<?php

/**

 * Implementation of ELIZA in PHP. Ported from Javascript by Dan Fuhry

 * Chat Bot by George Dunlop, www.peccavi.com

 * May be used/modified if credit line is retained

 * @author George Dunlop <http://www.peccavi.com/>

 * @author Dan Fuhry <dan@enanocms.org>

 * @copyright (c) 1997-2008 George Dunlop. All rights reserved, portions copyright (C) 2008 Dan Fuhry.

 */

class Psychotherapist

{

  private $maxKey = 36;

  private $keyNotFound = 0;

  private $keyword = array();

  private $maxresponses = 116;

  private $response = array();

  private $maxConj = 19;

  private $max2ndConj = 7;

  private $conj1 = Array();

  private $conj2 = Array();

  private $conj3 = Array();

  private $conj4 = Array();

  private $punct = Array(".", ",", "!", "?", ":", ";", "&", '"', "@", "#", "(", ")" );

  /**

   * Constructor.

   */

  public function __construct()

  {

    $this->keyNotFound = $this->maxKey - 1;

    $this->keyword = $this->create_array($this->maxKey);

    $this->response = $this->create_array($this->maxresponses);

    $this->conj1 = $this->create_array($this->maxConj);

    $this->conj2 = $this->create_array($this->maxConj);

    $this->conj3 = $this->create_array($this->max2ndConj);

    $this->conj4 = $this->create_array($this->max2ndConj);

    $this->table_setup();

  }

  /**

   * Replacement for str_replace that provides more options.

   * if type == 0 straight string replacement

   * if type == 1 assumes padded strings and replaces whole words only

   * if type == 2 non case sensitive assumes padded strings to compare whole word only

   * if type == 3 non case sensitive straight string replacement

   * @param string Haystack

   * @param string Needle

   * @param string Replacement

   * @param int Mode - defaults to 0

   */

  private function replaceStr($strng, $substr1, $substr2, $type = 0)

  {

    if ( $type == 0 )

    {  

      return str_replace($substr1, $substr2, $strng);

    }

    else if ( $type == 1 )

    {

      return str_replace(" $substr1 ", " $substr2 ", $strng);

    }

    else if ( $type == 2 || $type == 3 )

    {

      if ( $type == 2 )

      {

        $substr1 = " $substr1 ";

        $substr2 = " $substr2 ";

      }

      return preg_replace('/' . preg_quote($substr1) . '/i', $substr2, $strng);

    }

    else

    {

      throw new Exception("Invalid parameter");

    }

  }

  /**

   * Function to pad a string. head, tail & punctuation

   * @param string

   * @return string

   */

  private function padString($strng)

  {

    $punct =& $this->punct;

    $aString = " " . $strng . " ";

    for ( $i = 0; $i < count($punct); $i++ )

    {

      $aString = $this->replaceStr( $aString, $punct[$i], " " . $punct[$i] . " ", 0 );

    }

    return $aString;

  }

  /**

   * Function to strip padding

   */

  private function unpadString($strng)

  {

    $punct =& $this->punct;

    $aString = $strng;

    $aString = $this->replaceStr( $aString, "  ", " ", 0 );         // compress spaces

    $aString = trim($aString, ' ');

    for ( $i = 0; $i < count($punct); $i++ )

    {

      $aString = $this->replaceStr( $aString, " " . $punct[$i], $punct[$i], 0 );

    }

    return $aString;

  }

  /**

   * Dress Input formatting i.e leading & trailing spaces and tail punctuation

   * @param string

   * @return string

   */

  function strTrim($strng)

  {

    static $ht = 0;

    if ( $ht == 0 )

    {

      $loc = 0;

    }                                    // head clip

    else

    {

      $loc = strlen($strng) - 1;

    }                        // tail clip  ht = 1 

    if ( substr($strng, $loc, 1) == " " )

    {

      $aString = substr($strng, - ( $ht - 1 ), strlen($strng) - $ht);

      $aString = $this->strTrim($aString);

