package org.briarproject.briar.blog;

import org.briarproject.bramble.api.FormatException;
import org.briarproject.bramble.api.client.ClientHelper;
import org.briarproject.bramble.api.data.BdfDictionary;
import org.briarproject.bramble.api.data.BdfEntry;
import org.briarproject.bramble.api.data.BdfList;
import org.briarproject.bramble.api.data.MetadataEncoder;
import org.briarproject.bramble.api.identity.Author;
import org.briarproject.bramble.api.identity.AuthorId;
import org.briarproject.bramble.api.sync.ClientId;
import org.briarproject.bramble.api.sync.Group;
import org.briarproject.bramble.api.sync.GroupFactory;
import org.briarproject.bramble.api.sync.GroupId;
import org.briarproject.bramble.api.sync.Message;
import org.briarproject.bramble.api.sync.MessageFactory;
import org.briarproject.bramble.api.sync.MessageId;
import org.briarproject.bramble.api.system.Clock;
import org.briarproject.bramble.system.SystemClock;
import org.briarproject.bramble.test.TestUtils;
import org.briarproject.briar.api.blog.Blog;
import org.briarproject.briar.api.blog.BlogFactory;
import org.briarproject.briar.test.BriarTestCase;
import org.jmock.Expectations;
import org.jmock.Mockery;
import org.junit.Test;

import java.io.IOException;
import java.security.GeneralSecurityException;

import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_PUBLIC_KEY_LENGTH;
import static org.briarproject.briar.api.blog.BlogConstants.KEY_AUTHOR;
import static org.briarproject.briar.api.blog.BlogConstants.KEY_AUTHOR_ID;
import static org.briarproject.briar.api.blog.BlogConstants.KEY_AUTHOR_NAME;
import static org.briarproject.briar.api.blog.BlogConstants.KEY_COMMENT;
import static org.briarproject.briar.api.blog.BlogConstants.KEY_ORIGINAL_MSG_ID;
import static org.briarproject.briar.api.blog.BlogConstants.KEY_ORIGINAL_PARENT_MSG_ID;
import static org.briarproject.briar.api.blog.BlogConstants.KEY_PARENT_MSG_ID;
import static org.briarproject.briar.api.blog.BlogConstants.KEY_PUBLIC_KEY;
import static org.briarproject.briar.api.blog.BlogConstants.KEY_READ;
import static org.briarproject.briar.api.blog.BlogPostFactory.SIGNING_LABEL_COMMENT;
import static org.briarproject.briar.api.blog.BlogPostFactory.SIGNING_LABEL_POST;
import static org.briarproject.briar.api.blog.MessageType.COMMENT;
import static org.briarproject.briar.api.blog.MessageType.POST;
import static org.briarproject.briar.api.blog.MessageType.WRAPPED_COMMENT;
import static org.briarproject.briar.api.blog.MessageType.WRAPPED_POST;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;

public class BlogPostValidatorTest extends BriarTestCase {

	private final Mockery context = new Mockery();
	private final Blog blog;
	private final BdfDictionary authorDict;
	private final ClientId clientId;
	private final byte[] descriptor;
	private final Group group;
	private final Message message;
	private final BlogPostValidator validator;
	private final GroupFactory groupFactory = context.mock(GroupFactory.class);
	private final MessageFactory messageFactory =
			context.mock(MessageFactory.class);
	private final BlogFactory blogFactory = context.mock(BlogFactory.class);
	private final ClientHelper clientHelper = context.mock(ClientHelper.class);
	private final Author author;
	private final String body = TestUtils.getRandomString(42);

	public BlogPostValidatorTest() {
		GroupId groupId = new GroupId(TestUtils.getRandomId());
		clientId = BlogManagerImpl.CLIENT_ID;
		descriptor = TestUtils.getRandomBytes(42);
		group = new Group(groupId, clientId, descriptor);
		AuthorId authorId =
				new AuthorId(TestUtils.getRandomBytes(AuthorId.LENGTH));
		byte[] publicKey = TestUtils.getRandomBytes(MAX_PUBLIC_KEY_LENGTH);
		author = new Author(authorId, "Author", publicKey);
		authorDict = BdfDictionary.of(
				new BdfEntry(KEY_AUTHOR_ID, author.getId()),
				new BdfEntry(KEY_AUTHOR_NAME, author.getName()),
				new BdfEntry(KEY_PUBLIC_KEY, author.getPublicKey())
		);
		blog = new Blog(group, author);

