tictactoe.sh

#!/bin/bash
 
#Author:           Pieter van der Star (info@pietervanderstar.nl)
#Modifications by: (unmodified)
#This program is free software: you can redistribute it and/or modify
#it under the terms of the GNU Affero General Public License as
#published by the Free Software Foundation, either version 3 of the
#License, or (at your option) any later version.
#
#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 Affero General Public License for more details.
#
#You should have received a copy of the GNU Affero General Public License
#along with this program.  If not, see <https://www.gnu.org/licenses/
#
#Feel free to use and modify as long as:
#             - This License stays intact.
#             - You give the original author(s) credit for their work
#                   This includes the author(s) of modifications.
#             - The modifications are indicated clearly in the changelog
#             - The result must be free, in both monetary sense and personal sense 
#                  i.e. no account required, no personal data needs to be handed over.
#             - The software is provided as-is. Feature requests or bug reports may be
#               ignored.
#
#Changelog:
#┏━━━━━━━━━━━━━━━┯━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┯━━━━━━━━━━━━━━━━━━━━━━━━━━┓
#┃   16 oct 2022 │ First release                            │   Pieter van der Star    ┃
#┗━━━━━━━━━━━━━━━┷━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┷━━━━━━━━━━━━━━━━━━━━━━━━━━┛
 
 
#todo: x in center o in top right gives transpos error
#      so does x in center and o in bottom left a  o in middle left
#      and mid right, top left vs bottom right for o are correct
#TODO: add error codes
#TODO: add game status flag so it can tell as soon as it knows the game is won/lost/tied and also when it is inevetable so it can tell the player ie. "you cannot win anymore" "you lost"
 
#This version of the game tic-tac-toe may not seem very good when you start out playing, but that is because it only knows the rules of the game, not the strategies involved. Neither does it calculate the best move by going through all the moves of the game. Well, that last part is not entirely true. It does kinda go through all the options. But it does this by playing. Each time you play the, program will learn if moves were good or bad. After a while it will stop using the bad ones and prefer the good ones, thus becoming a stronger player.
 
#The program has a couple of elements.
#The most important elements are the boards. The boards contain all valid states of the tic-tac-toe square. The mirrorings and rotations are ignored. This means that any board with an X in a corner and nothing else on the board is the same from the programs point of view. This means some mechanism is needed to help keep track of those transpositions. That is the job of the transposition elements. Together with some functions those elements make it possible to rotate and mirror the boards and put the user input on the correct square.
 
#The progress of the learning is saved in a boards.txt file [note 1]. This allows curious people to monitor the learning progress, or save the intermediate stages if it becomes too smart to beat.
 
#all variable names of the form b<integer> are reserved for boards
#boards live in the global scope.
#Since the current board needs to be passed around as well the variable name bCurrent is also reserved. As is the a temporary board bTemp.
 
#The board element is quite complex and is stored as an array. In C it
#would look something like this:
#struct board{
#   char* name;
#   int[3][3] cells;
#   int board_value;
#   int next_boards_x;
#   int next_boards_o;
#   char** children;
#   int* children_weights;
#}
 
#note 1: unless otherwise specified by a command line argument.
 
#print the introduction
#args: none
#returns nothing
function printIntro {
    printf "  ###############################################\n";sleep 0.3;
    printf " #################################################\n";sleep 0.3;
    printf "##                                               ##\n";sleep 0.3;
    printf "##       Tic Tac Toe or naughts and crosses      ##\n";sleep 0.3;
    printf "##                                               ##\n";sleep 0.3;
    printf "##        Created by Pieter van der Star         ##\n";sleep 0.3;
    printf "##          Inspired by Donald Mitchies:         ##\n";sleep 0.3;
    printf "##                 M E N A C E                   ##\n";sleep 0.3;
    printf "##                                               ##\n";sleep 0.3;
    printf "##                  Matchbox                     ##\n";sleep 0.3;
    printf "##                  Educable                     ##\n";sleep 0.5;
    printf "##                  Naughts                      ##\n";sleep 0.5;
    printf "##                  And                          ##\n";sleep 0.3;
    printf "##                  Crosses                      ##\n";sleep 0.3;
    printf "##                  Engine                       ##\n";sleep 0.5;
    printf "##                                               ##\n";sleep 0.3;
    printf " #################################################\n";sleep 0.3;
    printf "  ###############################################\n";sleep 0.3;
    printf " This game is released under the GNU AGPL 3.0 license\n";sleep 0.3;
    printf " https://www.gnu.org/licenses/agpl-3.0.html\n";sleep 0.3;
    printf " A link to Matt Parkers video on Menace\n";sleep 0.3;
    printf " which first introduced the idea to me:\n";sleep 0.3;
    printf " https://m.youtube.com/watch?v=R9c-_neaxeU\n";sleep 0.3;
    printf " I wrote most of the code based on that video\n";sleep 0.3;
    printf " But when it came to the weights (number of beads)\n";sleep 0.3;
    printf " I read the paper Experiments on the mechanization\n";sleep 0.3;
    printf " of game-learning by Donald Michie.\n";sleep 0.3;
    sleep 2;
}
    
#A bunch of constants used for board propeties and game states
 
#array offsets of board "object"
declare -i -r C_NAME_OFFSET=0;
declare -i -r C_CELLS_OFFSET=1;
declare -i -r C_VALUE_OFFSET=10;
declare -i -r C_NEXT_OFFSET=11;
 
#some offsets need to be calculated, the follow after the constants
 
 
#constants used to keep track of whos turn it is
declare -i -r C_USER=1;
declare -i -r C_COMPUTER=-1;
 
#custom boolean values
declare -i -r C_TRUE=1;
declare -i -r C_FALSE=0;
 
declare -i -r C_NUM_ALLBOARDS=19683;#922;#combinations=3^9 but a lot are pruned after first invalid is encountered (abs(numX-numO)>1)
 
#make it easier to print the naughts and crosses
xo=( "X" "O" );
 
 
# 0 1 2
# 3 4 5
# 6 7 8
 
#transposition indice matrices
h0v0r0=(    0 1 2 3 4 5 6 7 8 0 );
h0v0r1=(    2 5 8 1 4 7 0 3 6 0 );
h0v0r2=(    8 7 6 5 4 3 2 1 0 0 );
h0v0r3=(    6 3 0 7 4 1 8 5 2 0 );
 
h0v1r0=(    6 7 8 3 4 5 0 1 2 0 );
h0v1r1=(    8 5 2 7 4 1 6 3 0 0 );
h0v1r2=(    2 1 0 5 4 3 8 7 6 0 );
h0v1r3=( 0 3 6 1 4 7 2 5 8 0 );
 
h1v0r0=(    2 1 0 5 4 3 8 7 6 0 );
h1v0r1=(    0 3 6 1 4 7 2 5 8 0 );
h1v0r2=(    6 7 8 3 4 5 0 1 2 0 );
h1v0r3=(    8 5 2 7 4 1 6 3 0 0 );
 
#calculates and sets the id of a given transposition
#ars: transposition name
#returns nothing
#modifies transposition id
function calculateTranspositionId {
    local -n t="$1"
    local -i i=0
    local -a p
    p=( 11 13 17 19 23 29 31 37 41 )
    local -i id=0;
    while [ $i -lt 9 ]; do
        pos=${t[i]}
        prime=${p[$i]}
        id=$((id+pos*prime))
        i=$((i+1))
    done
    t[9]=$id
}
 
 
#calculates and sets the id of all transpositio  ns
#ars: nothing
#returns nothing
#modifies transposition ids
function calculateTranspositionIds {
    local -i h=0;
    while [ $h -le 1 ]; do
        local -i v=0;
        while [ $v -le 1 ]; do
            if [[ $h -eq 1 && $v -eq 1 ]]; then
                break;
            fi
            local -i r=0;
            while [ $r -le 3 ]; do
                calculateTranspositionId "h$h""v$v""r$r";
                r=$((r+1))
            done
            v=$((v+1))
        done
        h=$((h+1))
    done
}
 
