surface

--Surface Quarry v1.0
 --By: Fizzgig

 --Tested with: FTB Mod pack - Direwolf20 v3

 --Purpose: A turtle program designed to dig and collect blocks from the surface to a specified depth.
 -- Useful for collecting sand from the desert and keeping the terrain generally "untouched".
 -- No ugly quarry holes!

 --Usage: surface <Depth> <Length> <Width> [Optional <'left'(Default='right')> <Offset>]
 -- Recommended depths 1 or 2. Greater than 3 is not recommended.
 -- Fuel slots 1 and 2. Split stack or 2 stacks (Put fuel in each slot)
 -- Placement - Turtle ontop of a chest.

--Arguments
    local args = {...} --depth length width [Optional <'left'> <Offset>]
    if #args < 3 then
    print("Usage: surface <Depth> <Length> <Width> [Optional <'left'(Default='right')> <Offset>]")
    return
    end

    if tonumber(args[1]) < 1 then args[1] = "1" end
    if tonumber(args[2]) < 2 then args[2] = "2" end
    if tonumber(args[3]) < 2 then args[3] = "2" end

    local depth = tonumber(args[1])
    local length = tonumber(args[2])
    local width = tonumber(args[3])

    local quarry = "right"
    if #args >= 4 then
    if args[4] == "left" or args[4] == "Left" or args[4] == "LEFT" then quarry = "left" end
    end

    local offset = 0
    if #args == 5 then
    if tonumber(args[5]) < 0 then args[5] = "0" end
    offset = tonumber(args[5])
    end

--Declarations
    local xpos = -2
    local ypos = 0
    local zpos = 1
    local dir = 1
    local safe = false


--Functions
    function organize(num)
            --Sort the inv
            for i=num,16 do
                turtle.select(i)
                if turtle.getItemCount(i) > 0 then --same as below. that is intended
                    for j=1,4 do
                        if turtle.getItemCount(i) > 0 then --double condition is intended
                            if turtle.getItemSpace(j)>turtle.getItemCount(i) then
                                turtle.transferTo(j,turtle.getItemCount(i))
                                else
                                turtle.transferTo(j,turtle.getItemSpace(j))
                            end
                        end
                    end
                end
            end

            local athome = (xpos == -2 and ypos == 0 and zpos == 1)

            --Drop to chest
            if athome then
                for i=num,16 do
                    turtle.select(i)
                    if turtle.getItemCount(i) > 0 then
                    turtle.dropDown(turtle.getItemCount(i))
                    end
                end
            end
        end

    function setdir(ndir)
            if ndir == 4 and dir == 1 then
                turtle.turnLeft()
                dir = 4
            end

            if ndir == 1 and dir == 4 then
                turtle.turnRight()
                dir = 1
            end

            if ndir == 4 and dir == 2 then
                turtle.turnLeft()
                turtle.turnLeft()
                dir = 4
            end

            if ndir == 2 and dir == 4 then
                turtle.turnRight()
                turtle.turnRight()
                dir= 2
            end

            if ndir > dir then
                while dir ~= ndir do
                    turtle.turnRight()
                    dir = dir+1
                end
            end

            if ndir < dir then
                while dir ~= ndir do
                    turtle.turnLeft()
                    dir = dir-1
                end
            end
        end
    function forward(num)
            if num == nil then num=1 end
            local modifyer
            if dir <= 2 then modifyer = 1 else modifyer = -1 end

            if dir == 1 or dir == 3 then
                while num > 0 do
                    if turtle.forward() then
                        xpos=xpos+modifyer
                        num = num-1
                    elseif safe then
                        if turtle.getFuelLevel() == 0 then fuel(1,2)
                        elseif turtle.up() then zpos=zpos+1
                        elseif turtle.down() then zpos=zpos-1 end
                    else
                        turtle.dig()
                        fuel(1,2)
                    end
                end
            end

            if dir == 2 or dir == 4 then
                while num > 0 do
                    if turtle.forward() then
                        ypos=ypos+modifyer
                        num = num-1
                    elseif safe then
                        if turtle.getFuelLevel() == 0 then fuel(1,2)
                        elseif turtle.up() then zpos=zpos+1
                        elseif turtle.down() then zpos=zpos-1 end
                    else
                        turtle.dig()
                        fuel(1,2)
                    end
                end
            end
        end
    function up(num)
            if num == nil then num = 1 end
            while num > 0 do
                if turtle.up() then
                    zpos=zpos+1
                    num = num-1
                else
                    turtle.digUp()
                    fuel(1,2)
                end
            end
        end
    function down(num)
            if num == nil then num = 1 end
            while num > 0 do
                if turtle.down() then
                    zpos=zpos-1
                    num = num-1
                else
                    turtle.digDown()
                    fuel(1,2)
                end
            end
        end
    function home()
            safe = true

            go(0,ypos)
            go(xpos,0)
            if zpos > 1 then down(zpos-1) end
            if zpos < 1 then up(1-zpos) end
            go(-2,0)
            setdir(1)

            safe = false

        end
    function start()
            go(0,ypos)
        end
    function go(x,y)
            if y ~= ypos then
                    if y < ypos then
                            setdir(4)
                            forward(ypos-y)
                        end
                    if y > ypos then
                            setdir(2)
                            forward(y-ypos)
                        end
                end
            if x ~= xpos then
                    if x < xpos then
                            setdir(3)
                            forward(xpos-x)
                        end
                    if x > xpos then
                            setdir(1)
                            forward(x-xpos)
                        end
                end
        end
    function fuel(num1,num2)
            if num1 == nil then num1 = 1 end
            if num2 == nil then num2 = num1 end

            if turtle.getFuelLevel() == 0 then
                while turtle.getFuelLevel() == 0 do
                    if turtle.getItemCount(num1)-1 > 0 then
                        turtle.select(num1)
                        turtle.refuel(1)
                    elseif turtle.getItemCount(num2)-1 > 0 then
                        turtle.select(num2)
                        turtle.refuel(1)
                    end

                    if turtle.getFuelLevel() == 0 then
                        term.clear()
                        term.setCursorPos(1,1)
                        if num1 ~= num2 then print("Waiting for fuel - Slot "..num1.." or "..num2.."...")
                        else print("Waiting for fuel - Slot "..num1.."...") end
                    end

                    sleep(0.05)
                end
                term.clear()
                term.setCursorPos(1,1)
            end
        end

--Main

    start()
    if quarry == "left" then go(xpos,ypos-(offset+1)) else go(xpos,ypos+offset) end
    setdir(1)


    for i=1,width-offset do
        for j=1,length do
            while turtle.detectDown() == false do down() end

            if depth > 1 then down(depth-1) end
            turtle.digDown()

            while turtle.detect() do up() end

            if j ~= length then forward() end
        end

        if i ~= width-offset then

            while turtle.detect() do up() end

            if xpos==0 then
                xstore=xpos
                ystore= ypos
                zstore=zpos

                home()
                organize(3)

                start()

                safe = true

                go(xstore,ypos)
                go(xpos,ystore)
                if zstore > zpos then up(zstore-zpos) end
                if zstore < zpos then down(zpos-zstore) end

                safe = false
            end

            if quarry == "left" then setdir(4) else setdir(2) end
            forward()
            if xpos==0 then setdir(1) else setdir(3) end
        end
    end

    home()
    organize(3)