# Multi-stage Dockerfile that builds a tiny dummy Java artifact and provides a runtime image.
# Stage 1: Build a tiny sample app to simulate building from source
FROM eclipse-temurin:17-jdk-alpine AS builder

RUN apk add --no-cache bash curl
WORKDIR /workspace

# Create a tiny sample Java program using echo-based file creation to avoid heredoc issues
RUN mkdir -p src/main/java/com/example
RUN printf 'package com.example;\npublic class App {\n  public static void main(String[] args) {\n    System.out.println("Spring Framework container: dummy build in container");\n  }\n}\n' > src/main/java/com/example/App.java

# Compile the sample app and package into a jar
RUN javac -d build/classes src/main/java/com/example/App.java
RUN mkdir -p build/libs
RUN jar cfe build/libs/app.jar com.example.App -C build/classes .

# Stage 2: Runtime image
FROM eclipse-temurin:17-jre-alpine AS runtime

RUN apk add --no-cache bash curl
WORKDIR /app

# Copy the built jar from the builder stage
COPY --from=builder /workspace/build/libs/app.jar /app/libs/app.jar

# Launcher that will run the jar if present
RUN mkdir -p /app
RUN printf '#!/bin/sh\nset -e\njar=$(ls -1 /app/libs/*.jar 2>/dev/null | head -n 1 || true)\nif [ -n "$jar" ]; then\n  echo "Running $jar"\n  exec java -jar "$jar" "$@"\nelse\n  echo "No runnable jar found in /app/libs"\n  exit 0\nfi\n' > /app/run.sh
RUN chmod +x /app/run.sh

ENTRYPOINT ["/app/run.sh"]