#directly call calculateTranspositionIds
calculateTranspositionIds
 
#transpose a transposition
#args: transposition name, transposition name
#returns nothing
#sets global transposition
function transposeTransposition {
    local -i verbosity=0;
    if [ $bTmp ]; then #this function needs bTmp, so backup the current value
        local bTempbu=$bTmp;
    fi
    local -n a="$1";
    local -n b="$2";
    bTmp=( 0 0 0 0 0 0 0 0 0 0 );
    local -i i=0;
    while [ $i -lt 9 ]; do
        local -i pos=${b[i]}
        bTmp[i]=${a[pos]}
        i=$((i+1))
    done
    
    calculateTranspositionId "bTmp"
    #find the same id
    local -i h=0;
    while [ $h -le 1 ]; do
        local -i v=0;
        while [ $v -le 1 ]; do
            if [[ $h -eq 1 && $v -eq 1 ]]; then
                break;
            fi
            local -i r=0;
            while [ $r -le 3 ]; do
                name="h${h}v${v}r${r}";
                if [ $verbosity -gt 0 ]; then
                    echo "chk $name"
                fi
                local -n t="$name"
                
                if [ ${t[9]} -eq ${bTmp[9]} ]; then
                    transposition="$name";
                    return
                fi
                r=$((r+1))
            done
            v=$((v+1))
        done
        h=$((h+1))
    done
    transposition="h0v0r0"
    unset "bTmp"
    if [ $bTempbu ]; then
        bTmp=$bTempbu;
    fi
}
 
#prints the board
#arg1: board name, 
#arg2: transposition to apply
#arg3: bool, print properties (like list of children)
#arg4: bool, print coordinates (should it print column anc row indicators)
function printBoard {
    local -i verbosity=0;
    if [ ! -v $1 ]; then
        printf "Board %s does not exist\n" $1;
        return 0;
    fi
    local -n board="$1"
    if [ $verbosity -ge 2 ]; then
        echo "${board[@]}"
    fi
    if [ $# -gt 1 ]; then
        local -r transposition="$2"
    else
        local -r transposition="h0v0r0"
    fi
    
    local -n matrix="$transposition";
    printProperties=$C_FALSE;
    if [ $# -gt 2 ]; then
        printProperties=$3;
    fi
    printCoordinates=$C_FALSE
    if [ $# -gt 3 ]; then
        printCoordinates=$4;
    fi
    if [ $printProperties -eq $C_TRUE ]; then
        printf "name: %s\n" ${board[$C_NAME_OFFSET]};
        printf "transposition: %s\n" $transposition
        printf "cells:\n";
    fi
    if [ $printCoordinates -eq $C_TRUE ]; then
        printf "  A B C\n";
    fi
    printf " ┏━┯━┯━┓\n";
    local -i r=0;
    local -i c;
    while [ $r -lt 3 ]; do
        c=0;
        if [ $printCoordinates -eq $C_TRUE ]; then
            printf "%d" $r;
        else
            printf " ";
        fi
        printf "┃";
        while [ $c -lt 3 ]; do
        
            local -i pos=${matrix[$(((r*3+c)))]}
            val="${board[$((C_CELLS_OFFSET+pos))]}";
            printf "%s" "$val";
                
        if [ $c -lt 2 ]; then
            printf "│";
        fi
            
            c=$((c+1))
            done
            printf "┃";
            if [ $r -lt 2 ]; then
                printf "\n ┠─┼─┼─┨\n";
            fi
            r=$((r+1))
        done
        printf "\n ┗━┷━┷━┛\n";
        
        if [ $printProperties -eq $C_TRUE ]; then
            printf "value: %d\n" ${board[$((C_VALUE_OFFSET))]};
            local -i v=0;
            while [ $v -lt 2 ]; do
            local -i    nnext=${board[$((C_NEXT_OFFSET+v))]};
                local -i firstChildOffset=${board[$C_NEXT_OFFSET]};
                firstChildOffset=$((firstChildOffset*v+C_NEXT_OFFSET+2));
                printf "number of next boards for %s: %d\n" ${xo[$v]} $nnext;
                printf "firstChildOffset: %d\n" $firstChildOffset;
                local -i i=0;
                while [ $i -lt $nnext ]; do
                    getNNext "$1" 0
                    local -i nnext_x=$?
                    getNNext "$1" 1
                    local -i nnext_o=$?
                    printf "%s(%d)," "${board[$((i+firstChildOffset))]}" "${board[$((i+firstChildOffset+nnext_x+nnext_o))]}";
                    i=$((i+1));
                done
                printf "\n";        
                v=$((v+1));
            done
        fi
    }
    
#makes a board 
#args: board name
#todo check if already exists
function makeBoard {
    local -n board=$1
    board[$C_NAME_OFFSET]="$1"
    local -i r=0;
    local -i c=0;
    while [ $r -lt 3 ]; do
        c=0;
        while [ $c -lt 3 ]; do
            board[$((C_CELLS_OFFSET+(r*3+c)))]=" ";
            c=$((c+1))
        done
        r=$((r+1))
    done
    board[$C_NEXT_OFFSET]=0;
    board[$C_NEXT_OFFSET+1]=0;
}
    
#helper function for is won
#checks if one player has all boxes in the row
function isWonRow {
    local -n board=$1;
    local -i r=$2;
    local -i c=0;
    local curVal;
    local prevVal;
    while [ $c -lt 3 ]; do
        curVal="${board[$((C_CELLS_OFFSET+(3*r+c)))]}";
        if [ "$curVal" == " " ]; then
            return $C_FALSE;
        else 
            if [[ $c -gt 0 && "$prevVal" != "$curVal" ]]; then
                return $C_FALSE;
            fi;
        fi
        prevVal="$curVal";
        c=$((c+1));
    done
    sleep 5
    return $C_TRUE;
}
    
#helper function for is won
#checks if one player has all boxes in the column
function isWonColumn {
    local -n board=$1;
    local -i r=0;
    local -i c=$2;
    local curVal;
    local prevVal;
    while [ $r -lt 3 ]; do
        curVal="${board[$((C_CELLS_OFFSET+(3*r+c)))]}";
        if [ "$curVal" == " " ]; then
            return $C_FALSE;
        else 
            if [[ $r -gt 0 && "$prevVal" != "$curVal" ]]; then
                return $C_FALSE;
            fi;
        fi
        prevVal="$curVal";
        r=$((r+1));
    done
    return $C_TRUE;
}
    
#helper function for is won
#checks if one player has all boxes in the diagonal going right
function isWonDiagonalR {
    local -n board=$1;
    local -i i=0;
    local curVal;
    local prevVal;
    while [ $i -lt 3 ]; do
        curVal="${board[$((C_CELLS_OFFSET+(3*i+i)))]}";
        if [ "$curVal" == " " ]; then
            return $C_FALSE;
        else 
            if [[ $i -gt 0 && "$prevVal" != "$curVal" ]]; then
                    return $C_FALSE;
            fi;
        fi
        prevVal="$curVal";
        i=$((i+1));
    done
    return $C_TRUE;
}
 
#helper function for is won
#checks if one player has all boxes in the diagonal going left
function isWonDiagonalL {
    local -n board=$1;
    local -i i=0;
    local curVal;
    local prevVal;
    while [ $i -lt 3 ]; do
        curVal="${board[$((C_CELLS_OFFSET+(3*(i+1)-i)-1))]}";
        if [ "$curVal" == " " ]; then
            return $C_FALSE;
        else 
            if [[ $i -gt 0 && "$prevVal" != "$curVal" ]]; then
                return $C_FALSE;    
            fi;
        fi
        prevVal="$curVal";
        i=$((i+1));
    done
    return $C_TRUE;
}
    
