robot.lua

-- robot is an abstraction of turtle giving some more advanced functions involving gps

-- default fuel value - reset to desired value
-- notice that if below minFuelLevel intended behavior is for the turtle to continue what it's doing
-- it is assumed that if you get below the minFuelLevel that the program will bring the turtle to where it can get fuel
local minFuelLevel = 80
function setFuelLevel(fuelLevel)
    if fuelLevel >= 100000 then
        fuelLevel = 100000
    else
        minFuelLevel = fuelLevel
    end

end

function getMinFuelLevel()
    return minFuelLevel
end

-- variable that determines which slots can be refueled from
-- by default its all slots
local refuelSlot = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}
function setRefuelSlots(var)
    refuelSlot = var
end

-- return refuelSlot
function getRefuelSlots()
    return refuelSlot
end

-- function to return pos as a table of x, y, and z
function getPos()
    local x, y, z = gps.locate()
    local pos = {
        x = x,
        y = y,
        z = z
    }
    return pos
end


-- return r1 - r2
function getPosDiff(r1, r2)
    local diff = {
        x=nil,
        y=nil,
        z=nil
    }

    diff.x = r1.x - r2.x
    diff.y = r1.y - r2.y
    diff.z = r1.z - r2.z
end

local reservesPrinted = false -- if running on reserves print only once
-- refuels until above minFuelLevel
function refuel()
    local refueled = false
    local outPrinted = false

    while (turtle.getFuelLevel() < minFuelLevel) do
        refueled = false

        for k,v in pairs(refuelSlot) do
            if turtle.refuel(1) then
                refueled = true
                break
            end
        end

        if not refueled then
            if turtle.getFuelLevel() > 0 then
                if not reservesPrinted then
                    reservesPrinted = true
                    print("Running on reserves!")
                end
                return false
            else
                if not outPrinted then
                    outPrinted = true
                    print("Outta fuel!")
                end
            end
        end
    end

    reservesPrinted = false
    return true
end

-- function that checks fuel level before moving
-- will try to refuel from 1st slot first then others
-- returns false if it can't move
-- gets stuck if out of fuel
function forward()
    refuel()
    return turtle.forward()
end

function back()
    refuel()
    return turtle.back()
end

function up()
    refuel()
    return turtle.up()
end

function down()
    refuel()
    return turtle.down()
end

-- making taking turtle functions and calling them using robot api
function turnLeft()
    turtle.turnLeft()
end

function turnRight()
    turtle.turnRight()
end

-- gets the turtle to move 1 block horizontally
-- returns false if it cannot move
-- tries to move all 4 directions
-- if it can't then it will move up
-- if it can no longer move up it will try to move all the way down
-- if it can no longer move down it return to its starting pos and dir and returns false
local function moveHor()
    local moved = false
    local yDiff = 0

    -- tries to move, if it can't move it goes up
    while not moved do
        for i = 1, 4 do
            moved = forward()
            if not moved then
                turnLeft()
            else
                break
            end
        end
        if not moved and up() then
            yDiff = yDiff + 1
        else
            break
        end
    end

    -- tries to move, if it can't move it goes down
    if not moved then
        -- goes to 1 position lower than where it started
        for i = 1, yDiff+1 do
            if down() then
                yDiff = yDiff - 1
            end
        end

        -- if it was able to go to 1 position lower than it started try to move forward again
        if yDiff == -1 then
            while not moved do
                for i = 1, 4 do
                    moved = forward()
                    if not moved then
                        turnLeft()
                    else
                        break
                    end
                end
                if not moved and down() then
                    yDiff = yDiff - 1
                else
                    break
                end
            end
        end
    end
    return moved

end

-- function to get the turtle's direction then returns to its startPos and direction
-- return 0 for east, 1 for north, 2 for west, and 3 for south
-- return false for a failed attempt
function getDir()
    local startPos = getPos()
    -- try to move
    if not moveHor() then
        print("Door stuck! Please! I beg you!")
        return false
    end

    local newPos = getPos()
    local diffPos = getPosDiff(startPos, newPos)

    if diffPos.x == 1 then
        return 2
    elseif diffPos.x == -1 then
        return 0
    elseif diffPos.z == 1 then
        return 3
    elseif diffPos.z == -1 then
        return 1
    else
        print("Something went very wrong trying to get the direction!")
        return false
    end
end

-- function to move the turtle to a given x, y, z coordinate
function moveTo(x, y, z)
    local dir = getDir()
end