TokenReplacer.cs

// Copyright © 2017 - 2021 Chocolatey Software, Inc
// Copyright © 2011 - 2017 RealDimensions Software, LLC
//
// 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.

namespace chocolatey.infrastructure.tokens
{
    using System.Collections.Generic;
    using System.Reflection;
    using System.Text.RegularExpressions;

    public sealed class TokenReplacer
    {
        public static string replace_tokens<TConfig>(TConfig configuration, string textToReplace, string tokenPrefix = "[[", string tokenSuffix = "]]")
        {
            if (string.IsNullOrEmpty(textToReplace)) return string.Empty;

            IDictionary<string, string> dictionary = create_dictionary_from_configuration(configuration);
            if (dictionary.Count == 0) return textToReplace;

            var regex = new Regex("{0}(?<key>\\w+){1}".format_with(Regex.Escape(tokenPrefix), Regex.Escape(tokenSuffix)));

            string output = regex.Replace(textToReplace, m =>
                {
                    string key = "";

                    var originalKey = m.Groups["key"].Value;
                    key = originalKey.to_lower();
                    if (!dictionary.ContainsKey(key))
                    {
                        return tokenPrefix + originalKey + tokenSuffix;
                    }

                    string value = dictionary[key];
                    return value;
                });

            return output;
        }

        private static IDictionary<string, string> create_dictionary_from_configuration<TConfig>(TConfig configuration)
        {
            if (configuration is IDictionary<string, string>) return configuration as IDictionary<string, string>;

            var propertyDictionary = new Dictionary<string, string>();
            foreach (PropertyInfo property in configuration.GetType().GetProperties())
            {
                propertyDictionary.Add(property.Name.to_lower(), property.GetValue(configuration, null).to_string());
            }

            return propertyDictionary;
        }

        public static IEnumerable<string> get_tokens(string textWithTokens, string tokenPrefix = "[[", string tokenSuffix = "]]")
        {
            var regexMatches = Regex.Matches(textWithTokens, "{0}(?<key>\\w+){1}"
                .format_with(Regex.Escape(tokenPrefix), Regex.Escape(tokenSuffix))
            );
            foreach (Match regexMatch in regexMatches)
            {
                yield return regexMatch.Groups["key"].to_string();
            }
        }
    }
}