class="columns">
                    <div class="layoutItem" v-for="item in layout">
                        <b>{{ item.i }}</b>: [{{ item.x }}, {{ item.y }}, {{ item.w }}, {{ item.h }}]
                    </div>
                </div>
            </div>
        </div>
        <br/>
        <div @drag="drag" @dragend="dragend" class="droppable-element" draggable="true"
             unselectable="on">Droppable Element (Drag me!)</div>
        <div id="content">
            <grid-layout ref="gridlayout" :layout.sync="layout"
                         :col-num="12"
                         :row-height="30"
                         :is-draggable="true"
                         :is-resizable="true"
                         :vertical-compact="true"
                         :use-css-transforms="true"
            >
                <grid-item :key="item.i" v-for="item in layout"
                           :x="item.x"
                           :y="item.y"
                           :w="item.w"
                           :h="item.h"
                           :i="item.i"
                >
                    <span class="text">{{ item.i }}</span>
                </grid-item>
            </grid-layout>
        </div>
    </div>
</template>

<script setup>
import { ref, onMounted, unref, getCurrentInstance, defineExpose } from 'vue'

const ctx = getCurrentInstance().ctx
let mouseXY = { x: null, y: null }
let DragPos = { x: null, y: null, w: 1, h: 1, i: null }
let colNum = 10
const gridlayout = ref(null)
const gridItemRefs = ref([])
const getGridItemRef = (el, index) => {
  if (el) {
    gridItemRefs.value[index] = el
  }
}

const layout = ref([
  { x: 0, y: 0, w: 10, h: 1, i: '0' },
  { x: 0, y: 0, w: 10, h: 2, i: '1' },
  { x: 0, y: 0, w: 2, h: 3, i: '2' },
  { x: 0, y: 0, w: 2, h: 4, i: '3' },
  { x: 0, y: 0, w: 2, h: 5, i: '4' },
  { x: 0, y: 0, w: 2, h: 6, i: '5' },
])

onMounted(() => {
  document.addEventListener(
    'dragover',
    function (e) {
      mouseXY.x = e.clientX
      mouseXY.y = e.clientY
    },
    false,
  )
})

function removeItem(val) {
  const layoutUnref = unref(layout)
  const index = layoutUnref.map((item) => item.i).indexOf(val)
  this.layout.splice(index, 1)
}

function clickGridItem(item) {
  console.log(item)
}

function drag() {
  const layoutUnref = unref(layout)
  let parentRect = document.getElementById('content').getBoundingClientRect()
  let mouseInGrid = false
  if (
    mouseXY.x > parentRect.left &&
    mouseXY.x < parentRect.right &&
    mouseXY.y > parentRect.top &&
    mouseXY.y < parentRect.bottom
  ) {
    mouseInGrid = true
  }
  if (mouseInGrid === true && layoutUnref.findIndex((item) => item.i === 'drop') === -1) {
    layoutUnref.push({
      x: (layoutUnref.length * 2) % (colNum || 12),
      y: layoutUnref.length + (colNum || 12), // puts it at the bottom
      w: 1,
      h: 1,
      i: 'drop',
    })
  }
  let index = layoutUnref.findIndex((item) => item.i === 'drop')
  if (index !== -1) {
    try {
      gridItemRefs.value[layoutUnref.length].style.display = 'none'
    } catch {}
    let el = gridItemRefs.value[index]

    if (mouseInGrid === true && el) {
      el.dragging = { top: mouseXY.y - parentRect.top, left: mouseXY.x - parentRect.left }

      let new_pos = el.calcXY(mouseXY.y - parentRect.top, mouseXY.x - parentRect.left)
      gridlayout.value.dragEvent('dragstart', 'drop', new_pos.x, new_pos.y, 1, 1)
      DragPos.i = String(index)
      DragPos.x = layoutUnref[index].x
      DragPos.y = layoutUnref[index].y
    }
    if (mouseInGrid === false) {
      gridlayout.value.dragEvent('dragend', 'drop', 1, 1, 1, 1)
      layout.value = layoutUnref.filter((obj) => obj.i !== 'drop')
    }
  }
}
function dragend() {
  const layoutUnref = unref(layout)
  let parentRect = document.getElementById('content').getBoundingClientRect()
  let mouseInGrid = false
  if (
    mouseXY.x > parentRect.left &&
    mouseXY.x < parentRect.right &&
    mouseXY.y > parentRect.top &&
    mouseXY.y < parentRect.bottom
  ) {
    mouseInGrid = true
  }
  if (mouseInGrid === true) {
    gridlayout.value.dragEvent('dragend', 'drop', DragPos.x, DragPos.y, 1, 1)
    layout.value = layoutUnref.filter((obj) => obj.i !== 'drop')

    layout.value.push({
      x: DragPos.x,
      y: DragPos.y,
      w: componentInfo?.w ?? 1,
      h: componentInfo?.h ?? 1,
      i: DragPos.i,
    })
    console.log(layout.value)
    // gridlayout.value.dragEvent('dragend', DragPos.i, DragPos.x, DragPos.y, 1, 1)
    // try {
    //   gridItemRefs.value[layoutUnref.length].style.display = 'block'
    // } catch {}
  }
}

defineExpose({
  drag,
  dragend,
})
</script>

<style scoped>

.droppable-element {
    width: 150px;
    text-align: center;
    background: #fdd;
    border: 1px solid black;
    margin: 10px 0;
    padding: 10px;
}


.vue-grid-layout {
    background: #eee;
}

.vue-grid-item:not(.vue-grid-placeholder) {
    background: #ccc;
    border: 1px solid black;
}

.vue-grid-item .resizing {
    opacity: 0.9;
}

.vue-grid-item .static {
    background: #cce;
}

.vue-grid-item .text {
    font-size: 24px;
    text-align: center;
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    margin: auto;
    height: 100%;
    width: 100%;
}

.vue-grid-item .no-drag {
    height: 100%;
    width: 100%;
}

.vue-grid-item .minMax {
    font-size: 12px;
}

.vue-grid-item .add {
    cursor: pointer;
}

.vue-draggable-handle {
    position: absolute;
    width: 20px;
    height: 20px;
    top: 0;
    left: 0;
    background: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='10' height='10'><circle cx='5' cy='5' r='5' fill='#999999'/></svg>") no-repeat;
    background-position: bottom right;
    padding: 0 8px 8px 0;
    background-repeat: no-repeat;
    background-origin: content-box;
    box-sizing: border-box;
    cursor: pointer;
}

.layoutJSON {
    background: #ddd;
    border: 1px solid black;
    margin-top: 10px;
    padding: 10px;
}

.layoutJSON {
    background: #ddd;
    border: 1px solid black;
    margin-top: 10px;
    padding: 10px;
}

.columns {
    -moz-columns: 120px;
    -webkit-columns: 120px;
    columns: 120px;
}
</style>