local startpos = vector.new(0, 0, 0)
local toDig = 66
local width = 31
local length = 31
local refuelLevel = 5000
local sleepTime = 0.5
local currentpos = vector.new(0, 0, 0)
local fuelName = "minecraft:coal"
local direction = 0
local success = false
local startDepth = 35
local resume_x = 0
local resume_z = 0
local resume_y = 0
local resume_direction = 0
local turn = 0
local breakTime = false

function debugPos()
print("x: "..currentpos.x);
print("y: "..currentpos.y);
print("z: "..currentpos.z);
end

function face(fDir)
	while(direction ~= fDir) do
		turtle.turnRight()
		sleep(sleepTime)
		direction = direction + 1
		if(direction > 3) then
            direction = direction - 4
        elseif(direction < 0) then
            direction = direction + 4
        end
	end
end

function isEmpty()
    local i = 1
    i = 1
    while(i <= 16) do
        if(turtle.getItemCount(i) == 0) then
            return true
        end
    end
    if(i >= 16) then
        return false
    end
end

function mRefuel(f_x)
	local i = 1
    while(turtle.getFuelLevel() < f_x) do
		face(3)
		turtle.suck(64)
		while(i < 17) do
			turtle.select(i)
			turtle.refuel()
			i = i + 1
		end
		turtle.select(1)
		i = 1
		print("Refuel Loop End")
    end
	face(0)
	print("Refueled")
end

function checkCoal()
    if(turtle.getItemDetail(1).name == fuelName) then
        return turtle.getItemDetail(1).count
    else
        return 0
    end
end

function updatePos()
    if(direction == 0) then
        currentpos.z = currentpos.z + 1
    elseif(direction == 1) then
        currentpos.x = currentpos.x + 1
    elseif(direction == 2) then
        currentpos.z = currentpos.z - 1
    elseif(direction == 3) then
        currentpos.x = currentpos.x - 1
    end
end

function goHome()
    local home = false
	resume_x = currentpos.x
	resume_z = currentpos.z
	resume_direction = direction
    while(not home) do
        if(currentpos.x == 0 and currentpos.y == 0 and currentpos.z == 0) then
            home = true
            break
        end

        while(currentpos.x ~= 0) do
            if(currentpos.x > 0) then
                if(direction ~= 3) then
                    turtle.turnLeft()
                    direction = direction - 1
                    sleep(sleepTime)
                    if(direction > 3) then
                        direction = direction - 4
                    elseif(direction < 0) then
                        direction = direction + 4
                    end
                end

                if(direction == 3) then
                    while(success == false) do
                        success = turtle.forward()
                    end
                    success = false
                    updatePos()
                    sleep(sleepTime)
                end

            elseif(currentpos.x < 0) then
                if(direction ~= 1) then
                    turtle.turnLeft()
                    direction = direction - 1
                    sleep(sleepTime)
                    if(direction > 3) then
                        direction = direction - 4
                    elseif(direction < 0) then
                        direction = direction + 4
                    end
                end

                if(direction == 1) then
                    while(success == false) do
                        success = turtle.forward()
                    end
                    success = false
                    updatePos()
                    sleep(sleepTime)
                end
            end
        end
       print("x is 0")
        while(currentpos.z ~= 0) do
            if(currentpos.z > 0) then
                if(direction ~= 2) then
                    turtle.turnLeft()
                    direction = direction - 1
                    sleep(sleepTime)
                    if(direction > 3) then
                        direction = direction - 4
                    elseif(direction < 0) then
                        direction = direction + 4
                    end
                end

                if(direction == 2) then
                    while(success == false) do
                        success = turtle.forward()
                    end
                    success = false
                    updatePos()
                    sleep(sleepTime)
                end

            elseif(currentpos.z < 0) then
                if(direction ~= 0) then
                    turtle.turnLeft()
                    direction = direction - 1
                    sleep(sleepTime)
                    if(direction > 3) then
                        direction = direction - 4
                    elseif(direction < 0) then
                        direction = direction + 4
                    end
                end

                if(direction == 0) then
                    while(success == false) do
                        success = turtle.forward()
                    end
                    success = false
                    updatePos()
                    sleep(sleepTime)
                end
            end
        end
		print("z is 0")
		home = true
		while(direction ~= 0) do
			turtle.turnLeft()
			sleep(sleepTime)
			direction = direction - 1
			if(direction > 3) then
                direction = direction - 4
            elseif(direction < 0) then
                direction = direction + 4
            end
		end
    end
	face(0)
end

