/*******************************************************************************
 * Copyright (c) 2005, 2017 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 *******************************************************************************/
package org.eclipse.dltk.core.tests.model;

import java.util.ArrayList;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.dltk.core.BufferChangedEvent;
import org.eclipse.dltk.core.IBuffer;
import org.eclipse.dltk.core.IBufferChangedListener;
import org.eclipse.dltk.core.ISourceModule;

import junit.framework.Test;

public class BufferTests extends ModifyingResourceTests
		implements IBufferChangedListener {

	final static String[] TEST_NATURES = new String[] {
			ModelTestsPlugin.TEST_NATURE };

	protected ArrayList<BufferChangedEvent> events = null;

	public BufferTests(String name) {
		super(ModelTestsPlugin.PLUGIN_NAME, name);
	}

	public static Test suite() {
		return new Suite(BufferTests.class);
	}

	/**
	 * @see AbstractModelTests#setUpSuite()
	 */
	@Override
	public void setUpSuite() throws Exception {
		super.setUpSuite();
		try {
			this.createScriptProject("P", TEST_NATURES, new String[] { "" });
			this.createFolder("P/x/y");
		} catch (CoreException e) {
			e.printStackTrace();
		}
	}

	/**
	 * @see AbstractModelTests#tearDownSuite()
	 */
	@Override
	public void tearDownSuite() throws Exception {
		super.tearDownSuite();
		AbstractModelTests.deleteProject("P");
	}

	protected IBuffer createBuffer(String path, String content)
			throws CoreException {
		waitUntilIndexesReady(); // ensure that the indexer is not reading the
									// file
		this.createFile(path, content);
		ISourceModule sm = this.getSourceModule(path);
		IBuffer buffer = sm.getBuffer();
		buffer.addBufferChangedListener(this);
		this.events = new ArrayList<>();
		return buffer;
	}

	/**
	 * Verify the buffer changed event. The given text must contain '\n' line
	 * separators.
	 */
	protected void assertBufferEvent(int offset, int length, String text) {
		assertTrue("events should not be null", this.events != null);
		assertTrue("events should not be empty", !this.events.isEmpty());
		BufferChangedEvent event = this.events.get(0);
		assertEquals("unexpected offset", offset, event.getOffset());
		assertEquals("unexpected length", length, event.getLength());
		if (text == null) {
			assertTrue("text should be null", event.getText() == null);
		} else {
			assertSourceEquals("unexpected text", text, event.getText());
		}
	}

	protected void deleteBuffer(IBuffer buffer) throws CoreException {
		buffer.removeBufferChangedListener(this);
		IResource resource = buffer.getUnderlyingResource();
		if (resource != null) {
			deleteResource(resource);
		}
	}

	/**
	 * Tests appending to a buffer.
	 */
	public void testAppend() throws CoreException {
		IBuffer buffer = this.createBuffer("P/x/y/A.txt",
				"package x.y;\n" + "public class A {\n" + "}");
		try {
			int oldLength = buffer.getLength();
			buffer.append("\nclass B {}");
			assertBufferEvent(oldLength, 0, "\nclass B {}");
			assertSourceEquals(
					"unexpected buffer contents", "package x.y;\n"
							+ "public class A {\n" + "}\n" + "class B {}",
					buffer.getContents());
			assertTrue("should have unsaved changes",
					buffer.hasUnsavedChanges());
		} finally {
			this.deleteBuffer(buffer);
		}
	}

	public void testClose() throws CoreException {
		IBuffer buffer = this.createBuffer("P/x/y/A.txt",
				"package x.y;\n" + "public class A {\n" + "}");
		try {
			buffer.close();
			assertBufferEvent(0, 0, null);
		} finally {
			this.deleteBuffer(buffer);
		}
	}

	/**
	 * Tests getting the underlying resource of a buffer.
	 */
	public void testGetUnderlyingResource() throws CoreException {
		IBuffer buffer = this.createBuffer("P/x/y/A.txt",
				"package x.y;\n" + "public class A {\n" + "}");
		ISourceModule copy = null;
		try {
			IFile file = this.getFile("P/x/y/A.txt");
			assertEquals("Unexpected underlying resource", file,
					buffer.getUnderlyingResource());

			copy = this.getSourceModule("P/x/y/A.txt").getWorkingCopy(null);
			assertEquals("Unexpected underlying resource 2", file,
					copy.getBuffer().getUnderlyingResource());
		} finally {
			this.deleteBuffer(buffer);
			if (copy != null) {
				copy.discardWorkingCopy();
			}
		}
	}

