/**
 * FreeRDP: A Remote Desktop Protocol Client
 * Time Zone Redirection Table Generator
 *
 * Copyright 2012 Marc-Andre Moreau <marcandre.moreau@gmail.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *	 http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

using System;
using System.IO;
using System.Globalization;
using System.Collections.ObjectModel;

namespace TimeZones
{
	struct SYSTEM_TIME_ENTRY
	{
		public UInt16 wYear;
		public UInt16 wMonth;
		public UInt16 wDayOfWeek;
		public UInt16 wDay;
		public UInt16 wHour;
		public UInt16 wMinute;
		public UInt16 wSecond;
		public UInt16 wMilliseconds;
	};

	struct TIME_ZONE_RULE_ENTRY
	{
		public long TicksStart;
		public long TicksEnd;
		public Int32 DaylightDelta;
		public SYSTEM_TIME_ENTRY StandardDate;
		public SYSTEM_TIME_ENTRY DaylightDate;
	};

	struct TIME_ZONE_ENTRY
	{
		public string Id;
		public UInt32 Bias;
		public bool SupportsDST;
		public string DisplayName;
		public string StandardName;
		public string DaylightName;
		public string RuleTable;
		public UInt32 RuleTableCount;
	};

	class TimeZones
	{
		static void Main(string[] args)
		{
			int i;
			UInt32 index;
			const string file = @"TimeZones.txt";
			TimeZoneInfo.AdjustmentRule[] rules;
			StreamWriter stream = new StreamWriter(file, false);
			ReadOnlyCollection<TimeZoneInfo> timeZones = TimeZoneInfo.GetSystemTimeZones();

			stream.WriteLine();

			stream.WriteLine("struct _SYSTEM_TIME_ENTRY");
			stream.WriteLine("{");
			stream.WriteLine("\tuint16 wYear;");
			stream.WriteLine("\tuint16 wMonth;");
			stream.WriteLine("\tuint16 wDayOfWeek;");
			stream.WriteLine("\tuint16 wDay;");
			stream.WriteLine("\tuint16 wHour;");
			stream.WriteLine("\tuint16 wMinute;");
			stream.WriteLine("\tuint16 wSecond;");
			stream.WriteLine("\tuint16 wMilliseconds;");
			stream.WriteLine("};");
			stream.WriteLine("typedef struct _SYSTEM_TIME_ENTRY SYSTEM_TIME_ENTRY;");
			stream.WriteLine();

			stream.WriteLine("struct _TIME_ZONE_RULE_ENTRY");
			stream.WriteLine("{");
			stream.WriteLine("\tuint64 TicksStart;");
			stream.WriteLine("\tuint64 TicksEnd;");
			stream.WriteLine("\tsint32 DaylightDelta;");
			stream.WriteLine("\tSYSTEM_TIME_ENTRY StandardDate;");
			stream.WriteLine("\tSYSTEM_TIME_ENTRY DaylightDate;");
			stream.WriteLine("};");
			stream.WriteLine("typedef struct _TIME_ZONE_RULE_ENTRY TIME_ZONE_RULE_ENTRY;");
			stream.WriteLine();

			stream.WriteLine("struct _TIME_ZONE_ENTRY");
			stream.WriteLine("{");
			stream.WriteLine("\tconst char* Id;");
			stream.WriteLine("\tuint32 Bias;");
			stream.WriteLine("\tboolean SupportsDST;");
			stream.WriteLine("\tconst char* DisplayName;");
			stream.WriteLine("\tconst char* StandardName;");
			stream.WriteLine("\tconst char* DaylightName;");
			stream.WriteLine("\tTIME_ZONE_RULE_ENTRY* RuleTable;");
			stream.WriteLine("\tuint32 RuleTableCount;");
			stream.WriteLine("};");
			stream.WriteLine("typedef struct _TIME_ZONE_ENTRY TIME_ZONE_ENTRY;");
			stream.WriteLine();

			index = 0;

			foreach (TimeZoneInfo timeZone in timeZones)
			{
				rules = timeZone.GetAdjustmentRules();

				if ((!timeZone.SupportsDaylightSavingTime) || (rules.Length < 1))
				{
					index++;
					continue;
				}

				stream.WriteLine("static const TIME_ZONE_RULE_ENTRY TimeZoneRuleTable_{0}[] =", index);
				stream.WriteLine("{");

				i = 0;
				foreach (TimeZoneInfo.AdjustmentRule rule in rules)
				{
					DateTime time;
					TIME_ZONE_RULE_ENTRY tzr;
					TimeZoneInfo.TransitionTime transition;

					tzr.TicksStart = rule.DateEnd.ToUniversalTime().Ticks;
					tzr.TicksEnd = rule.DateStart.ToUniversalTime().Ticks;
					tzr.DaylightDelta = (Int32)rule.DaylightDelta.TotalMinutes;

