From 140711b5b642d454fe3e0134ff5cb4c9fc5c93e0 Mon Sep 17 00:00:00 2001
From: Natalia Portillo <claunia@claunia.com>
Date: Thu, 15 Sep 2016 01:54:13 +0100
Subject: [PATCH] 	* DiscImageChef.Helpers/StringHandlers.cs: 	  Adds
 support for OSTA Compressed Unicode.

	* DiscImageChef.Helpers/DateHandlers.cs:
	  Adds support for timestamps in ECMA-167 format.
---
 DateHandlers.cs   | 26 ++++++++++++++++++++++++++
 StringHandlers.cs | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+)

diff --git a/DateHandlers.cs b/DateHandlers.cs
index e634e713d..2a0e5fd5b 100644
--- a/DateHandlers.cs
+++ b/DateHandlers.cs
@@ -198,6 +198,32 @@ namespace DiscImageChef
         {
             return AppleDoubleEpoch.AddSeconds(AppleDoubleTimeStamp);
         }
+
+        public static DateTime ECMAToDateTime(ushort typeAndTimeZone, short year, byte month, byte day, byte hour, byte minute, byte second, byte centiseconds, byte hundredsOfMicroseconds, byte microseconds)
+        {
+            byte specification = (byte)((typeAndTimeZone & 0xF000) >> 12);
+            long ticks = (long)centiseconds * 100000 + (long)hundredsOfMicroseconds * 1000 + (long)microseconds * 10;
+            if(specification == 0)
+                return new DateTime(year, month, day, hour, minute, second, DateTimeKind.Utc).AddTicks(ticks);
+
+            ushort preOffset = (ushort)(typeAndTimeZone & 0xFFF);
+            short offset;
+
+            if((preOffset & 0x800) == 0x800)
+            {
+                offset = (short)(preOffset | 0xF000);
+            }
+            else
+                offset = (short)(preOffset & 0x7FF);
+
+            if(offset == -2047)
+                return new DateTime(year, month, day, hour, minute, second, DateTimeKind.Unspecified).AddTicks(ticks);
+            
+            if(offset < -1440 || offset > 1440)
+                offset = 0;
+
+            return new DateTimeOffset(year, month, day, hour, minute, second, new TimeSpan(0, offset, 0)).AddTicks(ticks).DateTime;
+        }
     }
 }
 
diff --git a/StringHandlers.cs b/StringHandlers.cs
index 2e43fb5bb..a17a2acbe 100644
--- a/StringHandlers.cs
+++ b/StringHandlers.cs
@@ -118,6 +118,40 @@ namespace DiscImageChef
 
             return length == 0 ? "" : Encoding.ASCII.GetString(SpacePaddedString, 0, length);
         }
+
+        /// <summary>
+        /// Converts an OSTA compressed unicode byte array to a C# string
+        /// </summary>
+        /// <returns>The C# string.</returns>
+        /// <param name="dstring">OSTA compressed unicode byte array.</param>
+        public static string DecompressUnicode(byte[] dstring)
+        {
+            ushort unicode;
+            byte compId = dstring[0];
+            string temp = "";
+
+            if(compId != 8 && compId != 16)
+                return null;
+
+            for(int byteIndex = 1; byteIndex < dstring.Length;)
+            {
+                if(compId == 16)
+                    unicode = (ushort)(dstring[byteIndex++] << 8);
+                else
+                    unicode = 0;
+
+                if(byteIndex < dstring.Length)
+                    unicode |= dstring[byteIndex++];
+
+                if(unicode == 0)
+                    break;
+
+                temp += Encoding.Unicode.GetString(System.BitConverter.GetBytes(unicode));
+            }
+
+            return temp;
+        }
+
     }
 }