Strip Mine

local m = require( "blib" )
local torch = "minecraft:torch"
local chest = "minecraft:chest"

local Length
local Width

local fuelMin = 25

local reqTorches

local function ends_with(str, ending)
    if(str == nil) then
        return false
    end

    return ending == "" or str:sub(-#ending) == ending -- colon operator and string doc - https://docs.coronalabs.com/api/library/string/sub.html
 end

 function Shutdown(message)
    print(message)
    print("Powering down...")
    return 1 -- By C convention 0 is success, 1 is failure
end

function IsOre(OreName)
    local returnVal = ends_with(OreName, "ore")
    if(OreName == "minecraft:diamond_ore") then
        returnVal = false
    end
    return(returnVal)
end

function MineIfOre(direction)
    local success, inspection
    if(direction == "up") then
        success, inspection = turtle.inspectUp()
        if(IsOre(inspection.name)) then
            turtle.digUp()
        end
        return
    elseif(direction == "down") then
        success, inspection = turtle.inspectDown()
        if(IsOre(inspection.name) or inspection.name == "minecraft:lava") then
            turtle.digDown()
            if(m.SelectItem("minecraft:cobblestone") == true) then
                turtle.placeDown()
            end
        end
        return
    elseif(direction == "forward") then
        success, inspection = turtle.inspect()
    else
        success, inspection = turtle.inspect()
    end

    if(IsOre(inspection.name)) then
        turtle.dig()
    end
end


function InspectLR()
    m.CheckFuel(fuelMin)
    turtle.turnLeft()
    MineIfOre()
    turtle.turnRight()
    turtle.turnRight()
    MineIfOre()
    turtle.turnLeft()
end

function DigSequence()
    m.CheckFuel(fuelMin)
    m.DetectAndDig()
    turtle.forward()
    MineIfOre("down")
    InspectLR()
    turtle.digUp()
    turtle.up()
    MineIfOre("up")
    InspectLR()
    turtle.down()
end

function FirstLap()
    local trueWidth = (Width - 1)*2 + Width

    for y = 1, Length do
        m.CheckFuel(fuelMin)
        m.DetectAndDig()
        turtle.forward()
        turtle.digUp()
    end
    turtle.turnRight()
    for x = 1, trueWidth - 1 do
        m.CheckFuel(fuelMin)
        m.DetectAndDig()
        turtle.forward()
        turtle.digUp()
    end
    turtle.turnRight()
    for y = 1, Length - 1 do
        m.CheckFuel(fuelMin)
        m.DetectAndDig()
        turtle.forward()
        turtle.digUp()
    end
    turtle.turnRight()
    for x = 1, trueWidth - 1 do
        m.CheckFuel(fuelMin)
        m.DetectAndDig()
        turtle.forward()
        turtle.digUp()
    end
    turtle.turnRight()
end

function Start()

    FirstLap()

    m.CheckFuel(fuelMin)
    InspectLR()
    turtle.digUp()
    turtle.up()
    InspectLR()
    turtle.down()

    local torchL = 6

    for x = 1, Width do                         -- starting length cuts one turn off, but not one column off. see below


        for y = 1, Length - 1 do                -- width cuts one length down off the next

            -- check for fuel
             if(not m.CheckFuel(fuelMin)) then
                return Shutdown("Out of Fuel!")
            end

            -- check if inventory is full
            if(m.InventoryFull() == true) then
                if(m.DumpItemsChest() == false) then
                    return Shutdown("Out of chests!")
                end
            end

            -- check for torch placement
            torchL = torchL + 1                         -- increment torchPlacementLength

            if(reqTorches == true) then
                if(torchL >= 6) then    -- if its been 6 blocks wide and traveled 8 blocks down, place a torch
                    if(not m.PlaceTorch("left")) then
                        return Shutdown("Out of torches!")
                    end
                    torchL = 0
                end
            end

            -- Actual Mining Sequence
            DigSequence()

        end

        if( Width - x ~= 0) then -- Technically on the last column, we continue forward, but don't turn into the next column
            m.CheckFuel(fuelMin)
            if(math.fmod(x, 2) == 0) then -- if we're on an even column, turn left (LUA STARTS WITH 1 weird i know)
                turtle.turnLeft()
                DigSequence()
                DigSequence()
                DigSequence()
                turtle.turnLeft()

            else -- odd columns (start is 1 btw) turn right!
                turtle.turnRight()
                DigSequence()
                DigSequence()
                DigSequence()
                turtle.turnRight()
            end
        end

    end

end

function Main()
    local response
    print("Welcome to the Strip Mining Program")
    print("Strip Mining will mine hallways 2 blocks apart, and try its best to mine out all surrounding ore")
    print("")
    print("Do you want to require torches?")
    print("(y for yes, n for no)")
    response = read()
    if(response == "y") then
        reqTorches = true
    else
        reqTorches = false
    end

     --------------- check if has items --------------------------
     if(m.GetItemIndex(torch) == nil and reqTorches == true)then
        print("You don't have any torches!")
        return
    elseif( m.GetItemIndex(chest) == nil) then
        print("You don't have any chests!")
        return
    end

    ----------------- check if has fuel ---------------------------
    if(not m.CheckFuel(10))then
        print("You don't have fuel!")
        return
    end

    --------------- Gets Y Input from user ------------------------
    print("Length?")
    Length = tonumber(io.read())
    while Length == nil do
        print("oops! enter a number!")
        Length = tonumber(io.read())
    end

    ---------------- Gets X Input from user ---------------------
    print("")
    print("Width?")
    Width = tonumber(io.read())
    while Width == nil do
        print("oops! enter a number!")
        Width = tonumber(io.read())
    end

    print("Strip Mining Started ... ")
    Start()
    print("finished!")

end
Main()