					transition = rule.DaylightTransitionEnd;
					time = transition.TimeOfDay;

					tzr.StandardDate.wYear = (UInt16)0;
					tzr.StandardDate.wMonth = (UInt16)transition.Month;
					tzr.StandardDate.wDayOfWeek = (UInt16)transition.DayOfWeek;
					tzr.StandardDate.wDay = (UInt16)transition.Day;
					tzr.StandardDate.wHour = (UInt16)time.Hour;
					tzr.StandardDate.wMinute = (UInt16)time.Minute;
					tzr.StandardDate.wSecond = (UInt16)time.Second;
					tzr.StandardDate.wMilliseconds = (UInt16)time.Millisecond;

					transition = rule.DaylightTransitionStart;
					time = transition.TimeOfDay;

					tzr.DaylightDate.wYear = (UInt16)0;
					tzr.DaylightDate.wMonth = (UInt16)transition.Month;
					tzr.DaylightDate.wDayOfWeek = (UInt16)transition.DayOfWeek;
					tzr.DaylightDate.wDay = (UInt16)transition.Day;
					tzr.DaylightDate.wHour = (UInt16)time.Hour;
					tzr.DaylightDate.wMinute = (UInt16)time.Minute;
					tzr.DaylightDate.wSecond = (UInt16)time.Second;
					tzr.DaylightDate.wMilliseconds = (UInt16)time.Millisecond;

					stream.Write("\t{");
					stream.Write(" {0}ULL, {1}ULL, {2},", tzr.TicksStart, tzr.TicksEnd, tzr.DaylightDelta);

					stream.Write(" { ");
					stream.Write("{0}, {1}, {2}, {3}, {4}, {5}",
						tzr.StandardDate.wYear, tzr.StandardDate.wMonth, tzr.StandardDate.wDayOfWeek,
						tzr.StandardDate.wDay, tzr.StandardDate.wHour, tzr.StandardDate.wMinute,
						tzr.StandardDate.wSecond, tzr.StandardDate.wMilliseconds);
					stream.Write(" }, ");

					stream.Write("{ ");
					stream.Write("{0}, {1}, {2}, {3}, {4}, {5}",
						tzr.DaylightDate.wYear, tzr.DaylightDate.wMonth, tzr.DaylightDate.wDayOfWeek,
						tzr.DaylightDate.wDay, tzr.DaylightDate.wHour, tzr.DaylightDate.wMinute,
						tzr.DaylightDate.wSecond, tzr.DaylightDate.wMilliseconds);
					stream.Write(" },");

					if (++i < rules.Length)
						stream.WriteLine(" },");
					else
						stream.WriteLine(" }");
				}

				stream.WriteLine("};");
				stream.WriteLine();
				index++;
			}

			index = 0;
			stream.WriteLine("static const TIME_ZONE_ENTRY TimeZoneTable[] =");
			stream.WriteLine("{");

			foreach (TimeZoneInfo timeZone in timeZones)
			{
				TIME_ZONE_ENTRY tz;
				TimeSpan offset = timeZone.BaseUtcOffset;

				rules = timeZone.GetAdjustmentRules();

				tz.Id = timeZone.Id;

				if (offset.Hours >= 0)
					tz.Bias = (UInt32)((offset.Hours * 60) + offset.Minutes);
				else
					tz.Bias = (UInt32)(((-1 * offset.Hours) * 60) + offset.Minutes + 720);

				tz.SupportsDST = timeZone.SupportsDaylightSavingTime;

				tz.DisplayName = timeZone.DisplayName;
				tz.StandardName = timeZone.StandardName;
				tz.DaylightName = timeZone.DaylightName;

				if ((!tz.SupportsDST) || (rules.Length < 1))
				{
					tz.RuleTableCount = 0;
					tz.RuleTable = "NULL";
				}
				else
				{
					tz.RuleTableCount = (UInt32)rules.Length;
					tz.RuleTable = "&TimeZoneRuleTable_" + index;
					tz.RuleTable = "(TIME_ZONE_RULE_ENTRY*) &TimeZoneRuleTable_" + index;
				}

				stream.WriteLine("\t{");

				stream.WriteLine("\t\t\"{0}\", {1}, {2}, \"{0}\",",
					tz.Id, tz.Bias, tz.SupportsDST ? "true" : "false", tz.DisplayName);

				stream.WriteLine("\t\t\"{0}\", \"{0}\",", tz.StandardName, tz.DaylightName);
				stream.WriteLine("\t\t{0}, {1}", tz.RuleTable, tz.RuleTableCount);

				index++;

				if ((int) index < timeZones.Count)
					stream.WriteLine("\t},");
				else
					stream.WriteLine("\t}");
			}
			stream.WriteLine("};");
			stream.WriteLine();

			stream.Close();
		}
	}
}