nuxt-app/app/components/chat/ChatWidget.vue

<script setup lang="ts">
/**
 * ChatWidget — floating chat button + panel in bottom-right corner.
 * Only visible to logged-in users. Shows unread badge for @mentions
 * and toast notifications when the author gets @mentioned.
 */
const { loggedIn, user } = useAuthSession()
const { $toast } = useNuxtApp()
const { lastMention } = useChat()

const open = ref(false)
const unread = ref(0)
let pollTimer: ReturnType<typeof setInterval> | null = null

// Watch for @mention notifications → toast (admin only, when panel closed)
watch(lastMention, (data) => {
  if (!data) return
  if (user.value?.role === 'admin' && !open.value) {
    $toast.info(`${data.from}: ${data.content}`, { autoClose: 5000 })
  }
  lastMention.value = null // always reset after handling
})

if (import.meta.client) {
  onMounted(() => {
    if (!loggedIn.value) return
    fetchUnread()
    pollTimer = setInterval(fetchUnread, 10_000)
  })

  onUnmounted(() => {
    if (pollTimer) clearInterval(pollTimer)
  })
}

watch(loggedIn, (val) => {
  if (val && !pollTimer) {
    fetchUnread()
    pollTimer = setInterval(fetchUnread, 10_000)
  } else if (!val && pollTimer) {
    clearInterval(pollTimer)
    pollTimer = null
  }
})

async function fetchUnread() {
  try {
    const res = await $fetch<{ code: number; data: { count: number } }>('/api/chat/unread', { credentials: 'include' })
    unread.value = res.data?.count || 0
  } catch { /* ignore */ }
}

async function clearUnread() {
  try {
    await $fetch('/api/chat/unread/clear', { method: 'POST', credentials: 'include' })
    unread.value = 0
  } catch { /* ignore */ }
}

function toggle() {
  open.value = !open.value
  if (open.value) {
    if (unread.value > 0) clearUnread()
    if (pollTimer) { clearInterval(pollTimer); pollTimer = null }
  } else {
    fetchUnread()
    pollTimer = setInterval(fetchUnread, 10_000)
  }
}
</script>

<template>
  <div v-if="loggedIn" class="chat-widget" :class="{ 'is-open': open }">
    <!-- Floating button -->
    <button class="widget-trigger" @click="toggle" :title="open ? '关闭聊天' : '打开聊天'">
      <span v-if="unread > 0" class="widget-badge">{{ unread > 99 ? '99+' : unread }}</span>
      <svg v-if="!open" width="22" height="22" viewBox="0 0 22 22" fill="none">
        <path d="M2 4h18v12H6l-4 4V4z" stroke="currentColor" stroke-width="1.6" stroke-linecap="round" stroke-linejoin="round"/>
      </svg>
      <svg v-else width="22" height="22" viewBox="0 0 22 22" fill="none">
        <path d="M6 6l10 10M16 6L6 16" stroke="currentColor" stroke-width="1.6" stroke-linecap="round"/>
      </svg>
    </button>

    <!-- Chat panel -->
    <Transition name="chat-panel">
      <div v-if="open" class="widget-panel">
        <ChatRoom @close="open = false" />
      </div>
    </Transition>
  </div>
</template>

<style scoped>
.chat-widget {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 12px;
}

/* ── Trigger button ── */
.widget-trigger {
  position: relative;
  z-index: 10;
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: var(--color-primary, #cc785c);
  color: #fff;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  box-shadow: 0 4px 16px rgba(204, 120, 92, 0.35);
  transition: transform 0.2s, box-shadow 0.2s;
}

.widget-trigger:hover {
  transform: scale(1.08);
  box-shadow: 0 6px 24px rgba(204, 120, 92, 0.45);
}

.widget-trigger:active {
  transform: scale(0.96);
}

/* Badge */
.widget-badge {
  position: absolute;
  top: -4px;
  right: -4px;
  min-width: 20px;
  height: 20px;
  border-radius: 10px;
  background: #c64545;
  color: #fff;
  font-size: 11px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 5px;
  box-shadow: 0 2px 6px rgba(198, 69, 69, 0.4);
}

/* ── Panel ── */
.widget-panel {
  width: 380px;
  height: 480px;
  max-height: calc(100vh - 100px);
  background: var(--color-canvas, #faf9f5);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.12), 0 2px 8px rgba(0, 0, 0, 0.06);
  border: 1px solid var(--color-hairline-soft, #ebe6df);
  display: flex;
  flex-direction: column;
}

/* Panel transition */
.chat-panel-enter-active {
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.chat-panel-leave-active {
  transition: all 0.2s ease-in;
}

.chat-panel-enter-from {
  opacity: 0;
  transform: translateY(16px) scale(0.96);
}

.chat-panel-leave-to {
  opacity: 0;
  transform: translateY(8px) scale(0.98);
}

/* ── Mobile ── */
@media (max-width: 640px) {
  .chat-widget {
    bottom: 16px;
    right: 16px;
  }

  .chat-widget.is-open .widget-trigger {
    display: none;
  }

  .widget-panel {
    position: fixed;
    bottom: 0;
    right: 0;
    width: 100vw;
    height: 100vh;
    height: 100dvh;
    max-height: none;
    border-radius: 0;
  }
}
</style>