<?php

/*
* @author Balaji
* @name Rainbow PHP Framework
* @copyright 2021 ProThemes.Biz
*
*/

class txtConversion
{
    private $filename;
    var $errTxt = "Something Went Wrong!";
    var $file404 = "File not exists";
    var $errNS = "Not supported file format";
    var $multibyte = 4; //Only PDF - Use setUnicode(TRUE|FALSE)
	var $convertquotes = ENT_QUOTES; //Only PDF - ENT_COMPAT (double-quotes), ENT_QUOTES (Both), ENT_NOQUOTES (None)

    public function __construct($filename)
    {
        $this->filename = $filename;
    }

    private function readDoc()
    {
        if (($fh = fopen($this->filename, 'r')) !== false)
        {
            $headers = fread($fh, 0xA00);

            $n1 = (ord($headers[0x21C]) - 1);

            $n2 = ((ord($headers[0x21D]) - 8) * 256);

            $n3 = ((ord($headers[0x21E]) * 256) * 256);

            $n4 = (((ord($headers[0x21F]) * 256) * 256) * 256);

            $textLength = ($n1 + $n2 + $n3 + $n4);
            $output = fread($fh, $textLength);

            return $output;
        }
        //Incase of error
        return $this->errTxt;
    }

    private function readDocx()
    {
        $content = '';

        $zip = zip_open($this->filename);

        if ($zip || is_numeric($zip))
        {
        while ($zip_entry = zip_read($zip)) {

            if (zip_entry_open($zip, $zip_entry) == FALSE) continue;

            if (zip_entry_name($zip_entry) != "word/document.xml") continue;

            $content .= zip_entry_read($zip_entry, zip_entry_filesize($zip_entry));

            zip_entry_close($zip_entry);
        }

        zip_close($zip);

        $document = str_replace('</w:r></w:p></w:tc><w:tc>', " ", $content);
        $document = str_replace('</w:r></w:p>', "\r\n", $document);
        $document = strip_tags($document);
        
        $output = $this->fixSpecialChar($document);
        
        return $output;
        }
        
        //Incase of error
        return $this->errTxt;
    }
    
    private function readTxt()
    {
        $output = file_get_contents($this->filename);
        return $output;
    }
    
    private function readPdf()
    {
  		$infile = @file_get_contents($this->filename, FILE_BINARY);
		if (empty($infile))
			return "";

		$transformations = array();
		$texts = array();

		preg_match_all("#obj[\n|\r](.*)endobj[\n|\r]#ismU", $infile . "endobj\r", $objects);
		$objects = @$objects[1];

		for ($i = 0; $i < count($objects); $i++) {
			$currentObject = $objects[$i];

			if (preg_match("#stream[\n|\r](.*)endstream[\n|\r]#ismU", $currentObject . "endstream\r", $stream )) {
				$stream = ltrim($stream[1]);
				$options = $this->getObjectOptions($currentObject);

				if (!(empty($options["Length1"]) && empty($options["Type"]) && empty($options["Subtype"])) )
//				if ( $options["Image"] && $options["Subtype"] )
//				if (!(empty($options["Length1"]) &&  empty($options["Subtype"])) )
					continue;

				unset($options["Length"]);

				$data = $this->getDecodedStream($stream, $options);

				if (strlen($data)) {
	                if (preg_match_all("#BT[\n|\r](.*)ET[\n|\r]#ismU", $data . "ET\r", $textContainers)) {
						$textContainers = @$textContainers[1];
						$this->getDirtyTexts($texts, $textContainers);
					} else
						$this->getCharTransformations($transformations, $data);
				}
			}
		}

		$output = $this->fixSpecialChar($this->getTextUsingTransformations($texts, $transformations));
        return $output;
    }
    
    private function decodeAsciiHex($input) {
		$output = "";

		$isOdd = true;
		$isComment = false;

		for($i = 0, $codeHigh = -1; $i < strlen($input) && $input[$i] != '>'; $i++) {
			$c = $input[$i];

			if($isComment) {
				if ($c == '\r' || $c == '\n')
					$isComment = false;
				continue;
			}

			switch($c) {
				case '\0': case '\t': case '\r': case '\f': case '\n': case ' ': break;
				case '%':
					$isComment = true;
				break;

				default:
					$code = hexdec($c);
					if($code === 0 && $c != '0')
						return "";

					if($isOdd)
						$codeHigh = $code;
					else
						$output .= chr($codeHigh * 16 + $code);

