3DnRaya best IA

IA = {}

function IA.play(str,mode)
local x;
local y;
local d;
if str == "easy" then  -- Easy mode, everything is random
    if mode == "3D" then
        y = math.random(1,board.height)
        x = math.random(1,board.width)
        d = math.random(1,board.depth)
        while true do
            y = math.random(1,board.height)
            x = math.random(1,board.width)
            d = math.random(1,board.depth)
            if board.table[d][y][x] == "" then
                board.table[d][y][x] = board.player[board.turn].st
                return true;
            end
        end
    elseif mode == "C4" then
        y = board.height
        d = math.random(1,board.depth)
        x = math.random(1,board.width)
        while true do
            d = math.random(1,board.depth)
            x = math.random(1,board.width)
            for i = board.height, 1, -1 do
                if board.table[d][i][x] == "" then
                    board.table[d][i][x] = board.player[board.turn].st
                    return true;
                end
            end
        end
    end

elseif str == "medium" then
        local cont = {horizontal = 1,vertical = 1,dia_up = 1,dia_down = 1};
        local t = "";
        for n = board.row-1, 1, -1 do
            for d = 1, board.depth do
                for y = 1,board.height do
                    for x = 1, board.width do
                        cont = {horizontal = 1,vertical = 1,dia_up = 1,dia_down = 1};
                        t = board.table[d][y][x]
                        if t != "" then --The current chip is not empty.
                            for r = 1, n do
                                if board.inside(x+r,y) and board.table[d][y][x+r] == t then cont.horizontal = cont.horizontal +1 end    --Horizontal
                                if board.inside(x,y+r) and board.table[d][y+r][x] == t then cont.vertical = cont.vertical +1 end    --Vertical
                                if board.inside(x+r,y-r) and board.table[d][y-r][x+r] == t then cont.dia_up = cont.dia_up +1 end    --Diagonal up
                                if board.inside(x+r,y+r) and board.table[d][y+r][x+r] == t then cont.dia_down = cont.dia_down +1 end    --Diagonal down
                            end
                            if cont.horizontal >= n then --Horizontal
                                    if board.inside(x+n,y) and board.table[d][y][x+n] == "" then
                                        board.table[d][y][x+n] = board.player[board.turn].st
                                        return true
                                    end
                                    if board.inside(x-1,y) and board.table[d][y][x-1] == "" then
                                        board.table[d][y][x-1] = board.player[board.turn].st
                                        return true
                                    end
                            end
                            if cont.vertical >= n then --Vertical
                                    if board.inside(x,y+n) and board.table[d][y+n][x] == "" then
                                        board.table[d][y+n][x] = board.player[board.turn].st
                                        return true
                                    end
                                    if board.inside(x,y-1) and board.table[d][y-1][x] == "" then
                                        board.table[d][y-1][x] = board.player[board.turn].st
                                        return true
                                    end
                            end
                            if cont.dia_up >= n then --Diagonal up
                                    if board.inside(x+n,y-n) and board.table[d][y-n][x+n] == "" then
                                        board.table[d][y-n][x+n] = board.player[board.turn].st
                                        return true
                                    end
                                    if board.inside(x-1,y+1) and board.table[d][y+1][x-1] == "" then
                                        board.table[d][y+1][x-1] = board.player[board.turn].st
                                        return true
                                    end
                            end
                            if cont.dia_down >= n then  --Diagonal down
                                    if board.inside(x+n,y+n) and board.table[d][y+n][x+n] == "" then
                                        board.table[d][y+n][x+n] = board.player[board.turn].st
                                        return true
                                    end
                                    if board.inside(x-1,y-1) and board.table[d][y-1][x-1] == "" then
                                        board.table[d][y-1][x-1] = board.player[board.turn].st
                                        return true
                                    end
                            end
                        end
                    end
                end
            end
        end
elseif str == "hard" then
    --
end
return false;
end