robot

local x = 0
local y = 0
local z = 0
local direction = 0

DIRECTION_SOUTH = 0
DIRECTION_WEST = 1
DIRECTION_NORTH = 2
DIRECTION_EAST = 3

local CONFIG_PATH = "robot_config"

function load()
    if fs.exists(CONFIG_PATH) then
        handle = fs.open(CONFIG_PATH, 'r')
        x = tonumber(handle.readLine())
        y = tonumber(handle.readLine())
        z = tonumber(handle.readLine())
        direction = tonumber(handle.readLine())
        handle.close()
    else
        initGPS()
    end
end

function save()
    handle = fs.open(CONFIG_PATH, 'w')
    handle.writeLine(x)
    handle.writeLine(y)
    handle.writeLine(z)
    handle.writeLine(direction)
    handle.close()
end

function log()
    print("x: " .. x)
    print("y: " .. y)
    print("z: " .. z)
    print("dir: " .. direction)
end

function initGPS()
    term.write("x-pos: ")
    x = tonumber(read())
    term.write("y-pos: ")
    y = tonumber(read())
    term.write("z-pos: ")
    z = tonumber(read())
    term.write("direction (0-3)")
    direction = tonumber(read())
    save()
end

function getX()
    return x
end
function getY()
    return y
end
function getZ()
    return z
end
function getDirection()
    return direction
end

function moveX(count, cb)
    if count > 0 then
        turnTo(3)
    elseif count < 0 then
        turnTo(1)
    end
    forward(math.abs(count), cb)
end

function moveToX(c, cb)
    moveX(c - x, cb)
end

function moveY(count, cb)
    if count > 0 then
        up(count, cb)
    elseif count < 0 then
        down(math.abs(count), cb)
    end
end

function moveToY(c, cb)
    moveY(c - y, cb)
end

function moveZ(count, cb)
    if count > 0 then
        turnTo(0)
    elseif count < 0 then
        turnTo(2)
    end
    forward(math.abs(count), cb)
end

function moveToZ(c, cb)
    moveZ(c - z, cb)
end

function move(cx, cy, cz, cb)
    moveX(cx, cb)
    moveY(cy, cb)
    moveZ(cz, cb)
end

function moveTo(cx, cy, cz, cb)
    moveToX(cx, cb)
    moveToY(cy, cb)
    moveToZ(cz, cb)
end

function forward(count, cb)
    count = count or 1
    for i = 1, count do
        while not turtle.forward() do
            turtle.dig()
        end
        if direction == DIRECTION_SOUTH then
            z = z + 1
        elseif direction == DIRECTION_NORTH then
            z = z - 1
        elseif direction == DIRECTION_WEST then
            x = x - 1
        elseif direction == DIRECTION_EAST then
            x = x + 1
        end
        if cb then cb() end
    end
end

function back(count, cb)
    count = count or 1
    for i = 1, count do
        if turtle.back() then
            if direction == DIRECTION_SOUTH then
                z = z + 1
            elseif direction == DIRECTION_NORTH then
                z = z - 1
            elseif direction == DIRECTION_WEST then
                x = x - 1
            elseif direction == DIRECTION_EAST then
                x = x + 1
            end
        end
        if cb then cb() end
    end
end

function down(count, cb)
    count = count or 1
    for i = 1, count do
        while not turtle.down() do
            turtle.digDown()
        end
        y = y - 1
        if cb then cb() end
    end
end

function up(count, cb)
    count = count or 1
    for i = 1, count do
        while not turtle.up() do
            turtle.digUp()
        end
        y = y + 1
        if cb then cb() end
    end
end

function turnleft(count, cb)
    count = count or 1
    for i = 1, count do
        if turtle.turnLeft() then
            if direction <= 0 then
                direction = 3
            else
                direction = direction - 1
            end
            if cb then cb() end
        end
    end
end

function turnright(count, cb)
    count = count or 1
    for i = 1, count do
        if turtle.turnRight() then
            if direction >= 3 then
                direction = 0
            else
                direction = direction + 1
            end
            if cb then cb() end
        end
    end
end

function turnTo(dir, cb)
    count = direction - dir
    dif = math.abs(count)
    if dif > 2 then
        count = -(count / dif)
    end
    if count > 0 then
        turnleft(count)
    elseif count < 0 then
        turnright(-count)
    end
    if cb then cb() end
end

function dropAmount(slot, amount)
    if amount == nil then
        return turtle.getItemCount(slot)
    elseif amount < 0 then
        return turtle.getItemCount(slot) + amount
    else return amount
    end
end

function drop(slot, amount)
    amount = dropAmount(slot, amount)
    turtle.select(slot)
    turtle.drop(amount)
end

function dropUp(slot, amount)
    amount = dropAmount(slot, amount)
    turtle.select(slot)
    turtle.dropUp(amount)
end

function dropDown(slot, amount)
    amount = dropAmount(slot, amount)
    turtle.select(slot)
    turtle.dropDown(amount)
end

function compareItems(s1, s2)
    turtle.select(s1)
    return turtle.compareTo(s2)
end

function compareFrontTo(slot)
    turtle.select(slot)
    return turtle.compare()
end

function compareDownTo(slot)
    turtle.select(slot)
    return turtle.compareDown()
end

function compareUpTo(slot)
    turtle.select(slot)
    return turtle.compareUp()
end