ComputerCraft: Quarry

local iRight = 0
local iForward = 0
local iDepth = 0

local bFacingForward = true

local iTorches = 16

write("How far Forward should I go?")

local iForwardTarget = read("*")
iForwardTarget = iForwardTarget + 0;

write("How far Right should I go?")

local iRightTarget = read("*")
iRightTarget = iRightTarget + 0;

write("How far Down should I go?")

local iDepthTarget = read("*")
iDepthTarget = iDepthTarget + 0;

function returnToProcessPoint(iForward, iRight, iDepth, bFacingForward)

    print("Returning to Position")

    if iForward > 0 then
        for i = 1, iForward, 1 do
            while not turtle.forward() do
                turtle.attack()
            end
        end
    end

    if iRight > 0 then
        turtle.turnRight()
        for i = 1, iRight, 1 do
            while turtle.detect() do
                turtle.dig()
            end
            while not turtle.forward() do
                turtle.attack()
            end
        end
        turtle.turnLeft()
    end

    if iDepth > 0 then
        for i = 2, iDepth, 1 do
            turtle.digDown()
            while not turtle.down() do
                turtle.attackDown()
            end
        end
    end

end

function returnHome(iForward, iRight, iDepth, bFacingForward)

    print("Returning Home")

    if bFacingForward then
        turtle.turnRight()
        turtle.turnRight()
    end

    if iDepth > 1 then
        for i = 2, iDepth, 1 do
            while not turtle.up() do
                turtle.attackUp()
            end
        end
    end

    if iRight > 0 then
        turtle.turnRight()
        for i = 1, iRight, 1 do
            while not turtle.forward() do
                turtle.attack()
            end
        end
        turtle.turnLeft()
    end

    for i = 1, iForward, 1 do
        while turtle.detect() do
            turtle.dig()
        end
        while not turtle.forward() do
            turtle.attack()
        end
    end

end

while true do

    -- Return to where you left off
    returnToProcessPoint(iForward, iRight, iDepth, bFacingForward)

    while true do

        turtle.select(1)

        if iDepth > 0 then
            turtle.digDown()
        end

        -- Do the Digging
        for i = 2, iForwardTarget, 1 do

            if iDepth > 0 then

                -- Grab a torch in front
                while turtle.detect() do
                    turtle.select(iTorches)
                    turtle.dig()
                end

                while not turtle.forward() do
                    turtle.attack()
                end

                if bFacingForward then
                    iForward = iForward + 1
                else
                    iForward = iForward - 1
                end

                turtle.digDown()

                -- Place torch
                if iDepth > 0 and math.fmod(iForward, 4) == 1 and math.fmod(iRight, 4) == 1 then
                    turtle.select(iTorches)
                    turtle.placeDown()
                end
            else
                while turtle.detect() do
                    turtle.dig()
                end

                while not turtle.forward() do
                    turtle.attack()
                end
                if bFacingForward then
                    iForward = iForward + 1
                else
                    iForward = iForward - 1
                end

            end

        end

        if turtle.getItemCount(15) == 0 then

            iRight = iRight + 1

            if iRight == iRightTarget then
                print("You're at the most right column")
                iRight = iRight - 1
                break
            end

            if bFacingForward then
                turtle.turnRight()
                if iDepth == 0 then
                    while turtle.detect() do
                        turtle.dig()
                    end
                end

                turtle.forward()
                turtle.turnRight()

            else
                turtle.turnLeft()
                if iDepth == 0 then
                    while turtle.detect() do
                        turtle.dig()
                    end
                end

                turtle.forward()
                turtle.turnLeft()


            end

            bFacingForward = not bFacingForward;

        else

            print("Your inventory is full")
            break

        end

    end

    -- Return back
    returnHome(iForward, iRight, iDepth, bFacingForward)

    -- Empty Inventory
    for sel = 1, 15 do
        turtle.select(sel)
        turtle.drop()
    end

    -- Reset Direction
    turtle.turnRight()
    turtle.turnRight()

    iForward = 0

    iRight = iRight + 1

    bFacingForward = true

    if iRight == iRightTarget then
        iDepth = iDepth + 1
        iRight = 0
    end

    if iDepth == iDepthTarget then
        return
    end

end