feat(chat): add multi-model comparison mode (M9.1)

Split-screen comparison of two AI models streaming simultaneously. Toggle via header button. Desktop shows side-by-side panes, mobile shows swipeable tabs. Uses streamWithModel() for provider-agnostic parallel streaming. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-03 23:19:46 +00:00
parent 5fdf62520c
commit 0ae497f1db
5 changed files with 245 additions and 3 deletions
@@ -326,6 +326,32 @@ async function generateAutoTitle(conversationId: string) {
  }
 }

+/** Stream a specific provider/model — used by comparison mode */
+export async function streamWithModel(
+  provider: string,
+  model: string,
+  messages: { role: string; content: string }[],
+  onToken: (text: string) => void,
+  onError: (err: string) => void,
+  signal: AbortSignal,
+): Promise<void> {
+  const history = messages.map(m => ({ role: m.role as 'user' | 'assistant', content: m.content }))
+  const savedModel = activeModel.value
+  activeModel.value = model
+
+  try {
+    if (provider === 'claude') {
+      await streamClaude(history, onToken, onError, 'You are a helpful assistant.', false, signal)
+    } else if (provider === 'openrouter') {
+      await streamOpenRouter(history, onToken, onError, 'You are a helpful assistant.', signal)
+    } else {
+      await streamMock(history, onToken, signal)
+    }
+  } finally {
+    activeModel.value = savedModel
+  }
+}
+
 export function useAI() {
  const chatStore = useChatStore()

@@ -0,0 +1,101 @@
+import { ref, computed } from 'vue'
+
+const comparisonEnabled = ref(false)
+const model1 = ref({ provider: 'claude' as string, model: 'claude-haiku-4.5' })
+const model2 = ref({ provider: 'openrouter' as string, model: 'meta-llama/llama-4-maverick' })
+const response1 = ref('')
+const response2 = ref('')
+const isStreaming1 = ref(false)
+const isStreaming2 = ref(false)
+const error1 = ref<string | null>(null)
+const error2 = ref<string | null>(null)
+let abortController: AbortController | null = null
+
+export function useComparisonMode() {
+  const isComparing = computed(() => comparisonEnabled.value)
+  const isAnyStreaming = computed(() => isStreaming1.value || isStreaming2.value)
+
+  function toggleComparison() {
+    comparisonEnabled.value = !comparisonEnabled.value
+  }
+
+  function setModel(slot: 1 | 2, provider: string, modelId: string) {
+    const target = slot === 1 ? model1 : model2
+    target.value = { provider, model: modelId }
+  }
+
+  function clearResponses() {
+    response1.value = ''
+    response2.value = ''
+    error1.value = null
+    error2.value = null
+  }
+
+  function stopComparison() {
+    if (abortController) {
+      abortController.abort()
+      abortController = null
+    }
+    isStreaming1.value = false
+    isStreaming2.value = false
+  }
+
+  async function streamBothModels(
+    streamFn: (
+      provider: string,
+      model: string,
+      messages: { role: string; content: string }[],
+      onToken: (text: string) => void,
+      onError: (err: string) => void,
+      signal: AbortSignal,
+    ) => Promise<void>,
+    messages: { role: string; content: string }[],
+  ) {
+    clearResponses()
+    abortController = new AbortController()
+    const signal = abortController.signal
+
+    isStreaming1.value = true
+    isStreaming2.value = true
+
+    const p1 = streamFn(
+      model1.value.provider,
+      model1.value.model,
+      messages,
+      (token) => { response1.value += token },
+      (err) => { error1.value = err },
+      signal,
+    ).finally(() => { isStreaming1.value = false })
+
+    const p2 = streamFn(
+      model2.value.provider,
+      model2.value.model,
+      messages,
+      (token) => { response2.value += token },
+      (err) => { error2.value = err },
+      signal,
+    ).finally(() => { isStreaming2.value = false })
+
+    await Promise.allSettled([p1, p2])
+    abortController = null
+  }
+
+  return {
+    comparisonEnabled,
+    isComparing,
+    isAnyStreaming,
+    model1,
+    model2,
+    response1,
+    response2,
+    isStreaming1,
+    isStreaming2,
+    error1,
+    error2,
+    toggleComparison,
+    setModel,
+    clearResponses,
+    stopComparison,
+    streamBothModels,
+  }
+}