/*
    * 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.eclipse.aether.connector.basic;
  
  import java.io.File;
  import java.io.IOException;
  import java.net.URI;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.HashMap;
  import java.util.LinkedHashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.eclipse.aether.internal.test.util.TestChecksumProcessor;
  import org.eclipse.aether.internal.test.util.TestFileUtils;
  import org.eclipse.aether.spi.connector.checksum.ChecksumAlgorithmFactory;
  import org.eclipse.aether.spi.connector.checksum.ChecksumPolicy;
  import org.eclipse.aether.spi.connector.checksum.ChecksumPolicy.ChecksumKind;
  import org.eclipse.aether.spi.connector.layout.RepositoryLayout;
  import org.eclipse.aether.transfer.ChecksumFailureException;
  import org.junit.jupiter.api.BeforeEach;
  import org.junit.jupiter.api.Test;
  
  import static org.eclipse.aether.connector.basic.TestChecksumAlgorithmSelector.MD5;
  import static org.eclipse.aether.connector.basic.TestChecksumAlgorithmSelector.SHA1;
  import static org.junit.jupiter.api.Assertions.*;
  
  public class ChecksumValidatorTest {
  
      private static class StubChecksumPolicy implements ChecksumPolicy {
  
          boolean inspectAll;
  
          boolean tolerateFailure;
  
          private final ArrayList<String> callbacks = new ArrayList<>();
  
          private Object conclusion;
  
          @Override
          public boolean onChecksumMatch(String algorithm, ChecksumKind kind) {
              callbacks.add(String.format("match(%s, %s)", algorithm, kind));
              if (inspectAll) {
                  if (conclusion == null) {
                      conclusion = true;
                  }
                  return false;
              }
              return true;
          }
  
          @Override
          public void onChecksumMismatch(String algorithm, ChecksumKind kind, ChecksumFailureException exception)
                  throws ChecksumFailureException {
              callbacks.add(String.format("mismatch(%s, %s)", algorithm, kind));
              if (inspectAll) {
                  conclusion = exception;
                  return;
              }
              throw exception;
          }
  
          @Override
          public void onChecksumError(String algorithm, ChecksumKind kind, ChecksumFailureException exception) {
              callbacks.add(String.format(
                      "error(%s, %s, %s)", algorithm, kind, exception.getCause().getMessage()));
          }
  
          @Override
          public void onNoMoreChecksums() throws ChecksumFailureException {
              callbacks.add(String.format("noMore()"));
              if (conclusion instanceof ChecksumFailureException) {
                  throw (ChecksumFailureException) conclusion;
              } else if (!Boolean.TRUE.equals(conclusion)) {
                  throw new ChecksumFailureException("no checksums");
              }
          }
  
          @Override
          public void onTransferRetry() {
             callbacks.add(String.format("retry()"));
         }
 
         @Override
         public boolean onTransferChecksumFailure(ChecksumFailureException exception) {
             callbacks.add(String.format("fail(%s)", exception.getMessage()));
             return tolerateFailure;
         }
 
         void assertCallbacks(String... callbacks) {
             assertEquals(Arrays.asList(callbacks), this.callbacks);
         }
     }
 
     private static class StubChecksumFetcher implements ChecksumValidator.ChecksumFetcher {
 
         HashMap<URI, Object> checksums = new HashMap<>();
 
         ArrayList<Path> checksumFiles = new ArrayList<>();
 
         private final ArrayList<URI> fetchedFiles = new ArrayList<>();
 
         @Override
         public boolean fetchChecksum(URI remote, Path local) throws Exception {
             fetchedFiles.add(remote);
             Object checksum = checksums.get(remote);
             if (checksum == null) {
                 return false;
             }
             if (checksum instanceof Exception) {
                 throw (Exception) checksum;
             }
             TestFileUtils.writeString(local.toFile(), checksum.toString());
             checksumFiles.add(local);
             return true;
         }
 
         void mock(String algo, Object value) {
             checksums.put(toUri(algo), value);
         }
 
         void assertFetchedFiles(String... algos) {
             List<URI> expected = new ArrayList<>();
             for (String algo : algos) {
                 expected.add(toUri(algo));
             }
             assertEquals(expected, fetchedFiles);
         }
 
         private static URI toUri(String algo) {
             return newChecksum(algo).getLocation();
         }
     }
 
     private StubChecksumPolicy policy;
 
     private StubChecksumFetcher fetcher;
 
     private File dataFile;
 
     private static final TestChecksumAlgorithmSelector selector = new TestChecksumAlgorithmSelector();
 
     private List<ChecksumAlgorithmFactory> newChecksumAlgorithmFactories(String... factories) {
         List<ChecksumAlgorithmFactory> checksums = new ArrayList<>();
         for (String factory : factories) {
             checksums.add(selector.select(factory));
         }
         return checksums;
     }
 
     private static RepositoryLayout.ChecksumLocation newChecksum(String factory) {
         return RepositoryLayout.ChecksumLocation.forLocation(URI.create("file"), selector.select(factory));
     }
 
