turtleutils

--  f = 0 = norden [y+1]  | f = 1 = osten   [x+1]
--  f = 2 = sueden [y-1]  | f = 3 = westen  [x-1]

local way = "way.dat";

status = "_home";

local function split(pString, pPattern)
    local Table = {}  -- NOTE: use {n = 0} in Lua-5.0
    local fpat = "(.-)" .. pPattern
    local last_end = 1
    local s, e, cap = pString:find(fpat, 1)
    while s do
        if s ~= 1 or cap ~= "" then
            table.insert(Table,cap)
        end
        last_end = e+1
        s, e, cap = pString:find(fpat, last_end)
    end

    if last_end <= #pString then
        cap = pString:sub(last_end)
        table.insert(Table, cap)
    end
    return Table
end

local function savePosition( varName, content, replace )
    if not replace then
        if not fs.exists(way) then
            local file = fs.open(varName .. ".dat", "w" )
            if file then
                file.write( content )
                file.close()
            else
                return false
            end
        else
            return false
        end
    else
        fs.delete(varName .. ".dat" )
        local file = fs.open(varName .. ".dat", "w" )
        if file then
            file.write( content )
            file.close()
        else
            return false
        end
    end
    return true
end

local function saveWay(moved, amount)
    if fs.exists(way) then option = "a"; else option = "w"; end
    local file = fs.open(way, option)
    print("moved: ",moved, " amount: ", amount);
    if ( option == "a" ) then
        file.write(";" .. moved .. "," .. amount);
    else
        file.write(moved .. "," .. amount);
    end
    file.close();
end

function getPositionVar( varName )
    if fs.exists(varName .. ".dat") then
        local file = fs.open(varName .. ".dat", "r")
        if file then
            local var = file.readLine()
            file.close()
            return var
        else
            return false
        end
    else
        return false
    end
end

position = {}
position["x"] = 0; position["y"] = 0;
position["z"] = 0; position["f"] = 0;
if ( getPositionVar("x") ) then position["x"] = tonumber(getPositionVar("x")); end
if ( getPositionVar("y") ) then position["y"] = tonumber(getPositionVar("y")); end
if ( getPositionVar("z") ) then position["z"] = tonumber(getPositionVar("z")); end
if ( getPositionVar("f") ) then position["f"] = tonumber(getPositionVar("f")); end

local function move(k, v)
    v = tonumber(v);
    if ( k ~= nil and v ~= nil ) then
        if ( k == "f" ) then
            if ( v == -1 ) then turnLeft(1,1);
            elseif ( v == 1 ) then turnRight(1,1); end
        end

        if ( k == "y" ) then
            if ( v == -1 ) then
                back(1,1);
            elseif ( v == 1 ) then
                forward(1,1);
            end
        end

        if ( k == "z" ) then
            if ( v == -1 ) then
                down(1,1);
            elseif ( v == 1 ) then
                up(1,1);
            end
        end

        if ( k == "x") then
            if ( v == 1 ) then
                back(1,1);
            elseif ( v == -1 ) then
                forward(1,1);
            end
        end
    end
end

function status()
    return status;
end

function home()
    if fs.exists(way) then
        status = "_moveHome";
        local file = fs.open(way, "r")
        local mystring = file.readAll();
        local ta = split(mystring, ";")
        for index = #ta, 1, -1 do
            tt = split(ta[index], ",")
            for k, v in pairs(tt) do
                if ( k == 1 ) then doThis = v;
                elseif ( k == 2 ) then move1 = v; end
            end
            move(doThis, move1);
        end
        file.close();
        sleep(0.3);
        shell.run("remove way.dat");
        shell.run("remove x.dat");
        shell.run("remove y.dat");
        shell.run("remove z.dat");
        shell.run("remove f.dat");
        status = "_home";
        return status;
    else
        status = "_moveHomeFailed"
        return "_moveHomeFailed";
    end
end

function forward(amounts, value)
    if ( amounts == nil ) then amounts = 1; end
    for i = 1, amounts do
        if ( turtle.forward() ) then
            if ( position["f"] == 0 ) then
                position["y"] = position["y"] + 1;
                if ( value == nil ) then saveWay("y", -1); end
            elseif ( position["f"] == 1 ) then
                position["x"] = position["x"] + 1;
                if ( value == nil ) then saveWay("x", -1); end
            elseif ( position["f"] == 2 ) then
                position["y"] = position["y"] - 1;
                if ( value == nil ) then saveWay("y", 1); end
            elseif ( position["f"] == 3 ) then
                position["x"] = position["x"] - 1;
                if ( value == nil ) then saveWay("x", 1); end
            end
            savePosition("y", position["y"], true);
            savePosition("x", position["x"], true);
            status = "_isMoving";
        else
            return "_movingFailed";
        end
    end
end

function back(amounts, value)
    if ( amounts == nil ) then amounts = 1; end
    for i = 1, amounts do
        if ( turtle.back() ) then
            if ( position["f"] == 0 ) then
                position["y"] = position["y"] - 1;
                if ( value == nil ) then saveWay("y", 1); end
            elseif ( position["f"] == 1 ) then
                position["x"] = position["x"] - 1;
                if ( value == nil ) then saveWay("x", 1); end
            elseif ( position["f"] == 2 ) then
                position["y"] = position["y"] + 1;
                if ( value == nil ) then saveWay("y", -1); end
            elseif ( position["f"] == 3 ) then
                position["x"] = position["x"] + 1;
                if ( value == nil ) then saveWay("x", -1); end
            end
            savePosition("y", position["y"], true);
            savePosition("x", position["x"], true);
            status = "_isMoving";
        else
            return "_movingFailed";
        end
    end
end

function up(amounts, value)
    if ( amounts == nil ) then amounts = 1; end
    for i = 1, amounts do
        if ( turtle.up() ) then
            position["z"] = position["z"] + 1;
            savePosition("z", position["z"], true);
            if ( value == nil ) then saveWay("z", -1); end
            status = "_isMoving";
        else
            return "_movingFailed";
        end
    end
end

function down(amounts, value)
    if ( amounts == nil ) then amounts = 1; end
    for i = 1, amounts do
        if ( turtle.down() ) then
            position["z"] = position["z"] - 1;
            savePosition("z", position["z"], true);
            if ( value == nil ) then saveWay("z", 1); end
            status = "_isMoving";
        else
            return "_movingFailed";
        end
    end
end

function turnRight(amounts, value)
    if ( amounts == nil ) then amounts = 1; end
    for i = 1, amounts do
        if ( turtle.turnRight() ) then
            position["f"] = position["f"] + 1;
            if ( position["f"] > 3 ) then position["f"] = 0; end
            if ( value == nil ) then saveWay("f", -1); end
            savePosition("f", position["f"], true);
            status = "_isMoving";
        else
            status = "_movingFailed";
            return false;
        end
    end
end

function turnLeft(amounts, value)
    if ( amounts == nil or amounts < 0 ) then amounts = 1; end
    for i = 1, amounts do
        if ( turtle.turnLeft() ) then
            position["f"] = position["f"] - 1;
            if ( position["f"] < 0 ) then position["f"] = 3; end
            if ( value == nil ) then saveWay("f", 1); end
            savePosition("f", position["f"], true);
            status = "_isMoving";
        else
            status = "_movingFailed";
            return false;
        end
    end
end