/*
 * Copyright 2025 Google LLC
 *
 * 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.
 */

package genai.counttokens;

import static com.google.common.truth.Truth.assertThat;
import static com.google.common.truth.Truth.assertWithMessage;

import com.google.genai.types.GenerateContentResponseUsageMetadata;
import com.google.genai.types.TokensInfo;
import java.io.ByteArrayOutputStream;
import java.io.PrintStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import org.junit.After;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

@RunWith(JUnit4.class)
public class CountTokensIT {

  private static final String GEMINI_FLASH = "gemini-2.5-flash";
  private ByteArrayOutputStream bout;
  private PrintStream out;

  // Check if the required environment variables are set.
  public static void requireEnvVar(String envVarName) {
    assertWithMessage(String.format("Missing environment variable '%s' ", envVarName))
        .that(System.getenv(envVarName))
        .isNotEmpty();
  }

  @BeforeClass
  public static void checkRequirements() {
    requireEnvVar("GOOGLE_CLOUD_PROJECT");
  }

  @Before
  public void setUp() {
    bout = new ByteArrayOutputStream();
    out = new PrintStream(bout);
    System.setOut(out);
  }

  @After
  public void tearDown() {
    System.setOut(null);
  }

  @Test
  public void testCountTokensWithText() {
    Optional<Integer> response = CountTokensWithText.countTokens(GEMINI_FLASH);
    assertThat(response).isPresent();
    assertThat(response.get()).isGreaterThan(0);
  }

  @Test
  public void testCountTokensWithTextAndVideo() {
    Optional<Integer> response = CountTokensWithTextAndVideo.countTokens(GEMINI_FLASH);
    assertThat(response).isPresent();
    assertThat(response.get()).isGreaterThan(6);
  }

  @Test
  public void testCountTokensComputeWithText() {

    List<TokensInfo> response =
        CountTokensComputeWithText.computeTokens(GEMINI_FLASH).orElse(new ArrayList<>());

    assertThat(response).isNotEmpty();
    TokensInfo tokensInfo = response.get(0);

    assertThat(tokensInfo.role()).isPresent();

    assertThat(tokensInfo.tokenIds()).isPresent();
    assertThat(tokensInfo.tokenIds().get()).isNotEmpty();

    assertThat(tokensInfo.tokens()).isPresent();
    assertThat(tokensInfo.tokens().get()).isNotEmpty();
  }

  @Test
  public void testCountTokensLocalTokenizerComputeWithTxt() {

    List<TokensInfo> response =
        CountTokensLocalTokenizerComputeWithTxt.computeTokens(GEMINI_FLASH)
            .orElse(new ArrayList<>());

    assertThat(response).isNotEmpty();
    TokensInfo tokensInfo = response.get(0);

    assertThat(tokensInfo.role()).isPresent();

    assertThat(tokensInfo.tokenIds()).isPresent();
    assertThat(tokensInfo.tokenIds().get()).isNotEmpty();

    assertThat(tokensInfo.tokens()).isPresent();
    assertThat(tokensInfo.tokens().get()).isNotEmpty();
  }

  @Test
  public void testCountTokensLocalTokenizerWithTxt() {
    Optional<Integer> response = CountTokensLocalTokenizerWithTxt.countTokens(GEMINI_FLASH);
    assertThat(response).isPresent();
    assertThat(response.get()).isGreaterThan(0);
  }

  @Test
  public void testCountTokensResponseWithText() {

    Optional<GenerateContentResponseUsageMetadata> response =
        CountTokensResponseWithText.countTokens(GEMINI_FLASH);

    assertThat(response).isPresent();
    assertThat(response.get().totalTokenCount()).isPresent();
    assertThat(response.get().totalTokenCount().get()).isGreaterThan(0);
    assertThat(response.get().promptTokenCount()).isPresent();
    assertThat(response.get().promptTokenCount().get()).isGreaterThan(0);
  }
}