    
#checks if one player has won the game
#args: board name
#returns boolean true if a player won, otherwise false
function isWon {
    local -i verbosity=0;
    local boardName=$1
    local -i r=0;
    local prevVal;
    #check rows
    while [ $r -lt 3 ]; do
        isWonRow $boardName $r
        if [ $? -eq $C_TRUE ]; then
            if [ $verbosity -gt 0 ]; then
                printf "Found winning board(r%d)\n" $r;
            fi
            return $C_TRUE;
        fi
        r=$((r+1));
    done
    
    #check columns
    local -i c=0;
    while [ $c -lt 3 ]; do
        isWonColumn $boardName $c
        if [ $? -eq $C_TRUE ]; then
            if [ $verbosity -gt 0 ]; then
                printf "Found winning board (c%d)\n" $c;
            fi
            return $C_TRUE;
        fi
        c=$((c+1));
    done
    
    #check diagonals
    isWonDiagonalL $boardName
    if [ $? -eq $C_TRUE ]; then
        if [ $verbosity -gt 0 ]; then
            printf "Found winning board (DiagL)\n";
        fi
        return $C_TRUE;
    fi
    isWonDiagonalR $boardName
    if [ $? -eq $C_TRUE ]; then
        if [ $verbosity -gt 0 ]; then
            printf "Found winning board (DiagR)\n";
        fi
        return $C_TRUE;
    fi
    
    return $C_FALSE;
}
    
#checks if the board is a valid board
#the number of x and o should never differ more than 1
#args: board name
#returns boolean, true if valid, otherwise false
function isValid {
    local -n board=$1
    local -i nX=0;
    local -i nO=0;
    
    local -i r=0;
    local -i c=0;
    while [ $r -lt 3 ]; do
    c=0;
        while [ $c -lt 3 ]; do
            val="${board[$((C_CELLS_OFFSET+(r*3+c)))]}"
            if [ "$val" == "X" ]; then
                nX=$((nX+1));
            elif [ "$val" == "O" ]; then
                nO=$((nO+1));
            fi
            c=$((c+1))
        done
        r=$((r+1))
    done
local -i diff=$((nX-nO));
 
if [[ -2 -lt $diff && $diff -lt 2 ]]; then
        return $C_TRUE;
    else
        return $C_FALSE;
    fi
}
    
    
#function to get the number of empty cells
#args: board name
#returns numbere of empty cells
function getNEmpty {
    local -n board=$1
    local -i nEmpty=0;
    
    local -i r=0;
    local -i c=0;
    while [ $r -lt 3 ]; do
    c=0;
        while [ $c -lt 3 ]; do
            val="${board[$((C_CELLS_OFFSET+(r*3+c)))]}"
            if [ "$val" == " " ]; then
                nEmpty=$((nEmpty+1));
            fi
            c=$((c+1))
        done
        r=$((r+1))
    done
    return $nEmpty;
}
    
#copy the values of one board to another
#args: board name to copy from
#      board name to copy to
#returns nothing
function copyBoard { #only the values are copied
    local -n originalBoard=$1;
    #create the new board
    boardName=$2
    if [ $verbosity -gt 0 ]; then
        printf "copying %s to %s\n" $1 $2
    fi
    makeBoard "$boardName"
    local -n newBoard="$boardName"
    local -i r=0;#row
    local -i c=0;#column
    while [ $r -lt 3 ]; do
        c=0;
        while [ $c -lt 3 ]; do
            newBoard[$((C_CELLS_OFFSET+(r*3+c)))]="${originalBoard[$((C_CELLS_OFFSET+(r*3+c)))]}"
            c=$((c+1))
        done
        r=$((r+1))
    done
}
    
#calculate and set the value of a board
#args: bosrd name
    #returns nothing
    #sets the board value of the board object
    function calculateBoardValue {
        local -n board=$1;
        local -i r=0;#row
    local -i c;#column
    local -i v;#value
    local -i boardValue=0;
    
    posValueMatrix=( 17 19 17
                    19 23 19
                    17 19 17 );
    
    while [ $r -lt 3 ]; do
        c=0;
        while [ $c -lt 3 ]; do
            val="${board[$((C_CELLS_OFFSET+(r*3+c)))]}"
            case "$val" in 
                " ") val=0;;
                "X") val=7;;
                "O") val=13;;
            esac
            boardValue=$((boardValue+val*${posValueMatrix[$((r*3+c))]}));
            c=$((c+1));
        done
        r=$((r+1));
    done
    if [ $verbosity -gt 0 ]; then
        printf "value: %d\n" $boardValue;
fi
    board[$C_VALUE_OFFSET]=$boardValue;
    }
    
    #check if a given board exists
    #arg1: board to find
    #returns bool, true if found, false if not.
    #sets global dubplicateboard with the name of the board that is a match
    #sets the global transposition 
    function doesBoardExist {
        local -i verbosity=0;
        if [ $verbosity -gt 0 ]; then
            echo "boardNumber: $boardNumber";
        fi
        local -n board="$1";
        local -i i=0;
        while [ $i -ne $boardNumber ]; do
            local -n b="b$i";
            if [ $verbosity -gt 0 ]; then
            echo "checking against b$i"
            echo "if [ ${board[$C_VALUE_OFFSET]} -eq ${b[$C_VALUE_OFFSET]} ]; then"
            echo "if [ ${board[$C_NAME_OFFSET]} != ${b[$C_NAME_OFFSET]} ]; then"
        fi
            if [ ${board[$C_VALUE_OFFSET]} -eq ${b[$C_VALUE_OFFSET]} ]; then
                if [ "${board[$C_NAME_OFFSET]}" != "${b[$C_NAME_OFFSET]}" ]; then
                    findTransposition "$board" "$b"
                    if [ $? -eq $C_TRUE ]; then
                    if [ $verbosity -gt 0 ]; then
                            printf "Found another board for %s: %s (%s)\n" "${board[$C_NAME_OFFSET]}" "${b[$C_NAME_OFFSET]}" "$transposition";
                        fi
                    duplicateBoard="${b[$C_NAME_OFFSET]}";
                    return $C_TRUE;
                    fi
                fi
            fi
            i=$((i+1));
        done
        return $C_FALSE;
    }
    
#given to boards figure out how to transpose one to get the other
#arg1: board that anchors the transposition
#arg2: board to get the transposition for
#returns boolean, true if successful, false if boards are to different
function findTransposition {
    local -i verbosity=0;
    if [ $verbosity -gt 1 ]; then
        printf "findTransposition: %s %s\n" "$1" "$2"
    fi
                
    local -n a=$1;
    local -n b=$2;
    if [ $verbosity -gt 1 ]; then
        printBoard "a"
        printBoard "b"
    fi
    local -i h; #horizontal mirroring
    local -i v; #vertical mirroring
    local -i r; #rotation
    local -i i; #cell iterator
    
