package org.projectfloodlight.openflow.types;

import static org.junit.Assert.assertArrayEquals;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertThat;
import static org.junit.Assert.fail;

import java.net.Inet6Address;
import java.net.InetAddress;
import java.net.UnknownHostException;

import org.hamcrest.CoreMatchers;
import org.jboss.netty.buffer.ChannelBuffers;
import org.junit.Test;
import org.projectfloodlight.openflow.exceptions.OFParseError;

import com.google.common.io.BaseEncoding;

public class IPv6AddressTest {

    String[] testStrings = {
            "::",
            "::1",
            "ffe0::",
            "1:2:3:4:5:6:7:8"
    };


    private final BaseEncoding hex = BaseEncoding.base16().omitPadding().lowerCase();

    private class WithMaskTaskCase {
        final String input;
        boolean hasMask;
        byte[] expectedMask = hex.decode("ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff".replaceAll(" ", ""));

        public WithMaskTaskCase(String input) {
            super();
            this.input = input;
        }

        public WithMaskTaskCase maskHex(String string) {
            string = string.replaceAll(" ", "");
            this.hasMask = true;
            expectedMask = hex.decode(string);
            return this;
        }

    }

    WithMaskTaskCase[] withMasks = new WithMaskTaskCase[] {
            new WithMaskTaskCase("1::1/80")
                .maskHex("ff ff ff ff ff ff ff ff ff ff 00 00 00 00 00 00"),

            new WithMaskTaskCase("ffff:ffee:1::/ff00:ff00:ff00:ff00::")
                .maskHex("ff 00 ff 00 ff 00 ff 00 00 00 00 00 00 00 00 00"),
            new WithMaskTaskCase("8:8:8:8:8:8:8:8"),
            new WithMaskTaskCase("8:8:8:8:8:8:8:8"),
            new WithMaskTaskCase("1:2:3:4:5:6:7:8/128"),
            new WithMaskTaskCase("::/0")
                .maskHex("00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00")
    };

    @Test
    public void testMasked() throws UnknownHostException {
        for(WithMaskTaskCase w: withMasks) {
            IPv6AddressWithMask value = IPv6AddressWithMask.of(w.input);
            if (!w.hasMask) {
                IPv6Address ip = value.getValue();
                InetAddress inetAddress = InetAddress.getByName(w.input.split("/")[0]);

                assertArrayEquals(ip.getBytes(), inetAddress.getAddress());
                assertEquals(w.input.split("/")[0], ip.toString());
            } else {
                InetAddress inetAddress = InetAddress.getByName(w.input.substring(0, w.input.indexOf('/')));

                byte[] address = inetAddress.getAddress();
                assertEquals(address.length, value.getValue().getBytes().length);

                for (int j = 0; j < address.length; j++) {
                    address[j] &= w.expectedMask[j];
                }

                assertThat("Address bytes for input " + w.input + ", value=" + value, value.getValue().getBytes(), CoreMatchers.equalTo(address));
                assertThat("mask check for input " + w.input + ", value=" + value, value.getMask().getBytes(), CoreMatchers.equalTo(w.expectedMask));
            }
        }
    }


    @Test
    public void testOfString() throws UnknownHostException {
        for(int i=0; i < testStrings.length; i++ ) {
            IPv6Address ip = IPv6Address.of(testStrings[i]);
            InetAddress inetAddress = InetAddress.getByName(testStrings[i]);

            assertArrayEquals(ip.getBytes(), inetAddress.getAddress());
            assertEquals(testStrings[i], ip.toString());
        }
    }

    @Test
    public void testOfByteArray() throws UnknownHostException {
        for(int i=0; i < testStrings.length; i++ ) {
            byte[] bytes = Inet6Address.getByName(testStrings[i]).getAddress();
            IPv6Address ip = IPv6Address.of(bytes);
            assertEquals(testStrings[i], ip.toString());
            assertArrayEquals(bytes, ip.getBytes());
        }
    }

    @Test
    public void testReadFrom() throws OFParseError, UnknownHostException {
        for(int i=0; i < testStrings.length; i++ ) {
            byte[] bytes = Inet6Address.getByName(testStrings[i]).getAddress();
            IPv6Address ip = IPv6Address.read16Bytes(ChannelBuffers.copiedBuffer(bytes));
            assertEquals(testStrings[i], ip.toString());
            assertArrayEquals(bytes, ip.getBytes());
        }
    }

    String[] invalidIPs = {
            "",
            ":",
            "1:2:3:4:5:6:7:8:9",
            "1:2:3:4:5:6:7:8:",
            "1:2:3:4:5:6:7:8g",
            "1:2:3:",
            "12345::",
            "1::3::8",
            "::3::"
    };

    @Test
    public void testInvalidIPs() throws OFParseError {
        for(String invalid : invalidIPs) {
            try {
                IPv6Address.of(invalid);
                fail("Invalid IP "+invalid+ " should have raised IllegalArgumentException");
            } catch(IllegalArgumentException e) {
                // ok
            }
        }
    }

    @Test
    public void testZeroCompression() throws OFParseError {
        assertEquals("::", IPv6Address.of("::").toString(true, false));
        assertEquals("0:0:0:0:0:0:0:0", IPv6Address.of("::").toString(false, false));
        assertEquals("0000:0000:0000:0000:0000:0000:0000:0000", IPv6Address.of("::").toString(false, true));
        assertEquals("1::4:5:6:0:8", IPv6Address.of("1:0:0:4:5:6:0:8").toString(true, false));
        assertEquals("1:0:0:4::8", IPv6Address.of("1:0:0:4:0:0:0:8").toString(true, false));
    }
}