					$isOdd = !$isOdd;
				break;
			}
		}

		if($input[$i] != '>')
			return "";

		if($isOdd)
			$output .= chr($codeHigh * 16);

		return $output;
	}

	private function decodeAscii85($input) {
		$output = "";

		$isComment = false;
		$ords = array();

		for($i = 0, $state = 0; $i < strlen($input) && $input[$i] != '~'; $i++) {
			$c = $input[$i];

			if($isComment) {
				if ($c == '\r' || $c == '\n')
					$isComment = false;
				continue;
			}

			if ($c == '\0' || $c == '\t' || $c == '\r' || $c == '\f' || $c == '\n' || $c == ' ')
				continue;
			if ($c == '%') {
				$isComment = true;
				continue;
			}
			if ($c == 'z' && $state === 0) {
				$output .= str_repeat(chr(0), 4);
				continue;
			}
			if ($c < '!' || $c > 'u')
				return "";

			$code = ord($input[$i]) & 0xff;
			$ords[$state++] = $code - ord('!');

			if ($state == 5) {
				$state = 0;
				for ($sum = 0, $j = 0; $j < 5; $j++)
					$sum = $sum * 85 + $ords[$j];
				for ($j = 3; $j >= 0; $j--)
					$output .= chr($sum >> ($j * 8));
			}
		}
		if ($state === 1)
			return "";
		elseif ($state > 1) {
			for ($i = 0, $sum = 0; $i < $state; $i++)
				$sum += ($ords[$i] + ($i == $state - 1)) * pow(85, 4 - $i);
			for ($i = 0; $i < $state - 1; $i++) {
				try {
					if(false == ($o = chr($sum >> ((3 - $i) * 8)))) {
						throw new Exception('Error');
					}
					$output .= $o;
				} catch (Exception $e) { /*Dont do anything*/ }
			}
		}

		return $output;
	}

	private function decodeFlate($data) {
		return @gzuncompress($data);
	}

	private function getObjectOptions($object) {
		$options = array();

		if (preg_match("#<<(.*)>>#ismU", $object, $options)) {
			$options = explode("/", $options[1]);
			@array_shift($options);

			$o = array();
			for ($j = 0; $j < @count($options); $j++) {
				$options[$j] = preg_replace("#\s+#", " ", trim($options[$j]));
				if (strpos($options[$j], " ") !== false) {
					$parts = explode(" ", $options[$j]);
					$o[$parts[0]] = $parts[1];
				} else
					$o[$options[$j]] = true;
			}
			$options = $o;
			unset($o);
		}

		return $options;
	}

	private function getDecodedStream($stream, $options) {
		$data = "";
		if (empty($options["Filter"]))
			$data = $stream;
		else {
			$length = !empty($options["Length"]) ? $options["Length"] : strlen($stream);
			$_stream = substr($stream, 0, $length);

			foreach ($options as $key => $value) {
				if ($key == "ASCIIHexDecode")
					$_stream = $this->decodeAsciiHex($_stream);
				elseif ($key == "ASCII85Decode")
					$_stream = $this->decodeAscii85($_stream);
				elseif ($key == "FlateDecode")
					$_stream = $this->decodeFlate($_stream);
				elseif ($key == "Crypt") { // TO DO
				}
			}
			$data = $_stream;
		}
		return $data;
	}

	private function getDirtyTexts(&$texts, $textContainers) {
		for ($j = 0; $j < count($textContainers); $j++) {
			if (preg_match_all("#\[(.*)\]\s*TJ[\n|\r]#ismU", $textContainers[$j], $parts))
				$texts = array_merge($texts, array(@implode('', $parts[1])));
			elseif (preg_match_all("#T[d|w|m|f]\s*(\(.*\))\s*Tj[\n|\r]#ismU", $textContainers[$j], $parts))
				$texts = array_merge($texts, array(@implode('', $parts[1])));
			elseif (preg_match_all("#T[d|w|m|f]\s*(\[.*\])\s*Tj[\n|\r]#ismU", $textContainers[$j], $parts))
				$texts = array_merge($texts, array(@implode('', $parts[1])));
		}

