Create expense from receipt (#69)

* Create expense from receipt

* Add modal

* Update README

src/app/groups/[groupId]/expenses/create-from-receipt-button-actions.ts

@@ -0,0 +1,48 @@
+'use server'
+import { getCategories } from '@/lib/api'
+import { env } from '@/lib/env'
+import OpenAI from 'openai'
+
+const openai = new OpenAI({ apiKey: env.OPENAI_API_KEY })
+
+export async function extractExpenseInformationFromImage(imageUrl: string) {
+  'use server'
+  const categories = await getCategories()
+
+  const body = {
+    model: 'gpt-4-vision-preview',
+    messages: [
+      {
+        role: 'user',
+        content: [
+          {
+            type: 'text',
+            text: `
+              This image contains a receipt.
+              Read the total amount and store it as a non-formatted number without any other text or currency.
+              Then guess the category for this receipt amoung the following categories and store its ID: ${categories.map(
+                ({ id, grouping, name }) => `"${grouping}/${name}" (ID: ${id})`,
+              )}.
+              Guess the expense’s date and store it as yyyy-mm-dd.
+              Guess a title for the expense.
+              Return the amount, the category, the date and the title with just a comma between them, without anything else.`,
+          },
+        ],
+      },
+      {
+        role: 'user',
+        content: [{ type: 'image_url', image_url: { url: imageUrl } }],
+      },
+    ],
+  }
+  const completion = await openai.chat.completions.create(body as any)
+
+  const [amountString, categoryId, date, title] = completion.choices
+    .at(0)
+    ?.message.content?.split(',') ?? [null, null, null, null]
+  return { amount: Number(amountString), categoryId, date, title }
+}
+
+export type ReceiptExtractedInfo = Awaited<
+  ReturnType<typeof extractExpenseInformationFromImage>
+>