package model.pki;

import model.asn1.ASN1Object;
import model.asn1.Null;
import model.asn1.ObjectIdentifier;
import model.asn1.exceptions.ParseException;
import model.asn1.parsing.BytesReader;
import org.junit.jupiter.api.Test;

import static model.asn1.ObjectIdentifier.*;
import static org.junit.jupiter.api.Assertions.*;

public class AlgorithmIdentifierTest {
    @Test
    void testConstructor() {
        assertArrayEquals(OID_SHA256_WITH_RSA_ENCRYPTION,
                new AlgorithmIdentifier(
                        ASN1Object.TAG_SEQUENCE, null,
                        new ObjectIdentifier(ObjectIdentifier.TAG, null, OID_SHA256_WITH_RSA_ENCRYPTION),
                        new Null(Null.TAG, null))
                        .getType().getInts());
        assertEquals(Null.TAG.getNumber(),
                new AlgorithmIdentifier(
                        ASN1Object.TAG_SEQUENCE, null,
                        new ObjectIdentifier(ObjectIdentifier.TAG, null, OID_SHA256_WITH_RSA_ENCRYPTION),
                        new Null(Null.TAG, null))
                        .getParameters().getTag().getNumber());
    }

    @Test
    void testParse() throws ParseException {
        AlgorithmIdentifier parsed = new AlgorithmIdentifier(new BytesReader(new Byte[]{
                0x30, 0x0d, // SEQUENCE AlgorithmIdentifier
                0x06, 0x09, 0x2a, -122, 0x48, -122, -9, 0x0d, // OID (rsaEncryption)
                0x01, 0x01, 0x01,
                0x05, 0x00, // Null (Parameter)
        }), false);
        assertArrayEquals(OID_RSA_ENCRYPTION, parsed.getType().getInts());
        assertEquals(Null.TAG.getNumber(), parsed.getParameters().getTag().getNumber());

        parsed = new AlgorithmIdentifier(new BytesReader(new Byte[]{
                0x30, 0x0D, // SEQUENCE AlgorithmIdentifier
                0x06, 0x09, 0x2A, -122, 0x48, -122, -9, 0x0D, // OID (sha256WithRsaEncryption)
                0x01, 0x01, 0x0B,
                0x05, 0x00 // Null (Parameter)
        }), false);
        assertArrayEquals(OID_SHA256_WITH_RSA_ENCRYPTION, parsed.getType().getInts());
        assertEquals(Null.TAG.getNumber(), parsed.getParameters().getTag().getNumber());

        parsed = new AlgorithmIdentifier(new BytesReader(new Byte[]{
                0x30, 0x0A, // SEQUENCE AlgorithmIdentifier
                0x06, 0x08, 0x2A, -122, 0x48, -50, 0x3D, 0x04, 0x03, 0x02 // OID (ecdsaWithSHA256)
        }), false);
        assertArrayEquals(OID_ECDSA_WITH_SHA256, parsed.getType().getInts());
        assertNull(parsed.getParameters());
    }

    @Test
    void testParseFail() {
        // No type
        assertThrows(ParseException.class, () -> new AlgorithmIdentifier(new BytesReader(new Byte[]{
                0x30, 0x0
        }), false));
        // Incorrect type tag (should be OID)
        assertThrows(ParseException.class, () -> new AlgorithmIdentifier(new BytesReader(new Byte[]{
                0x30, 0x0B, // SEQUENCE AlgorithmIdentifier
                0x07, 0x09, 0x2A, -122, 0x48, -122, -9, 0x0D, // Incorrect tag
                0x01, 0x01, 0x0B,
        }), false));
    }

    @Test
    void testEncode() throws ParseException {
        assertArrayEquals(new Byte[]{
                        0x30, 0x0D, // SEQUENCE AlgorithmIdentifier
                        0x06, 0x09, 0x2A, -122, 0x48, -122, -9, 0x0D, // OID (sha256WithRsaEncryption)
                        0x01, 0x01, 0x0B,
                        0x05, 0x00 // Null (Parameter)
                }, new AlgorithmIdentifier(
                        ASN1Object.TAG_SEQUENCE, null,
                new ObjectIdentifier(ObjectIdentifier.TAG, null, OID_SHA256_WITH_RSA_ENCRYPTION),
                new Null(Null.TAG, null)).encodeDER());
    }
}