	/**
	 * Tests deleting text at the beginning of a buffer.
	 */
	public void testDeleteBeginning() throws CoreException {
		IBuffer buffer = this.createBuffer("P/x/y/A.txt",
				"package x.y;\n" + "public class A {\n" + "}");
		try {
			buffer.replace(0, 13, "");
			assertBufferEvent(0, 13, null);
			assertSourceEquals("unexpected buffer contents",
					"public class A {\n" + "}", buffer.getContents());
			assertTrue("should have unsaved changes",
					buffer.hasUnsavedChanges());
		} finally {
			this.deleteBuffer(buffer);
		}
	}

	/**
	 * Tests deleting text in the middle of a buffer.
	 */
	public void testDeleteMiddle() throws CoreException {
		IBuffer buffer = this.createBuffer("P/x/y/A.txt",
				"package x.y;\n" + "public class A {\n" + "}");
		try {
			// delete "public "
			buffer.replace(13, 7, "");
			assertBufferEvent(13, 7, null);
			assertSourceEquals("unexpected buffer contents",
					"package x.y;\n" + "class A {\n" + "}",
					buffer.getContents());
			assertTrue("should have unsaved changes",
					buffer.hasUnsavedChanges());
		} finally {
			this.deleteBuffer(buffer);
		}
	}

	/**
	 * Tests deleting text at the end of a buffer.
	 */
	public void testDeleteEnd() throws CoreException {
		IBuffer buffer = this.createBuffer("P/x/y/A.txt",
				"package x.y;\n" + "public class A {\n" + "}");
		try {
			// delete "public class A {\n}"
			buffer.replace(13, 18, "");
			assertBufferEvent(13, 18, null);
			assertSourceEquals("unexpected buffer contents", "package x.y;\n",
					buffer.getContents());
			assertTrue("should have unsaved changes",
					buffer.hasUnsavedChanges());
		} finally {
			this.deleteBuffer(buffer);
		}
	}

	/**
	 * Tests the buffer char retrieval via source position
	 */
	public void testGetChar() throws CoreException {
		IBuffer buffer = this.createBuffer("P/x/y/A.txt",
				"package x.y;\n" + "public class A {\n" + "}");
		try {
			assertEquals("Unexpected char at position 17", 'i',
					buffer.getChar(17));
		} finally {
			this.deleteBuffer(buffer);
		}
	}

	/**
	 * Tests the buffer char retrieval via source position doesn't throw an
	 * exception if the buffer is closed. (regression test for bug 46040 NPE in
	 * Eclipse console)
	 */
	public void testGetChar2() throws CoreException {
		IBuffer buffer = this.createBuffer("P/x/y/A.txt",
				"package x.y;\n" + "public class A {\n" + "}");
		buffer.close();
		try {
			assertEquals("Unexpected char at position 17", Character.MIN_VALUE,
					buffer.getChar(17));
		} finally {
			this.deleteBuffer(buffer);
		}
	}

	/**
	 * Tests the buffer getLength()
	 */
	public void testGetLength() throws CoreException {
		IBuffer buffer = this.createBuffer("P/x/y/A.txt",
				"package x.y;\n" + "public class A {\n" + "}");
		try {
			assertEquals("Unexpected length", 31, buffer.getLength());
		} finally {
			this.deleteBuffer(buffer);
		}
	}

	/**
	 * Tests the buffer text retrieval via source position
	 */
	public void testGetText() throws CoreException {
		IBuffer buffer = this.createBuffer("P/x/y/A.txt",
				"package x.y;\n" + "public class A {\n" + "}");
		try {
			assertSourceEquals("Unexpected text (1)", "p",
					buffer.getText(0, 1));
			assertSourceEquals("Unexpected text (2)", "public",
					buffer.getText(13, 6));
			assertSourceEquals("Unexpected text (3)", "",
					buffer.getText(10, 0));
		} finally {
			this.deleteBuffer(buffer);
		}
	}

