<template>
  <div class="kole-upload">
    <div class="kole-upload-drop" :class="{ 'is-over': over }" @click="$refs.file.click()" @dragover.prevent="over = true" @dragleave="over = false" @drop.prevent="onDrop">
      <span class="kole-upload-icon">⬆️</span>
      <div class="kole-upload-hint">将文件拖到此处，或 <b>点击选择</b></div>
    </div>
    <input ref="file" type="file" multiple style="display:none" @change="onChange" />
    <div class="kole-upload-list">
      <div v-for="it in files" :key="it.id" class="kole-upload-item">
        <div class="kole-upload-thumb"><img v-if="it.thumb" :src="it.thumb" /><span v-else>文件</span></div>
        <div class="kole-upload-meta">
          <div class="kole-upload-name">{{ it.name }}</div>
          <div class="kole-upload-bar"><i :style="{ width: it.progress + '%' }"></i></div>
        </div>
        <div class="kole-upload-status">{{ it.done ? '已完成' : Math.round(it.progress) + '%' }}</div>
        <button class="kole-upload-del" @click="remove(it.id)">×</button>
      </div>
    </div>
  </div>
</template>

<script>
export default {
  name: 'KoleDragUpload',
  data() {
    return { files: [], over: false };
  },
  methods: {
    addFiles(flist) {
      var self = this;
      Array.prototype.forEach.call(flist, function (f) {
        var id = 'f' + Date.now() + Math.random().toString(36).slice(2, 6);
        var item = { id: id, name: f.name, progress: 0, done: false, thumb: '' };
        if (/^image\//.test(f.type) && f.size < 2 * 1024 * 1024) {
          var reader = new FileReader();
          reader.onload = function (e) { item.thumb = e.target.result; };
          reader.readAsDataURL(f);
        }
        self.files.push(item);
        self.simulate(item);
      });
    },
    onChange(e) { this.addFiles(e.target.files); e.target.value = ''; },
    onDrop(e) { this.over = false; this.addFiles(e.dataTransfer.files); },
    simulate(item) {
      var t = setInterval(function () {
        item.progress = Math.min(100, item.progress + Math.random() * 22);
        if (item.progress >= 100) { item.progress = 100; item.done = true; clearInterval(t); }
      }, 220);
    },
    remove(id) { this.files = this.files.filter(function (x) { return x.id !== id; }); }
  }
};
</script>

<style src="./DragUpload.css"></style>
