/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */
package org.apache.iceberg.util;

import static org.assertj.core.api.Assertions.assertThat;
import static org.assertj.core.api.Assumptions.assumeThat;

import java.util.Map;
import java.util.Optional;
import org.apache.iceberg.relocated.com.google.common.collect.ImmutableMap;
import org.junit.jupiter.api.Test;

class TestEnvironmentUtil {
  @Test
  public void testEnvironmentSubstitution() {
    Optional<Map.Entry<String, String>> envEntry = System.getenv().entrySet().stream().findFirst();
    assumeThat(envEntry).as("Expecting at least one env. variable to be present").isPresent();
    Map<String, String> resolvedProps =
        EnvironmentUtil.resolveAll(ImmutableMap.of("env-test", "env:" + envEntry.get().getKey()));
    assertThat(resolvedProps)
        .as("Should get the user from the environment")
        .isEqualTo(ImmutableMap.of("env-test", envEntry.get().getValue()));
  }

  @Test
  public void testMultipleEnvironmentSubstitutions() {
    Map<String, String> result =
        EnvironmentUtil.resolveAll(
            ImmutableMap.of("USER", "u", "VAR", "value"),
            ImmutableMap.of("user-test", "env:USER", "other", "left-alone", "var", "env:VAR"));

    assertThat(result)
        .as("Should resolve all values starting with env:")
        .isEqualTo(ImmutableMap.of("user-test", "u", "other", "left-alone", "var", "value"));
  }

  @Test
  public void testEnvironmentSubstitutionWithMissingVar() {
    Map<String, String> result =
        EnvironmentUtil.resolveAll(ImmutableMap.of(), ImmutableMap.of("user-test", "env:USER"));

    assertThat(result)
        .as("Should not contain values with missing environment variables")
        .isEqualTo(ImmutableMap.of());
  }
}