    }

    else

    {

      $flg = false;

      for ( $i = 0; $i <= 5; $i++ )

      {

        $flg = $flg || ( substr($strng, $loc, 1) == $this->punct[$i]);

      }

      if ( $flg )

      {    

        $aString = substr($strng, - ( $ht - 1 ), strlen($strng) - $ht);

      }

      else

      {

        $aString = $strng;

      }

      if ( $aString != $strng )

      {

        $aString = $this->strTrim($aString);

      }

    }

    if ( $ht == 0 )

    {

      $ht = 1;

      $aString = $this->strTrim($aString);

    } 

    else

    {

      $ht = 0;

    }        

    return $aString;

  }

  /**

   * adjust pronouns and verbs & such

   * @param string

   * @return string

   */

  private function conjugate($sStrg)

  {

    $sString = $sStrg;

    for ( $i = 0; $i < $this->maxConj; $i++ )

    {            // decompose

      $sString = $this->replaceStr( $sString, $this->conj1[$i], "#@&" . $i, 2 );

    }

    for( $i = 0; $i < $this->maxConj; $i++ )

    {            // recompose

      $sString = $this->replaceStr( $sString, "#@&" . $i, $this->conj2[$i], 2 );

    }

    // post process the resulting string

    for( $i = 0; $i < $this->max2ndConj; $i++ )

    {            // decompose

      $sString = $this->replaceStr( $sString, $this->conj3[$i], "#@&" . $i, 2 );

    }

    for( $i = 0; $i < $this->max2ndConj; $i++ )

    {            // recompose

      $sString = $this->replaceStr( $sString, "#@&" . $i, $this->conj4[$i], 2 );

    }

    return $sString;

  }

  /**

   * Build our response string

   * get a random choice of response based on the key

   * Then structure the response

   * @param string

   * @param int Key index

   * @return string

   */

  function phrase( $sString, $keyidx )

  {

    $idxmin  = $this->keyword[$keyidx]->idx;

    $idrange = $this->keyword[$keyidx]->end - $idxmin + 1;

    while ( $pass < 5 )

    {

      $choice = $this->keyword[$keyidx]->idx + mt_rand(0, $idrange);

      if ( $choice == $this->keyword[$keyidx]->last )

      { 

        $pass++;

        continue;

      }

      break;

    }

    $this->keyword[$keyidx]->last = $choice;

    $rTemp = $this->response[$choice];

    $tempt = substr($rTemp, strlen($rTemp) - 1, 1);

    if ( ( $tempt == "*" ) || ( $tempt == "@" ) )

    {

      $sTemp = $this->padString($sString);

      $wTemp = strtoupper($sTemp);

      $strpstr = intval(strpos($wTemp, " {$this->keyword[$keyidx]->key} "));

      $strpstr += strlen($this->keyword[$keyidx]->key) + 1;

      $thisstr = $this->conjugate( substr($sTemp, $strpstr, strlen($sTemp)) );

      $thisstr = $this->strTrim( $this->unpadString($thisstr) );

      if( $tempt == "*" )

      {

        $sTemp = $this->replaceStr( $rTemp, "<*", " " . $thisstr . "?", 0 );

      }

      else

      {

        $sTemp = $this->replaceStr( $rTemp, "<@", " " . $thisstr . ".", 0 );

      }

    }

    else

    {

      $sTemp = $rTemp;

    }

    return $sTemp;

  }

  /**

   * returns array index of first key found

   * @param string

   */

  private function testkey($wString)

  {

    for ( $keyid = 0; $keyid < count($this->keyword); $keyid++ )

    {

      if ( strpos($wString, " {$this->keyword[$keyid]->key} ") !== false )

      { 

        return $keyid;

      }

    }

    return false;

  }

  /**

   * 

   */

  private function findkey($wString)

  { 

    $keyid = $this->testkey($wString);

    if( !$keyid )

    {

      $keyid = $this->keyNotFound;

    }

    return $keyid;

  }

  /**

   * Process a line from the user.

