platform

--[[
Creates a platform based on length and width given by the player. Also clears a 2 block high space above the platform,
in case there are any blocks there to impede the player's path.

Instructions:
- place blocks in turtle's inventory, starting from the first slot
- the turtle will move in a snake pattern, from left to right (looking from behind)
- if sand/gravel is used, the turtle will keep placing blocks down until the hole is full
]]--

-- The turtle must snake right and left as it makes the platform
rightturn = true
turncounter = 0

-- Ask user to enter width and length of the platform
write("Enter width: ")
local platform_width = tonumber(read())
write("Enter length: ")
local platform_length = tonumber(read())
platform_total = platform_width * platform_length

-- Check that the turtle has enough blocks to make the platform
block_count = 0
for slotnum = 1,16 do
    block_count = block_count + turtle.getItemCount(slotnum)
end
if block_count < platform_total then
    print("Blocks required: ",platform_total)
    print("Blocks in inventory: ",block_count)
    print("The turtle does not have enough blocks to build the platform requested. Stopping program now.")
    return
end

slotnum = 1

for a=1,platform_total do

    turtle.dig()
    turtle.forward()
    turtle.digUp()
    turtle.digDown()
    turtle.select(slotnum)
    turtle.placeDown()
    -- Check to see if there are any blocks in the selected slot
    if turtle.getItemCount(slotnum) == 0 then
        repeat
            slotnum = slotnum + 1
        until turtle.getItemCount(slotnum) ~= 0
    end
        --[[ Check to see if block placed has fallen (ie gravel/sand) and if yes place another block ]]--
        while turtle.detectDown() == false do
            turtle.select(slotnum)
            turtle.placeDown()
            -- Check to see if there are any blocks in the selected slot
                if turtle.getItemCount(slotnum) == 0 then
                    repeat
                        slotnum = slotnum + 1
                    until turtle.getItemCount(slotnum) ~= 0
                end
        end

    turncounter = turncounter + 1
    print(turncounter,platform_length)

--[[ First turn ]]--
    if turncounter == platform_length then
        print("First turn")
        if rightturn == true then turtle.turnRight() else turtle.turnLeft() end
    end

--[[ Second turn ]]--
    if turncounter == platform_length+1 then
        print("Second turn")
        if rightturn == true then turtle.turnRight() else turtle.turnLeft() end
        -- Reverse the snake!
        if rightturn == true then rightturn = false else rightturn = true end
        turncounter = 1
    end
end

-- Return to starting position
for a = 1,platform_width-1 do
    turtle.back()
end
turtle.turnLeft()
if (platform_width % 2 == 0) then
    turtle.back()
else
    for a = 1,platform_length do
        turtle.back()
    end
end