using System.Reflection;
using System;
using System.Text.RegularExpressions;
using System.Linq;
using UnityEngine;
using Perforce.P4;

namespace P4Connect
{
	/// <summary>
	/// Version wrappers for P4Connect
	/// </summary>
    public static class Version
    {
        public static string appName = "p4connect";
		public static string perforceRelease = "2016.1.0.0";

        // Cache _PerforceReleaseString for re-use
        private static string _PerforceReleaseString = null;
        private static string _BuildType = "";
        private static string _BuildString = "";
        private static string changeIdStr;

#if DEBUG
        private static string _build = "Debug";
#else
        private static string _build = "Release"; 
#endif

        public static string Build
        {
            get
            {
                if (_BuildString != null)
                {
                     _BuildString = _build;
                }
                return _BuildString;
            }
        }

        public static string ChangeId { 
            get {
                string change = " $Change: 18418 $";  // File must be stored +k so the RCS Keyword expands

                if (String.IsNullOrEmpty(changeIdStr))
                {
                   changeIdStr = Regex.Match(change, @"\d+").Value;
                }
                return changeIdStr;
            }
        }

        
        public static string PerforceReleaseString
        {
            get
            {
                if (_PerforceReleaseString != null)
                    return _PerforceReleaseString;

                char[] delims = { '.' };

                string[] fields = perforceRelease.Split(delims);

                // If UpdateVersion.exe is missing, perforceRelease will be unchanged, 
                // so we instead generate the last two version fields from the contents of the "Change" RCS Keyword
                if (fields[2].Equals("0") && fields[3].Equals("0") && ChangeId.ToCharArray().Any(char.IsDigit))
                {
                    // Convert change ID into last two fields of version string.  each field is limited to 16 bits, so we split values so they look appropriate in decimal.
                    int changeId = Convert.ToInt32(ChangeId);
                    fields[2] = (changeId / 10000).ToString();
                    fields[3] = (changeId % 10000).ToString();
                    _BuildType = "W";    // Mark workshop builds
                }
                _PerforceReleaseString = string.Join(".",fields) + _BuildType;
                return _PerforceReleaseString;
            }
        }

        static Options NameVerOpts = null;

        // Create an Array of options for the Connect call.  You can see these in the Perforce server log
        public static Options ConnectOptions
        {
            get {
                if (NameVerOpts == null)
                {
                    NameVerOpts = new Options();
                    NameVerOpts.Add("ProgramName", appName);
                    NameVerOpts.Add("ProgramVersion", PerforceReleaseString);
                }
                return NameVerOpts;
            }
        }
    }
}