		MessageId messageId = new MessageId(TestUtils.getRandomId());
		long timestamp = System.currentTimeMillis();
		byte[] raw = TestUtils.getRandomBytes(123);
		message = new Message(messageId, group.getId(), timestamp, raw);

		MetadataEncoder metadataEncoder = context.mock(MetadataEncoder.class);
		Clock clock = new SystemClock();
		validator =
				new BlogPostValidator(groupFactory, messageFactory, blogFactory,
						clientHelper, metadataEncoder, clock);
		context.assertIsSatisfied();
	}

	@Test
	public void testValidateProperBlogPost()
			throws IOException, GeneralSecurityException {
		final byte[] sigBytes = TestUtils.getRandomBytes(42);
		BdfList m = BdfList.of(POST.getInt(), body, sigBytes);

		BdfList signed =
				BdfList.of(blog.getId(), message.getTimestamp(), body);
		expectCrypto(SIGNING_LABEL_POST, signed, sigBytes);
		final BdfDictionary result =
				validator.validateMessage(message, group, m).getDictionary();

		assertEquals(authorDict, result.getDictionary(KEY_AUTHOR));
		assertFalse(result.getBoolean(KEY_READ));
		context.assertIsSatisfied();
	}

	@Test(expected = FormatException.class)
	public void testValidateBlogPostWithoutAttachments()
			throws IOException, GeneralSecurityException {
		BdfList content = BdfList.of(null, null, body);
		BdfList m = BdfList.of(POST.getInt(), content, null);

		validator.validateMessage(message, group, m).getDictionary();
	}

	@Test(expected = FormatException.class)
	public void testValidateBlogPostWithoutSignature()
			throws IOException, GeneralSecurityException {
		BdfList content = BdfList.of(null, null, body, null);
		BdfList m = BdfList.of(POST.getInt(), content, null);

		validator.validateMessage(message, group, m).getDictionary();
	}

	@Test
	public void testValidateProperBlogComment()
			throws IOException, GeneralSecurityException {
		// comment, parent_original_id, parent_id, signature
		String comment = "This is a blog comment";
		MessageId pOriginalId = new MessageId(TestUtils.getRandomId());
		MessageId currentId = new MessageId(TestUtils.getRandomId());
		final byte[] sigBytes = TestUtils.getRandomBytes(42);
		BdfList m =
				BdfList.of(COMMENT.getInt(), comment, pOriginalId, currentId,
						sigBytes);

		BdfList signed =
				BdfList.of(blog.getId(), message.getTimestamp(), comment,
						pOriginalId, currentId);
		expectCrypto(SIGNING_LABEL_COMMENT, signed, sigBytes);
		final BdfDictionary result =
				validator.validateMessage(message, group, m).getDictionary();

		assertEquals(comment, result.getString(KEY_COMMENT));
		assertEquals(authorDict, result.getDictionary(KEY_AUTHOR));
		assertEquals(pOriginalId.getBytes(),
				result.getRaw(KEY_ORIGINAL_PARENT_MSG_ID));
		assertEquals(currentId.getBytes(), result.getRaw(KEY_PARENT_MSG_ID));
		assertFalse(result.getBoolean(KEY_READ));
		context.assertIsSatisfied();
	}

	@Test
	public void testValidateProperEmptyBlogComment()
			throws IOException, GeneralSecurityException {
		// comment, parent_original_id, signature, parent_current_id
		MessageId originalId = new MessageId(TestUtils.getRandomId());
		MessageId currentId = new MessageId(TestUtils.getRandomId());
		final byte[] sigBytes = TestUtils.getRandomBytes(42);
		BdfList m =
				BdfList.of(COMMENT.getInt(), null, originalId, currentId,
						sigBytes);

