openpencil/src/components/ChatPanel.vue

<script setup lang="ts">
import { ScrollAreaRoot, ScrollAreaScrollbar, ScrollAreaThumb, ScrollAreaViewport } from 'reka-ui'
import { computed, markRaw, nextTick, ref, watch } from 'vue'

import ProviderSetup from '@/components/chat/ProviderSetup.vue'
import ChatInput from '@/components/chat/ChatInput.vue'
import ChatMessage from '@/components/chat/ChatMessage.vue'
import { useAIChat } from '@/composables/use-chat'

import type { Chat } from '@ai-sdk/vue'
import type { UIMessage } from 'ai'

const { isConfigured, ensureChat } = useAIChat()

const chat = ref<Chat<UIMessage> | null>(null)
const messagesEnd = ref<HTMLDivElement>()

const messages = computed(() => chat.value?.messages ?? [])
const status = computed(() => chat.value?.status ?? 'ready')

function scrollToBottom() {
  nextTick(() => {
    messagesEnd.value?.scrollIntoView({ behavior: 'smooth', block: 'end' })
  })
}

watch(messages, scrollToBottom, { deep: true })

function handleSubmit(text: string) {
  if (!chat.value) {
    const c = ensureChat()
    if (c) chat.value = markRaw(c)
  }
  chat.value?.sendMessage({ text }).catch(() => {})
}

function handleStop() {
  chat.value?.stop()
}
</script>

<template>
  <div data-test-id="chat-panel" class="flex min-w-0 flex-1 select-text flex-col overflow-hidden">
    <ProviderSetup v-if="!isConfigured" />

    <template v-else>
      <ScrollAreaRoot class="min-h-0 flex-1">
        <ScrollAreaViewport class="h-full px-3 py-3 [&>div]:h-full">
          <!-- Empty state -->
          <div
            v-if="messages.length === 0"
            data-test-id="chat-empty-state"
            class="flex h-full flex-col items-center justify-center gap-3 text-muted"
          >
            <icon-lucide-message-circle class="size-8 opacity-50" />
            <p class="text-center text-xs">Describe what you want to create or change.</p>
          </div>

          <!-- Messages -->
          <div v-else data-test-id="chat-messages" class="flex flex-col gap-3">
            <ChatMessage v-for="msg in messages" :key="msg.id" :message="msg" />

            <!-- Typing indicator -->
            <div
              v-if="status === 'submitted'"
              data-test-id="chat-typing-indicator"
              class="flex gap-2"
            >
              <div
                class="flex size-6 shrink-0 items-center justify-center rounded-full bg-muted/20 text-[10px] font-bold text-muted"
              >
                AI
              </div>
              <div class="flex items-center gap-1 py-2">
                <span
                  class="size-1.5 animate-bounce rounded-full bg-muted"
                  style="animation-delay: 0ms"
                />
                <span
                  class="size-1.5 animate-bounce rounded-full bg-muted"
                  style="animation-delay: 150ms"
                />
                <span
                  class="size-1.5 animate-bounce rounded-full bg-muted"
                  style="animation-delay: 300ms"
                />
              </div>
            </div>

            <div ref="messagesEnd" />
          </div>
        </ScrollAreaViewport>
        <ScrollAreaScrollbar orientation="vertical" class="flex w-1.5 touch-none select-none p-px">
          <ScrollAreaThumb class="relative flex-1 rounded-full bg-muted/30" />
        </ScrollAreaScrollbar>
      </ScrollAreaRoot>

      <ChatInput :status="status" @submit="handleSubmit" @stop="handleStop" />
    </template>
  </div>
</template>