   * @param string User input

   * @return string AI output

   */

  function listen($User)

  {

    static $wTopic = "";                                            // Last worthy responce

    static $sTopic = "";                                            // Last worthy responce

    static $greet = false;

    static $wPrevious = "";                                    // so we can check for repeats

    $sInput = $User;

    $sInput = $this->strTrim($sInput);                            // dress input formating

    if ( $sInput != "" )

    { 

      $wInput = $this->padString(strtoupper($sInput));    // Work copy

      $foundkey = $this->maxKey;                          // assume it's a repeat input

      if ( $wInput != $wPrevious )

      {                       // check if user repeats himself

        $foundkey = $this->findkey($wInput);               // look for a keyword.

      }

      if( $foundkey == $this->keyNotFound )

      {

        if( !$greet )

        {

          $greet = true;

          return "Don't you ever say Hello?";

        }

        else

        {

          $wPrevious = $wInput;                      // save input to check repeats

          if (( strlen($sInput) < 10 ) && ( $wTopic != "" ) && ( $wTopic != $wPrevious ))

          {

            $lTopic = $this->conjugate( $sTopic );

            $sTopic = "";

            $wTopic = "";

            return 'OK... "' + $lTopic + '". Tell me more.';

          }

          else

          {

            if ( strlen($sInput) < 15 )

            { 

              return "Tell me more..."; 

            }

            else

            {

              return $this->phrase( $sInput, $foundkey );

            }

          }

        }

      }

      else

      { 

        if ( strlen($sInput) > 12 )

        {

          $sTopic = $sInput;

          $wTopic = $wInput;

        }

        $greet = true;

        $wPrevious = $wInput;              // save input to check repeats

        return $this->phrase( $sInput, $foundkey );            // Get our response

      }

    }

    else

    {

      return "I can't help if you will not chat with me!";

    }

  }

  /**

   * Creates an array of the specified length, and fills it with null values.

   * @param int Array size

   * @return array

   */

  function create_array($len)

  {

    $ret = array();

    for ( $i = 0; $i < $len; $i++ )

    {

      $ret[] = null;

    }

    return $ret;

  }

  /**

   * Sets up the tables of phrases, etc.

   */

  private function table_setup()

  {

    // build our data base here

    $this->conj1[0]  = "are";           $this->conj2[0]  = "am";

    $this->conj1[1]  = "am";            $this->conj2[1]  = "are";

    $this->conj1[2]  = "were";          $this->conj2[2]  = "was";

    $this->conj1[3]  = "was";           $this->conj2[3]  = "were";

    $this->conj1[4]  = "I";             $this->conj2[4]  = "you";    

    $this->conj1[5]  = "me";            $this->conj2[5]  = "you";    

    $this->conj1[6]  = "you";           $this->conj2[6]  = "me";

    $this->conj1[7]  = "my";            $this->conj2[7]  = "your";    

    $this->conj1[8]  = "your";          $this->conj2[8]  = "my";

    $this->conj1[9]  = "mine";          $this->conj2[9]  = "your's";    

    $this->conj1[10] = "your's";        $this->conj2[10] = "mine";    

    $this->conj1[11] = "I'm";           $this->conj2[11] = "you're";

    $this->conj1[12] = "you're";        $this->conj2[12] = "I'm";    

    $this->conj1[13] = "I've";          $this->conj2[13] = "you've";

    $this->conj1[14] = "you've";        $this->conj2[14] = "I've";

    $this->conj1[15] = "I'll";          $this->conj2[15] = "you'll";

    $this->conj1[16] = "you'll";        $this->conj2[16] = "I'll";

    $this->conj1[17] = "myself";        $this->conj2[17] = "yourself";

    $this->conj1[18] = "yourself";      $this->conj2[18] = "myself";

    // array to post process correct our tenses of pronouns such as "I/me"

    $this->conj3[0]  = "me am";         $this->conj4[0]  = "I am";

    $this->conj3[1]  = "am me";         $this->conj4[1]  = "am I";

    $this->conj3[2]  = "me can";        $this->conj4[2]  = "I can";

    $this->conj3[3]  = "can me";        $this->conj4[3]  = "can I";

