package io.trygvis.rules.network;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;

@JsonSerialize(using = Ipv4Cidr.Serializer.class)
public class Ipv4Cidr {
    public final int network;
    public final int netmask;
    public final int size;
    public final int bits;

    public Ipv4Cidr(int network, int netmask, int size, int bits) {
        this.network = network;
        this.netmask = netmask;
        this.size = size;
        this.bits = bits;
    }

    @Override
    public String toString() {
        return "%d.%d.%d.%d/%d".formatted(
                network >> 24 & 0xff,
                network >> 16 & 0xff,
                network >> 8 & 0xff,
                network & 0xff,
                bits);
    }

    public Collection<Ipv4Address> addresses() {
        var end = network + size;
        var addresses = new ArrayList<Ipv4Address>(size);
        for (int address = network; address < end; address++) {
            addresses.add(new Ipv4Address(address));
        }

        return addresses;
    }

    public static class Serializer extends JsonSerializer<Ipv4Cidr> {
        @Override
        public void serialize(Ipv4Cidr value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
            gen.writeStartObject();
            gen.writeObjectField("value", value.toString());
            gen.writeEndObject();
        }
    }
}