#!/usr/bin/env perl

# Copyright 2019 Imply Data, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

use strict;
use warnings;
use File::Basename;

sub fail_check {
  my ($current_version) = @_;
  my $current_version_text = $current_version
    ? "Your current version is: $current_version."
    : "No Java runtime was detected on your system.";

  print STDERR <<"EOT";
Imply requires Java 11, 17 or 21. $current_version_text

If you believe this check is in error or you want to proceed with an unsupported
Java runtime, you can skip this check using an environment variable:

  export IMPLY_SKIP_JAVA_CHECK=1

Otherwise, install Java 11, 17 or 21 in one of the following locations.

  * DRUID_JAVA_HOME
  * JAVA_HOME
  * java (installed on PATH)

EOT
  exit 1;
}

my $skip_var = $ENV{'IMPLY_SKIP_JAVA_CHECK'};
if ($skip_var && $skip_var ne "0" && $skip_var ne "false" && $skip_var ne "f") {
  exit 0;
}

my $cwd =  dirname(__FILE__);
my $java_bin_dir = `. $cwd/java-util && get_java_bin_dir 2>&1`;

# If we could not find java
if ($java_bin_dir eq "") {
  fail_check()
}
my $java_exec = "${java_bin_dir}/java";
my $java_version = qx["$java_exec" -version 2>&1];
if ($?) {
  fail_check();
}

# If we know it won't work, die. Otherwise hope for the best.
if ($java_version =~ /version \"((\d+)\.(\d+).*?)\"/ && $2 != 11 && $2 != 17 && $2 != 21 ) {
  fail_check($1);
}