     private List<RepositoryLayout.ChecksumLocation> newChecksums(
             List<ChecksumAlgorithmFactory> checksumAlgorithmFactories) {
         List<RepositoryLayout.ChecksumLocation> checksums = new ArrayList<>();
         for (ChecksumAlgorithmFactory factory : checksumAlgorithmFactories) {
             checksums.add(RepositoryLayout.ChecksumLocation.forLocation(URI.create("file"), factory));
         }
         return checksums;
     }
 
     private ChecksumValidator newValidator(String... factories) {
         return newValidator(null, factories);
     }
 
     private ChecksumValidator newValidator(Map<String, String> providedChecksums, String... factories) {
         List<ChecksumAlgorithmFactory> checksumAlgorithmFactories = newChecksumAlgorithmFactories(factories);
         return new ChecksumValidator(
                 dataFile.toPath(),
                 checksumAlgorithmFactories,
                 new TestChecksumProcessor(),
                 fetcher,
                 policy,
                 providedChecksums,
                 newChecksums(checksumAlgorithmFactories));
     }
 
     private Map<String, ?> checksums(String... algoDigestPairs) {
         Map<String, Object> checksums = new LinkedHashMap<>();
         for (int i = 0; i < algoDigestPairs.length; i += 2) {
             String algo = algoDigestPairs[i];
             String digest = algoDigestPairs[i + 1];
             if (digest == null) {
                 checksums.put(algo, new IOException("error"));
             } else {
                 checksums.put(algo, digest);
             }
         }
         return checksums;
     }
 
     @BeforeEach
     void init() throws Exception {
         dataFile = TestFileUtils.createTempFile("");
         dataFile.delete();
         policy = new StubChecksumPolicy();
         fetcher = new StubChecksumFetcher();
     }
 
     @Test
     void testValidate_NullPolicy() throws Exception {
         policy = null;
         ChecksumValidator validator = newValidator(SHA1);
         validator.validate(checksums(SHA1, "ignored"), null);
         fetcher.assertFetchedFiles();
     }
 
     @Test
     void testValidate_AcceptOnFirstMatch() throws Exception {
         ChecksumValidator validator = newValidator(SHA1);
         fetcher.mock(SHA1, "foo");
         validator.validate(checksums(SHA1, "foo"), null);
         fetcher.assertFetchedFiles(SHA1);
         policy.assertCallbacks("match(SHA-1, REMOTE_EXTERNAL)");
     }
 
     @Test
     void testValidate_FailOnFirstMismatch() {
         ChecksumValidator validator = newValidator(SHA1);
         fetcher.mock(SHA1, "foo");
         try {
             validator.validate(checksums(SHA1, "not-foo"), null);
             fail("expected exception");
         } catch (ChecksumFailureException e) {
             assertEquals("foo", e.getExpected());
             assertEquals(ChecksumKind.REMOTE_EXTERNAL.name(), e.getExpectedKind());
             assertEquals("not-foo", e.getActual());
             assertTrue(e.isRetryWorthy());
         }
         fetcher.assertFetchedFiles(SHA1);
         policy.assertCallbacks("mismatch(SHA-1, REMOTE_EXTERNAL)");
     }
 
     @Test
     void testValidate_AcceptOnEnd() throws Exception {
         policy.inspectAll = true;
         ChecksumValidator validator = newValidator(SHA1, MD5);
         fetcher.mock(SHA1, "foo");
         fetcher.mock(MD5, "bar");
         validator.validate(checksums(SHA1, "foo", MD5, "bar"), null);
         fetcher.assertFetchedFiles(SHA1, MD5);
         policy.assertCallbacks("match(SHA-1, REMOTE_EXTERNAL)", "match(MD5, REMOTE_EXTERNAL)", "noMore()");
     }
 
     @Test
     void testValidate_FailOnEnd() {
         policy.inspectAll = true;
         ChecksumValidator validator = newValidator(SHA1, MD5);
         fetcher.mock(SHA1, "foo");
         fetcher.mock(MD5, "bar");
         try {
             validator.validate(checksums(SHA1, "not-foo", MD5, "bar"), null);
             fail("expected exception");
         } catch (ChecksumFailureException e) {
             assertEquals("foo", e.getExpected());
             assertEquals(ChecksumKind.REMOTE_EXTERNAL.name(), e.getExpectedKind());
             assertEquals("not-foo", e.getActual());
             assertTrue(e.isRetryWorthy());
         }
         fetcher.assertFetchedFiles(SHA1, MD5);
         policy.assertCallbacks("mismatch(SHA-1, REMOTE_EXTERNAL)", "match(MD5, REMOTE_EXTERNAL)", "noMore()");
     }
 
     @Test
     void testValidate_IncludedBeforeExternal() throws Exception {
         policy.inspectAll = true;
         HashMap<String, String> provided = new HashMap<>();
         provided.put(SHA1, "foo");
         ChecksumValidator validator = newValidator(provided, SHA1, MD5);
         fetcher.mock(SHA1, "foo");
         fetcher.mock(MD5, "bar");
         validator.validate(checksums(SHA1, "foo", MD5, "bar"), checksums(SHA1, "foo", MD5, "bar"));
         fetcher.assertFetchedFiles(SHA1, MD5);
         policy.assertCallbacks(
                 "match(SHA-1, PROVIDED)",
                 "match(SHA-1, REMOTE_INCLUDED)",
                 "match(MD5, REMOTE_INCLUDED)",
                 "match(SHA-1, REMOTE_EXTERNAL)",
                 "match(MD5, REMOTE_EXTERNAL)",
                 "noMore()");
     }
 
