using System;
using System.IO;
using System.Linq;

namespace JD.Core
{
    /// <summary>
    /// The project id is used to find the data corresponding to an executable.
    /// </summary>
    public static class ProjectId
    {
        private static string _value;
        private static string _location;

        /// <summary>
        /// Full project id. Example: JD2017_Main
        /// </summary>
        public static string Value
        {
            get
            {
                if (_value == null)
                {
                    return _value = ReadProjectId();
                }
                return _value;
            }
        }

        /// <summary>
        /// Game name is the first part of the id
        /// </summary>
        public static string GameName => Value.Split('_').First();

        /// <summary>
        /// Branch name is the second part of the id
        /// </summary>
        public static string BranchName => Value.Substring(GameName.Length + 1);

        /// <summary>
        /// Location where to look for ProjectId.txt, default is current assembly location
        /// </summary>
        public static string Location
        {
            get
            {
                if (string.IsNullOrEmpty(_location))
                {
                    _location = Path.GetDirectoryName(typeof(ProjectId).Assembly.Location());
                }
                return _location;

            }
            set
            {
                _location = value;
                _value = ReadProjectId();
            }
        }

        private static string ReadProjectId()
        {
            var projectIdFile = Path.Combine(Location, "ProjectId.txt");

            if (!File.Exists(projectIdFile))
            {
                throw new InvalidProgramException($"Cannot find file {projectIdFile} so the initialization of the data path cannot be done.");
            }

            try
            {
                var projectId = File.ReadAllText(projectIdFile).Trim();
                return projectId;
            }
            catch (IOException)
            {
                throw new InvalidProgramException($"Cannot read file {projectIdFile} so the initialization of the data path cannot be done.");
            }
        }
    }
}