    $this->conj3[4]  = "me have";       $this->conj4[4]  = "I have";

    $this->conj3[5]  = "me will";       $this->conj4[5]  = "I will";

    $this->conj3[6]  = "will me";       $this->conj4[6]  = "will I";

    // Keywords

    $this->keyword[ 0]=new Psychotherapist_Key( "CAN YOU",          1,  3);

    $this->keyword[ 1]=new Psychotherapist_Key( "CAN I",            4,  5);

    $this->keyword[ 2]=new Psychotherapist_Key( "YOU ARE",          6,  9);

    $this->keyword[ 3]=new Psychotherapist_Key( "YOU'RE",           6,  9);

    $this->keyword[ 4]=new Psychotherapist_Key( "I DON'T",          10, 13);

    $this->keyword[ 5]=new Psychotherapist_Key( "I FEEL",           14, 16);

    $this->keyword[ 6]=new Psychotherapist_Key( "WHY DON'T YOU", 17, 19);

    $this->keyword[ 7]=new Psychotherapist_Key( "WHY CAN'T I",     20, 21);

    $this->keyword[ 8]=new Psychotherapist_Key( "ARE YOU",          22, 24);

    $this->keyword[ 9]=new Psychotherapist_Key( "I CAN'T",          25, 27);

    $this->keyword[10]=new Psychotherapist_Key( "I AM",             28, 31);

    $this->keyword[11]=new Psychotherapist_Key( "I'M",              28, 31);

    $this->keyword[12]=new Psychotherapist_Key( "YOU",              32, 34);

    $this->keyword[13]=new Psychotherapist_Key( "I WANT",           35, 39);

    $this->keyword[14]=new Psychotherapist_Key( "WHAT",             40, 48);

    $this->keyword[15]=new Psychotherapist_Key( "HOW",              40, 48);

    $this->keyword[16]=new Psychotherapist_Key( "WHO",              40, 48);

    $this->keyword[17]=new Psychotherapist_Key( "WHERE",            40, 48);

    $this->keyword[18]=new Psychotherapist_Key( "WHEN",             40, 48);

    $this->keyword[19]=new Psychotherapist_Key( "WHY",              40, 48);

    $this->keyword[20]=new Psychotherapist_Key( "NAME",             49, 50);

    $this->keyword[21]=new Psychotherapist_Key( "CAUSE",            51, 54);

    $this->keyword[22]=new Psychotherapist_Key( "SORRY",            55, 58);

    $this->keyword[23]=new Psychotherapist_Key( "DREAM",            59, 62);

    $this->keyword[24]=new Psychotherapist_Key( "HELLO",            63, 63);

    $this->keyword[25]=new Psychotherapist_Key( "HI",               63, 63);

    $this->keyword[26]=new Psychotherapist_Key( "MAYBE",            64, 68);

    $this->keyword[27]=new Psychotherapist_Key( "NO",               69, 73);

    $this->keyword[28]=new Psychotherapist_Key( "YOUR",             74, 75);

    $this->keyword[29]=new Psychotherapist_Key( "ALWAYS",           76, 79);

    $this->keyword[30]=new Psychotherapist_Key( "THINK",            80, 82);

    $this->keyword[31]=new Psychotherapist_Key( "ALIKE",            83, 89);

    $this->keyword[32]=new Psychotherapist_Key( "YES",              90, 92);

    $this->keyword[33]=new Psychotherapist_Key( "FRIEND",           93, 98);

    $this->keyword[34]=new Psychotherapist_Key( "COMPUTER",         99, 105);

    $this->keyword[35]=new Psychotherapist_Key( "NO KEY FOUND",     106, 112);

    $this->keyword[36]=new Psychotherapist_Key( "REPEAT INPUT",     113, 116);

    $this->response[  0]="ELIZA - PHP version ported from Javascript (George Dunlop) code by Dan Fuhry";

    $this->response[  1]="Don't you believe that I can<*";

    $this->response[  2]="Perhaps you would like to be able to<*";

