nuxt-app/app/components/agent/AgentSwitcher.vue

<script setup lang="ts">
interface AgentInfo {
  slug: string;
  name: string;
  description?: string | null;
}

const props = defineProps<{
  currentSlug: string;
}>();

const emit = defineEmits<{
  switch: [slug: string];
}>();

const open = ref(false);
const agents = ref<AgentInfo[]>([]);
const loading = ref(false);
const dropdownRef = ref<HTMLElement | null>(null);

const currentAgent = computed(() =>
  agents.value.find((a) => a.slug === props.currentSlug) ?? null,
);
const displayName = computed(() => currentAgent.value?.name ?? "智能助手");

async function loadAgents() {
  loading.value = true;
  try {
    const res = await $fetch<{ code: number; data: { list: AgentInfo[] } }>("/api/agents");
    agents.value = res.data?.list ?? [];
  } catch {
    agents.value = [];
  } finally {
    loading.value = false;
  }
}

function toggle() {
  if (!open.value && agents.value.length === 0) {
    loadAgents();
  }
  open.value = !open.value;
}

function pick(slug: string) {
  open.value = false;
  if (slug !== props.currentSlug) {
    emit("switch", slug);
  }
}

function handleClickOutside(e: MouseEvent) {
  if (dropdownRef.value && !dropdownRef.value.contains(e.target as Node)) {
    open.value = false;
  }
}

onMounted(() => {
  document.addEventListener("click", handleClickOutside);
});

onBeforeUnmount(() => {
  document.removeEventListener("click", handleClickOutside);
});
</script>

<template>
  <div ref="dropdownRef" class="agent-switcher">
    <button class="switcher-trigger" :class="{ active: open }" @click="toggle">
      <Icon name="lucide:bot" class="trigger-icon" />
      <span class="trigger-name">{{ displayName }}</span>
      <Icon name="lucide:chevron-down" class="trigger-arrow" :class="{ rotated: open }" />
    </button>

    <Transition name="dropdown">
      <div v-if="open" class="switcher-dropdown">
        <div v-if="loading" class="dropdown-loading">加载中…</div>
        <template v-else>
          <button
            v-for="a in agents"
            :key="a.slug"
            class="dropdown-item"
            :class="{ selected: a.slug === currentSlug }"
            @click="pick(a.slug)"
          >
            <Icon
              :name="a.slug === currentSlug ? 'lucide:check' : 'lucide:bot'"
              class="item-icon"
            />
            <div class="item-meta">
              <div class="item-name">{{ a.name }}</div>
              <div v-if="a.description" class="item-desc">{{ a.description }}</div>
            </div>
          </button>
          <div v-if="agents.length === 0" class="dropdown-empty">暂无可用 agent</div>
        </template>
      </div>
    </Transition>
  </div>
</template>

<style scoped>
.agent-switcher {
  position: relative;
  flex-shrink: 0;
}

.switcher-trigger {
  display: flex;
  align-items: center;
  gap: 8px;
  width: 100%;
  padding: 8px 10px;
  background: var(--color-surface-card);
  border: 1px solid var(--color-hairline);
  border-radius: 10px;
  font-size: 13px;
  font-weight: 500;
  color: var(--color-ink);
  cursor: pointer;
  transition: all 0.15s;
}

.switcher-trigger:hover {
  border-color: var(--color-primary);
  background: var(--color-canvas);
}

.switcher-trigger.active {
  border-color: var(--color-primary);
}

.trigger-icon {
  font-size: 15px;
  color: var(--color-primary);
  flex-shrink: 0;
}

.trigger-name {
  flex: 1;
  text-align: left;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.trigger-arrow {
  font-size: 14px;
  color: var(--color-muted);
  flex-shrink: 0;
  transition: transform 0.2s;
}

.trigger-arrow.rotated {
  transform: rotate(180deg);
}

.switcher-dropdown {
  position: absolute;
  top: calc(100% + 4px);
  left: 0;
  right: 0;
  background: var(--color-canvas);
  border: 1px solid var(--color-hairline);
  border-radius: 10px;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
  z-index: 50;
  max-height: 320px;
  overflow-y: auto;
  padding: 4px;
}

.dropdown-loading,
.dropdown-empty {
  padding: 16px;
  text-align: center;
  font-size: 13px;
  color: var(--color-muted);
}

.dropdown-item {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  width: 100%;
  padding: 8px 10px;
  border: none;
  background: none;
  border-radius: 8px;
  cursor: pointer;
  text-align: left;
  transition: background 0.12s;
}

.dropdown-item:hover {
  background: var(--color-surface-soft);
}

.dropdown-item.selected {
  background: var(--color-surface-soft);
}

.item-icon {
  font-size: 15px;
  color: var(--color-primary);
  flex-shrink: 0;
  margin-top: 1px;
}

.dropdown-item.selected .item-icon {
  color: var(--color-primary);
}

.item-meta {
  flex: 1;
  min-width: 0;
}

.item-name {
  font-size: 13px;
  font-weight: 500;
  color: var(--color-ink);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.item-desc {
  font-size: 11px;
  color: var(--color-muted);
  margin-top: 2px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.dropdown-enter-active,
.dropdown-leave-active {
  transition: opacity 0.15s, transform 0.15s;
}

.dropdown-enter-from,
.dropdown-leave-to {
  opacity: 0;
  transform: translateY(-4px);
}
</style>