=test_update_homework_tests_and_work_log

src/shared/lib/ai.ts

@@ -0,0 +1,247 @@
+import "server-only"
+
+import { createCipheriv, createDecipheriv, createHash, randomBytes } from "node:crypto"
+import OpenAI from "openai"
+import type { ChatCompletionMessageParam } from "openai/resources/chat/completions"
+
+import { env } from "@/env.mjs"
+import { db } from "@/shared/db"
+import { aiProviders } from "@/shared/db/schema"
+import { desc, eq } from "drizzle-orm"
+
+type ChatRole = "system" | "user" | "assistant"
+
+type ChatMessage = {
+  role: ChatRole
+  content: string
+}
+
+type AiChatRequest = {
+  messages: ChatCompletionMessageParam[]
+  model: string
+  temperature: number
+  maxTokens?: number
+  thinking?: Record<string, unknown>
+  providerId?: string
+}
+
+const isRecord = (v: unknown): v is Record<string, unknown> => typeof v === "object" && v !== null
+
+const isChatMessage = (v: unknown): v is ChatMessage => {
+  if (!isRecord(v)) return false
+  const role = String(v.role ?? "")
+  if (role !== "system" && role !== "user" && role !== "assistant") return false
+  const content = String(v.content ?? "")
+  return content.trim().length > 0
+}
+
+const extractText = (value: unknown): string => {
+  if (typeof value === "string") return value.trim()
+  if (Array.isArray(value)) {
+    const joined = value.map((item) => extractText(item)).filter(Boolean).join("\n")
+    return joined.trim()
+  }
+  if (isRecord(value)) {
+    const candidates = ["text", "content", "output_text", "reasoning", "reasoning_content", "thinking"]
+    for (const key of candidates) {
+      const text = extractText(value[key])
+      if (text) return text
+    }
+  }
+  return ""
+}
+
+const extractMessageContent = (message: unknown): string => {
+  if (!isRecord(message)) return ""
+  const direct = extractText(message.content)
+  if (direct) return direct
+  const candidates = ["reasoning", "reasoning_content", "thinking", "output", "text"]
+  for (const key of candidates) {
+    const text = extractText(message[key])
+    if (text) return text
+  }
+  for (const value of Object.values(message)) {
+    const text = extractText(value)
+    if (text) return text
+  }
+  return ""
+}
+
+export const parseAiChatPayload = (body: unknown): AiChatRequest => {
+  if (!isRecord(body)) throw new Error("Invalid payload")
+
+  const rawMessages = Array.isArray(body.messages) ? body.messages : []
+  const messages = rawMessages
+    .filter(isChatMessage)
+    .map((m) => ({ role: m.role, content: m.content })) as ChatCompletionMessageParam[]
+
+  if (messages.length === 0) throw new Error("Messages are required")
+
+  const model = String(body.model ?? env.AI_MODEL ?? "gpt-4o-mini").trim()
+  const temperatureRaw = Number(body.temperature ?? 0.2)
+  const temperature = Number.isFinite(temperatureRaw) ? Math.min(Math.max(temperatureRaw, 0), 2) : 0.2
+  const maxTokensRaw = Number(body.max_tokens ?? body.maxTokens ?? 0)
+  const maxTokens = Number.isFinite(maxTokensRaw) && maxTokensRaw > 0 ? Math.floor(maxTokensRaw) : undefined
+  const thinking = isRecord(body.thinking) ? body.thinking : undefined
+  const providerId = typeof body.providerId === "string" ? body.providerId.trim() : undefined
+
+  return {
+    messages,
+    model,
+    temperature,
+    maxTokens,
+    thinking,
+    providerId: providerId && providerId.length > 0 ? providerId : undefined,
+  }
+}
+
+const getEncryptionKey = () => {
+  const secret = String(env.NEXTAUTH_SECRET ?? "").trim()
+  if (!secret) throw new Error("AI encryption secret missing")
+  return createHash("sha256").update(secret).digest()
+}
+
+export const encryptAiApiKey = (value: string) => {
+  const iv = randomBytes(12)
+  const key = getEncryptionKey()
+  const cipher = createCipheriv("aes-256-gcm", key, iv)
+  const encrypted = Buffer.concat([cipher.update(value, "utf8"), cipher.final()])
+  const tag = cipher.getAuthTag()
+  return Buffer.concat([iv, tag, encrypted]).toString("base64")
+}
+
+export const decryptAiApiKey = (value: string) => {
+  const raw = Buffer.from(value, "base64")
+  if (raw.length < 28) throw new Error("Invalid API key payload")
+  const iv = raw.subarray(0, 12)
+  const tag = raw.subarray(12, 28)
+  const encrypted = raw.subarray(28)
+  const key = getEncryptionKey()
+  const decipher = createDecipheriv("aes-256-gcm", key, iv)
+  decipher.setAuthTag(tag)
+  const decrypted = Buffer.concat([decipher.update(encrypted), decipher.final()])
+  return decrypted.toString("utf8")
+}
+
+const getAiProviderConfig = async (providerId?: string) => {
