package nom.tam.util;

/*
 * #%L
 * nom.tam FITS library
 * %%
 * Copyright (C) 1996 - 2024 nom-tam-fits
 * %%
 * This is free and unencumbered software released into the public domain.
 *
 * Anyone is free to copy, modify, publish, use, compile, sell, or
 * distribute this software, either in source code form or as a compiled
 * binary, for any purpose, commercial or non-commercial, and by any
 * means.
 *
 * In jurisdictions that recognize copyright laws, the author or authors
 * of this software dedicate any and all copyright interest in the
 * software to the public domain. We make this dedication for the benefit
 * of the public at large and to the detriment of our heirs and
 * successors. We intend this dedication to be an overt act of
 * relinquishment in perpetuity of all present and future rights to this
 * software under copyright law.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 * #L%
 */
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNotEquals;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertTrue;

import java.io.ByteArrayInputStream;
import java.io.EOFException;
import java.io.File;
import java.io.IOException;
import java.math.BigInteger;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;

import org.junit.After;
import org.junit.Test;

import nom.tam.fits.FitsFactory;

public class FitsDecoderTest {

    @After
    public void setDefaults() {
        FitsFactory.setDefaults();
    }

    @Test
    public void testIncompleteReadByteArray() throws Exception {
        byte[] data = new byte[100];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        byte[] need = new byte[101];
        assertEquals(data.length, e.read(need, 0, need.length));
    }

    @Test
    public void testIncompleteReadBooleanObjectArray() throws Exception {
        byte[] data = new byte[100];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        Boolean[] b = new Boolean[data.length + 1];
        assertEquals(data.length, e.readArray(b));
    }

    @Test
    public void testIncompleteReadObjectArray() throws Exception {
        byte[] data = new byte[100];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        Boolean[] b = new Boolean[1];
        Object[] array = new Object[] {data, b};
        assertEquals(data.length, e.readArray(array));
    }

    @Test(expected = EOFException.class)
    public void testIncomleteReadFully() throws Exception {
        byte[] data = new byte[100];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        byte[] need = new byte[101];
        e.readFully(need, 0, need.length);
    }

    @Test(expected = EOFException.class)
    public void testIncomleteReadArrayFully() throws Exception {
        byte[] data = new byte[100];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        int[] need = new int[26];
        e.readArrayFully(need);
    }

    @Test
    public void testReadNullArray() throws Exception {
        byte[] data = new byte[100];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.readArray(null);
    }

    @Test(expected = IllegalArgumentException.class)
    public void testReadInvalidArray() throws Exception {
        byte[] data = new byte[100];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        Object[] array = new Object[] {new BigInteger("123235536566547747")};
        e.readArray(array);
    }

    @Test
    public void testByteOrder() throws Exception {
        byte[] data = new byte[100];

        ByteBuffer b = ByteBuffer.wrap(data);
        b.putDouble(Math.PI);
        b.order(ByteOrder.LITTLE_ENDIAN);
        b.putDouble(Math.PI);

        double[] d = new double[2];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.readArray(d);

        assertEquals("BE", Math.PI, d[0], 1e-12);
        assertNotEquals("!BE", Math.PI, d[1], 1e-12);

        e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.getInputBuffer().setByteOrder(ByteOrder.LITTLE_ENDIAN);
        e.read(d, 0, d.length);

        assertEquals("byteorder", ByteOrder.LITTLE_ENDIAN, e.getInputBuffer().byteOrder());
        assertNotEquals("!LE", Math.PI, d[0], 1e-12);
        assertEquals("LE", Math.PI, d[1], 1e-12);
    }

    @Test
    public void testBoolean() throws Exception {
        byte[] data = new byte[] {'T', 'F', 0, 1, 2};
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        Boolean[] b = new Boolean[data.length];
        e.read(b, 0, b.length);

        assertTrue("T", b[0]);
        assertFalse("F", b[1]);
        assertNull("0", b[2]);
        assertTrue("1", b[3]); // alternative non-standard 'true'
        assertFalse("2", b[4]); // everything else 'false'
    }

    @Test(expected = EOFException.class)
    public void testReadByteEOF() throws Exception {
        byte[] data = new byte[100];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        for (int i = 0; i < data.length; i++) {
            assertEquals(0, e.readByte());
        }
        e.readByte(); // should throw exception.
    }

    @Test(expected = EOFException.class)
    public void testReadShortEOF() throws Exception {
        byte[] data = new byte[100];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        int n = data.length >>> 1;
        for (int i = 0; i < n; i++) {
            assertEquals(0, e.readShort());
        }
        e.readShort(); // should throw exception.