    $this->response[  3]="You want me to be able to<*";

    $this->response[  4]="Perhaps you don't want to<*";

    $this->response[  5]="Do you want to be able to<*";

    $this->response[  6]="What makes you think I am<*";

    $this->response[  7]="Does it please you to believe I am<*";

    $this->response[  8]="Perhaps you would like to be<*";

    $this->response[  9]="Do you sometimes wish you were<*";

    $this->response[ 10]="Don't you really<*";

    $this->response[ 11]="Why don't you<*";

    $this->response[ 12]="Do you wish to be able to<*";

    $this->response[ 13]="Does that trouble you?";

    $this->response[ 14]="Tell me more about such feelings.";

    $this->response[ 15]="Do you often feel<*";

    $this->response[ 16]="Do you enjoy feeling<*";

    $this->response[ 17]="Do you really believe I don't<*";

    $this->response[ 18]="Perhaps in good time I will<@";

    $this->response[ 19]="Do you want me to<*";

    $this->response[ 20]="Do you think you should be able to<*";

    $this->response[ 21]="Why can't you<*";

    $this->response[ 22]="Why are you interested in whether or not I am<*";

    $this->response[ 23]="Would you prefer if I were not<*";

    $this->response[ 24]="Perhaps in your fantasies I am<*";

    $this->response[ 25]="How do you know you can't<*";

    $this->response[ 26]="Have you tried?";

    $this->response[ 27]="Perhaps you can now<*";

    $this->response[ 28]="Did you come to me because you are<*";

    $this->response[ 29]="How long have you been<*";

    $this->response[ 30]="Do you believe it is normal to be<*";

    $this->response[ 31]="Do you enjoy being<*";

    $this->response[ 32]="We were discussing you, not me.";

    $this->response[ 33]="Oh... <*";

    $this->response[ 34]="You're not really talking about me, are you?";

    $this->response[ 35]="What would it mean to you if you got<*";

    $this->response[ 36]="Why do you want<*";

    $this->response[ 37]="Suppose you got<*";

    $this->response[ 38]="What if you never got<*";

    $this->response[ 39]="I sometimes also want<@";

    $this->response[ 40]="Why do you ask?";

    $this->response[ 41]="Does that question interest you?";

    $this->response[ 42]="What answer would please you the most?";

    $this->response[ 43]="What do you think?";

    $this->response[ 44]="Are such questions on your mind often?";

    $this->response[ 45]="What is it that you really want to know?";

    $this->response[ 46]="Have you asked anyone else?";

    $this->response[ 47]="Have you asked such questions before?";

    $this->response[ 48]="What else comes to mind when you ask that?";

    $this->response[ 49]="Names don't interest me.";

    $this->response[ 50]="I don't care about names, please go on.";

    $this->response[ 51]="Is that the real reason?";

    $this->response[ 52]="Don't any other reasons come to mind?";

    $this->response[ 53]="Does that reason explain anything else?";

    $this->response[ 54]="What other reasons might there be?";

    $this->response[ 55]="Please don't apologise!";

    $this->response[ 56]="Apologies are not necessary.";

    $this->response[ 57]="What feelings do you have when you apologise?";

    $this->response[ 58]="Don't be so defensive!";

    $this->response[ 59]="What does that dream suggest to you?";

    $this->response[ 60]="Do you dream often?";

    $this->response[ 61]="What persons appear in your dreams?";

    $this->response[ 62]="Are you disturbed by your dreams?";

    $this->response[ 63]="How are you today.. What would you like to discuss?";

    $this->response[ 64]="You don't seem quite certain.";

    $this->response[ 65]="Why the uncertain tone?";

    $this->response[ 66]="Can't you be more positive?";

    $this->response[ 67]="You aren't sure?";

    $this->response[ 68]="Don't you know?";

    $this->response[ 69]="Are you saying no just to be negative?";

    $this->response[ 70]="You are being a bit negative.";

    $this->response[ 71]="Why not?";

    $this->response[ 72]="Are you sure?";

    $this->response[ 73]="Why no?";