package terminal;

import static org.junit.Assert.assertTrue;

import java.io.*;

import org.junit.*;

import com.googlecode.lanterna.*;
import com.googlecode.lanterna.input.*;
import com.googlecode.lanterna.terminal.virtual.*;

public class LispTerminalAttempt {

    private PipedInputStream inputReader;
    private PipedOutputStream inputWriter;
    private PipedInputStream outputReader;
    private PipedOutputStream outputWriter;
    private VirtualTerminal virtualTerminal;
    private LispTerminal lispTerminal;

    private void pressKey(KeyType keyType) {
        virtualTerminal.addInput(new KeyStroke(keyType));
        sleep();
    }

    private void enterCharacter(char character) {
        virtualTerminal.addInput(new KeyStroke(character, false, false));
        sleep();
    }

    private void enterCharacters(String characters) {
        for (char c : characters.toCharArray())
            virtualTerminal.addInput(new KeyStroke(c, false, false));

        sleep();
    }

    private void sleep() {
        try {
            Thread.sleep(15);
        } catch (InterruptedException e) {}
    }

    private void assertCursorPosition(int column, int row) {
        assertTrue(virtualTerminal.getCursorBufferPosition().getColumn() == column);
        assertTrue(virtualTerminal.getCursorBufferPosition().getRow() == row);
    }

    private void assertCharacterAtPosition(char character, int column, int row) {
        TerminalPosition position = new TerminalPosition(column, row);
        assertTrue(virtualTerminal.getBufferCharacter(position).getCharacter() == character);
    }

    private void setColumns(int columns) {
        virtualTerminal.setTerminalSize(new TerminalSize(columns, virtualTerminal.getTerminalSize().getRows()));
    }

    @Before
    public void setUp() throws IOException {
        inputReader = new PipedInputStream();
        inputWriter = new PipedOutputStream(inputReader);
        outputReader = new PipedInputStream();
        outputWriter = new PipedOutputStream(outputReader);
        virtualTerminal = new DefaultVirtualTerminal();
        lispTerminal = new LispTerminal(virtualTerminal, inputWriter, outputReader);
        lispTerminal.run();
    }

    @After
    public void tearDown() throws IOException {
        lispTerminal.finish();
        outputWriter.close();
    }

    @Test
    public void leftArrowDoesNotMovePastOrigin() {
        pressKey(KeyType.ArrowLeft);
        assertCursorPosition(0, 0);
    }

    @Test
    public void leftArrowWorksAfterEnteringCharacters() {
        enterCharacters("abc");
        assertCursorPosition(3, 0);
        pressKey(KeyType.ArrowLeft);
        assertCursorPosition(2, 0);
        pressKey(KeyType.ArrowLeft);
        assertCursorPosition(1, 0);
        pressKey(KeyType.ArrowLeft);
        assertCursorPosition(0, 0);
        pressKey(KeyType.ArrowLeft);
        assertCursorPosition(0, 0);
    }

    @Test
    public void leftArrowWorksAcrossRows() {
        setColumns(5);
        enterCharacters("123451");
        assertCursorPosition(1, 1);
        pressKey(KeyType.ArrowLeft);
        pressKey(KeyType.ArrowLeft);
        assertCursorPosition(4, 0);
    }

    @Test
    public void rightArrowDoesNotMovePastEndOfInput() {
        pressKey(KeyType.ArrowRight);
        assertCursorPosition(0, 0);
    }

    @Test
    public void rightArrowWorksAfterMovingLeft() {
        enterCharacters("12");
        assertCursorPosition(2, 0);
        pressKey(KeyType.ArrowLeft);
        assertCursorPosition(1, 0);
        pressKey(KeyType.ArrowRight);
        assertCursorPosition(2, 0);
        pressKey(KeyType.ArrowRight);
        assertCursorPosition(2, 0);
    }

    @Test
    public void rightArrowWorksAcrossRow() {
        setColumns(5);
        enterCharacters("123451");
        assertCursorPosition(1, 1);
        pressKey(KeyType.ArrowLeft);
        pressKey(KeyType.ArrowLeft);
        pressKey(KeyType.ArrowLeft);
        assertCursorPosition(3, 0);
        pressKey(KeyType.ArrowRight);
        pressKey(KeyType.ArrowRight);
        pressKey(KeyType.ArrowRight);
        assertCursorPosition(1, 1);
    }

    @Test
    public void characterKeyIsEchoed() {
        enterCharacter('a');
        assertCursorPosition(1, 0);
        assertCharacterAtPosition('a', 0, 0);
    }

    @Test
    public void characterIsInserted() {
        enterCharacters("abcd");
        pressKey(KeyType.ArrowLeft);
        pressKey(KeyType.ArrowLeft);
        enterCharacter('x');
        assertCharacterAtPosition('a', 0, 0);
        assertCharacterAtPosition('b', 1, 0);
        assertCharacterAtPosition('x', 2, 0);
        assertCharacterAtPosition('c', 3, 0);
        assertCharacterAtPosition('d', 4, 0);
    }

    @Test
    public void characterIsInserted_PushesInputToNextRow() {
        setColumns(4);
        enterCharacters("abcd");
        pressKey(KeyType.ArrowLeft);
        pressKey(KeyType.ArrowLeft);
        enterCharacter('x');
        assertCharacterAtPosition('a', 0, 0);
        assertCharacterAtPosition('b', 1, 0);
        assertCharacterAtPosition('x', 2, 0);
        assertCharacterAtPosition('c', 3, 0);
        assertCharacterAtPosition('d', 0, 1);
    }

    @Test
    public void backspaceDoesNothingAtOrigin() {
        pressKey(KeyType.Backspace);
        assertCursorPosition(0, 0);
    }

    @Test
    public void backspaceWorksAfterInput() {
        enterCharacters("12345");
        pressKey(KeyType.Backspace);
        pressKey(KeyType.Backspace);
        assertCursorPosition(3, 0);
        assertCharacterAtPosition('1', 0, 0);
        assertCharacterAtPosition('2', 1, 0);
        assertCharacterAtPosition('3', 2, 0);
        assertCharacterAtPosition(' ', 3, 0);
        assertCharacterAtPosition(' ', 4, 0);
        assertCharacterAtPosition(' ', 5, 0);
    }

    @Test
    public void backspaceWorksAcrossRow() {
        setColumns(4);
        enterCharacters("1234567");
        pressKey(KeyType.Backspace);
        pressKey(KeyType.Backspace);
        pressKey(KeyType.Backspace);
        pressKey(KeyType.Backspace);
        pressKey(KeyType.Backspace);
        assertCursorPosition(2, 0);
        assertCharacterAtPosition('1', 0, 0);
        assertCharacterAtPosition('2', 1, 0);
        assertCharacterAtPosition(' ', 2, 0);
        assertCharacterAtPosition(' ', 3, 0);
        assertCharacterAtPosition(' ', 0, 1);
        assertCharacterAtPosition(' ', 1, 1);
        assertCharacterAtPosition(' ', 2, 1);
    }

    @Test
    public void backspaceWorksInMiddleOfInput() {
        enterCharacters("12345");
        pressKey(KeyType.ArrowLeft);
        pressKey(KeyType.ArrowLeft);
        pressKey(KeyType.Backspace);
        assertCursorPosition(2, 0);
        assertCharacterAtPosition('1', 0, 0);
        assertCharacterAtPosition('2', 1, 0);
        assertCharacterAtPosition('4', 2, 0);
        assertCharacterAtPosition('5', 3, 0);
    }

}