feat: 初版

lib/ai/conversations.ts

@@ -0,0 +1,91 @@
+import { createClient } from "@/lib/supabase/client"
+
+export type AIConversation = {
+  id: string
+  knowledge_item_id: string | null
+  title: string | null
+  created_at: string
+  updated_at: string
+}
+
+export type AIMessageRow = {
+  id: string
+  conversation_id: string
+  role: "user" | "assistant" | "system"
+  content: string
+  created_at: string
+}
+
+/** Get the latest conversation for a knowledge item, if any. */
+export async function getLatestConversation(knowledgeItemId: string): Promise<AIConversation | null> {
+  const supabase = createClient()
+  const { data, error } = await supabase
+    .from("ai_conversations")
+    .select("*")
+    .eq("knowledge_item_id", knowledgeItemId)
+    .order("updated_at", { ascending: false })
+    .limit(1)
+    .maybeSingle()
+  if (error) throw error
+  return (data as AIConversation) ?? null
+}
+
+export async function createConversation(knowledgeItemId: string, title: string): Promise<AIConversation> {
+  const supabase = createClient()
+  const { data, error } = await supabase
+    .from("ai_conversations")
+    .insert({ knowledge_item_id: knowledgeItemId, title })
+    .select("*")
+    .single()
+  if (error) throw error
+  return data as AIConversation
+}
+
+export async function fetchMessages(conversationId: string): Promise<AIMessageRow[]> {
+  const supabase = createClient()
+  const { data, error } = await supabase
+    .from("ai_messages")
+    .select("*")
+    .eq("conversation_id", conversationId)
+    .order("created_at", { ascending: true })
+  if (error) throw error
+  return (data ?? []) as AIMessageRow[]
+}
+
+export async function addMessage(
+  conversationId: string,
+  role: "user" | "assistant",
+  content: string,
+): Promise<AIMessageRow> {
+  const supabase = createClient()
+  const { data, error } = await supabase
+    .from("ai_messages")
+    .insert({ conversation_id: conversationId, role, content })
+    .select("*")
+    .single()
+  if (error) throw error
+  // touch conversation updated_at
+  await supabase.from("ai_conversations").update({ updated_at: new Date().toISOString() }).eq("id", conversationId)
+  return data as AIMessageRow
+}
+
+export async function clearMessages(conversationId: string): Promise<void> {
+  const supabase = createClient()
+  const { error } = await supabase.from("ai_messages").delete().eq("conversation_id", conversationId)
+  if (error) throw error
+}
+
+export async function deleteLastAssistantMessage(conversationId: string): Promise<void> {
+  const supabase = createClient()
+  const { data, error } = await supabase
+    .from("ai_messages")
+    .select("id, role")
+    .eq("conversation_id", conversationId)
+    .order("created_at", { ascending: false })
+    .limit(1)
+    .maybeSingle()
+  if (error) throw error
+  if (data && (data as { role: string }).role === "assistant") {
+    await supabase.from("ai_messages").delete().eq("id", (data as { id: string }).id)
+  }
+}