stripMiner

--goes through the turtles inventory and drops anything not included in the list.
local function purgeInventory( list )
    local goodItem = false
    for i = 1, 16 do
        goodItem = false
        local itemTbl = turtle.getItemDetail(i)
        for j = 1, #list do
            if itemTbl then
                if itemTbl.name then
                    if itemTbl.name == list[j] then
                        goodItem = true
                        break
                    end
                end
            end
        end
        if goodItem == false then
            turtle.select(i)
            turtle.drop()
        end
    end
    turtle.select(1)
end

--attempts to move forward. If fails, mines the block/s in front of and above the turtle until it can
local function mineForward(blocks)
    blocks = blocks or 1
    for i = 1, blocks do
        while not turtle.forward() do
            turtle.dig()
        end
        turtle.digUp()
    end
end

local function drawDisplay(rowNumber,length,depth)
    term.clear()
    term.setCursorPos(1,1)
    term.setTextColor(colors.yellow)
    term.write("Running: ")
    term.setTextColor(colors.lime)
    term.write("simpleStripMiner")
    term.setTextColor(colors.yellow)
    term.write(" !")

    term.setCursorPos(1,3)
    term.setTextColor(colors.orange)
    term.write("Current row: ")
    term.setTextColor(colors.cyan)
    term.write(rowNumber)
    term.setTextColor(colors.orange)
    term.write("/")
    term.setTextColor(colors.blue)
    term.write(length)

    local estimatedMined = (rowNumber)*depth*2 + (rowNumber)*6
    local maxBlocks = length*depth*2 + length*6

    term.setCursorPos(1,4)
    term.setTextColor(colors.orange)
    term.write("Estimated mined blocks:")
    term.setTextColor(colors.pink)
    term.write(estimatedMined)
    term.setTextColor(colors.orange)
    term.write("/")
    term.setTextColor(colors.magenta)
    term.write(maxBlocks)
    term.setTextColor(colors.orange)
    term.write("!")

    term.setCursorPos(1,5)
    term.setTextColor(colors.red)
    term.write("Fuel ")
    term.setTextColor(colors.orange)
    term.write("remaining: ")
    term.setTextColor(colors.gray)
    print(turtle.getFuelLevel())
    term.setTextColor(colors.brown)
    term.write("Blocks ")
    term.setTextColor(colors.orange)
    term.write("remaining: ")
    term.setTextColor(colors.gray)
    term.write(maxBlocks-estimatedMined)

    term.setCursorPos(1,8)
    term.setTextColor(colors.orange)
    term.write("* Hold 'ctr + t' to stop!")
    term.setTextColor(colors.red)
    term.setCursorPos(9,8)
    term.write("ctr + t")
    term.setTextColor(colors.orange)
    term.setCursorPos(13,8)
    term.write("+")

    term.setCursorPos(1,9)
    print("* Use the 'refuel' command after stopping the program to refuel the turtle!")
    term.setTextColor(colors.red)
    term.setCursorPos(12,9)
    term.write("refuel")
    term.setTextColor(colors.yellow)
    term.setCursorPos(28,9)
    term.write("after")

    term.setTextColor(colors.white)
end

local function run(length,depth,dir)
    local whitelist = {
        "minecraft:diamond",
        "minecraft:emerald",
        "minecraft:raw_gold",
        "minecraft:raw_iron",
        "minecraft:raw_copper",
        "minecraft:coal",
        "minecraft:lapis_lazuli",
        "minecraft:quartz",
        "minecraft:ancient_debris"
    }

    local turn1 = turtle.turnLeft
    local turn2 = turtle.turnRight

    if dir == 0 then
        dir = "right"
    else
        dir = "left"
    end

    if dir == "right" then
        turn1 = turtle.turnRight
        turn2 = turtle.turnLeft
    end

    local blocksSinceLastPurge = 0

    drawDisplay(0,length,depth)

    for x = 1, length do
        mineForward(depth)

        if x%2 ~= 0 then
            turn1()
            mineForward(3)
            turn1()
        else
            turn2()
            mineForward(3)
            turn2()
        end

        drawDisplay(x,length,depth)
        blocksSinceLastPurge = blocksSinceLastPurge + depth*2

        if blocksSinceLastPurge > 500 then
            purgeInventory(whitelist)
            blocksSinceLastPurge = 0
        end
    end
end

return {
    run = run
}