<template>
  <div class="upload-file">
    <el-upload 
      multiple 
      :action="uploadFileUrl" 
      :before-upload="handleBeforeUpload" 
      :file-list="fileList" 
      :limit="limit"
      :on-error="handleUploadError" 
      :on-exceed="handleExceed" 
      :on-success="handleUploadSuccess" 
      :on-remove="handleFileRemove"
      :show-file-list="true"
      :headers="headers" 
      class="upload-file-uploader" 
      ref="fileUpload"
    >
      <!-- 上传按钮 -->
      <el-button type="primary">选取文件</el-button>
      <!-- 上传提示 -->
      <template #tip>
        <div class="el-upload__tip" v-if="showTip">
          请上传
          <template v-if="fileSize"> 大小不超过 <b style="color: #f56c6c">{{ fileSize }}MB</b> </template>
          <template v-if="fileType"> 格式为 <b style="color: #f56c6c">{{ fileType.join("/") }}</b> </template>
          的文件
        </div>
      </template>
    </el-upload>
    
    <!-- 自定义文件列表（可选，取决于是否需要自定义文件列表） -->
    <template v-if="false">
      <transition-group class="upload-file-list el-upload-list el-upload-list--text" name="el-fade-in-linear" tag="ul">
        <li :key="file.uid" class="el-upload-list__item ele-upload-list__item-content" v-for="(file, index) in fileList">
          <el-button link :href="`${baseUrl}${file.url}`" target="_blank">
            <span class="el-icon-document"> {{ getFileName(file.name) }} </span>
          </el-button>
          <div class="ele-upload-list__item-content-action">
            <el-button link @click="handleDelete(index)" type="danger">删除</el-button>
          </div>
        </li>
      </transition-group>
    </template>
  </div>
</template>

<script setup>
import { getToken } from "@/utils/auth";
import { ref, computed, watch, getCurrentInstance } from 'vue';

const props = defineProps({
  modelValue: [String, Object, Array],
  // 数量限制
  limit: {
    type: Number,
    default: 5,
  },
  // 大小限制(MB)
  fileSize: {
    type: Number,
    default: 100,
  },
  // 文件类型, 例如['png', 'jpg', 'jpeg']
  fileType: {
    type: Array,
    default: () => ["doc", "xls", "ppt", "txt", "pdf"],
  },
  // 是否显示提示
  isShowTip: {
    type: Boolean,
    default: true
  },
  // 新增：自定义上传地址
  uploadFileUrl: {
    type: String,
    default: ''
  }
});

const { proxy } = getCurrentInstance();
const emit = defineEmits();
const number = ref(0);
const uploadList = ref([]);
const baseUrl = import.meta.env.VITE_APP_BASE_API;
const uploadFileUrl = computed(() => {
  // 优先使用外部传入的 uploadFileUrl 属性
  if (props.uploadFileUrl) {
    return props.uploadFileUrl;
  }
  return baseUrl + "/common/upload"; // 修改为通用上传接口
});
const headers = ref({ Authorization: "Bearer " + getToken() });
const fileList = ref([]);
const showTip = computed(
  () => props.isShowTip && (props.fileType || props.fileSize)
);

watch(() => props.modelValue, val => {
  if (val) {
    let temp = 1;
    try {
      // 首先将值转为数组
      let list = [];
      if (typeof val === 'string') {
        // 尝试解析为JSON
        try {
          const parsedValue = JSON.parse(val);
          list = Array.isArray(parsedValue) ? parsedValue : [parsedValue];
        } catch (e) {
          // 不是有效的JSON，按逗号分隔处理
          list = val.split(',');
        }
      } else if (Array.isArray(val)) {
        list = val;
      } else {
        list = [val];
      }
      
      // 然后将数组转为对象数组
      fileList.value = list.map(item => {
        if (typeof item === "string") {
          item = { name: getFileName(item), url: item };
        }
        item.uid = item.uid || new Date().getTime() + temp++;
        return item;
      });
    } catch (error) {
      console.error('解析文件列表失败:', error);
      fileList.value = [];
    }
  } else {
    fileList.value = [];
  }
}, { deep: true, immediate: true });

