# ---------- Base build image (pins Gradle + JDK) ----------
FROM gradle:8.10.2-jdk21-alpine AS build-base
WORKDIR /workspace

# Pre-copy only files that affect dependency resolution
COPY settings.gradle settings.gradle
COPY build.gradle build.gradle
COPY gradlew gradlew

# Warm Gradle wrapper & dependency cache (layer-cached in the image)
RUN ./gradlew --version || gradle --version
RUN ./gradlew --no-daemon --stacktrace dependencies || true

# ---------- Test stage (fail fast but reuse the warmed deps) ----------
FROM build-base AS test
# Copy the full project now (invalidates later layers only when code changes)
COPY . .
RUN ./gradlew --no-daemon clean test

# ---------- Package stage (reuses compiled classes incrementally) ----------
FROM test AS package
RUN ./gradlew --no-daemon bootJar
# Find the built jar path
RUN ls -lah build/libs

# ---------- Runtime image ----------
FROM eclipse-temurin:21-jre-alpine
RUN addgroup -S app && adduser -S app -G app
USER app
WORKDIR /app

# Copy the application jar
COPY --from=package /workspace/build/libs/*SNAPSHOT*.jar /app/app.jar

# Healthcheck via Spring Actuator (optional if you have it)
# HEALTHCHECK --interval=30s --timeout=3s --start-period=20s --retries=3 \
#   CMD wget -qO- http://localhost:8080/actuator/health/liveness | grep -q '"status":"UP"' || exit 1

# Graceful shutdown
ENV JAVA_OPTS="-XX:+UseContainerSupport -XX:MaxRAMPercentage=75 -XX:InitialRAMPercentage=50"
ENV SERVER_SHUTDOWN=graceful
ENV SPRING_LIFECYCLE_TIMEOUT=20s

LABEL com.centurylinklabs.watchtower.enable=true

EXPOSE 8080
ENTRYPOINT ["sh","-c","java $JAVA_OPTS -Dserver.shutdown=${SERVER_SHUTDOWN} -Dspring.lifecycle.timeout-per-shutdown-phase=${SPRING_LIFECYCLE_TIMEOUT} -jar /app/app.jar"]