From d1f197ba1a26c40e61583b820d1388730291030b Mon Sep 17 00:00:00 2001
From: Fabio Niephaus <fabio.niephaus@oracle.com>
Date: Tue, 1 Oct 2024 10:53:09 +0200
Subject: [PATCH] Add GraalPy JBang QRCode Demo.

---
 .github/workflows/graalpy-jbang-qrcode.yml | 29 ++++++++++++
 graalpy/README.md                          |  1 +
 graalpy/graalpy-jbang-qrcode/README.md     | 35 ++++++++++++++
 graalpy/graalpy-jbang-qrcode/qrcode.java   | 55 ++++++++++++++++++++++
 4 files changed, 120 insertions(+)
 create mode 100644 .github/workflows/graalpy-jbang-qrcode.yml
 create mode 100644 graalpy/graalpy-jbang-qrcode/README.md
 create mode 100644 graalpy/graalpy-jbang-qrcode/qrcode.java

diff --git a/.github/workflows/graalpy-jbang-qrcode.yml b/.github/workflows/graalpy-jbang-qrcode.yml
new file mode 100644
index 0000000..14bab11
--- /dev/null
+++ b/.github/workflows/graalpy-jbang-qrcode.yml
@@ -0,0 +1,29 @@
+name: Test GraalPy JBang QRCode Demo
+on:
+  push:
+    paths:
+      - 'graalpy/graalpy-jbang-qrcode/**'
+      - '.github/workflows/graalpy-jbang-qrcode.yml'
+  pull_request:
+    paths:
+      - 'graalpy/graalpy-jbang-qrcode/**'
+      - '.github/workflows/graalpy-jbang-qrcode.yml'
+  workflow_dispatch:
+permissions:
+  contents: read
+jobs:
+  run:
+    name: 'graalpy-jbang-qrcode'
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    steps:
+      - uses: actions/checkout@v4
+      - uses: graalvm/setup-graalvm@v1
+        with:
+          java-version: '23.0.0'
+          distribution: 'graalvm'
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+      - name: Run 'graalpy-jbang-qrcode' demo
+        run: |
+          cd graalpy/graalpy-jbang-qrcode
+          curl -Ls https://sh.jbang.dev | bash -s - run qrcode.java "Hello from GraalPy!"
diff --git a/graalpy/README.md b/graalpy/README.md
index ac3c726..9750ea1 100644
--- a/graalpy/README.md
+++ b/graalpy/README.md
@@ -8,6 +8,7 @@ This directory contains demo applications and guides for [GraalPy](https://www.g
 
 - [Minimal Java application that embeds GraalPy](graalpy-starter/README.md)
 - [Minimal Java application that embeds `openai` Python package with GraalPy](graalpy-openai-starter/README.md)
+- [Embed `qrcode` Python package with GraalPy in JBang](graalpy-jbang-qrcode/README.md)
 
 ## Guides
 
diff --git a/graalpy/graalpy-jbang-qrcode/README.md b/graalpy/graalpy-jbang-qrcode/README.md
new file mode 100644
index 0000000..1e3b923
--- /dev/null
+++ b/graalpy/graalpy-jbang-qrcode/README.md
@@ -0,0 +1,35 @@
+# GraalPy JBang QRCode Demo
+
+This demo illustrates how GraalPy can be used to embed the [`qrcode` Python package](https://pypi.org/project/qrcode/) in a script that runs on [JBang](https://www.jbang.dev/).
+
+## Preparation
+
+Install GraalVM for JDK 23 and set the value of `JAVA_HOME` accordingly.
+We recommend using [SDKMAN!](https://sdkman.io/). (For other download options, see [GraalVM Downloads](https://www.graalvm.org/downloads/).)
+
+```bash
+sdk install java 23-graal
+```
+
+Afterward, [install `jbang`](https://www.jbang.dev/download/), for with:
+
+```bash
+sdk install jbang
+```
+
+## Run the Application
+
+To start the demo, run:
+
+```bash
+jbang run QRCodeMaker.java "Hello from GraalPy!"
+```
+
+## Implementation Details
+
+[qrcode.java](qrcode.java) defines required dependencies on GraalPy, which also allows to depend on Python packages.
+`//PIP qrcode==7.4.2` defines the dependency on the `qrcode` Python package.
+The `main()` method checks the arguments and then creates a new `Context`.
+It then fetches the `qrcode` Python module and maps it to a `QRCode` Java interface.
+Afterward, it uses the `qrcode` module as illustrated in [this example](https://github.com/lincolnloop/python-qrcode/tree/v7.4.2?tab=readme-ov-file#examples) through Java interfaces.
+Finally, it prints the result to `System.out`.
diff --git a/graalpy/graalpy-jbang-qrcode/qrcode.java b/graalpy/graalpy-jbang-qrcode/qrcode.java
new file mode 100644
index 0000000..603bf80
--- /dev/null
+++ b/graalpy/graalpy-jbang-qrcode/qrcode.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2024, Oracle and/or its affiliates.
+ *
+ * Licensed under the Universal Permissive License v 1.0 as shown at https://opensource.org/license/UPL.
+ */
+
+//DEPS org.graalvm.python:python-language:24.1.0
+//DEPS org.graalvm.python:python-launcher:24.1.0
+//DEPS org.graalvm.python:python-resources:24.1.0
+//DEPS org.graalvm.python:python-embedding:24.1.0
+//DEPS org.graalvm.python:python-embedding-tools:24.1.0
+//PIP qrcode==7.4.2
+
+import org.graalvm.python.embedding.utils.GraalPyResources;
+
+public class qrcode {
+
+    public static void main(String[] args) {
+        if (args.length != 1 || args[0].equals("-h") || args[0].equals("--help")) {
+            System.out.println("This tool takes only a single argument, the QR code data.");
+            return;
+        }
+        try (var context = GraalPyResources.contextBuilder().option("python.PythonHome", "").build()) {
+            QRCodeModule qrcodeModule = context.eval("python", "import qrcode; qrcode").as(QRCodeModule.class);
+            IO io = context.eval("python", "import io; io").as(IO.class);
+
+            QRCode qr = qrcodeModule.QRCode();
+            qr.add_data(args[0]);
+
+            StringIO f = io.StringIO();
+            qr.print_ascii(f);
+            String qrCodeString = f.getvalue();
+
+            System.out.println(qrCodeString);
+        }
+    }
+
+    public interface QRCodeModule {
+        QRCode QRCode();
+    }
+
+    public interface QRCode {
+        void add_data(String text);
+
+        void print_ascii(StringIO out);
+    }
+
+    public interface IO {
+        StringIO StringIO();
+    }
+
+    public interface StringIO {
+        String getvalue();
+    }
+}
\ No newline at end of file