<template>
  <div class="row form-group" :key="$attrs.key">
    <label :for="localFormElement?.key" class="col-md-3">{{
      localFormElement?.label
    }}:</label>

    <div v-if="isInitial" class="dropbox">
      <input
        type="file"
        multiple
        :name="uploadFieldName"
        :disabled="isSaving"
        @change="
          filesChange($event.target.name, $event.target.files);
          fileCount = $event.target.files.length;
        "
        accept="image/*"
        class="input-file"
      />
      <p v-if="isInitial">
        Drag your file(s) here to begin<br />
        or click to browse
      </p>
      <p v-if="isSaving">Uploading {{ fileCount }} files...</p>
    </div>

    <!--SUCCESS-->
    <div v-if="isSuccess">
      <h2>{{ uploadedFiles.length }} فایل با موفقیت آپلود شد.</h2>
      <p>
        <a href="javascript:void(0)" @click="reset()">فایل جدید</a>
      </p>
      <ul class="list-unstyled">
        <li v-for="item in uploadedFiles">
          <img
            :src="item.url"
            class="img-responsive img-thumbnail"
            :alt="item.originalName"
          />
        </li>
      </ul>
    </div>
    <!--FAILED-->
    <div v-if="isFailed">
      <h2>آپلود فایل ناموفق بود.</h2>
      <p>
        <a href="javascript:void(0)" @click="reset()">تلاش مجدد</a>
      </p>
      <pre>{{ uploadError }}</pre>
    </div>
  </div>
</template>

<script>
const STATUS_INITIAL = 0,
  STATUS_SAVING = 1,
  STATUS_SUCCESS = 2,
  STATUS_FAILED = 3;

import { upload } from "@services/fileUploadService";
import { wait } from "@utilities/utilities.js";

import formBuilderMixin from "@mixins/formBuilderMixin";
export default {
  mixins: [formBuilderMixin],
  mounted() {
    this.reset();
  },
  data() {
    return {
      uploadedFiles: [],
      uploadError: null,
      currentStatus: null,
      uploadFieldName: "photos",
    };
  },
  computed: {
    isInitial() {
      return this.currentStatus === STATUS_INITIAL;
    },
    isSaving() {
      return this.currentStatus === STATUS_SAVING;
    },
    isSuccess() {
      return this.currentStatus === STATUS_SUCCESS;
    },
    isFailed() {
      return this.currentStatus === STATUS_FAILED;
    },
  },
  methods: {
    filesChange(fieldName, fileList) {
      // handle file changes
      const formData = new FormData();

      if (!fileList.length) return;

      // append the files to FormData
      Array.from(Array(fileList.length).keys()).map((x) => {
        formData.append(fieldName, fileList[x], fileList[x].name);
      });

      // save it
      this.save(formData);
    },
    save(formData) {
      // upload data to the server
      this.currentStatus = STATUS_SAVING;

      upload(formData)
        .then(wait(1500)) // DEV ONLY: wait for 1.5s
        .then((x) => {
          this.uploadedFiles = [].concat(x);
          this.currentStatus = STATUS_SUCCESS;
        })
        .catch((err) => {
          this.uploadError = err.response;
          this.currentStatus = STATUS_FAILED;
        });
    },
    reset() {
      // reset form to initial state
      this.currentStatus = STATUS_INITIAL;
      this.uploadedFiles = [];
      this.uploadError = null;
    },
  },
};
</script>

<!-- SASS styling -->
<style lang="scss">
.dropbox {
  outline: 2px dashed grey; /* the dash box */
  outline-offset: -10px;
  background: lightcyan; 
  color: dimgray;
  padding: 10px 10px;
  min-height: 200px; /* minimum height */
  position: relative;
  cursor: pointer;
}

.input-file {
  opacity: 0; /* invisible but it's there! */
  width: 100%;
  height: 200px;
  position: absolute;
  cursor: pointer;
}

.dropbox:hover {
  background: lightblue; /* when mouse over to the drop zone, change color */
}

.dropbox p {
  font-size: 1.2em;
  text-align: center;
  padding: 50px 0;
}
</style>