     @Test
     void testValidate_CaseInsensitive() throws Exception {
         policy.inspectAll = true;
         ChecksumValidator validator = newValidator(SHA1);
         fetcher.mock(SHA1, "FOO");
         validator.validate(checksums(SHA1, "foo"), checksums(SHA1, "foo"));
         policy.assertCallbacks("match(SHA-1, REMOTE_INCLUDED)", "match(SHA-1, REMOTE_EXTERNAL)", "noMore()");
     }
 
     @Test
     void testValidate_MissingRemoteChecksum() throws Exception {
         ChecksumValidator validator = newValidator(SHA1, MD5);
         fetcher.mock(MD5, "bar");
         validator.validate(checksums(MD5, "bar"), null);
         fetcher.assertFetchedFiles(SHA1, MD5);
         policy.assertCallbacks("match(MD5, REMOTE_EXTERNAL)");
     }
 
     @Test
     void testValidate_InaccessibleRemoteChecksum() throws Exception {
         ChecksumValidator validator = newValidator(SHA1, MD5);
         fetcher.mock(SHA1, new IOException("inaccessible"));
         fetcher.mock(MD5, "bar");
         validator.validate(checksums(MD5, "bar"), null);
         fetcher.assertFetchedFiles(SHA1, MD5);
         policy.assertCallbacks("error(SHA-1, REMOTE_EXTERNAL, inaccessible)", "match(MD5, REMOTE_EXTERNAL)");
     }
 
     @Test
     void testValidate_InaccessibleLocalChecksum() throws Exception {
         ChecksumValidator validator = newValidator(SHA1, MD5);
         fetcher.mock(SHA1, "foo");
         fetcher.mock(MD5, "bar");
         validator.validate(checksums(SHA1, null, MD5, "bar"), null);
         fetcher.assertFetchedFiles(MD5);
         policy.assertCallbacks("error(SHA-1, REMOTE_EXTERNAL, error)", "match(MD5, REMOTE_EXTERNAL)");
     }
 
     @Test
     void testHandle_Accept() {
         policy.tolerateFailure = true;
         ChecksumValidator validator = newValidator(SHA1);
         assertTrue(validator.handle(new ChecksumFailureException("accept")));
         policy.assertCallbacks("fail(accept)");
     }
 
     @Test
     void testHandle_Reject() {
         policy.tolerateFailure = false;
         ChecksumValidator validator = newValidator(SHA1);
         assertFalse(validator.handle(new ChecksumFailureException("reject")));
         policy.assertCallbacks("fail(reject)");
     }
 
     @Test
     void testRetry_ResetPolicy() {
         ChecksumValidator validator = newValidator(SHA1);
         validator.retry();
         policy.assertCallbacks("retry()");
     }
 
     @Test
     void testRetry_RemoveTempFiles() throws Exception {
         ChecksumValidator validator = newValidator(SHA1);
         fetcher.mock(SHA1, "foo");
         validator.validate(checksums(SHA1, "foo"), null);
         fetcher.assertFetchedFiles(SHA1);
         assertEquals(1, fetcher.checksumFiles.size());
         validator.retry();
         for (Path file : fetcher.checksumFiles) {
             assertFalse(Files.exists(file), file.toAbsolutePath().toString());
         }
     }
 
     @Test
     void testCommit_SaveChecksumFiles() throws Exception {
         policy.inspectAll = true;
         ChecksumValidator validator = newValidator(SHA1, MD5);
         fetcher.mock(MD5, "bar");
         validator.validate(checksums(SHA1, "foo", MD5, "bar"), checksums(SHA1, "foo"));
         assertEquals(1, fetcher.checksumFiles.size());
         validator.commit();
         File checksumFile = new File(dataFile.getPath() + ".sha1");
         assertTrue(checksumFile.isFile(), checksumFile.getAbsolutePath());
         assertEquals("foo", TestFileUtils.readString(checksumFile));
         checksumFile = new File(dataFile.getPath() + ".md5");
         assertTrue(checksumFile.isFile(), checksumFile.getAbsolutePath());
         assertEquals("bar", TestFileUtils.readString(checksumFile));
         for (Path file : fetcher.checksumFiles) {
             assertFalse(Files.exists(file), file.toAbsolutePath().toString());
         }
     }
 
     @Test
     void testNoCommit_NoTempFiles() throws Exception {
         ChecksumValidator validator = newValidator(SHA1);
         fetcher.mock(SHA1, "foo");
         validator.validate(checksums(SHA1, "foo"), null);
         fetcher.assertFetchedFiles(SHA1);
         assertEquals(1, fetcher.checksumFiles.size());
         for (Path file : fetcher.checksumFiles) {
             assertFalse(Files.exists(file), file.toAbsolutePath().toString());
         }
     }
 }