using System.Collections.Generic;
using System.Windows.Forms;

namespace JDSongConverter
{
    /// <summary>
    ///   Singleton, which contains usual standard constants.
    /// </summary>
    public class ConstantDefinitions
    {
        protected static readonly Dictionary<string, string> _definitions;

        #region Constructor

        static ConstantDefinitions()
        {
            _definitions = new Dictionary<string, string>();
        }

        /// <summary>
        ///   Protected constructor. Use inherited version of this class. 
        /// </summary>
        protected ConstantDefinitions()
        {
            _definitions["executablePath"] = Application.ExecutablePath;
            _definitions["productName"] = Application.ProductName;
            _definitions["productVersion"] = Application.ProductVersion;
            _definitions["startupPath"] = Application.StartupPath;
            _definitions["productName"] = Application.ProductName;
            _definitions["userAppDataPath"] = Application.UserAppDataPath;
            _definitions["userAppDataRegistry"] = Application.UserAppDataRegistry.Name;
#if RELEASE
            _definitions["buildConfig"] = "Release";
#else
            _definitions["buildConfig"] = "Debug";
#endif

        }

        #endregion

        /// <summary>
        ///   Return a clone of the internal constant dictionary. 
        /// </summary>
        public Dictionary<string, string> CloneDefinitions()
        {
            return new Dictionary<string, string>(_definitions);
        }

        #region Protected methods

        /// <summary>
        ///   Add constants to the internal constant dictionary. 
        /// </summary>
        protected void InternalAddConstants(IEnumerable<Constant> constants)
        {
            foreach (var constant in constants)
            {
                _definitions[constant.Name] = constant.Value;
            }
        }

        public string EvaluateExpression(string expression, IDictionary<string, string> definitions = null, bool expandEnvironment = false)
        {
            return JDSongConverter.EvaluateExpression.Do(expression, definitions ?? _definitions, expandEnvironment);
        }

        #endregion

    }

}