package model.asn1;

import model.asn1.exceptions.ParseException;
import model.asn1.parsing.BytesReader;
import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.*;

public class BitStringTest {
    @Test
    void testConstructor() {
        assertArrayEquals(new Byte[]{ 0x2, 0x3 },
                new BitString(BitString.TAG, null, 0, new Byte[]{ 0x2, 0x3 })
                        .getVal());
        assertEquals(3,
                new BitString(BitString.TAG, null, 3, new Byte[]{ 0x2, 0x8 })
                        .getUnused());
    }

    @Test
    void testConvert() {
        // 00000010 00001000
        // 00000000 01000001 = 65
        assertArrayEquals(new Byte[]{ 65 },
                new BitString(BitString.TAG, null, 3, new Byte[]{ 0x2, 0x8 })
                        .getConvertedVal());

        assertArrayEquals(new Byte[]{ 0x2, 0x8 },
                new BitString(BitString.TAG, null, 0, new Byte[]{ 0x2, 0x8 })
                        .getConvertedVal());
    }

    @Test
    void testParse() throws ParseException {
        assertArrayEquals(new Byte[]{ 0x6e, 0x5d, -64 },
                new BitString(new BytesReader(new Byte[]{ 0x03, 0x04, 0x06, 0x6e, 0x5d, -64 }), false)
                        .getVal());
        assertEquals(6,
                new BitString(new BytesReader(new Byte[]{ 0x03, 0x04, 0x06, 0x6e, 0x5d, -64 }), false)
                        .getUnused());
        assertArrayEquals(new Byte[]{ 0x01, -71, 0x77 },
                new BitString(new BytesReader(new Byte[]{ 0x03, 0x04, 0x06, 0x6e, 0x5d, -64 }), false)
                        .getConvertedVal());
    }

    @Test
    void testParseFail() {
        assertThrows(ParseException.class, () ->
                new BitString(new BytesReader(new Byte[]{ 0x03, 0x04 }), false));
        // 0b11100000
        assertThrows(ParseException.class, () ->
                new BitString(new BytesReader(new Byte[]{ 0x03, 0x04, 0x06, 0x6e, 0x5d, -32 }), false));
        // 0b11000001
        assertThrows(ParseException.class, () ->
                new BitString(new BytesReader(new Byte[]{ 0x03, 0x04, 0x06, 0x6e, 0x5d, -63 }), false));
        // Unused bits = 8
        assertThrows(ParseException.class, () ->
                new BitString(new BytesReader(new Byte[]{ 0x03, 0x04, 0x08, 0x6e, 0x5d, -64 }), false));
        // Unused bits = 6 -> 7
        assertThrows(ParseException.class, () ->
                new BitString(new BytesReader(new Byte[]{ 0x03, 0x04, 0x07, 0x6e, 0x5d, -64 }), false));
        // Illegal unused bits: 8 and -1
        assertThrows(ParseException.class, () ->
                new BitString(new BytesReader(new Byte[]{ 0x03, 0x04, 0x08, 0x6e, 0x5d, -64 }), false));
        assertThrows(ParseException.class, () ->
                new BitString(new BytesReader(new Byte[]{ 0x03, 0x04, -1, 0x6e, 0x5d, -64 }), false));
    }

    @Test
    void testEncode() throws ParseException {
        assertArrayEquals(new Byte[]{ 0x03, 0x04, 0x06, 0x6e, 0x5d, -64 },
                new BitString(new BytesReader(new Byte[]{ 0x03, 0x04, 0x06, 0x6e, 0x5d, -64 }), false)
                        .encodeDER());
    }
}