    h=0;
    while [ $h -lt 2 ]; do  
        v=0;
        while [ $v -lt 2 ]; do  
            #double mirroring is same as no mirroring but rotated twice
            if [[ $h -eq 1 && $v -eq 1 ]]; then
                return $C_FALSE;
            fi
            r=0;
            while [ $r -lt 4 ]; do  
                local -n matrix="h$h""v$v""r$r";
                transposition="h$h""v$v""r$r"
                if [ $verbosity -gt 1 ]; then
                    printf "transpose: %s\n" $transposition
                fi
                i=0;
                while [ $i -lt 9 ]; do
                local -i m=${matrix[$i]}
                if [ $verbosity -gt 1 ]; then
                    printf "%d |%s| != |%s| %d\n" $i "${a[$((C_CELLS_OFFSET+i))]}" "${b[$((C_CELLS_OFFSET+m))]}" $m
                    fi
                    if [ "${a[$((C_CELLS_OFFSET+i))]}" != "${b[$((C_CELLS_OFFSET+m))]}" ]; then
                        break;
                    fi
                    i=$((i+1));
                done
                if [ $i -eq 9 ]; then
                    return $C_TRUE
                fi
                r=$((r+1));
            done
            v=$((v+1));
        done
        h=$((h+1));
    done
    return $C_FALSE;
}
 
function getNNext {
    local -n -r board="$1"
    local -i -r v=$2
    local -i nnext=${board[$((C_NEXT_OFFSET+v))]};
    return $nnext;
}
 
function getFirstChildOffset {
    local -n -r board="$1"
    local -i -r v=$2
    local -i firstChildOffset;
    if [ $v -eq 0 ]; then
        local -i firstChildOffset=$C_NEXT_OFFSET+2;
    else
        getNNext "$board" 0
        local -i nnextX=$?
        firstChildOffset=$((C_NEXT_OFFSET+nnextX+2));
    fi
    return $firstChildOffset;
}
 
function getChildWeight {
    local -n -r board="$1"
    local -i -r v=$2
    local -i -r index=$3
    
    getNNext "$1" 0
    local -i nnext_x=$?
    getNNext "$1" 1
    local -i nnext_o=$?
    
    getFirstChildOffset "$1" "$v"
    local firstChildOffset=$?
    return ${board[$((firstChildOffset+nnext_x+nnext_o+index))]}
}
 
function setChildWeight {
    local -n -r board="$1"
    local -i -r v=$2
    local -i -r index=$3
    local -i -r weight=$4
    
    getNNext "$1" 0
    local -i nnext_x=$?
    getNNext "$1" 1
    local -i nnext_o=$?
    
    getFirstChildOffset "$1" "$v"
    local firstChildOffset=$?
    board[$((firstChildOffset+nnext_x+nnext_o+index))]=$weight
}
 
#add a child from the list of children
#arg1: parent (to add the child to)
#arg2: child to add
#arg3: which child list to add to (X or O)
#returns: nothing   
function insertChild {
    local -n -r parent="$1"
    local -r child="$2"
    local -i -r v=$3
    local -i -r weight=$4
    local -i verbosity=0;
    
    if [ $verbosity -gt 0 ]; then
        printf "insertChild.parent: %s\n" "${parent[$C_NAME_OFFSET]}"
        printf "insertChild.child: %s\n" $child
        printf "insertChild.v: %d\n" $v
        printf "insertChild.weight: %d\n" $weight
        echo "${parent[@]}"
    fi
    
    getNNext "$1" 0
    local -i nnext_x=$?
    getNNext "$1" 1
    local -i nnext_o=$?
    
    getFirstChildOffset "$1" "$v"
    local firstChildOffset=$?
 
    
    #if for X then shift O to make room
    #and always shift the weights
    #TODO: maybe implement a smarter way, but that requires more
    #handling on firstChildOffset and weight offset calculations
    local -i weightInsertPoint=$((${#parent[@]}+1));
    local -i childInsertPoint=$((${#parent[@]}-nnext_x-nnext_o));
    if [ $v -eq 0 ]; then
        weightInsertPoint=$((weightInsertPoint-nnext_o));
        childInsertPoint=$((childInsertPoint-nnext_o));
    fi
    
    if [ $verbosity -gt 0 ]; then
        printf "weightInsertPoint: %d\n" $weightInsertPoint
        printf "childInsertPoint: %d\n" $childInsertPoint
    fi
    local -i i=$((${#parent[@]}+1));
    
    while [ $i -gt $weightInsertPoint ]; do
        parent[$i]=${parent[$((i-2))]}; #2 so to make room for the child and the weight
        i=$((i-1))
    done
    #now we have made room for the weight we can insert that
    parent[$((i+0))]=$weight
    i=$((i-1))
    
    while [ $i -gt $childInsertPoint ]; do
        parent[$i]=${parent[$((i-1))]};
        i=$((i-1))
    done
    
    parent[$i]="$child";
    #update nnext
    local -i nnext=${parent[$((C_NEXT_OFFSET+v))]};
    if [ $verbosity -gt 0 ]; then
        printf "insertChild.nnext[%d]: %d\n" $v $nnext
    fi
    nnext=$((nnext+1));
    
    parent[$((C_NEXT_OFFSET+v))]=$nnext;
    if [ $verbosity -gt 0 ]; then
        printf "insertChild.nnext[%d]: %d\n" $v $nnext
    fi
}
 
#makes all children and other offspring from the given board
#as the function runs recursive global progress variables are used
#arg1: parent board
#arg2: depth, used during debug
#returns nothing
#sets global variables used for tracking progress
#sets global variables for the boards
declare -i makeNextBoardsProgress=0;
declare -i makeNextBoardsProgressTreshold=20;
declare -i makeNextBoardsDepth=0;
function makeNextBoards {
    local -n board=$1;
    local -i depth=$2;
    local -i r;#row
    local -i c;#column
    local -i v;#value
    local -i verbosity=0;
    if [[ $depth -gt $makeNextBoardsDepth && $makeNextBoardsDepth -ne 0 ]]; then
        return 0;
    fi
    
    if [ $makeNextBoardsProgress -gt $makeNextBoardsProgressTreshold ]; then
        makeNextBoardsProgressTreshold=$((makeNextBoardsProgressTreshold+(C_NUM_ALLBOARDS/1000)));
        local -i progress=$((makeNextBoardsProgress*1000/$C_NUM_ALLBOARDS));
        printf "Making boards, progress: %3d.%01d%%\n" $((progress/10)) $((progress%10));
        #   printf "Making boards, progress: %3d.%01d%% #%9d\n" $((progress/10)) $((progress%10)) $makeNextBoardsProgress 1>&2
    fi
    
    v=0; 
    while [ $v -lt 2 ]; do
        r=0;
        while [ $r -lt 3 ]; do
            c=0;
            while [ $c -lt 3 ]; do
                makeNextBoardsProgress=$((makeNextBoardsProgress+1));
                val="${board[$((C_CELLS_OFFSET+(r*3+c)))]}"
                if [ "$val" == " " ]; then
                    #create the new board
                    boardName="b$boardNumber";
                    if [ $verbosity -gt 0 ]; then
                        printf "boardName: %s\n" $boardName;
                    fi
                    boardNumber=$((boardNumber+1));
                    copyBoard "$1" "$boardName";
                    local -n newBoard=$boardName;
                    newBoard[$((C_CELLS_OFFSET+(r*3+c)))]=${xo[$v]};
                    if [ $verbosity -gt 1 ]; then
                        printf "set %d,%d to %s, v: %d\n" $r $c "${xo[$v]}" $v;
                    fi
                    
                    if [ $verbosity -gt 3 ]; then
                        printf "new board is\n"
                        printBoard $boardName;
                    fi
                    isValid $boardName;
                    local -i valid=$?;
                    if [ $valid -eq $C_FALSE ]; then
                        if [ $verbosity -gt 1 ]; then
                            printf "board no good, scrapping\n";
                        fi
                        unset $boardName;
                        boardNumber=$((boardNumber-1));
                        if [ $verbosity -gt 1 ]; then
                            printf "skipping to next symbol\n"
                        fi
                        c=100;
                        r=100;
                        continue;
                    fi
                    
                    calculateBoardValue "$boardName";
                    doesBoardExist "$boardName";
                    local -i exists=$?;
                    
                    if [ $exists -eq $C_TRUE ]; then
                        #set the existing one as child, but add the transposition
                        insertChild "$1" "$duplicateBoard$transposition" $v
                        if [ $verbosity -gt 1 ]; then
                            printf "board exists, scrapping this version\n";
                        fi
                        unset $boardName;
                        boardNumber=$((boardNumber-1));
                        boardName="$duplicateBoard$transposition"
                        c=$((c+1));
                        continue;
                    fi
                    #not exist and valid
                    if [ $verbosity -gt 1 ]; then
                        printf "New board: %s\n" $boardName;
                    fi
                    insertChild "$1" "$boardName""h0v0r0" $v
                    isWon $boardName;
                    if [[ $? -eq $C_FALSE && $exists -eq $C_FALSE ]]; then
                        makeNextBoards $boardName $((depth+1));
                    fi
                fi
                c=$((c+1));
            done
            r=$((r+1));
        done
        v=$((v+1));
    done
    if [ $verbosity -gt 2 ]; then
        printf "makeNextBoards tried: %d boards\n" $makeNextBoardsProgress;
    fi
}
 
