/*

* Copyright 2012 Splunk, Inc.

*

* Licensed under the Apache License, Version 2.0 (the "License"): you may

* not use this file except in compliance with the License. You may obtain

* a copy of the License at

*

* http://www.apache.org/licenses/LICENSE-2.0

*

* Unless required by applicable law or agreed to in writing, software

* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT

* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the

* License for the specific language governing permissions and limitations

* under the License.

*/

package com.splunk;

import java.io.UnsupportedEncodingException;

import java.net.URLEncoder;

import java.util.LinkedHashMap;

import java.util.Map;

import java.util.Map.Entry;

/**

* The {@code Args} class is a helper class for working with Splunk REST API

* arguments.

*

* This extension is used mainly for encoding arguments for UTF8 transmission

* to a Splunk instance in a key=value pairing for a string, or

* {@code key=value1&key=value2 } (and so on) for an array of strings.

*/

public class Args extends LinkedHashMap<String, Object> {

/**

* Class constructor.

*/

public Args() { super(); }

/**

* Class constructor. Initializes a single key-value pair.

*

* @param key The key name.

* @param value The value, as a {@code String:String} or

* {@code String:String[]}.

*/

public Args(String key, Object value) {

super();

put(key, value);

}

/**

* Class constructor. Initializes a pre-existing hash map.

*

* @param values A set of key-value pairs.

*/

public Args(Map<String, Object> values) {

super(values);

}

/**

* Adds an argument to an {@code Args} object.

*

* @param key The key name.

* @param value The value, as a {@code String:String} or

* {@code String:String[]}.

* @return This {@code Args} set.

*/

public Args add(String key, Object value) {

put(key, value);

return this;

}

/**

* Creates a new empty instance of {@code Args}.

*

* @return The {@code Args} instance.

*/

public static Args create() {

return new Args();

}

/**

* Creates a new {@code Args} instance and initializes it with a single

* key-value pair.

*

* @param key The key name.

* @param value The value, as a {@code String:String} or

* {@code String:String[]}.

* @return The {@code Args} instance.

*/

public static Args create(String key, Object value) {

return new Args(key, value);

}

/**

* Creates a new {@code Args} instance and initializes it with a

* pre-existing hash map.

*

* @param values The pre-existing hash map.

* @return The {@code Args} instance.

*/

public static Args create(Map<String, Object> values) {

return values == null ? new Args() : new Args(values);

}

/**

* Encodes a single string with UTF8 encoding.

*

* @param value The string.

* @return The encoded string.

*/

public static String encode(String value) {

if (value == null) return "";

String result = null;

try {

result = URLEncoder.encode(value, "UTF-8");

}

catch (UnsupportedEncodingException e) { assert false; }

return result;

}

/**

* Encodes a hash map of {@code String:String} or {@code String:String[]}

* into a single UTF8-encoded string.

*

* @param args The hash map.

* @return The string.

*/

public static String encode(Map<String, Object> args) {

return Args.create(args).encode();

}

// Encodes an argument with a list-valued argument.

private void

encodeValues(StringBuilder builder, String key, String[] values) {

key = encode(key);

for (String value : values) {

if (builder.length() > 0) builder.append('&');

builder.append(key);

builder.append('=');

builder.append(encode(value));

}

}

/**

* Encodes an {@code Args} instance into a UTF8-encoded string.

*

* @return The UTF8-encoded string.

*/

public String encode() {

StringBuilder builder = new StringBuilder();

for (Entry<String, Object> entry : entrySet()) {

if (builder.length() > 0) builder.append('&');

String key = entry.getKey();

Object value = entry.getValue();

if (value instanceof String[]) {

encodeValues(builder, key, (String[])value);

}

else {

builder.append(encode(key));

builder.append('=');

builder.append(encode(value.toString()));

}

}

return builder.toString();

}

/**

* Returns the hash-map value of a specific key, or the default value if

* the key is not found.

*

* @param args The hash map.

* @param key The key to look for.

* @param defaultValue The default value, if the key is not found.

* @param <T> The class type.

* @return The value.

*/

public static <T> T

get(Map<String, Object> args, String key, T defaultValue) {

if (!args.containsKey(key)) return defaultValue;

return (T)args.get(key);

}

}