		BdfList signed =
				BdfList.of(blog.getId(), message.getTimestamp(), null,
						originalId, currentId);
		expectCrypto(SIGNING_LABEL_COMMENT, signed, sigBytes);
		final BdfDictionary result =
				validator.validateMessage(message, group, m).getDictionary();

		assertFalse(result.containsKey(KEY_COMMENT));
		context.assertIsSatisfied();
	}

	@Test
	public void testValidateProperWrappedPost()
			throws IOException, GeneralSecurityException {
		// group descriptor, timestamp, content, signature
		final byte[] sigBytes = TestUtils.getRandomBytes(42);
		BdfList m =
				BdfList.of(WRAPPED_POST.getInt(), descriptor,
						message.getTimestamp(), body, sigBytes);

		BdfList signed =
				BdfList.of(blog.getId(), message.getTimestamp(), body);
		expectCrypto(SIGNING_LABEL_POST, signed, sigBytes);

		final BdfList originalList = BdfList.of(POST.getInt(), body, sigBytes);
		final byte[] originalBody = TestUtils.getRandomBytes(42);

		context.checking(new Expectations() {{
			oneOf(groupFactory).createGroup(clientId, descriptor);
			will(returnValue(blog.getGroup()));
			oneOf(clientHelper).toByteArray(originalList);
			will(returnValue(originalBody));
			oneOf(messageFactory)
					.createMessage(group.getId(), message.getTimestamp(),
							originalBody);
			will(returnValue(message));
		}});

		final BdfDictionary result =
				validator.validateMessage(message, group, m).getDictionary();

		assertEquals(authorDict, result.getDictionary(KEY_AUTHOR));
		context.assertIsSatisfied();
	}

	@Test
	public void testValidateProperWrappedComment()
			throws IOException, GeneralSecurityException {
		// group descriptor, timestamp, comment, parent_original_id, signature,
		// parent_current_id
		String comment = "This is another comment";
		MessageId originalId = new MessageId(TestUtils.getRandomId());
		MessageId oldId = new MessageId(TestUtils.getRandomId());
		final byte[] sigBytes = TestUtils.getRandomBytes(42);
		MessageId currentId = new MessageId(TestUtils.getRandomId());
		BdfList m = BdfList.of(WRAPPED_COMMENT.getInt(), descriptor,
				message.getTimestamp(), comment, originalId, oldId, sigBytes,
				currentId);

		BdfList signed = BdfList.of(blog.getId(), message.getTimestamp(),
				comment, originalId, oldId);
		expectCrypto(SIGNING_LABEL_COMMENT, signed, sigBytes);

		final BdfList originalList = BdfList.of(COMMENT.getInt(), comment,
				originalId, oldId, sigBytes);
		final byte[] originalBody = TestUtils.getRandomBytes(42);

		context.checking(new Expectations() {{
			oneOf(groupFactory).createGroup(clientId, descriptor);
			will(returnValue(blog.getGroup()));
			oneOf(clientHelper).toByteArray(originalList);
			will(returnValue(originalBody));
			oneOf(messageFactory)
					.createMessage(group.getId(), message.getTimestamp(),
							originalBody);
			will(returnValue(message));
		}});

		final BdfDictionary result =
				validator.validateMessage(message, group, m).getDictionary();

		assertEquals(comment, result.getString(KEY_COMMENT));
		assertEquals(authorDict, result.getDictionary(KEY_AUTHOR));
		assertEquals(
				message.getId().getBytes(), result.getRaw(KEY_ORIGINAL_MSG_ID));
		assertEquals(currentId.getBytes(), result.getRaw(KEY_PARENT_MSG_ID));
		context.assertIsSatisfied();
	}

	private void expectCrypto(final String label, final BdfList signed,
			final byte[] sig) throws IOException, GeneralSecurityException {
		context.checking(new Expectations() {{
			oneOf(blogFactory).parseBlog(group);
			will(returnValue(blog));
			oneOf(clientHelper)
					.verifySignature(label, sig, author.getPublicKey(), signed);
		}});
	}

}