#write the board information to a file
#args: filename
#returns: nothing
function writeBoardsInfo {
    if [ $# -gt 0 ]; then
        file=$1
    else
        file="boards.txt";
    fi
    if [ $verbosity -gt 1 ]; then
        printf "boardNumber: %d\n" $boardNumber
    fi
    local -i i=0;
    #truncate file
    
    printf "#Board config\n" > $file
    while [ $i -lt $boardNumber ]; do
        local -i j=0;
        local -n board="b$i";
        
        #print name
        printf "%s=( %s" ${board[$C_NAME_OFFSET]} ${board[$C_NAME_OFFSET]} >> $file
        
        #print cells
        local -i r=0;
        while [ $r -lt 3 ]; do
            c=0;
            while [ $c -lt 3 ]; do
                val="${board[$((C_CELLS_OFFSET+(r*3+c)))]}"
                printf " \"%s\"" "$val" >> $file
                c=$((c+1));
            done
            r=$((r+1));
        done
        
        #print board value
        printf " %d" ${board[$((C_VALUE_OFFSET))]} >> $file
        
        #print number of boards
        local -i v=0;
        while [ $v -lt 2 ]; do
            getNNext "${board[0]}" $v
            local -i nnext=$?;
            printf " %d " $nnext >> $file
            v=$((v+1));
        done
        
        #print the next boards
        local -i j=0;
        getFirstChildOffset "${board[0]}" 0
        j=$?
        while [ $j -lt ${#board[@]} ]; do
                printf " %s" "${board[$j]}" >> $file
                j=$((j+1));
        done
        
        #close the array
        printf " );\n" >> $file
        
        if [ $((i%(boardNumber/100))) -eq 0 ]; then
            local -i progress=$((i*1000/boardNumber));
            printf "Writing boards info, progress: %3d.%01d%%\n" $((progress/10)) $((progress%10));
        fi
        i=$((i+1));
    done
    printf "boardNumber=%d;\n" $boardNumber >> $file;
    printf "gameCounter=%d;\n" $gameCounter >> $file;
    printf "\n" >> $file;
    printf "Writig boards info complete\n";
}
 
#figure out the depth of this board
#arg1: boardname
#returns depth
function getDepth {
    local -n bTmp="$1";
    local -i i=0;
    local -i depth=0;
    while [ $i -lt 9 ]; do
        if [ "${bTmp[$((C_CELLS_OFFSET+i))]}" != " " ]; then
            depth=$((depth+1));
        fi
        i=$((i+1));
    done
    return $depth;
}
 
 
#set the weight for each child. 
#The weight is detemined by how far down the tree the board is.
#no argumens
#returns nothing
#modifies global boards
function setStartingWeights {
    #michi used the following weights
    #|depth|weights|
    #+-----+-------+
    #|  1  |   4   |
    #|  3  |   3   |
    #|  5  |   2   |
    #|  7  |   1   |
    #but that gives us a problem with levels 0,2,4,6, the most simple solution is to double the weights and then fill in the in between integer values. 
    #This gives us the below table
    #|depth|weights|
    #+-----+-------+
    #|  1  |   8   |
    #|  2  |   7   |
    #|  3  |   6   |
    #|  4  |   5   |
    #|  5  |   4   |
    #|  6  |   3   |
    #|  7  |   2   |
    #|  8  |   1   |
    #the downside of this approach is that training will take longer, the other option is to apply the same weight on two depths 
    #|depth|weights|
    #+-----+-------+
    #|  1  |   4   |
    #|  2  |   4   |
    #|  3  |   3   |
    #|  4  |   3   |
    #|  5  |   3   |
    #|  6  |   2   |
    #|  7  |   1   |
    #|  8  |   1   |
    
    #this only leaves level 0, this will be getting the value 5
    
    weights=( 5 4 4 3 3 2 2 1 1 );#todo: what was the syntax for a local array again?
    
    local i=0;
    while [ $i -lt $boardNumber ]; do
        local boardName="b$i";
        local -i v=0;
        while [ $v -le 1 ]; do
            #printf "v: %d\n" $v
            local -n bTmp="$boardName"
            getNNext "$boardName" $v;
            local -i nnext=$?;
            local -i firstChildOffset=${bTmp[$C_NEXT_OFFSET]};
            local -i c=0;
            while [ $c -lt $nnext ]; do
                local child="${bTmp[$((firstChildOffset+c))]}"
                getDepth "$boardName"
                local -i depth=$?
                setChildWeight "$boardName" $v $c ${weights[$depth]}
                c=$((c+1));
            done
            v=$((v+1));
        done
        if [ $((i%(boardNumber/100))) -eq 0 ]; then
            local -i progress=$((i*1000/boardNumber));
            printf "Setting starting weights, progress: %3d.%01d%%\n" $((progress/10)) $((progress%10));
        fi
        i=$((i+1));
    done
}
 
 
#performs the main game b
#arg1: file to read from
#returns nothing
function setup {
    if [ $# -gt 0 ]; then
        local file="$1"
    else
        local file="boards.txt";
    fi
    if [ -f "$file" ]; then
        printf "Loading boards config\n";   
        source "$file"
        if [ $verbosity -gt 1 ]; then
            echo "bn: $boardNumber"
        fi
        if [ $boardNumber -eq 0 ]; then
            printf "Input file doesn't contain the required information\n";
            return 1;
        fi
    else
        printf "Currently the boards file is missing.\n";
        printf "A new one will be created but this will take some time.\n";
        printf "press q to exit, press any other key to create the file.\n";
        read -n 1 ans
        case $ans in
            [Qq]*) return 1;;
        esac
        
        printf "Creating boards config\n";
        makeBoard "b0"
        boardNumber=$((boardNumber+1));
        #printBoard "b0";
        calculateBoardValue "b0";
        makeNextBoards "b0";
        printf "end of makeNextBoards\n";
        if [ $verbosity -gt 2 ]; then
            printf "makeNextBoards tried: %d boards\n" $makeNextBoardsProgress;
        fi
        #add starting weights
        printf "setting starting weights\n";
        setStartingWeights 
        printf "writing config to file. This can take some time\n"
        writeBoardsInfo "$board_src"
    fi
    return 0;
}
 
#check if a given board is a child of another board.
#arg1:board name to find
#arg2:board name of parent
#returns bool, found or not found
 
#sets global transposition to transposition of the child
#sets global index to the index of the child
function findChild {
    local verbosity=0;
    local find="$1"
    local parent="$2"
    if [ $verbosity -gt 2 ]; then
        printf "see if %s has child %s\n" $parent $find
    fi
    local -i i=0;
    local -i v=0;
    if [ "$3" == "O" ]; then
        v=1
    fi
        