    }

    @Test(expected = EOFException.class)
    public void testReadCharEOF() throws Exception {
        FitsFactory.setUseUnicodeChars(false);
        byte[] data = new byte[100];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        int n = data.length;
        for (int i = 0; i < n; i++) {
            assertEquals(0, e.readChar());
        }
        e.readChar(); // should throw exception.
    }

    @Test(expected = EOFException.class)
    public void testBooleanArrayUnexpectedReadEOF1() throws Exception {
        FitsDecoder e = new FitsDecoder(new EOFExceptionInputReader());

        e.read(new boolean[1], 0, 1);
    }

    @Test(expected = EOFException.class)
    public void testBooleanArrayUnexpectedReadEOF2() throws Exception {
        FitsDecoder e = new FitsDecoder(new EOFExceptionInputReader());

        e.read(new Boolean[1], 0, 1);
    }

    @Test(expected = EOFException.class)
    public void testShortArrayUnexpectedReadEOF() throws Exception {
        FitsDecoder e = new FitsDecoder(new EOFExceptionInputReader());

        e.read(new short[1], 0, 1);
    }

    @Test(expected = EOFException.class)
    public void testCharArrayUnexpectedReadEOF() throws Exception {
        FitsDecoder e = new FitsDecoder(new EOFExceptionInputReader());
        e.read(new char[1], 0, 1);
    }

    @Test(expected = EOFException.class)
    public void testBooleanArrayEOFAtStart() throws Exception {
        byte[] data = new byte[1];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.read();
        e.read(new boolean[10], 0, 10);
    }

    @Test(expected = EOFException.class)
    public void testBooleanObjectsEOFAtStart() throws Exception {
        byte[] data = new byte[1];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.read();
        e.read(new Boolean[10], 0, 10);
    }

    @Test(expected = EOFException.class)
    public void testAsciiLineEOFAtStart() throws Exception {
        byte[] data = new byte[1];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.read();
        e.readAsciiLine();
    }

    @Test
    public void testAsciiLineReadToEOF() throws Exception {
        byte[] data = {(byte) 'a', (byte) 'b', (byte) 'c'};
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        assertEquals(data.length, e.readAsciiLine().length());
    }

    @Test
    public void testAsciiLineReadDelimited() throws Exception {
        byte[] data = "one\ntwo".getBytes();
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        assertEquals("one", e.readAsciiLine());
    }

    @Test
    public void testReadEmptyBoolean() throws Exception {
        byte[] data = new byte[10];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        assertEquals(0, e.read(new boolean[10], 5, 0));
    }

    @Test
    public void testReadEmptyBooleanObject() throws Exception {
        byte[] data = new byte[10];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        assertEquals(0, e.read(new Boolean[10], 5, 0));
    }

    @Test
    public void testReadEmptyChars() throws Exception {
        byte[] data = new byte[10];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        assertEquals(0, e.read(new char[10], 5, 0));
    }

    @Test(expected = EOFException.class)
    public void testCharsEOFAtStart() throws Exception {
        FitsFactory.setUseUnicodeChars(false);
        byte[] data = new byte[1];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.read();
        e.read(new char[10], 0, 10);
    }

    @Test
    public void testGetByte() throws Exception {
        byte[] data = new byte[100];
        for (int i = 0; i < data.length; i++) {
            data[i] = (byte) i;
        }
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.getInputBuffer().loadBytes(data.length, 1);
        for (int i = 0; i < data.length; i++) {
            assertEquals(i, e.getInputBuffer().get());
        }
    }

    @Test
    public void testGetByteEOF() throws Exception {
        byte[] data = new byte[1];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.getInputBuffer().loadBytes(data.length, 2);
        e.read();
        assertEquals(-1, e.getInputBuffer().get());
    }

    @Test(expected = EOFException.class)
    public void testGetShortsEOF() throws Exception {
        byte[] data = new byte[1];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.read();
        e.read(new short[10], 5, 1);
    }

    @Test(expected = EOFException.class)
    public void testGetIntsEOF() throws Exception {
        byte[] data = new byte[1];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.read();
        e.read(new int[10], 5, 1);
    }

    @Test(expected = EOFException.class)
    public void testGetLongsEOF() throws Exception {
        byte[] data = new byte[1];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.read();
        e.read(new long[10], 5, 1);
    }

    @Test(expected = EOFException.class)
    public void testGetFloatsEOF() throws Exception {
        byte[] data = new byte[1];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.read();
        e.read(new float[10], 5, 1);
    }