// 上传前校检格式和大小
function handleBeforeUpload(file) {
  // 校检文件类型
  if (props.fileType.length) {
    const fileName = file.name.split('.');
    const fileExt = fileName[fileName.length - 1].toLowerCase();
    const isTypeOk = props.fileType.some(type => 
      type.toLowerCase() === fileExt
    );
    if (!isTypeOk) {
      proxy.$modal.msgError(`文件格式不正确, 请上传${props.fileType.join("/")}格式文件!`);
      return false;
    }
  }
  // 校检文件大小
  if (props.fileSize) {
    const isLt = file.size / 1024 / 1024 < props.fileSize;
    if (!isLt) {
      proxy.$modal.msgError(`上传文件大小不能超过 ${props.fileSize} MB!`);
      return false;
    }
  }
  proxy.$modal.loading("正在上传文件，请稍候...");
  number.value++;
  return true;
}

// 文件个数超出
function handleExceed() {
  proxy.$modal.msgError(`上传文件数量不能超过 ${props.limit} 个!`);
}

// 上传失败
function handleUploadError(err) {
  number.value--;
  proxy.$modal.closeLoading();
  proxy.$modal.msgError("上传文件失败: " + (err.message || '未知错误'));
}

// El-Upload自带的文件移除事件
function handleFileRemove(file) {
  handleDelete(fileList.value.findIndex(item => item.uid === file.uid));
}

// 上传成功回调
function handleUploadSuccess(res, file) {
  if (res.code === 200) {
    uploadList.value.push({ 
      name: res.fileName || res.originalFilename || file.name,
      url: res.url 
    });
    uploadedSuccessfully();
  } else {
    number.value--;
    proxy.$modal.closeLoading();
    proxy.$modal.msgError(res.msg || '上传失败');
    proxy.$refs.fileUpload.handleRemove(file);
    uploadedSuccessfully();
  }
}

// 删除文件
function handleDelete(index) {
  if (index < 0 || index >= fileList.value.length) {
    return;
  }
  
  // 获取要删除的文件路径
  const file = fileList.value[index];
  if (!file || !file.url) {
    return;
  }
  
  // 确认删除
  proxy.$modal.confirm('确定要删除该文件吗？').then(() => {
    // 显示加载中
    proxy.$modal.loading("删除文件中，请稍候...");
    
    // 如果存在删除附件的API，调用它
    if (window.deleteAttachment) {
      window.deleteAttachment(file.url).then(() => {
        // 从前端列表中移除
        fileList.value.splice(index, 1);
        emit("update:modelValue", listToString(fileList.value));
        proxy.$modal.closeLoading();
        proxy.$modal.msgSuccess("删除成功");
      }).catch(error => {
        console.error("删除文件失败:", error);
        proxy.$modal.closeLoading();
        proxy.$modal.msgError("删除失败: " + (error.message || "未知错误"));
      });
    } else {
      // 仅从前端列表中移除
      fileList.value.splice(index, 1);
      emit("update:modelValue", listToString(fileList.value));
      proxy.$modal.closeLoading();
      proxy.$modal.msgSuccess("文件已从列表中移除");
    }
  }).catch(() => {
    // 取消删除
  });
}

// 上传结束处理
function uploadedSuccessfully() {
  if (number.value > 0 && uploadList.value.length === number.value) {
    fileList.value = fileList.value.filter(f => f.url !== undefined).concat(uploadList.value);
    uploadList.value = [];
    number.value = 0;
    emit("update:modelValue", listToString(fileList.value));
    proxy.$modal.closeLoading();
  }
}

// 获取文件名称
function getFileName(name) {
  if (!name) return '';
  if (name.lastIndexOf("/") > -1) {
    return name.slice(name.lastIndexOf("/") + 1);
  } else {
    return name;
  }
}

// 对象转成指定字符串分隔
function listToString(list, separator) {
  // 构建JSON数组
  const fileDataArray = list.map(item => ({
    name: item.name || getFileName(item.url),
    url: item.url
  }));
  
  // 返回JSON字符串
  return JSON.stringify(fileDataArray);
}
</script>

<style scoped lang="scss">
.upload-file-uploader {
  margin-bottom: 5px;
}

.upload-file-list .el-upload-list__item {
  border: 1px solid #e4e7ed;
  line-height: 2;
  margin-bottom: 10px;
  position: relative;
}

.upload-file-list .ele-upload-list__item-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: inherit;
}

.ele-upload-list__item-content-action .el-link {
  margin-right: 10px;
}
</style>