+  if (providerId) {
+    const [selected] = await db
+      .select({
+        apiKeyEncrypted: aiProviders.apiKeyEncrypted,
+        baseUrl: aiProviders.baseUrl,
+        model: aiProviders.model,
+      })
+      .from(aiProviders)
+      .where(eq(aiProviders.id, providerId))
+      .limit(1)
+    if (!selected) throw new Error("AI provider not configured")
+    return {
+      apiKey: decryptAiApiKey(selected.apiKeyEncrypted),
+      baseUrl: selected.baseUrl ?? undefined,
+      model: selected.model,
+    }
+  }
+
+  const [active] = await db
+    .select({
+      apiKeyEncrypted: aiProviders.apiKeyEncrypted,
+      baseUrl: aiProviders.baseUrl,
+      model: aiProviders.model,
+    })
+    .from(aiProviders)
+    .where(eq(aiProviders.isDefault, true))
+    .orderBy(desc(aiProviders.updatedAt))
+    .limit(1)
+  if (active) {
+    return {
+      apiKey: decryptAiApiKey(active.apiKeyEncrypted),
+      baseUrl: active.baseUrl ?? undefined,
+      model: active.model,
+    }
+  }
+
+  const [fallback] = await db
+    .select({
+      apiKeyEncrypted: aiProviders.apiKeyEncrypted,
+      baseUrl: aiProviders.baseUrl,
+      model: aiProviders.model,
+    })
+    .from(aiProviders)
+    .orderBy(desc(aiProviders.updatedAt))
+    .limit(1)
+  if (!fallback) throw new Error("AI provider not configured")
+
+  return {
+    apiKey: decryptAiApiKey(fallback.apiKeyEncrypted),
+    baseUrl: fallback.baseUrl ?? undefined,
+    model: fallback.model,
+  }
+}
+
+const getAiClient = async (config: { apiKey: string; baseUrl?: string }) => {
+  const baseUrl = String(config.baseUrl ?? "https://api.openai.com").replace(/\/+$/, "")
+  return new OpenAI({
+    apiKey: config.apiKey,
+    baseURL: baseUrl.length ? baseUrl : undefined,
+  })
+}
+
+export const testAiProviderConfig = async (input: { apiKey: string; baseUrl?: string; model: string }) => {
+  const client = await getAiClient({ apiKey: input.apiKey, baseUrl: input.baseUrl })
+  const result = await client.chat.completions.create({
+    model: input.model,
+    messages: [{ role: "user", content: "ping" }],
+    temperature: 0,
+    max_tokens: 1,
+  } as Parameters<typeof client.chat.completions.create>[0])
+  const hasChoices = "choices" in result && Array.isArray(result.choices) && result.choices.length > 0
+  if (!hasChoices) throw new Error("Empty response from provider. Check API URL, model, and API key.")
+  return true
+}
+
+export const testAiProviderById = async (
+  providerId: string,
+  overrides?: { baseUrl?: string; model?: string }
+) => {
+  const config = await getAiProviderConfig(providerId)
+  const client = await getAiClient({ apiKey: config.apiKey, baseUrl: overrides?.baseUrl ?? config.baseUrl })
+  const result = await client.chat.completions.create({
+    model: overrides?.model ?? config.model,
+    messages: [{ role: "user", content: "ping" }],
+    temperature: 0,
+    max_tokens: 1,
+  } as Parameters<typeof client.chat.completions.create>[0])
+  const hasChoices = "choices" in result && Array.isArray(result.choices) && result.choices.length > 0
+  if (!hasChoices) throw new Error("Empty response from provider. Check API URL, model, and API key.")
+  return true
+}
+
+export const createAiChatCompletion = async (input: AiChatRequest) => {
+  const config = await getAiProviderConfig(input.providerId)
+  const client = await getAiClient(config)
+  const result = (await client.chat.completions.create({
+    model: config.model || input.model,
+    messages: input.messages,
+    temperature: input.temperature,
+    ...(typeof input.maxTokens === "number" ? { max_tokens: input.maxTokens } : {}),
+    ...(input.thinking ? { thinking: input.thinking } : {}),
+  } as Parameters<typeof client.chat.completions.create>[0])) as Awaited<
+    ReturnType<typeof client.chat.completions.create>
+  >
+
+  const hasChoices = "choices" in result && Array.isArray(result.choices) && result.choices.length > 0
+  if (!hasChoices) throw new Error("Empty response from provider. Check API URL, model, and API key.")
+
+  const content = extractMessageContent(result.choices?.[0]?.message)
+  if (!content.trim()) throw new Error("Empty response content. Check model output settings.")
+
+  const usage = "usage" in result ? result.usage ?? null : null
+  return { content, usage }
+}
+
+export const getAiErrorMessage = (v: unknown) => {
+  if (v instanceof Error) return v.message
+  if (!isRecord(v)) return "AI request failed"
+  const message = String(v.message ?? "")
+  return message.trim().length ? message : "AI request failed"
+}