#!/usr/bin/env bash
# Can you actually use Propagation.NESTED with Spring Data JPA? Three attempts.
set -euo pipefail
set +m
cd "$(dirname "$0")/.."
source scripts/env.sh
{
  echo "== attempt 1: a stock Spring Boot JPA application =="
  echo "\$ java -jar $JAR"
  echo
  start_app > /dev/null
  curl -s "http://127.0.0.1:${APP_PORT}/tx/propagation" | python3 -c '
import json,sys
v=json.load(sys.stdin)["NESTED"]["withOuterTransaction"]
print("  " + v.get("exception","(no exception)"))
print("  " + v.get("message",""))'
  echo
  echo "== attempt 2: nestedTransactionAllowed = true, as the message instructs =="
  echo "\$ java -jar $JAR --demo.nested-allowed=true"
  echo
  start_app --demo.nested-allowed=true > /dev/null
  curl -s "http://127.0.0.1:${APP_PORT}/tx/propagation" | python3 -c '
import json,sys
v=json.load(sys.stdin)["NESTED"]["withOuterTransaction"]
print("  " + v.get("exception","(no exception)"))
print("  " + v.get("message",""))'
  echo
  echo "A different message, from a second check. The savepoint manager is obtained from the"
  echo "object the JpaDialect returns when it begins the transaction, and Hibernate's does not"
  echo "implement one -- so no amount of configuration gets NESTED working here."
  echo
  echo "== attempt 3: the same propagation on a JDBC transaction manager =="
  echo "\$ curl -s localhost:$APP_PORT/tx/nested-jdbc"
  echo
  curl -s "http://127.0.0.1:${APP_PORT}/tx/nested-jdbc" | python3 -m json.tool | sed 's/^/  /'
  echo
  echo "This is what NESTED is for: the nested scope rolled back to its savepoint, the outer"
  echo "transaction carried on and committed, and one of the two rows survived."
  echo
  echo "A savepoint is a JDBC concept. DataSourceTransactionManager holds the JDBC connection"
  echo "and can issue one; JpaTransactionManager holds an EntityManager and cannot. The"
  echo "reference documentation does say NESTED works with JDBC resource transactions -- what"
  echo "it does not say is that the JPA path fails, twice, with two different messages."
  stop_app
} > docs/output/03-nested.txt 2>&1
cat docs/output/03-nested.txt