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package jsonvalues;
import java.util.Arrays;
import java.util.Base64;
import java.util.Optional;
import static java.util.Objects.requireNonNull;

/**
 Represents an array of bytes. This type is not part of the Json specification. It it serialized into
 a string using Base64 encoding scheme. A JsBinary and a JsStr are equals if the string is the array
 of bytes encoded in base64.
 {@code
 byte[] bytes = "foo".getBytes();
 String base64 = Base64.getEncoder().encodeToString(bytes);
 JsBinary.of(bytes).equals(JsStr.of(base64)); // true
 }
 */
public class JsBinary implements JsValue {
    public static final int ID = 10;
    public final byte[] value;

    /**
     Creates a JsBinary from an array of bytes
     @param bytes the array of bytes
     @return an immutable JsBinary
     */
    public static JsBinary of(final byte[] bytes){
        return new JsBinary(requireNonNull(bytes));
    }

    /**
     Creates a JsBinary from an array of bytes encoded as a string in base64
     @param base64 the string
     @throws IllegalArgumentException if {@code base64} is not in valid Base64 scheme
     @return an immutable JsBinary
     */
    public static JsBinary of(final String base64){
        return new JsBinary(requireNonNull(Base64.getDecoder().decode(base64)));
    }

    private JsBinary(final byte[] value) {
        this.value = value;
    }

    /**
     prism between the sum type JsValue and JsBinary
     */
    public static Prism prism =
            new Prism<>(s -> {
                if(s.isBinary())return Optional.of(s.toJsBinary().value);
                if(s.isStr()){
                    return JsStr.base64Prism.getOptional.apply(s.toJsStr().value);
                }
                return  Optional.empty();
            },
                        JsBinary::of
            );


    @Override
    public int id() {
        return ID;
    }

    @Override
    public boolean isBinary() {
        return true;
    }

    @Override
    public String toString() {
        return Base64.getEncoder().encodeToString(value);
    }

    @Override
    public boolean equals(final Object o) {
        if (this == o) return true;
        if (o == null)
            return false;
        if(o instanceof JsValue){
            return JsBinary.prism.getOptional.apply(((JsValue) o))
                                      .map(bytes -> Arrays.equals(bytes,value))
                                      .orElse(false);
        }
        return false;
    }

    @Override
    public int hashCode() {
        return Arrays.hashCode(value);
    }
}