function fieldchangeapp(varargin)


if nargin==0 %initial screen
    %data
    data.fields = {'MSL_FIELD_A_a','MSL_FIELD_B_a'};
    data.pc = [cellstr(strcat('turtle',int2str([1:6]')));{'devpc'}];
    data.names = [{'all fields'},data.fields];
    
    %create figure
    data.c = [];
    figure('units','normalized','position',[.3 .3 .4 .3])
    w = 1/length(data.names);
    h = 1/(length(data.pc)+1);
    for i=1:length(data.names)
        data.b(i) = uicontrol('units','normalized','position',[(i-1)*w 1-h w h],'style','pushbutton','string',['ping ' data.names{i}],'callback',['fieldchangeapp(''all'',''' data.names{i} ''')']);
        for j=1:length(data.pc)
            if i==1
                data.c(j,i) = uicontrol('units','normalized','position',[(i-1)*w 1-(j+1)*h w h],'style','pushbutton','callback',['fieldchangeapp(''ping'',''' data.pc{j} ''')'],'string',data.pc{j});
            else
                data.c(j,i) = uicontrol('units','normalized','position',[(i-1)*w 1-(j+1)*h w h],'style','checkbox','callback',['fieldchangeapp(''checkbox'',[' int2str([j i-1]) '])']);
            end
            if j==length(data.pc) && i==1
                set(data.c(j,i),'callback','')
            end
        end
    end
    set(gcf,'userdata',data)
    currentfield
    
else %commands
    cmd = varargin{1};
    val = varargin{2};
    data = get(gcf,'userdata');
    
    %process inputs
    set(data.c,'enable','off')
    set(data.b,'enable','off')
    if isequal(cmd,'all')
        if isequal(val,data.names{1}) %ping/field check
            fld = currentfield;
            set(data.c,'backgroundcolor',[0.7020    0.7020    0.7020])
            for i=1:length(data.fields)
                changefield(data.fields{i})
                for j=1:6
                    pingturtle(['turtle' int2str(j)]);
                end
            end
            changefield(fld)
        else %check all fields of active turtles
            fld = currentfield;
            changefield(val)
            for i=1:6
                pingturtle(['turtle' int2str(i)]);
            end
            changefield(fld);
        end
        
    elseif isequal(cmd,'ping')
        fld = currentfield;
        set(data.c(str2num(val(end)),:),'backgroundcolor',[0.7020    0.7020    0.7020])
        for i=1:length(data.fields)
            changefield(data.fields{i})
            pause(2)
            pingturtle(val);
        end
        changefield(fld)
    elseif isequal(cmd,'checkbox')
        if val(1)==length(data.pc) %devpc
            changefield(data.fields{val(2)});
        else %turtle
            set(data.c(val(1),:),'backgroundcolor',[0.7020    0.7020    0.7020])
            set(data.c(val(1),:),'value',0)
            drawnow
            turtle = data.pc{val(1)};
            changefieldturtle(turtle,data.fields{val(2)});
        end
    else
        error('pruts code')
    end
    set(data.c,'enable','on')
    set(data.b,'enable','on')
end


function found = pingturtle(turtle)
data = get(gcf,'userdata');

j = str2num(turtle(end));
[fld,i] = currentfield;

[a,b]=system(['ping ' turtle ' -w4']);
if ~isempty(findstr(b,'time=')) %robot is at same field as devpc
    found = 1;
    set(data.c(j,i+1),'BackgroundColor',[0 .5 0])
    set(data.c(j,i+1),'value',1)
else
    found = 0;
    set(data.c(j,i+1),'BackgroundColor',[1 0 0])
    set(data.c(j,i+1),'value',0)
end
drawnow

function [fld,fldi] = currentfield
data = get(gcf,'userdata');

fid = fopen('/etc/Robocup/field.conf','r');
tmp = fgetl(fid);
while ischar(tmp)
    fld = tmp(regexp(tmp,'MSL_\w+'):end);
    if ~isempty(fld) && tmp(1)~='#'
        fclose(fid);
        fldi = 1;
        while ~isequal(data.fields{fldi},fld) fldi = fldi+1;end
        set(data.c(end,:),'value', 0);
        set(data.c(end,fldi+1),'value', 1);
        drawnow
        return;
    end
    tmp = fgetl(fid);
end
fclose(fid);
error('can''t find field')

function changefield(fld)
data = get(gcf,'userdata');
fldcur = currentfield;
if isequal(fldcur,fld)
    return;
end

%load data
fid = fopen('/etc/Robocup/field.conf','r');
tmp = fgets(fid);
str={};
while ischar(tmp)
    str{end+1}=tmp;
    tmp = fgets(fid);
end
fclose(fid);

%change data
for i=1:length(str)
    if ~isempty(strfind(str{i},fld))
        str{i} = sprintf('%s\n',fld);
    elseif str{i}(1)~='#'
        str{i} = ['# ' str{i}];
    end
end

%save data
fid = fopen('/etc/Robocup/field.conf','w');
tmp = fgets(fid);
for i=1:length(str)
    fwrite(fid,str{i},'char');
end
fclose(fid);

[a,b]=system('sudo /etc/Robocup/robocup_network');
pause(1)

currentfield;


function createnewfieldconf(fld)

%load data
fid = fopen('/etc/Robocup/field.conf','r');
tmp = fgets(fid);
str={};
while ischar(tmp)
    str{end+1}=tmp;
    tmp = fgets(fid);
end
fclose(fid);

%change data
for i=1:length(str)
    if ~isempty(strfind(str{i},fld))
        str{i} = sprintf('%s\n',fld);
    elseif str{i}(1)~='#'
        str{i} = ['# ' str{i}];
    end
end

%save data
fid = fopen('/etc/Robocup/field.conf','w');
tmp = fgets(fid);
for i=1:length(str)
    fwrite(fid,str{i},'char');
end
fclose(fid);


function changefieldturtle(turtle,field)
data = get(gcf,'userdata');

fldcur = currentfield;

for i=1:length(data.fields)
    changefield(data.fields{i});
    if pingturtle(turtle)
        
        %this sequence still can be optimized for speed....
        createnewfieldconf(field);
        [a,b]=system(['sudo scp /etc/Robocup/field.conf root@' turtle ':/etc/Robocup']);
        pause(2)
        [a,b]=system(['ssh ' turtle ' sudo /etc/Robocup/robocup_network&']);
        pause(8)
        !sudo killall -9 ssh
        changefield(data.fields{i});
        pause(1)
        pingturtle(turtle);
        pause(2)
        changefield(field);
        pause(4)
        [a,b]=system('sudo /etc/Robocup/robocup_network');
        pause(8)
        pingturtle(turtle);
        changefield(fldcur)
        return;
    end
end
changefield(fldcur)