using System;
using System.Collections.Generic;
using System.Text.RegularExpressions;
using WireMock.Validation;

namespace WireMock.RegularExpressions
{
    /// <summary>
    /// Extension to the <see cref="Regex"/> object, adding support for GUID tokens for matching on.
    /// </summary>
#if !NETSTANDARD1_3
    [Serializable]
#endif
    internal class RegexExtended : Regex
    {
        /// <inheritdoc cref="Regex"/>
        public RegexExtended(string pattern) : this(pattern, RegexOptions.None)
        {
        }

        /// <inheritdoc cref="Regex"/>
        public RegexExtended(string pattern, RegexOptions options) :
            this(pattern, options, Regex.InfiniteMatchTimeout)
        {
        }

        /// <inheritdoc cref="Regex"/>
        public RegexExtended(string pattern, RegexOptions options, TimeSpan matchTimeout) :
            base(ReplaceGuidPattern(pattern), options, matchTimeout)
        {
        }

#if !NETSTANDARD1_3
        /// <inheritdoc cref="Regex"/>
        protected RegexExtended(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context) :
            base(info, context)
        {
        }
#endif
        // Dictionary of various Guid tokens with a corresponding regular expression pattern to use instead.
        private static readonly Dictionary<string, string> GuidTokenPatterns = new Dictionary<string, string>
        {
            // Lower case format `B` Guid pattern
            { @"\guidb", @"(\{[a-z0-9]{8}-([a-z0-9]{4}-){3}[a-z0-9]{12}\})" },

            // Upper case format `B` Guid pattern
            { @"\GUIDB", @"(\{[A-Z0-9]{8}-([A-Z0-9]{4}-){3}[A-Z0-9]{12}\})" },

            // Lower case format `D` Guid pattern
            { @"\guidd", "([a-z0-9]{8}-([a-z0-9]{4}-){3}[a-z0-9]{12})" },

            // Upper case format `D` Guid pattern
            { @"\GUIDD", "([A-Z0-9]{8}-([A-Z0-9]{4}-){3}[A-Z0-9]{12})" },

            // Lower case format `N` Guid pattern
            { @"\guidn", "([a-z0-9]{32})" },

            // Upper case format `N` Guid pattern
            { @"\GUIDN", "([A-Z0-9]{32})" },

            // Lower case format `P` Guid pattern
            { @"\guidp", @"(\([a-z0-9]{8}-([a-z0-9]{4}-){3}[a-z0-9]{12}\))" },

            // Upper case format `P` Guid pattern
            { @"\GUIDP", @"(\([A-Z0-9]{8}-([A-Z0-9]{4}-){3}[A-Z0-9]{12}\))" },

            // Lower case format `X` Guid pattern
            { @"\guidx", @"(\{0x[a-f0-9]{8},0x[a-f0-9]{4},0x[a-f0-9]{4},\{(0x[a-f0-9]{2},){7}(0x[a-f0-9]{2})\}\})" },

            // Upper case format `X` Guid pattern
            { @"\GUIDX", @"(\{0x[A-F0-9]{8},0x[A-F0-9]{4},0x[A-F0-9]{4},\{(0x[A-F0-9]{2},){7}(0x[A-F0-9]{2})\}\})" },
        };

        /// <summary>
        /// Replaces all instances of valid GUID tokens with the correct regular expression to match.
        /// </summary>
        /// <param name="pattern">Pattern to replace token for.</param>
        private static string ReplaceGuidPattern(string pattern)
        {
            Check.NotNull(pattern, nameof(pattern));

            foreach (var tokenPattern in GuidTokenPatterns)
            {
                pattern = pattern.Replace(tokenPattern.Key, tokenPattern.Value);
            }

            return pattern;
        }
    }
}