<?php
/*
Copyright (c) 2005 Richard Stanway

This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software.

Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions:

    1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.

	2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.

    3. This notice may not be removed or altered from any source distribution.

*/

	//Version: 1.1 (2005-05-10)
	
	class classPak
	{
		var $files;

		function classPak ()
		{
			$this->files = array();
		}

		function add_file ($path, $pakpath)
		{
			// Check path exists and is valid and pakpath is valid
			if (!is_readable ($path) || strlen ($pakpath) > 55 || strchr ($pakpath, '\\'))
			{
				return FALSE;
			}

			array_push ($this->files, array("filepath" => $path, "pakpath" => $pakpath));
			return TRUE;
		}

		function add_directory ($basedir, $pakdir, $match = '/.*/')
		{
			// Check it's really a directory
			if (!is_dir ($basedir))
			{
				return FALSE;
			}

			// Be sure pakdir is proper path since readdir returns only filenames
			if (!preg_match ("/\/$/", $pakdir))
			{
				$pakdir .= '/';
			}

			// Open directory
			$dh = opendir ($basedir);

			// Read in entries
			while (($entry = readdir($dh)) !== FALSE)
			{
				// Generate proper paths
				$fullpath = $basedir . '/' . $entry;
				$pakpath = $pakdir . $entry;

				// If it's a valid file, add it
				if (is_file($fullpath) && is_readable($fullpath))
				{
					// Check it's wanted
					if (!preg_match ($match, $entry))
					{
						continue;
					}

					$this->add_file ($fullpath, $pakpath);
				}
				else if (is_dir ($fullpath) && $entry != '.' && $entry != '..')
				{
					// Descend into this directory
					$this->add_directory ($fullpath, $pakpath);
				}
			}

			closedir ($dh);
			return TRUE;
		}

		function remove_file_by_path ($path)
		{
			$num_items = count($this->files);
			for ($i = 0; $i < $num_items; $i++)
			{
				$file = &$this->files[$i];

				if ($file['filepath'] == $path)
				{
					array_splice ($files, $i, 1);
				}
			}
		}

		function remove_file_by_pakpath ($path)
		{
			$num_items = count($this->files);
			for ($i = 0; $i < $num_items; $i++)
			{
				$file = &$this->files[$i];

				if ($file['pakpath'] == $path)
				{
					array_splice ($this->files, $i, 1);
				}
			}
		}

		function generate_pak ($optimize)
		{
			$files = &$this->files;
			
			$num_items = count($files);

			$pak = NULL;

			// Pak data starts after the header
			$offset = 12;

			for ($i = 0; $i < $num_items; $i++)
			{
				$file = &$files[$i];

				// Read in the file data
				$filesize = filesize ($file['filepath']);
				$filedata = file_get_contents ($file['filepath']);
				if (!$filedata)
				{
					return FALSE;
				}
				
				// Record filesize for directory
				$file['size'] = $filesize;

				// Optimize .pak output?
				if ($optimize)
				{
					// Calculate hash for duplicate check
					$file['hash'] = sha1($filedata, TRUE);
					for ($j = 0; $j < $i; $j++)
					{
						if ($file['hash'] == $files[$j]['hash'])
						{
							// Duplicated data, only write as offset in directory
							$file['offset'] = $files[$j]['offset'];
							continue 2;
						}
					}
				}

				// Record offset for directory
				$file['offset'] = $offset;

				// Add data
				$pak .= $filedata;

				// Update current offset
				$offset += $filesize;
			}

			//Pak directory
			$direntries = NULL;
			$dirlen = 0;

			for ($i = 0; $i < $num_items; $i++)
			{
				$file = &$files[$i];
				$direntries .= pack ('a56@56VV', $file['pakpath'], $file['offset'], $file['size']);
				$dirlen += 64;
			}

			// Add directory
			$pak .= $direntries;

			// Add pak header and we're done
			$pack = pack ("VVV", 1262698832, $offset, $dirlen);
			$pack .= $pak;

			return $pack;
		}

		function save_pak ($path, $optimize)
		{
			$pak = $this->generate_pak ($optimize);
			$fh = fopen($path, "wb");
			if (!$fh)
			{
				return FALSE;
			}
			fwrite ($fh, $pak);
			fclose ($fh);
			return TRUE;
		}
	}
?>