#region ================== Copyright (c) 2007 Pascal vd Heiden

/*
 * Copyright (c) 2007 Pascal vd Heiden, www.codeimp.com
 * This program is released under GNU General Public License
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 */

#endregion

#region ================== Namespaces

using System;
using System.Collections;
using System.Collections.Generic;
using System.Globalization;
using System.Text;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using CodeImp.DoomBuilder.IO;
using ICSharpCode.SharpZipLib.Zip;

#endregion

namespace CodeImp.DoomBuilder.Data
{
	internal sealed class PK3Reader : PK3StructuredReader
	{
		#region ================== Variables

		private List<string> fileslist;

		#endregion

		#region ================== Constructor / Disposer

		// Constructor
		public PK3Reader(DataLocation dl) : base(dl)
		{
			General.WriteLogLine("Opening PK3 resource '" + location.location + "'");
			
			// Open the zip file
			ZipInputStream zipstream = OpenPK3File();
			
			// Make list of all files
			fileslist = new List<string>();
			ZipEntry entry = zipstream.GetNextEntry();
			while(entry != null)
			{
				if(entry.IsFile) fileslist.Add(entry.Name.ToLowerInvariant());
				
				// Next
				entry = zipstream.GetNextEntry();
			}

			// Done with the zip file
			zipstream.Close();
			zipstream.Dispose();
			
			// Initialize without path (because we use paths relative to the PK3 file)
			Initialize("");

			// We have no destructor
			GC.SuppressFinalize(this);
		}

		// Disposer
		public override void Dispose()
		{
			// Not already disposed?
			if(!isdisposed)
			{
				General.WriteLogLine("Closing PK3 resource '" + location.location + "'");
				
				// Done
				base.Dispose();
			}
		}

		#endregion

		#region ================== Management

		// This opens the zip file for reading
		private ZipInputStream OpenPK3File()
		{
			FileStream filestream = File.Open(location.location, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
			filestream.Seek(0, SeekOrigin.Begin);
			return new ZipInputStream(filestream);
		}

		#endregion
		
		#region ================== Methods
		
		// This creates an image
		protected override ImageData CreateImage(string name, string filename, bool flat)
		{
			return new PK3FileImage(this, name, filename, flat);
		}

		// This returns true if the specified file exists
		protected override bool FileExists(string filename)
		{
			string lowfile = filename.ToLowerInvariant();
			foreach(string f in fileslist)
			{
				if((string.Compare(f, lowfile) == 0)) return true;
			}

			return false;
		}
		
		// This returns all files in a given directory
		protected override string[] GetAllFiles(string path)
		{
			List<string> matches = new List<string>();
			string lowpath = path.ToLowerInvariant();
			foreach(string f in fileslist)
			{
				if((string.Compare(Path.GetDirectoryName(f), lowpath) == 0) &&
				   (Path.GetFileName(f).Length > 0))
					matches.Add(f);
			}
			
			return matches.ToArray();
		}

		// This returns all files in a given directory that match the given extension
		protected override string[] GetFilesWithExt(string path, string extension)
		{
			List<string> matches = new List<string>();
			string lowpath = path.ToLowerInvariant();
			string lowext = "." + extension.ToLowerInvariant();
			foreach(string f in fileslist)
			{
				if((string.Compare(Path.GetDirectoryName(f), lowpath) == 0) && f.EndsWith(lowext))
					matches.Add(f);
			}

			return matches.ToArray();
		}

		// This finds the first file that has the specific name, regardless of file extension
		protected override string FindFirstFile(string path, string beginswith)
		{
			string lowpath = path.ToLowerInvariant();
			string lowbegin = beginswith.ToLowerInvariant();
			foreach(string f in fileslist)
			{
				if((string.Compare(Path.GetDirectoryName(f), lowpath) == 0) &&
				   (string.Compare(Path.GetFileNameWithoutExtension(f), lowbegin) == 0))
					return f;
			}

			return null;
		}

		// This loads an entire file in memory and returns the stream
		// NOTE: Callers are responsible for disposing the stream!
		protected override MemoryStream LoadFile(string filename)
		{
			MemoryStream filedata = null;
			byte[] copybuffer = new byte[4096];

			// Open the zip file
			ZipInputStream zipstream = OpenPK3File();

			ZipEntry entry = zipstream.GetNextEntry();
			while(entry != null)
			{
				// Is this the entry we are looking for?
				if(string.Compare(entry.Name, filename, true) == 0)
				{
					int expectedsize = (int)entry.Size;
					if(expectedsize < 1) expectedsize = 1024;
					filedata = new MemoryStream(expectedsize);
					int readsize = zipstream.Read(copybuffer, 0, copybuffer.Length);
					while(readsize > 0)
					{
						filedata.Write(copybuffer, 0, readsize);
						readsize = zipstream.Read(copybuffer, 0, copybuffer.Length);
					}
					break;
				}
				
				// Next
				entry = zipstream.GetNextEntry();
			}

			// Done with the zip file
			zipstream.Close();
			zipstream.Dispose();
			
			// Nothing found?
			if(filedata == null)
			{
				throw new FileNotFoundException("Cannot find the file " + filename + " in PK3 file " + location.location + ".");
			}
			else
			{
				return filedata;
			}
		}

		// This creates a temp file for the speciied file and return the absolute path to the temp file
		// NOTE: Callers are responsible for removing the temp file when done!
		protected override string CreateTempFile(string filename)
		{
			// Just copy the file
			string tempfile = General.MakeTempFilename(General.Map.TempPath, "wad");
			MemoryStream filedata = LoadFile(filename);
			File.WriteAllBytes(tempfile, filedata.ToArray());
			filedata.Dispose();
			return tempfile;
		}

		// Public version to load a file
		internal MemoryStream ExtractFile(string filename)
		{
			return LoadFile(filename);
		}
		
		#endregion
	}
}