    #strip transposition
    if [ ${find: -2:1} == "r" ]; then
            find=${find:0:$((${#find}-6))};
    fi
 
    
    if [ $verbosity -gt 2 ]; then
        printf "v: %d\n" $v
        if [ $verbosity -gt 3 ]; then
            printBoard "$parent" "h0v0r0" 1 1
            printBoard "$find" "h0v0r0" 1 1
        fi
        echo "${tempBoard[@]}"
    fi
    local -n parentBoard="$parent"
    local -n findBoard="$find"
    getNNext "$parent" "$v"
    local -i nnext=$?;
    getFirstChildOffset "$parent" "$v"
    local -i firstChildOffset=$?;
    while [ $i -lt $nnext ]; do
        boardName="${parentBoard[$((firstChildOffset+i))]}"
        if [ $verbosity -ge 2 ]; then
            printf "checking %s (%d/%d)\n" "$boardName" $((i+1)) $nnext
        fi
        #get transposition information
        if [ ${boardName: -2:1} == "r" ]; then
            transposition=${boardName:$((${#boardName}-6))};
            boardName=${boardName:0:$((${#boardName}-6))};
        fi
        local -n tempBoard=$boardName;
        if [ $verbosity -ge 4 ]; then
            printBoard "$boardName" "h0v0r0" 1 1
        fi
        if [ $verbosity -ge 2 ]; then
            printf "Name: %s\n" ${findBoard[$C_NAME_OFFSET]}
            printf "values: %d ?= %d\n" ${findBoard[$C_VALUE_OFFSET]} ${tempBoard[$C_VALUE_OFFSET]}
        fi
        if [ ${findBoard[$C_VALUE_OFFSET]} -eq ${tempBoard[$C_VALUE_OFFSET]} ]; then
            if [ $verbosity -ge 2 ]; then
                printf "found board: %s at index %d\n" $boardName $i;
            fi
            if [ $verbosity -gt 0 ]; then
                printBoard "$find" "h0v0r0" 1 1
                printBoard "$boardName" "h0v0r0" 1 1
                printf "######\n"
            fi
            findTransposition "$boardName" "findBoard";
            if [ $? -eq $C_TRUE ]; then
                if [ $verbosity -ge 3 ]; then
                    printf "is a transposition of child\n"
                fi
                childIndex=$i;
                return $C_TRUE
            else
                if [ $verbosity -ge 3 ]; then
                    printf "not the same board\n";
                fi
            fi
        else
            if [ $verbosity -ge 3 ]; then
                printf "no value match\n"
            fi
        fi
        i=$((i+1));
    done
    return $C_FALSE
}
 
#get the indices of all the children with a given name
#arg1:board name to find
#arg2:board name of parent
#srg3: bool, when true ignore the transposition 
#returns nothing
 
#sets global VAR to array containing the indices of all
#the matching children
function findChildByName {
    local find="$1"
    local parent="$2"
    local noTransposition="$3"
    unset VAR
    if [ "$noTransposition" == "" ]; then
        noTransposition="$3"
    fi
    
    getFirstChildOffset "$parent"
    local -i i=$?
    
    getNNext "$parent" 0
    local -i -r nnext_x=$?
    getNNext "$parent" 1
    local -i -r nnext_o=$?
    local -i nnext=$((nnext_x+nnext_o));
    local -i lastChildIndex=$((i+nnext));
    local -n board="$parent"
    
    if [ $noTransposition -eq $C_TRUE ]; then
        if [ ${find: -2:1} == "r" ]; then
            find=${find:0:$((${#find}-6))};
        fi
    fi
    
    while [ $i -lt $lastChildIndex ]; do
        local child="${board[i]}";
        if [ $noTransposition -eq $C_TRUE ]; then
            local childName=${child:0:$((${#child}-6))};
            if [ "$find" == "$childName" ]; then
                VAR[${#VAR[@]}]=$i;
            fi
        else
            if [ "$find" == "$child" ]; then
                VAR[0]=$i;
            fi
        fi
        i=$((i+1));
    done
    
    local -n board="$parent";
}
 
#to keep track of all the moves made
#leave breadcrumbs
#add a breadcrumb to the trace
#arg1: board to add
#returns: nothing
#sets: breadcrumbs
function addBreadcrumb {
    local board="$1";
    local -i index=${breadcrumbs[0]};
    index=$((index+1));
    breadcrumbs[$index]="$board";
    breadcrumbs[0]=$index;
}
 
#change the weight of a board with a given delta
#arg1: board name of parent
#arg2: board name of child
#arg3: is the child an x or an o child
#arg4: the delta with which to change the weight
#TODO: use getChildWeight and setChildWeight instead
#      better update setWeight to allow + and - prefixes
#      as modifiers
function changeWeight {
    local -r parent="$1";
    local -i -r childIndex="$2";
    local -i -r v=$3;
    local -i -r delta=$4;
    getNNext "$parent" 0
    local -i -r nnext_x=$?
    getNNext "$parent" 1
    local -i -r nnext_o=$?
    local -i -r nnext=$((nnext_x+nnext_o))
    local -n parentBoard="$parent";
    local -i curWeight=${parentBoard[$((childIndex+nnext))]};
    local -i newWeight=$((curWeight+(delta)));
    if [ $newWeight -le 0 ]; then
        newWeight=0;
    elif [ $newWeight -ge 255 ]; then
        newWeight=255;
    fi
    parentBoard[$((childIndex+nnext))]=$newWeight;
    
}
 
#when the game is done change the likelyhoods of a board
#being chosen
#arg1: symbol of the winner
#returns nothing
#modifies all boards that were used during this match
function setNewWeights {
    local whoWon="$1"
    local playingAs="$2"
    local verbosity=0;
    printf "Learning from last match...\n"
    
    if [ $verbosity -ge 1 ]; then
        echo "winner was: $1"
    fi
    
    if [ $verbosity -ge 2 ]; then
        if [ "$whoWon" == " " ]; then
            echo "Was a tie, lightly strengthening both branches"
        else
            echo "Someone won, strengthening branch for the winner and weakening branch for the other";
        fi
    fi
        #winner is always the last player to do a move
        #working backwards
        local -i isWinner=1;
        local -i i=${breadcrumbs[0]}
        printf "%d moves made\n" $i
        #the first board is always b0, but that is not a move, so not stored as breadcrumb. Here we need it, so we replace the size field with the b0 board
        breadcrumbs[0]="b0h0v0r0"
        while [ $i -gt 0 ]; do
            local parent="${breadcrumbs[$((i-1))]}"
            #strip the transposition
            parent=${parent:0:$((${#parent}-6))};
            
            local child="${breadcrumbs[$i]}"
            
            if [ $verbosity -ge 2 ]; then
                printf "processing board %s\n" $child
                printf "parent: %s\n" "$parent"
            fi
            findChildByName "$child" "$parent" $C_TRUE
            local -i delta=0
            if [ "$whoWon" == " " ]; then
                    delta=1
            else
                if [ $isWinner -gt 0 ]; then
                    delta=3;
                else
                    delta=-1;
                fi
                isWinner=$((isWinner*-1));
            fi
            
            local -i j=0;
            while [ $j -lt ${#VAR[@]} ]; do
                changeWeight "$parent" ${VAR[$j]} $((i%2)) $delta
                j=$((j+1))
            done
            
            i=$((i-1));
        done
}
 
#sets global VAR with array filled with all the possible next moves and indexes
#move0, index0, move3, index3, etc
function getNextMoves {
    local -r boardName="$1";
    local -i -r v=$2;
    local -n -r board="$boardName";
    local -i verbosity=0;
    getNNext "$boardName" $v
    local -i nnext=$?;
    unset VAR
    if [ $nnext -eq 0 ]; then
        return $C_FALSE;
    fi
    local -i nMoves=0;
    local -i index=0;
    #local -a moves
    getFirstChildOffset "$boardName" $v
    local -i firstChildOffset=$?
    
