feat: impl function that call the OpenAI completion API

.env.example

@@ -0,0 +1 @@
+OPENAI_API_KEY=

.gitignore

@@ -0,0 +1,2 @@
+.env
+.env.local

README.md

@@ -6,3 +6,24 @@ ref: https://youtu.be/29p8kIqyU_Y
 
 - Supabase
 - Deno
+- VS Code
+  - https://github.com/denoland/vscode_deno/
+
+## Run local
+
+Setup your OpenAI API key in `.env.local`
+
+```bash
+$ cp .env.example .env.local
+```
+
+```bash
+$ supabase start
+
+$ supabase functions serve --env-file .env.local openai
+Starting supabase/functions/openai
+Serving supabase/functions/openai
+Watcher Process started.
+Check file:///home/deno/functions/openai/index.ts
+Listening on http://localhost:8000/
+```

supabase/functions/openai/index.ts

@@ -2,24 +2,50 @@
 // https://deno.land/manual/getting_started/setup_your_environment
 // This enables autocomplete, go to definition, etc.
 
-import { serve } from "https://deno.land/std@0.168.0/http/server.ts"
+import "https://deno.land/x/xhr@0.3.0/mod.ts"
+import { getLogger } from "https://deno.land/std@0.183.0/log/mod.ts"
+import { serve } from "https://deno.land/std@0.183.0/http/server.ts"
+import { Configuration, OpenAIApi } from "https://esm.sh/openai@3.2.1"
 
-console.log("Hello from Functions!")
+const configuration = new Configuration({
+  apiKey: Deno.env.get("OPENAI_API_KEY"),
+});
+const openai = new OpenAIApi(configuration);
 
 serve(async (req) => {
-  const { name } = await req.json()
-  const data = {
-    message: `Hello ${name}!`,
-  }
+  const { query } = await req.json();
+  try {
+    const response = await openai.createCompletion({
+      model: "text-davinci-003",
+      prompt: query,
+      max_tokens: 256,
+      temperature: 0,
+    });
+
+    const {
+      data: {
+        id,
+        choices: [{ text }]
+      },
+    } = response;
 
-  return new Response(
-    JSON.stringify(data),
-    { headers: { "Content-Type": "application/json" } },
-  )
+    return new Response(
+      JSON.stringify({ id, text }),
+      { headers: { "Content-Type": "application/json" } },
+    )
+  } catch (error) {
+    const logger = getLogger()
+    logger.error(error)
+
+    return new Response(
+      JSON.stringify({ error }),
+      { headers: { "Content-Type": "application/json" } },
+    )
+  }
 })
 
 // To invoke:
 // curl -i --location --request POST 'http://localhost:54321/functions/v1/' \
 //   --header 'Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJzdXBhYmFzZS1kZW1vIiwicm9sZSI6ImFub24iLCJleHAiOjE5ODM4MTI5OTZ9.CRXP1A7WOeoJeXxjNni43kdQwgnWNReilDMblYTn_I0' \
 //   --header 'Content-Type: application/json' \
-//   --data '{"name":"Functions"}'
+//   --data '{"query":"What is Supabase?"}'