/*
 * Copyright (c) 2011-2019 Contributors to the Eclipse Foundation
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 * which is available at https://www.apache.org/licenses/LICENSE-2.0.
 *
 * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 */
package io.vertx.core.json.impl;

import io.vertx.core.buffer.Buffer;
import io.vertx.core.json.JsonArray;
import io.vertx.core.json.JsonObject;
import io.vertx.core.shareddata.Shareable;

import java.time.Instant;
import java.util.Base64;
import java.util.List;
import java.util.Map;

import static java.time.format.DateTimeFormatter.ISO_INSTANT;

Implementation utilities (details) affecting the way JSON objects are wrapped.
/**
 * Implementation utilities (details) affecting the way JSON objects are wrapped.
 */
public final class JsonUtil {

  public static final Base64.Encoder BASE64_ENCODER;
  public static final Base64.Decoder BASE64_DECODER;

  static {
    /*
     * Vert.x 3.x Json supports RFC-7493, however the JSON encoder/decoder format was incorrect.
     * Users who might need to interop with Vert.x 3.x applications should set the system property
     * {@code vertx.json.base64} to {@code legacy}.
     */
    if ("legacy".equalsIgnoreCase(System.getProperty("vertx.json.base64"))) {
      BASE64_ENCODER = Base64.getEncoder();
      BASE64_DECODER = Base64.getDecoder();
    } else {
      BASE64_ENCODER = Base64.getUrlEncoder().withoutPadding();
      BASE64_DECODER = Base64.getUrlDecoder();
    }
  }

  
Wraps well known java types to adhere to the Json expected types.

  
Map will be wrapped to JsonObject
  
List will be wrapped to JsonArray
  
Instant will be converted to iso date String
  
byte[] will be converted to base64 String
  
Enum will be converted to enum name String

Params:
val – java type
Returns:
wrapped type or val if not applicable./**
   * Wraps well known java types to adhere to the Json expected types.
   * <ul>
   *   <li>{@code Map} will be wrapped to {@code JsonObject}</li>
   *   <li>{@code List} will be wrapped to {@code JsonArray}</li>
   *   <li>{@code Instant} will be converted to iso date {@code String}</li>
   *   <li>{@code byte[]} will be converted to base64 {@code String}</li>
   *   <li>{@code Enum} will be converted to enum name {@code String}</li>
   * </ul>
   *
   * @param val java type
   * @return wrapped type or {@code val} if not applicable.
   */
  public static Object wrapJsonValue(Object val) {
    if (val == null) {
      return null;
    }

    // perform wrapping
    if (val instanceof Map) {
      val = new JsonObject((Map) val);
    } else if (val instanceof List) {
      val = new JsonArray((List) val);
    } else if (val instanceof Instant) {
      val = ISO_INSTANT.format((Instant) val);
    } else if (val instanceof byte[]) {
      val = BASE64_ENCODER.encodeToString((byte[]) val);
    } else if (val instanceof Buffer) {
      val = BASE64_ENCODER.encodeToString(((Buffer) val).getBytes());
    } else if (val instanceof Enum) {
      val = ((Enum) val).name();
    }

    return val;
  }

  @SuppressWarnings("unchecked")
  public static Object checkAndCopy(Object val) {
    if (val == null) {
      // OK
    } else if (val instanceof Number) {
      // OK
    } else if (val instanceof Boolean) {
      // OK
    } else if (val instanceof String) {
      // OK
    } else if (val instanceof Character) {
      // OK
    } else if (val instanceof CharSequence) {
      // CharSequences are not immutable, so we force toString() to become immutable
      val = val.toString();
    } else if (val instanceof Shareable) {
      // Shareable objects know how to copy themselves, this covers:
      // JsonObject, JsonArray or any user defined type that can shared across the cluster
      val = ((Shareable) val).copy();
    } else if (val instanceof Map) {
      val = (new JsonObject((Map) val)).copy();
    } else if (val instanceof List) {
      val = (new JsonArray((List) val)).copy();
    } else if (val instanceof Buffer) {
      val = ((Buffer) val).copy();
    } else if (val instanceof byte[]) {
      // OK
    } else if (val instanceof Instant) {
      // OK
    } else if (val instanceof Enum) {
      // OK
    } else {
      throw new IllegalStateException("Illegal type in Json: " + val.getClass());
    }
    return val;
  }
}