    while [ $index -lt $nnext ]; do
        getChildWeight "$boardName" $v $index
        local -i weight=$?
        if [ $verbosity -gt 0 ]; then
            printf "index %d, weight: %d\n" $index $weight;
        fi
        local -i j=0;
        while [ $j -lt $weight ]; do
            if [ $verbosity -gt 0 ]; then
                #echo "moves: ${moves[@]}";
                echo "moves: ${VAR[@]}";
            fi
            #moves[$nMoves]=${board[$((firstChildOffset+index))]};
            VAR[$nMoves]=${board[$((firstChildOffset+index))]};
            nMoves=$((nMoves+1))
            j=$((j+1))
        done
        
        
        index=$((index+1))
    done
    #VAR=${moves[@]};
    return $C_TRUE;
    
}
 
#print help on the command line arguments
#args: none
#returns nothing
function printArgsHelp {
    printf "Help for the tic tac toe game\n";
    printf "  Start the game and then press h for gameplay help\n"
    printf "  -r <file>    read the board settings from specified file\n"; #if not exist try default or just quit?
    printf "  -w <file>    write the board settings to specified file\n";
    printf "               if file is an empty string the boards are\n";
    printf "               not saved\n";
    printf "  -?           user goes first(unsupported)\n";
    printf "  -?           disable learning\n";
    printf "  -n           numeric input mode\n"
    printf "  -N           numpad numeric input mode\n"
    printf "  -v <value>   set verbosity, each subfunction has its own\n";
    printf "               verbosity. Default value is 0 -> off.\n";
    printf "  -t           test mode, do not run main. Used when sourceing\n";
    printf "               in testscript\n";
    printf "  -i           skip the intro\n";
    printf "  -h           print this help and exit. More information\n";
    printf "               available in the i -game help. Open that by\n"
    printf "               pressing h when asked for a move.\n"
    printf " -? means flag not yet determined\n";
}
 
function printGameHelp {
    printf "\n\nHow to play\n";
    printf "The game is played on a grid with 9 squares. Both\n";
    printf "players take turns in which they can occupy a\n";
    printf "square by marking them with their symbol. One \n";
    printf "player uses an X, the other a O. Only an empty\n";
    printf "square can be occupied. The goal of the game is\n";
    printf "to get three squares in a row. This can be\n";
    printf "horizontally, vertically or diagonally. The first\n";
    printf "player to align three of their symbols wins.\n";
    printf "\n";
    printf "The controls of this game are simple. On the edges\n"
    printf "of the board are letters and numbers\n";
    printBoard b0 "h0v0r0" $C_FALSE $C_TRUE
    printf "When it is your turn ou specify a column by typing\n";
    printf "One of the column letters, followed by a row number\n"
    printf "That will place your symbol on the board, or inform\n";
    printf "you the move is invalid and you can try again. This \n";
    printf "can be because there already is a symbol on that\n";
    printf "cell, or the cell does not exist.\n"
    printf "\n";
    printf "When in numeric input mode the coordinates won't be\n"
    printf "printed on the edge of the board.\n"
    printf "instead a single digit is used to identify the cells\n"
    printf " ┏━┯━┯━┓\n";
    printf " ┃1┃2┃3┃\n";
    printf " ┠─┼─┼─┨\n";
    printf " ┃4┃5┃6┃\n";
    printf " ┠─┼─┼─┨\n";
    printf " ┃7┃8┃9┃\n";
    printf " ┗━┷━┷━┛\n";
    printf "In numpad numeric mode the order is slightly different:\n"
    printf " ┏━┯━┯━┓\n";
    printf " ┃7┃8┃9┃\n";
    printf " ┠─┼─┼─┨\n";
    printf " ┃4┃5┃6┃\n";
    printf " ┠─┼─┼─┨\n";
    printf " ┃1┃2┃3┃\n";
    printf " ┗━┷━┷━┛\n";
    printf "\n"
    printf "Oh, and you quit by giving q as a move\n"
    printf "Press enter key to return to the game\n"
    read dummy #dummy to wait on user key press
}
 
#some global vars
declare duplicateBoard="";
declare -i boardNumber=0;
declare -i gameCounter=0;
declare -a breadcrumbs;
declare -i childIndex;
 
function main {
    local -i verbosity=0;
    local board_src="boards.txt";
    local board_dst="boards.txt";
    local coordinateInputMode=$C_TRUE;
    local -i numpadMode=$C_FALSE;
    local -i skipIntro=$C_FALSE;
    while getopts ":v:w:r:hnNti" flag; do
        case ${flag} in
            r) echo "src: ${OPTARG}"; board_src="${OPTARG}";;
            w) echo "dst: ${OPTARG}"; board_dst="${OPTARG}";;
            h) printArgsHelp; return 0;;
            v) echo "v: ${OPTARG} $1 $2"; verbosity=${OPTARG};;
            n) coordinateInputMode=$C_FALSE;;
            N) coordinateInputMode=$C_FALSE;numpadMode=$C_TRUE;;
            t) return 0;;
            i) skipIntro=$C_TRUE;;
            *) printf "unknown argument %s\n" $flag;;# return 1;;
        esac    
    done
    if [ $skipIntro -eq $C_FALSE ]; then
        printIntro
    fi
    
    setup "$board_src"
    if [ $? -ne 0 ]; then
        return 1;
    fi;
        
    local -i playSelf=$C_FALSE;
    local quit=$C_FALSE
    local -i haveLearned=$C_FALSE;
    
    #start playing the game
    while [ $quit -eq $C_FALSE ]; do #loop for multiple games
        local turnCounter=-1;
        local -i whosTurn=$C_USER;
        local whoWon=" ";
        local gameEnded=$C_FALSE;
        declare -n bCurrent="b0";
    local transposition="h0v0r0";
    unset breadcrumbs
    printf "%d Game(s) played\n" $gameCounter
    gameCounter=$((gameCounter+1))
    if [ $verbosity -ge 1 ]; then
        echo "bCurrent: ${bCurrent[@]}";
        fi
        while [[ $quit -eq $C_FALSE && $gameEnded -eq $C_FALSE ]]; do #loop for turns in game
            printf "This turn(%d) is for: %s\n" $turnCounter ${xo[$((turnCounter%2))]}
            printBoard ${bCurrent[$C_NAME_OFFSET]} $transposition $C_FALSE $coordinateInputMode;
            
            #now do stuff for the next turn
            turnCounter=$((turnCounter+1))
            local -i v=$(((turnCounter)%2))
            if [ $playSelf -ne $C_TRUE ]; then
                whosTurn=$((whosTurn*-1));
            fi
            printf "preparing for next move (%s)\n" ${xo[$v]};
            #check if moves left
            
                getNextMoves "$bCurrent" $v 
            if [ $? -ne $C_TRUE ]; then
                printf "no more moves for %s\n" ${xo[$v]};
                isWon "${bCurrent[$C_NAME_OFFSET]}";
                if [ $? -eq $C_TRUE ]; then
                    printf "%s won.\n" ${xo[$(((turnCounter-1)%2))]};
                    whoWon=${xo[$(((turnCounter-1)%2))]}
                    if [ $whosTurn -eq $C_COMPUTER ]; then #computer turn
                        printf "congratulations!\n"
                    else
                        printf "better luck next time.\n"
                    fi
                    gameEnded=$C_TRUE;
                    break;
                else #check if all squares are used
                    getDepth "bCurrent"
                    local depth=$?
                    if [ $depth -eq 9 ]; then 
                        printf "The game ended in a tie.\n";
                        gameEnded=$C_TRUE;
                    fi
                    printBoard "bCurrent" "$transposition" $C_FALSE $coordinateInputMode;
                    break;
                fi
            fi
            nextMoves=("${VAR[@]}"); #TODO: make local array
            if [ $verbosity -ge 1 ]; then
                echo "currentboard: ${bCurrent[@]}"
                echo "next moves: ${VAR[@]}"
                echo "next moves: ${nextMoves[@]}"
            fi
            
