<template>
  <div class="kole-mention" ref="root">
    <div class="kole-mention-area">
      <textarea
        ref="input"
        class="kole-mention-input"
        :value="modelValue"
        rows="3"
        placeholder="输入 @ 提及同事…"
        @input="onInput"
        @keydown.down.prevent="move(1)"
        @keydown.up.prevent="move(-1)"
        @keydown.enter.prevent="enter"
        @keydown.esc="close"
      ></textarea>
      <div v-show="open" class="kole-mention-panel">
        <div
          v-for="(u, i) in users"
          :key="u.name"
          class="kole-mention-item"
          :class="{ 'is-active': i === active }"
          @click="insert(u.name)"
        >
          <span class="kole-mention-avatar">{{ u.name[0] }}</span>
          <span class="kole-mention-name">{{ u.name }}</span>
          <span class="kole-mention-dept">{{ u.dept }}</span>
        </div>
      </div>
    </div>
    <div class="kole-mention-chips">
      <span v-for="n in mentioned" :key="n" class="kole-mention-chip">@{{ n }} <b @click="remove(n)">×</b></span>
    </div>
  </div>
</template>

<script setup>
import { ref, onMounted, onBeforeUnmount } from 'vue';

const props = defineProps({
  modelValue: { type: String, default: '' },
  users: {
    type: Array,
    default: () => [
      { name: '王伟', dept: '华东大区' }, { name: '李娜', dept: '华南大区' }, { name: '张强', dept: '华北大区' },
      { name: '陈静', dept: '研发中心' }, { name: '刘洋', dept: '市场部' }
    ]
  }
});
const emit = defineEmits(['update:modelValue']);
const root = ref(null);
const input = ref(null);
const open = ref(false);
const active = ref(-1);
const mentioned = ref([]);

function onInput(e) {
  const pos = e.target.selectionStart, v = e.target.value;
  emit('update:modelValue', v);
  const at = v.lastIndexOf('@', pos - 1);
  if (at >= 0 && (at === 0 || /\s/.test(v[at - 1])) && !/\s/.test(v.slice(at + 1, pos))) { active.value = -1; open.value = true; }
  else open.value = false;
}
function move(d) { active.value = Math.max(-1, Math.min(props.users.length - 1, active.value + d)); }
function enter() { if (active.value >= 0) insert(props.users[active.value].name); }
function insert(name) {
  const el = input.value, pos = el.selectionStart, v = el.value;
  const at = v.lastIndexOf('@', pos - 1);
  if (at >= 0 && (at === 0 || /\s/.test(v[at - 1]))) el.value = v.slice(0, at) + '@' + name + ' ' + v.slice(pos);
  else el.value = v.slice(0, pos) + '@' + name + ' ' + v.slice(pos);
  if (mentioned.value.indexOf(name) < 0) mentioned.value.push(name);
  emit('update:modelValue', el.value);
  open.value = false;
  el.focus();
}
function remove(n) { mentioned.value = mentioned.value.filter((x) => x !== n); }
function close() { open.value = false; }
function onDoc(e) { if (root.value && !root.value.contains(e.target)) close(); }
onMounted(() => document.addEventListener('click', onDoc));
onBeforeUnmount(() => document.removeEventListener('click', onDoc));
</script>

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