SmartMine

print "functions: mining your inserted specifications, and detecting for fuel levels for the task"
-- Direction constants
local DIR_FORWARD = 0
local DIR_RIGHT = 1
local DIR_BACKWARD = 2
local DIR_LEFT = 3

-- Turtle's position and direction
local xPos, yPos, dir = 0, 0, DIR_FORWARD

-- Function to update the turtle's position
local function updatePosition()
    if dir == DIR_FORWARD then
        xPos = xPos + 1
    elseif dir == DIR_RIGHT then
        yPos = yPos + 1
    elseif dir == DIR_BACKWARD then
        xPos = xPos - 1
    elseif dir == DIR_LEFT then
        yPos = yPos - 1
    end
end

-- Function to mine forward and ensure a 2-block tall tunnel
local function mineForward()
    turtle.dig()
    turtle.forward()
    turtle.digUp()
    updatePosition()
end

-- Function to turn the turtle left and update direction
local function turnLeft()
    turtle.turnLeft()
    dir = (dir - 1) % 4
end

-- Function to turn the turtle right and update direction
local function turnRight()
    turtle.turnRight()
    dir = (dir + 1) % 4
end

-- Function to turn around at the end of a row
local function turnAround(isLeftTurn)
    if isLeftTurn then
        turnLeft()
        mineForward()
        turnLeft()
    else
        turnRight()
        mineForward()
        turnRight()
    end
end

-- Function to calculate fuel requirements
local function calculateFuelRequired(length, width)
    local forwardMovements = length * width
    local turnAroundMovements = (width - 1) * 2
    local returnMovements = width
    local totalMovements = forwardMovements + turnAroundMovements + returnMovements
    return totalMovements
end

-- Function to return to starting position
local function returnToStart()
    if dir == DIR_FORWARD or dir == DIR_BACKWARD then
        if xPos > 0 then
            while xPos > 0 do
                turtle.back()
                xPos = xPos - 1
            end
        else
            turnLeft()
            turnLeft()
            while xPos < 0 do
                turtle.forward()
                xPos = xPos + 1
            end
            turnLeft()
            turnLeft()
        end
    elseif dir == DIR_LEFT or dir == DIR_RIGHT then
        turnLeft()
        while xPos ~= 0 do
            turtle.forward()
            xPos = xPos + (dir == DIR_LEFT and -1 or 1)
        end
        turnRight()
    end

    if yPos > 0 then
        while yPos > 0 do
            turtle.back()
            yPos = yPos - 1
        end
    else
        turnLeft()
        turnLeft()
        while yPos < 0 do
            turtle.forward()
            yPos = yPos + 1
        end
        turnLeft()
        turnLeft()
    end

    while dir ~= DIR_FORWARD do
        turnLeft()
    end
end

-- Main strip mining function
local function stripMine(length, width)
    local isLeftTurn = true
    for w = 1, width do
        for l = 1, length do
            if turtle.getFuelLevel() <= calculateFuelRequired(length - l, width - w) + width then
                print("Low on fuel! Returning to start.")
                returnToStart()
                return
            end
            mineForward()
        end
        if w < width then
            turnAround(isLeftTurn)
            isLeftTurn = not isLeftTurn
        end
    end
    returnToStart()
end

-- Main function to initiate strip mining
local function main()
    print("Enter the length of the strip mine:")
    local length = tonumber(io.read())
    print("Enter the width of the strip mine:")
    local width = tonumber(io.read())
    local fuelRequired = calculateFuelRequired(length, width)
    if turtle.getFuelLevel() < fuelRequired then
        print("Not enough fuel to complete the task. Required: " .. fuelRequired .. ", Available: " .. turtle.getFuelLevel())
        return
    end
    stripMine(length, width)
    print("Mining complete!")
end

main()