Initial commit: Meshkee CMS API

NestJS backend with Prisma, Docker Compose for Postgres/Redis, and deploy docs for the production VM.

src/common/ai-provider.util.ts

@@ -0,0 +1,83 @@
+import { ServiceUnavailableException } from '@nestjs/common';
+import { ConfigService } from '@nestjs/config';
+
+export type AiProviderConfig = {
+  apiKey: string;
+  baseUrl: string;
+  model: string;
+};
+
+export function resolveAiProvider(config: ConfigService): AiProviderConfig {
+  const configured = config.get<string>('AI_PROVIDER')?.trim().toLowerCase();
+  const groqKey = config.get<string>('GROQ_API_KEY')?.trim();
+  const openAiKey = config.get<string>('OPENAI_API_KEY')?.trim();
+
+  const useGroq =
+    configured === 'groq' || (!configured && !!groqKey) || (!openAiKey && !!groqKey);
+
+  if (useGroq) {
+    if (!groqKey) {
+      throw new ServiceUnavailableException(
+        'AI is not configured. Set GROQ_API_KEY on the server.',
+      );
+    }
+
+    return {
+      apiKey: groqKey,
+      baseUrl: 'https://api.groq.com/openai/v1',
+      model: config.get<string>('GROQ_MODEL')?.trim() || 'llama-3.3-70b-versatile',
+    };
+  }
+
+  if (!openAiKey) {
+    throw new ServiceUnavailableException(
+      'AI is not configured. Set GROQ_API_KEY or OPENAI_API_KEY on the server.',
+    );
+  }
+
+  return {
+    apiKey: openAiKey,
+    baseUrl: 'https://api.openai.com/v1',
+    model: config.get<string>('OPENAI_MODEL')?.trim() || 'gpt-4o-mini',
+  };
+}
+
+export async function requestAiJsonCompletion(
+  provider: AiProviderConfig,
+  systemPrompt: string,
+  userPrompt: string,
+  temperature = 0.4,
+): Promise<string> {
+  const response = await fetch(`${provider.baseUrl}/chat/completions`, {
+    method: 'POST',
+    headers: {
+      Authorization: `Bearer ${provider.apiKey}`,
+      'Content-Type': 'application/json',
+    },
+    body: JSON.stringify({
+      model: provider.model,
+      temperature,
+      response_format: { type: 'json_object' },
+      messages: [
+        { role: 'system', content: systemPrompt },
+        { role: 'user', content: userPrompt },
+      ],
+    }),
+  });
+
+  if (!response.ok) {
+    const detail = await response.text();
+    throw new Error(`AI provider error (${response.status}): ${detail.slice(0, 240)}`);
+  }
+
+  const payload = (await response.json()) as {
+    choices?: { message?: { content?: string } }[];
+  };
+
+  const content = payload.choices?.[0]?.message?.content;
+  if (!content) {
+    throw new Error('AI returned an empty response');
+  }
+
+  return content;
+}

src/common/interceptors/bigint-serializer.interceptor.ts

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+import {
+  CallHandler,
+  ExecutionContext,
+  Injectable,
+  NestInterceptor,
+} from '@nestjs/common';
+import { Observable, map } from 'rxjs';
+
+function serializeBigInt(value: unknown): unknown {
+  if (typeof value === 'bigint') {
+    return Number(value);
+  }
+
+  if (value instanceof Date) {
+    return value.toISOString();
+  }
+
+  if (Array.isArray(value)) {
+    return value.map(serializeBigInt);
+  }
+
+  if (value !== null && typeof value === 'object') {
+    return Object.fromEntries(
+      Object.entries(value).map(([key, val]) => [key, serializeBigInt(val)]),
+    );
+  }
+
+  return value;
+}
+
+@Injectable()
+export class BigIntSerializerInterceptor implements NestInterceptor {
+  intercept(_context: ExecutionContext, next: CallHandler): Observable<unknown> {
+    return next.handle().pipe(map((data) => serializeBigInt(data)));
+  }
+}