#!/bin/bash
# Run unit tests in parallel in different regions
set -euo pipefail

export NODE_OPTIONS="--max-old-space-size=4096 ${NODE_OPTIONS:-}"

lerna=${LERNA:-node_modules/.bin/lerna}

# Only regions that support most services
tokyo=ap-northeast-1
sydney=ap-southeast-2
regions=(eu-west-1 eu-west-2 us-east-1 us-east-2 us-west-1 us-west-2 eu-central-1 ca-central-1 $tokyo $sydney)

if ! which parallel > /dev/null; then
    echo "Please install GNU Parallel." >&2
    exit 1
fi

parallel --help > /dev/null || if [[ $? -ne 255 ]]; then
    echo "You do have a program called 'parallel' on your machine, but it's not GNU Parallel." >&2
    echo "It might come from 'moreutils'. Please install the proper GNU Parallel tool." >&2
    exit 1
fi

if [[ "${1:-}" == "" ]]; then
    echo "Usage: run-integ-parallel PACKAGE [PACKAGE [..]]" >&2
    exit 1
fi

echo "Discovering tests..." >&2
# Zipped arrays
packages=()
tests=()
while [[ "${1:-}" != "" ]]; do
    # Yes, -- (end lerna args) -- (end npm args) --list (argument to cdk-integ)
    for tst in $(lerna --loglevel=silent --scope $1 run integ -- --silent -- --list); do
        packages+=("$1")
        tests+=("$tst")
    done

    shift
done


# CRAZY CRAZY CRAZY gnu parallel command line
#
# Here's the main shape:
#
#   parallel --xapply <command> ::: <packages> ::: <tests> ::: <regions>
#
# Runs the command with pairs of "<package> <test> <region"> as arguments,
# cycling through regions as necessary (packages and tests will have the same length)
# (--xapply is also sometimes called --link but --xapply is supported on more GNUP versions)
#
# The command that is run for each pair of arguments is:
#
#   parallel --semaphore --fg -j1 --id <semaphore_name> <actual_command>
#
# To make sure that there is only -j1 job for every --id semaphore at
# a time, --fg to see the command to completion. We use the <region> ({3}) as a semaphore,
# to make sure only one test is ever running on a single region.
#
# Mix in some -u to avoid buffering output, --delay to avoid tests trashing each other's cdk.json.
parallel --xapply -j0 -u --delay 3 \
    parallel \
        --fg --semaphore -j1 --id {3} -u \
        "echo Running {1}:{2} in {3}; env AWS_REGION={3} ${lerna} --loglevel=silent --scope {1} run integ -- --silent -- {2} || { echo Running {1}:{2} in {3} failed; exit 1; }" \
    ::: "${packages[@]}" \
    ::: "${tests[@]}" \
    ::: "${regions[@]}"