--[[digtunnel program from Sascha
Dig a tunnel until bedrock]] 

os.loadAPI('hare')
isBedrock = false
level = 0

function comming_back(distance)
    for i = 1, distance do
        turtle.up()
    end
end

function dig_around()
    if is_bedrock() then
        print('Found Bedrock. Comming back')
        comming_back(level)
        error('Done')
    end
    turtle.dig()
    turtle.turnLeft()
    if is_bedrock() == true then
        print('Found Bedrock. Comming back')
        comming_back(level)
        error('Done')
    end
    turtle.dig()
    turtle.turnRight()
    turtle.turnRight()
    if is_bedrock() then
        print('Found Bedrock comming back')
        comming_back(level)
        error('done')
    end
    turtle.dig()
    turtle.turnLeft()
end

function is_bedrock()
    -- Check if we have Bedrock in Front
    -- or underneath of us
    local success, item = turtle.inspect()
    if success == true and item['name'] == 'minecraft:bedrock' then
        isBedrock = true
        return true
    else
        return false
    end 
    local success, item = turtle.inspectDown()
    if success == true and item['name'] == 'minecraft;bedrock' then
        isBedrock = true
    else
        return false
    end
end

while isBedrock == false do
    -- Dig one level down
    if is_bedrock() then
        print('Found Bedrock. Comming back')
        comming_back(level)
        error('Done')
    end
    turtle.digDown()
    turtle.down()
    level = level + 1
    
    -- Dig a 3x3 Tunnel
    dig_around()
    turtle.forward()
    dig_around()
    turtle.forward()
    turtle.turnLeft()
    if is_bedrock() then
        print('Found Bedrock. Comming back')
        comming_back(level)
        error('Done')
    end
    turtle.dig()
    turtle.turnRight()
    turtle.turnRight()
    if is_bedrock() then
        print('Found Bedrock. Comming back')
        comming_back(level)
        error('Done')
    end
    turtle.dig()
    turtle.turnLeft()
    
    -- place a ladder
    local success, item = turtle.inspect()
    if not success then
        hare.selectItem('minecraft:cobblestone')
        turtle.place()
    end
    turtle.back()
    hare.selectItem('minecraft:ladder')
    turtle.place()
    hare.selectEmptySlot()
    -- Go back to Start Position
    turtle.back()
end