    @Test(expected = EOFException.class)
    public void testGetDoublesEOF() throws Exception {
        byte[] data = new byte[1];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.read();
        e.read(new double[10], 5, 1);
    }

    @Test(expected = EOFException.class)
    public void testGetSingleByteEOF() throws Exception {
        byte[] data = new byte[1];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.getInputBuffer().loadBytes(2, 1);
        e.read();
        e.getInputBuffer().get(new byte[10], 5, 1);
    }

    @Test(expected = EOFException.class)
    public void testGetBytesEOF() throws Exception {
        byte[] data = new byte[1];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.read();
        e.getInputBuffer().loadBytes(11, 1);
        e.getInputBuffer().get(new byte[10], 0, 10);
    }

    @Test
    public void testGetBytesPartial() throws Exception {
        byte[] data = new byte[9];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.getInputBuffer().loadBytes(10, 1);
        assertEquals(9, e.getInputBuffer().get(new byte[10], 0, 10));
    }

    @Test
    public void testGetMixed() throws Exception {
        byte[] data = new byte[400];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.getInputBuffer().loadBytes(400, 1);
        assertEquals(1, e.getInputBuffer().get(new byte[10], 5, 1));

        // no view / wrong view (single element)
        assertEquals(1, e.getInputBuffer().get(new short[10], 5, 1));
        // creates view (multiple elements)
        assertEquals(2, e.getInputBuffer().get(new short[10], 5, 2));
        // uses existing view (multiple elements)
        assertEquals(2, e.getInputBuffer().get(new short[10], 5, 2));
        // using view for single element
        assertEquals(1, e.getInputBuffer().get(new short[10], 5, 1));

        assertEquals(1, e.getInputBuffer().get(new int[10], 5, 1));
        assertEquals(2, e.getInputBuffer().get(new int[10], 5, 2));
        assertEquals(2, e.getInputBuffer().get(new int[10], 5, 2));
        assertEquals(1, e.getInputBuffer().get(new int[10], 5, 1));

        assertEquals(1, e.getInputBuffer().get(new long[10], 5, 1));
        assertEquals(2, e.getInputBuffer().get(new long[10], 5, 2));
        assertEquals(2, e.getInputBuffer().get(new long[10], 5, 2));
        assertEquals(1, e.getInputBuffer().get(new long[10], 5, 1));

        assertEquals(1, e.getInputBuffer().get(new float[10], 5, 1));
        assertEquals(2, e.getInputBuffer().get(new float[10], 5, 2));
        assertEquals(2, e.getInputBuffer().get(new float[10], 5, 2));
        assertEquals(1, e.getInputBuffer().get(new float[10], 5, 1));

        assertEquals(1, e.getInputBuffer().get(new double[10], 5, 1));
        assertEquals(2, e.getInputBuffer().get(new double[10], 5, 2));
        assertEquals(2, e.getInputBuffer().get(new double[10], 5, 2));
        assertEquals(1, e.getInputBuffer().get(new double[10], 5, 1));

        assertEquals(1, e.getInputBuffer().get(new short[10], 5, 1));
        assertEquals(2, e.getInputBuffer().get(new short[10], 5, 2));
        assertEquals(2, e.getInputBuffer().get(new short[10], 5, 2));
        assertEquals(1, e.getInputBuffer().get(new short[10], 5, 1));
    }

    @Test
    public void testReadNullImage() throws Exception {
        byte[] data = new byte[100];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.readImage(null);
        // No exception.
    }

    @Test
    public void testReadEmptyImage() throws Exception {
        byte[] data = new byte[100];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.readImage(new Object[] {new byte[10], new double[0]});
        // No exception.
    }

    @Test(expected = IllegalArgumentException.class)
    public void testReadImageNotArray() throws Exception {
        byte[] data = new byte[100];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.readImage(new File("blah"));
    }

    @Test(expected = IllegalArgumentException.class)
    public void testReadNonImage() throws Exception {
        byte[] data = new byte[100];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.readImage(new boolean[10]);
    }

    @Test
    public void testReadZeroLengthImage() throws Exception {
        byte[] data = new byte[100];
        FitsDecoder e = new FitsDecoder(InputReader.from(new ByteArrayInputStream(data)));
        e.readImage(new byte[0]);
        // No exception
    }

    private static class EOFExceptionInputReader implements InputReader {
        @Override
        public int read(byte[] b, int off, int len) throws IOException {
            return -1;
        }

        @Override
        public int read() throws IOException {
            return -1;
        }
    }
}