function yHome()
	resume_y = currentpos.y
	while(currentpos.y ~= 0) do
		if(currentpos.y > 0) then
            while(success == false) do
                success = turtle.up()
				sleep(sleepTime)
            end
			success = false
			currentpos.y = currentpos.y - 1
		end
		if(currentpos.y < 0) then
            while(success == false) do
                success = turtle.down()
				sleep(sleepTime)
            end
			success = false
			currentpos.y = currentpos.y + 1
		end
	end
	print("I am home")
end

function resume()
	while(currentpos.y < resume_y) do
		success = turtle.down()
		if(success) then
			currentpos.y = currentpos.y + 1
		end
		success = false
		sleep(sleepTime)
		if(currentpos.y >= resume_y) then
			currentpos.y = resume_y
		end
	end

	while(currentpos.x < resume_x) do
		face(1)
		success = turtle.forward()
		if(success) then
			currentpos.x = currentpos.x + 1
		end
		success = false
		sleep(sleepTime)
		if(currentpos.x >= resume_x) then
			currentpos.x = resume_x
		end
	end

	while(currentpos.z < resume_z) do
		face(0)
		success = turtle.forward()
		if(success) then
			currentpos.z = currentpos.z + 1
		end
		success = false
		sleep(sleepTime)
		if(currentpos.z >= resume_z) then
			currentpos.z = resume_z
		end
	end
	face(resume_direction)
end

function Forward()
	success = turtle.forward()
	sleep(sleepTime)
	while(not success) do
		turtle.dig()
		sleep(sleepTime)
		success = turtle.forward()
		sleep(sleepTime)
	end
	success = false
end
function Down()
	success = turtle.down()
	sleep(sleepTime)
	while(not success) do
		turtle.digDown()
		sleep(sleepTime)
		success = turtle.down()
		sleep(sleepTime)
	end
	success = false
end
function TurnRight()
	turtle.turnRight()
	sleep(sleepTime)
	direction = direction + 1
	if(direction > 3) then
        direction = direction - 4
    elseif(direction < 0) then
        direction = direction + 4
    end
end
function TurnLeft()
	turtle.turnLeft()
	sleep(sleepTime)
	direction = direction - 1
	if(direction > 3) then
        direction = direction - 4
    elseif(direction < 0) then
        direction = direction + 4
    end
end
function MineCurrentLayer()
	breakTime = false
	turn = 0
	while(currentpos.x < width) do
		if(turn == 0) then
			while(currentpos.z < length - 1) do
				turtle.digDown()
				Forward()
				updatePos()
			end
		elseif(turn == 1)then
			while(currentpos.z > 0) do
				turtle.digDown()
				Forward()
				updatePos()
			end
		end
		turtle.digDown()
		sleep(sleepTime)

		--Break Time
		dropCobble()
		breakTime = isEmpty()
		if(turtle.getFuelLevel() < (refuelLevel/2) or (not breakTime))then
			goHome()
			yHome()
			face(2)
			dropAll()
			face(0)
			mRefuel(refuelLevel)
			resume()
		end
		--Break Time End

		--Turn Corner to next strip
		if(turn == 0) then
			TurnRight()
		elseif(turn == 1) then
			TurnLeft()
		end
		if(currentpos.x == width - 1) then
			break
		end
		if(currentpos.x < width - 1) then
			Forward()
			updatePos()
		end
		turtle.digDown()
		sleep(sleepTime)
		if(turn == 0) then
			TurnRight()
		elseif(turn == 1) then
			TurnLeft()
		end
		if(turn == 0) then
			turn = 1
		elseif(turn == 1) then
			turn = 0
		end
		--End of turning corner
	end
end
function dropCobble()
	local i = 1
	while(i < 17) do
		turtle.select(i)
		if(turtle.getItemCount() > 0)then
			if(turtle.getItemDetail().name == "minecraft:cobblestone") then
				turtle.drop()
			end
		end
		if(turtle.getItemCount() > 0)then
			if(turtle.getItemDetail().name == "minecraft:dirt") then
				turtle.drop()
			end
		end
		if(turtle.getItemCount() > 0)then
			if(turtle.getItemDetail().name == "minecraft:gravel") then
				turtle.drop()
			end
		end
		i = i + 1
	end
	turtle.select(1)
end
function dropAll()
	local i = 1
	while(i < 17) do
		turtle.select(i)
		turtle.drop()
		i = i + 1
	end
end

function GoDepth()
	while(currentpos.y < startDepth) do
		Down()
		currentpos.y = currentpos.y + 1
		print("Down")
	end
	print("I am there")
end

function startMine()
	print("Start mining operation")
	while(currentpos.y < toDig) do
		MineCurrentLayer()
		goHome()
		Down()
		currentpos.y = currentpos.y + 1
		sleep(sleepTime)
	end
end

mRefuel(refuelLevel)
GoDepth(startDepth)
startMine()
goHome()
yHome()
face(2)
dropAll()
debugPos()
sleep(5)
goHome()