<template>
  <div style="margin-top: 16px">
    <a-form-model-item label="消息实例">
      <div style="display: flex; align-items: center; justify-content: space-between; flex-wrap: nowrap">
        <a-select v-model="bindMessageId" @change="updateTaskMessage">
          <el-option v-for="id in Object.keys(messageMap)" :value="id" :label="messageMap[id]" :key="id" />
        </a-select>
        <a-button size="small" type="primary" icon="el-icon-plus" style="margin-left: 8px" @click="openMessageModel" />
      </div>
    </a-form-model-item>
    <a-modal class="bpmn-design-modal" :visible.sync="messageModelVisible" title="创建新消息" @cancel="() => this.messageModelVisible = false" width="400px" destroy-on-close>
      <a-form-model :model="newMessageForm" :label-col="labelCol" :wrapper-col="wrapperCol" @submit.native.prevent>
        <a-form-model-item label="消息ID">
          <a-input v-model="newMessageForm.id" clearable />
        </a-form-model-item>
        <a-form-model-item label="消息名称">
          <a-input v-model="newMessageForm.name" clearable />
        </a-form-model-item>
      </a-form-model>
      <template slot="footer">
        <a-button size="small" type="primary" @click="createNewMessage">确 认</a-button>
      </template>
    </a-modal>
  </div>
</template>

<script>
export default {
  name: 'ReceiveTask',
  props: {
    id: String,
    type: String
  },
  data() {
    return {
      bindMessageId: '',
      newMessageForm: {},
      messageMap: {},
      messageModelVisible: false,
      labelCol: { span: 6 },
      wrapperCol: { span: 17 }
    }
  },
  watch: {
    id: {
      immediate: true,
      handler() {
        this.$nextTick(() => this.getBindMessage())
      }
    }
  },
  created() {
    this.bpmnMessageRefsMap = Object.create(null)
    this.bpmnRootElements = window.bpmnInstances.modeler.getDefinitions().rootElements
    this.bpmnRootElements
      .filter(el => el.$type === 'bpmn:Message')
      .forEach(m => {
        this.bpmnMessageRefsMap[m.id] = m
        this.$set(this.messageMap, m.id, m.name)
      })
    this.$set(this.messageMap, '-1', '无') // 添加一个空对象，保证可以取消原消息绑定
  },
  methods: {
    getBindMessage() {
      this.bpmnElement = window.bpmnInstances.bpmnElement
      this.bindMessageId = this.bpmnElement.businessObject?.messageRef?.id || '-1'
    },
    openMessageModel() {
      this.messageModelVisible = true
      this.newMessageForm = {}
    },
    createNewMessage() {
      if (this.messageMap[this.newMessageForm.id]) {
        this.$message.error('该消息已存在，请修改id后重新保存')
        return
      }
      const newMessage = window.bpmnInstances.moddle.create('bpmn:Message', this.newMessageForm)
      this.bpmnRootElements.push(newMessage)
      this.$set(this.messageMap, this.newMessageForm.id, this.newMessageForm.name)
      this.bpmnMessageRefsMap[this.newMessageForm.id] = newMessage
      this.messageModelVisible = false
    },
    updateTaskMessage(messageId) {
      if (messageId === '-1') {
        window.bpmnInstances.modeling.updateProperties(this.bpmnElement, {
          messageRef: null
        })
      } else {
        window.bpmnInstances.modeling.updateProperties(this.bpmnElement, {
          messageRef: this.bpmnMessageRefsMap[messageId]
        })
      }
    }
  },
  beforeDestroy() {
    this.bpmnElement = null
  }
}
</script>