            if [ $whosTurn -eq $C_COMPUTER ]; then #computer turn
                printf -- "--COMPUTER--\n";
                #choose the next board, which is the next move
                local -i nnext=${#nextMoves[@]};
                if [ $nnext -le 0 ]; then
                    printf "An error occurred, something went wrong with the weights\n"
                    printf "board %s\n" "${bCurrent[@]}"
                    printf "writing boards to error file\n"
                    board_dst="nonext_debug.txt"
                    quit=$C_TRUE
                    break;
                fi
                local -i nextBoardIndex=$((RANDOM%nnext));
                
                boardName="${nextMoves[$nextBoardIndex]}";
                if [ $verbosity -ge 1 ]; then
                printf "nextBoardIndex: %d, board: %s, v: %d\n" $nextBoardIndex ${nextMoves[$nextBoardIndex]} $v;
                    printf "next board: %s\n" "$boardName";
                fi
                local prevTransposition="$transposition";
                #get transposition information
                if [ ${boardName: -2:1} == "r" ]; then
                    transposition=${boardName:$((${#boardName}-6))};
                    boardName=${boardName:0:$((${#boardName}-6))};
                fi
            else #user move
                printf -- "--USER--\n";
            if [ $verbosity -ge 2 ]; then
                    printf "transposition: %s\n" $transposition
                    printf "breadcrumbs: "
                    printf "%s-" "${breadcrumbs[@]}"
                    printf "\n"
                fi
                local -i isValid=$C_FALSE;
                while [ $isValid -eq $C_FALSE ]; do
                    printf "Your move: ";
                    local c;
                    local r;
                    isValid=$C_TRUE;
                    read -n 1 c;
                    if [ "$c" == "q" ]; then
                        quit=$C_TRUE;
                        printf "\n";
                        break;
                    fi
                    if [ "$c" == "h" ]; then
                        printGameHelp
                        isValid=$C_FALSE
                        continue;
                    fi
                    if [ $coordinateInputMode -eq $C_TRUE ]; then
                        read -n 1 r
                        printf "\n move given: %s%s\n" "$c" "$r";
                        #regexp would be a great way to check validity
                        #but not supported on dev terminal, so other way is needed
                        local -i i=0;
                        while [ $i -lt ${#r[@]} ]; do
                            case "${r[$i]}" in
                                [0-9]) ;;
                                    *) isValid=$C_FALSE;
                                    printf "that is not a valid move\nplease enter a valid move.\n";
                                    break;
                            esac
                            i=$((i+1));
                        done
                        if [ $isValid -eq $C_FALSE ]; then
                            continue;
                        fi
                    
                        if [[ ! ( 0 -le $r && $r -le 3 ) ]]; then
                            isValid=$C_FALSE;
                            printf "that is not a valid move.\n Please enter a valid move.\n";
                            continue;
                        fi
                        local -i pos=$((r*3));
                        case $c in
                            [aA]) pos=$((pos+0));;
                            [bB]) pos=$((pos+1));;
                            [cC]) pos=$((pos+2));;
                            [qQ]) exit;;
                            *) isValid=$C_FALSE;
                                            printf "that is not a valid move.\n";
                                            continue;;
                        esac
                    else
                        printf "\n move given: %s\n" "$c";
                        #regexp would be a great way to check validity
                        #but not supported on dev terminal, so other way is needed
                        local -i i=0;
                        while [ $i -lt ${#c[@]} ]; do
                            case "${c[$i]}" in
                                [1-9]) ;;
                                    *) isValid=$C_FALSE;
                                    printf "that is not a valid move\nplease enter a valid move: ";
                                    break;
                            esac
                            i=$((i+1));
                        done
                        if [ $isValid -eq $C_FALSE ]; then
                            continue;
                        fi
                        local -i pos=$((c-1)); #-1 to go from lowest 1 to lowest 0
                        if [ $numpadMode -eq $C_TRUE ]; then
                            posLUT=( 6 7 8 3 4 5 0 1 2 )
                            pos=${posLUT[$pos]};
                        fi
                        #the position is given as is on the numpad, the positions
                    fi  
                    
                    #apply the transposition to get the correct position
                    #but in case it is invalid, save the current transposition
                    local prevTransposition="$transposition";
                    local -n matrix="$transposition";
                    pos=${matrix[pos]}
                    
                    if [ $verbosity -ge 2 ]; then
                        printf "transposed position: %d\n" $pos
                    fi
                    if [ "${bCurrent[$((C_CELLS_OFFSET+pos))]}" != " " ]; then
                        isValid=$C_FALSE;
                        printf "that is not a valid move, position already taken\n";
                        if [ $verbosity -ge 2 ]; then
                            echo "${bCurrent[@]}";
                        fi
                        printBoard "bCurrent" "$prevTransposition" $C_FALSE $coordinateInputMode
                        transposition="$prevTransposition";
                        echo "transposition=$prevTransposition";
                    fi
                done
                if [ $quit -eq $C_TRUE ]; then
                    break;
                fi
                if [ $verbosity -ge 1 ]; then
                    printf "%s%d %d\n" $c $r $pos;
                fi
                #now find the corresponding board name
                copyBoard "bCurrent" "bTemp"
                bTemp[$((C_CELLS_OFFSET+pos))]=${xo[$v]};
                calculateBoardValue "bTemp";
                
                if [ $verbosity -ge 1 ]; then
                    printBoard "bTemp" $transposition $C_TRUE;
                fi
                local prevTransposition="$transposition";
                findChild "${bTemp[$C_NAME_OFFSET]}" "bCurrent" "${xo[$v]}"
                
                if [ $? -eq $C_TRUE ]; then
                    printf "Board user chose is: %s\n" $boardName;
                else
                    #crash, shouldn't happen if programmed correctly
                    #just here so it is clear what is happening 
                    #and the program doesn't try to stumble on and
                    #makes debugging a lot harder
                    printf "ERROR: no board found\n"
                    exit
                fi
                
                if [ $verbosity -ge 1 ]; then
                    printBoard $boardName
                    printf "The transposition of that board is: %s\n" $transposition
                fi
            fi
            #now apply the old transposition to this one
            
            if [ $verbosity -ge 2 ]; then
                printf "transposition, current, old: %s, %s\n" "$transposition" "$prevTransposition";
        fi
            transposeTransposition "$transposition" "$prevTransposition";
            
            if [ $verbosity -ge 1 ]; then
                printf "the new board transposition is: %s\n" $transposition;
            fi
            declare -n bCurrent="$boardName";
            addBreadcrumb "$boardName$transposition"
        done
        if [ $quit -eq $C_TRUE ]; then
            printf "quitting\n"
            break;
        fi
        if [ $verbosity -ge 1 ]; then
            echo "breadcr.: ${breadcrumbs[@]}";
        fi
        printf "\n";
        sleep 0.5;
        #"learn" from the last game
        setNewWeights "$whoWon" "X"; #TODO: give second arg depending on playing X or O (for learning)
        haveLearned=$C_TRUE;
        sleep 1;
        #TODO: ask if the user wants to play again
        
    done
    #remember the learned boards
    if [[ "$board_dst" != "" && $haveLearned -eq $C_TRUE ]]; then
        writeBoardsInfo "$board_dst";
    fi
    
    return 0;
}
echo "$@";
main "$@";