	}

	private function getCharTransformations(&$transformations, $stream) {
		preg_match_all("#([0-9]+)\s+beginbfchar(.*)endbfchar#ismU", $stream, $chars, PREG_SET_ORDER);
		preg_match_all("#([0-9]+)\s+beginbfrange(.*)endbfrange#ismU", $stream, $ranges, PREG_SET_ORDER);

		for ($j = 0; $j < count($chars); $j++) {
			$count = $chars[$j][1];
			$current = explode("\n", trim($chars[$j][2]));
			for ($k = 0; $k < $count && $k < count($current); $k++) {
				if (preg_match("#<([0-9a-f]{2,4})>\s+<([0-9a-f]{4,512})>#is", trim($current[$k]), $map))
					$transformations[str_pad($map[1], 4, "0")] = $map[2];
			}
		}
		for ($j = 0; $j < count($ranges); $j++) {
			$count = $ranges[$j][1];
			$current = explode("\n", trim($ranges[$j][2]));
			for ($k = 0; $k < $count && $k < count($current); $k++) {
				if (preg_match("#<([0-9a-f]{4})>\s+<([0-9a-f]{4})>\s+<([0-9a-f]{4})>#is", trim($current[$k]), $map)) {
					$from = hexdec($map[1]);
					$to = hexdec($map[2]);
					$_from = hexdec($map[3]);

					for ($m = $from, $n = 0; $m <= $to; $m++, $n++)
						$transformations[sprintf("%04X", $m)] = sprintf("%04X", $_from + $n);
				} elseif (preg_match("#<([0-9a-f]{4})>\s+<([0-9a-f]{4})>\s+\[(.*)\]#ismU", trim($current[$k]), $map)) {
					$from = hexdec($map[1]);
					$to = hexdec($map[2]);
					$parts = preg_split("#\s+#", trim($map[3]));

					for ($m = $from, $n = 0; $m <= $to && $n < count($parts); $m++, $n++)
						$transformations[sprintf("%04X", $m)] = sprintf("%04X", hexdec($parts[$n]));
				}
			}
		}
	}
	private function getTextUsingTransformations($texts, $transformations) {
		$document = "";
		for ($i = 0; $i < count($texts); $i++) {
			$isHex = false;
			$isPlain = false;

			$hex = "";
			$plain = "";
			for ($j = 0; $j < strlen($texts[$i]); $j++) {
				$c = $texts[$i][$j];
				switch($c) {
					case "<":
						$hex = "";
						$isHex = true;
                        $isPlain = false;
					break;
					case ">":
						$hexs = str_split($hex, $this->multibyte); // 2 or 4 (UTF8 or ISO)
						for ($k = 0; $k < count($hexs); $k++) {

							$chex = str_pad($hexs[$k], 4, "0"); // Add tailing zero
							if (isset($transformations[$chex]))
								$chex = $transformations[$chex];
							$document .= html_entity_decode("&#x".$chex.";");
						}
						$isHex = false;
					break;
					case "(":
						$plain = "";
						$isPlain = true;
                        $isHex = false;
					break;
					case ")":
						$document .= $plain;
						$isPlain = false;
					break;
					case "\\":
						$c2 = $texts[$i][$j + 1];
						if (in_array($c2, array("\\", "(", ")"))) $plain .= $c2;
						elseif ($c2 == "n") $plain .= '\n';
						elseif ($c2 == "r") $plain .= '\r';
						elseif ($c2 == "t") $plain .= '\t';
						elseif ($c2 == "b") $plain .= '\b';
						elseif ($c2 == "f") $plain .= '\f';
						elseif ($c2 >= '0' && $c2 <= '9') {
							$oct = preg_replace("#[^0-9]#", "", substr($texts[$i], $j + 1, 3));
							$j += strlen($oct) - 1;
							$plain .= html_entity_decode("&#".octdec($oct).";", $this->convertquotes);
						}
						$j++;
					break;

					default:
						if ($isHex)
							$hex .= $c;
						elseif ($isPlain)
							$plain .= $c;
					break;
				}
			}
			$document .= "\n";
		}

		return $document;
	}
    private function fixSpecialChar($plainTxt)
    {
       return mb_convert_encoding($plainTxt, 'UTF-8', 'UTF-8');
    }
    public function convertToText()
    {

        if (isset($this->filename) && !file_exists($this->filename))
        {
            return $this->file404;
        }

        $fileArray = pathinfo($this->filename);
        $file_ext = $fileArray['extension'];
        if ($file_ext == "doc" || $file_ext == "docx" || $file_ext == "txt" || $file_ext == "pdf")
        {
            if ($file_ext == "doc")
            {
                return $this->readDoc();
            } elseif ($file_ext == "docx")
            {
                return $this->readDocx();
            } elseif ($file_ext == "txt")
            {
                return $this->readTxt();
            } elseif ($file_ext == "pdf")
            {
                return $this->readPdf();
            }
        } else
        {
            return $this->errNS;
        }
    }

}