computercraft mining

--[[
1 coal enough for a length of 19 to 96 "meters"
(it depends on the amount of liquid on the way)

Slots:
1  - diamond ore or another block that turtle must avoid
2  - filler block for making tonnels through liquids
3  - torches
4  - chests for unload mined resources
16 - coal or another fuel

Flags:
nochest, nc - program will be terminated if turtle's inventory is full.
passliquid, pl - turle will be digging in spite of liquids around.
fastmode, fm - disable a few difficult checks
--]]

-- config --
length = 40 --length of tonnel by default
faillimit = 10

-- initialisation --
local args = { ... }
arg1 = tonumber(args[1])

if args[1] ~= nil then
    if arg1 ~= nil then
        length = arg1
    elseif (args[1] == 'help') or (args[1] == '?') or (args[1] == '/?') then
        print('Usage: mine <(length_of_tonnel)> [flags]')
        print('type "mine flags" for more about flags')
        print('Slots:')
        print('1  - block that turtle shouldn\'t destroy (e.g. diamond ore)')
        print('2  - block for making tonnels through liquids (e.g. glass)')
        print('3  - torches')
        print('4  - chests for unload mined resources')
        print('16 - coal or another fuel [OPTIONAL]')
        do return end
    elseif  (args[1] == 'flags') or (args[1] == 'f') then
        print('nochest, nc - program will be terminated if turtle\'s inventory is full.')
        print('passliquid, pl - turle will be digging in spite of liquids around.')
        print('fastmode, fm - disable a few difficult checks')
        do return end
    else
        print('Usage: mine [(length_of_tonnel)] [flags]')
        print('type "mine help" for full help')
        do return end
    end
end

for a,content in ipairs(args) do
  if (content == 'nochest') or (content == 'nc') then nochest = true end
  if (content == 'passliquid') or (content == 'pl') then passliquid = true end
  if (content == 'fastmode') or (content == 'fm') then fastmode = true else fastmode = false end
end

turtle.select(16)
turtle.refuel()
print("fuel level: ", turtle.getFuelLevel())
turtle.select(1)
i = 0
failCount = 0
height = 0
torch = 0

-- code --
function placeLeft()
    turtle.turnLeft()
    local flag = turtle.place()
    turtle.turnRight()
    return flag
end

function placeRight()
    turtle.turnRight()
    local flag = turtle.place()
    turtle.turnLeft()
    return flag
end

function blockLiquid()
    if passliquid then
        print('Liquid detected! Ingoring due to "passliqid" flag...')
    else
    print('Liquid detected! Trying to fix...')
    if turtle.getItemCount(2) < 8 then
        print('Filler block running out! Refill slot 2 and restart program.')
        do return 'blockingfail' end
    end

    turtle.select(2)
    if turtle.up() then height = height + 1 end
    turtle.placeUp()
    placeLeft()
    placeRight()
    if turtle.down() then height = height - 1 end
    placeLeft()
    placeRight()
    if turtle.down() then height = height - 1 end
    placeLeft()
    placeRight()
    turtle.placeDown()
    if turtle.up() then height = height + 1 end
    turtle.select(1)

    if height ~= 0 then
        print('Wrong height!')
        do return end
    end
    end
end

while i < length do

    if not turtle.compareDown() then
        turtle.digDown()
    end

    if not turtle.compareUp() then
        if not turtle.detectUp() and turtle.digUp() then --blocking liquid
            if blockLiquid() == 'blockingfail' then
                    do return end
            end
        else -- or just digging
            turtle.digUp()
            if not fastmode then sleep(0.4) end
            for fail = 0,faillimit do
            if not turtle.detectUp() and turtle.digUp() then --blocking liquid
                if blockLiquid() == 'blockingfail' then
                    do return end
                end
                break
            end

            if not turtle.detectUp() and not turtle.digUp() then
                break
            end

            turtle.digUp()

            if fail == faillimit then
                print('Something strange above. Help me, master!')
                do return end
            end
            end
        end
    end

    if torch < 8 then --torch placing
        torch = torch + 1
    else
        turtle.turnRight()
        turtle.turnRight()
        turtle.select(3)
        turtle.place()
        turtle.select(1)
        turtle.turnRight()
        turtle.turnRight()
        torch = 0
    end

    if turtle.getItemCount(16)>0 then --unloading mined resources
        print('Invenory is full! Slot 4 must contain a chest. Trying to unloading items...')
        if nochest then
            print('Chests was denied by "nochest" flag! Clear inventory and restart program.')
            do return end
        end
        turtle.select(4)
        turtle.placeDown()
        for j = 5,16 do
            turtle.select(j)
            turtle.dropDown()
        end
        turtle.select(1)
    end

    if not turtle.compare() then
        for fail = 0,faillimit do --because it can be sand or gravel
            turtle.dig()
            if turtle.forward() then break end
            if fail == faillimit then
                print('Something strange in the front. Help me, master!')
                do return end
            end
        end
    else
        print('Block like in slot 1 detected, mine it and restart program.')
        do return end
    end

    i = i + 1
    if length == i then print(length,' blocks successfully pass!') end
end