	/**
	 * Tests inserting text at the beginning of a buffer.
	 */
	public void testInsertBeginning() throws CoreException {
		IBuffer buffer = this.createBuffer("P/x/y/A.txt",
				"package x.y;\n" + "public class A {\n" + "}");
		try {
			buffer.replace(0, 0, "/* copyright mycompany */\n");
			assertBufferEvent(0, 0, "/* copyright mycompany */\n");
			assertSourceEquals(
					"unexpected buffer contents", "/* copyright mycompany */\n"
							+ "package x.y;\n" + "public class A {\n" + "}",
					buffer.getContents());
			assertTrue("should have unsaved changes",
					buffer.hasUnsavedChanges());
		} finally {
			this.deleteBuffer(buffer);
		}
	}

	/**
	 * Tests replacing text at the beginning of a buffer.
	 */
	public void testReplaceBeginning() throws CoreException {
		IBuffer buffer = this.createBuffer("P/x/y/A.txt",
				"package x.y;\n" + "public class A {\n" + "}");
		try {
			buffer.replace(0, 13, "package other;\n");
			assertBufferEvent(0, 13, "package other;\n");
			assertSourceEquals("unexpected buffer contents",
					"package other;\n" + "public class A {\n" + "}",
					buffer.getContents());
			assertTrue("should have unsaved changes",
					buffer.hasUnsavedChanges());
		} finally {
			this.deleteBuffer(buffer);
		}
	}

	/**
	 * Tests replacing text in the middle of a buffer.
	 */
	public void testReplaceMiddle() throws CoreException {
		IBuffer buffer = this.createBuffer("P/x/y/A.txt",
				"package x.y;\n" + "public class A {\n" + "}");
		try {
			// replace "public class A" after the \n of package statement
			buffer.replace(13, 14, "public class B");
			assertBufferEvent(13, 14, "public class B");
			assertSourceEquals("unexpected buffer contents",
					"package x.y;\n" + "public class B {\n" + "}",
					buffer.getContents());
			assertTrue("should have unsaved changes",
					buffer.hasUnsavedChanges());
		} finally {
			this.deleteBuffer(buffer);
		}
	}

	/**
	 * Tests replacing text at the end of a buffer.
	 */
	public void testReplaceEnd() throws CoreException {
		IBuffer buffer = this.createBuffer("P/x/y/A.txt",
				"package x.y;\n" + "public class A {\n" + "}");
		try {
			// replace "}" at the end of cu with "}\n"
			int end = buffer.getLength();
			buffer.replace(end - 1, 1, "}\n");
			assertBufferEvent(end - 1, 1, "}\n");
			assertSourceEquals("unexpected buffer contents",
					"package x.y;\n" + "public class A {\n" + "}\n",
					buffer.getContents());
			assertTrue("should have unsaved changes",
					buffer.hasUnsavedChanges());
		} finally {
			this.deleteBuffer(buffer);
		}
	}

	/**
	 * Tests inserting text in the middle of a buffer.
	 */
	public void testInsertMiddle() throws CoreException {
		IBuffer buffer = this.createBuffer("P/x/y/A.txt",
				"package x.y;\n" + "public class A {\n" + "}");
		try {
			// insert after the \n of package statement
			buffer.replace(13, 0, "/* class comment */\n");
			assertBufferEvent(13, 0, "/* class comment */\n");
			assertSourceEquals("unexpected buffer contents", "package x.y;\n"
					+ "/* class comment */\n" + "public class A {\n" + "}",
					buffer.getContents());
			assertTrue("should have unsaved changes",
					buffer.hasUnsavedChanges());
		} finally {
			this.deleteBuffer(buffer);
		}
	}

	/**
	 * Tests inserting text at the end of a buffer.
	 */
	public void testInsertEnd() throws CoreException {
		IBuffer buffer = this.createBuffer("P/x/y/A.txt",
				"package x.y;\n" + "public class A {\n" + "}");
		try {
			// insert after the \n of package statement
			int end = buffer.getLength();
			buffer.replace(end, 0, "\nclass B {}");
			assertBufferEvent(end, 0, "\nclass B {}");
			assertSourceEquals(
					"unexpected buffer contents", "package x.y;\n"
							+ "public class A {\n" + "}\n" + "class B {}",
					buffer.getContents());
			assertTrue("should have unsaved changes",
					buffer.hasUnsavedChanges());
		} finally {
			this.deleteBuffer(buffer);
		}
	}

	@Override
	public void bufferChanged(BufferChangedEvent bufferChangedEvent) {
		this.events.add(bufferChangedEvent);
	}
}