import junitparams.JUnitParamsRunner;
import junitparams.Parameters;
import org.junit.After;
import org.junit.Rule;
import org.junit.Test;
import org.junit.contrib.java.lang.system.TextFromStandardInputStream;
import org.junit.runner.RunWith;

import java.io.IOException;
import java.util.NoSuchElementException;

import static org.hamcrest.Matchers.is;
import static org.junit.Assert.assertThat;

@RunWith(JUnitParamsRunner.class)
public class ShadReaderTest {
    private ShadReader reader;

    @Rule
    public TextFromStandardInputStream systemIn =
            TextFromStandardInputStream.emptyStandardInputStream();

    @Test
    @Parameters(method = "notBlankStrings")
    public void itShouldHasNext(String text) {
        systemIn.provideText(text);

        reader = new ShadReader(System.in);

        assertThat(reader.hasNext(), is(true));
    }

    private Object[][] notBlankStrings() {
        return new Object[][]{
                {"apple"},
                {" banana "},
                {" \t \r\n pear \n  \t"},
                {" \r\npeach\t\n "},
                {"\t 12345678901234567890 \r\n "}
        };
    }

    @Test
    @Parameters(method = "blankStrings")
    public void itShouldNotHaveNext(String text) {
        systemIn.provideText(text);

        reader = new ShadReader(System.in);

        assertThat(reader.hasNext(), is(false));
    }

    @Test(expected = NoSuchElementException.class)
    @Parameters(method = "blankStrings")
    public void itShouldThrowNoSuchElementExceptionOnBlankInput(String text) {
        systemIn.provideText(text);

        reader = new ShadReader(System.in);

        reader.nextToken();
    }

    private Object[][] blankStrings() {
        return new Object[][]{
                {""},
                {" \t "},
                {" \t \r\n  \n  \t"},
                {" \r\n \t\n "},
                {"\t  \r\n "}
        };
    }

    @Test
    @Parameters(method = "notBlankStrings,blankStrings")
    public void hasNextShouldBeIdempotent(String text) {
        systemIn.provideText(text);

        reader = new ShadReader(System.in);

        assertThat(reader.hasNext(), is(reader.hasNext()));
    }

    @Test
    @Parameters(method = "tokens")
    public void itShouldReadNextToken(String text, String token) {
        systemIn.provideText(text);

        reader = new ShadReader(System.in);

        assertThat(reader.nextToken(), is(token));
    }

    private Object[][] tokens() {
        return new Object[][]{
                {"apple", "apple"},
                {" banana ", "banana"},
                {" \t \r\n pear \n  \t", "pear"},
                {" \r\npeach\t\n ", "peach"},
                {"\t 12345678901234567890 \r\n ", "12345678901234567890"}
        };
    }

    @Test
    @Parameters(method = "ints")
    public void itShouldReadNextInt(String text, int number) {
        systemIn.provideText(text);

        reader = new ShadReader(System.in);

        assertThat(reader.nextInt(), is(number));
    }

    private Object[][] ints() {
        return new Object[][]{
                {"1", 1},
                {" 0 ", 0},
                {" \t \r\n 12345 \r\n  \t", 12345},
                {" \r\n-567890 \n ", -567890},
                {" \n+5 ", 5}
        };
    }

    @Test
    @Parameters(method = "longs")
    public void itShouldReadNextLong(String text, long number) {
        systemIn.provideText(text);

        reader = new ShadReader(System.in);

        assertThat(reader.nextLong(), is(number));
    }

    private Object[][] longs() {
        return new Object[][]{
                {"1", 1L},
                {" 0 ", 0L},
                {" \t \r\n 9876543210 \n  \t", 9876543210L},
                {" \n-1234567890\r\n", -1234567890L},
                {" \r\n+5 ", 5L}
        };
    }

    @Test
    @Parameters(method = "doubles")
    public void itShouldReadNextDouble(String text, double number) {
        systemIn.provideText(text);

        reader = new ShadReader(System.in);

        assertThat(reader.nextDouble(), is(number));
    }

    private Object[][] doubles() {
        return new Object[][]{
                {"1", 1D},
                {" 0 ", 0D},
                {" \t \r\n 9876543210 \n  \t", 9876543210D},
                {" \n-1234567890\r\n", -1234567890D},
                {" \r\n+5 ", 5D},
                {" \r\n1.2345678E7 ", 1.2345678E7},
                {" \r\n -1.2345678E-7 \t", -1.2345678E-7},
        };
    }

    @Test
    public void itShouldReadDataSequence() {
        systemIn.provideText(" \t apple   \r\n \t123 \n   2.0 \n 567 \t \n ");

        reader = new ShadReader(System.in);

        assertThat(reader.nextToken(), is("apple"));
        assertThat(reader.nextInt(), is(123));
        assertThat(reader.nextDouble(), is(2D));
        assertThat(reader.nextLong(), is(567L));
    }

    @After
    public void tearDown() throws IOException {
        reader.close();
    }

}