using System;
using System.Globalization;

namespace Org.BouncyCastle.Utilities
{
    internal static class Platform
    {
        private static readonly CompareInfo InvariantCompareInfo = CultureInfo.InvariantCulture.CompareInfo;

        internal static bool EqualsIgnoreCase(string a, string b)
        {
            return string.Equals(a, b, StringComparison.OrdinalIgnoreCase);
        }

        internal static string GetEnvironmentVariable(string variable)
        {
            try
            {
                return Environment.GetEnvironmentVariable(variable);
            }
            catch (System.Security.SecurityException)
            {
                // We don't have the required permission to read this environment variable,
                // which is fine, just act as if it's not set
                return null;
            }
        }

        internal static void Dispose(IDisposable d)
        {
            d.Dispose();
        }

        internal static int IndexOf(string source, string value)
        {
            return InvariantCompareInfo.IndexOf(source, value, CompareOptions.Ordinal);
        }

        internal static int LastIndexOf(string source, string value)
        {
            return InvariantCompareInfo.LastIndexOf(source, value, CompareOptions.Ordinal);
        }

        internal static bool StartsWith(string source, string prefix)
        {
            return InvariantCompareInfo.IsPrefix(source, prefix, CompareOptions.Ordinal);
        }

        internal static bool EndsWith(string source, string suffix)
        {
            return InvariantCompareInfo.IsSuffix(source, suffix, CompareOptions.Ordinal);
        }

        internal static string GetTypeName(object obj)
        {
            return obj.GetType().FullName;
        }
    }
}