#!/bin/sh
# docker-entrypoint.sh
#
# Spark 3.1.2 + JDK 11 container entrypoint.
#
# Three responsibilities, in order:
#   1. Resolve JAVA_HOME and SPARK_HOME from env (with sensible defaults
#      matching the Dockerfile).
#   2. Validate the resolved paths exist and contain the expected
#      binaries. Fail fast at container start with a clear error
#      message, instead of letting a job submission die later with an
#      opaque "no such file" or "command not found".
#   3. Update PATH so the (possibly overridden) JAVA_HOME/bin and
#      SPARK_HOME/bin are prepended — overrides via docker-compose / .env
#      take effect on the very next container start, without rebuilding
#      the image.
#
# Compared to the previous version this drops the awk-based PATH
# stripping (too brittle — would also strip the new JAVA_HOME/bin if
# it happened to be under /usr/lib/jvm/) and instead just prepends.
# Whatever was in the old PATH is preserved; the new paths win
# because they come first.
set -e

# Defaults match the Dockerfile's build-time ENV
: "${JAVA_HOME:=/usr/lib/jvm/java-11-openjdk-amd64}"
: "${SPARK_HOME:=/opt/spark}"

# --- Validation (fail fast with a clear error) ---
if [ ! -x "${JAVA_HOME}/bin/java" ]; then
    echo "[entrypoint] FATAL: JAVA_HOME=${JAVA_HOME} but ${JAVA_HOME}/bin/java is missing or not executable" >&2
    echo "[entrypoint] Hint: set JAVA_HOME to a directory containing bin/java (e.g. /usr/lib/jvm/java-11-openjdk-amd64)" >&2
    exit 1
fi

if [ ! -x "${SPARK_HOME}/bin/spark-submit" ]; then
    echo "[entrypoint] FATAL: SPARK_HOME=${SPARK_HOME} but ${SPARK_HOME}/bin/spark-submit is missing or not executable" >&2
    echo "[entrypoint] Hint: set SPARK_HOME to the Spark install root (e.g. /opt/spark)" >&2
    exit 1
fi

# Export the resolved values (so subprocesses see them)
export JAVA_HOME
export SPARK_HOME

# --- Update PATH ---
# Prepend the project venv and the (possibly overridden) JDK + Spark
# bin dirs. Order matters: /app/.venv/bin first (project tools win),
# then JAVA_HOME/bin (overrides any system java), then SPARK_HOME/bin,
# then whatever was already on PATH.
export PATH="/app/.venv/bin:${JAVA_HOME}/bin:${SPARK_HOME}/bin:${PATH}"

# --- Log the effective resolution so docker logs show what was picked ---
echo "[entrypoint] JAVA_HOME=${JAVA_HOME}" >&2
echo "[entrypoint] SPARK_HOME=${SPARK_HOME}" >&2
echo "[entrypoint] java:          $(command -v java)" >&2
echo "[entrypoint] spark-submit:  $(command -v spark-submit)" >&2
echo "[entrypoint] java version:  $(java -version 2>&1 | head -1)" >&2

# Run whatever CMD was passed (gunicorn main:app, or python main.py, etc.)
exec "$@"