names = {'minecraft:chest', 'ComputerCraft:CC-Turtle','minecraft:obsidian','minecraft:flowing_lava','minecraft:flowing_water','minecraft:lava','minecraft:water','chisel:andesite','chisel:limestone','minecraft:dirt','minecraft:stone','minecraft:granite','minecraft:diorite','minecraft:andesite','minecraft:gravel', 'minecraft:sand', 'minecraft:cobblestone'}

function is_stone(success, data)
	if success then
		for i = 1, #names do
			if names[i] == data.name then
				return ""
			end
		end
		return data.name
	end
	return ""
end

function dig_sides()
	turtle.turnLeft()
	local block_left = is_stone(turtle.inspect())
	if block_left ~= "" then
		print('found: ', block_left)
		dig_vein(1, {}, false)
		print('end of vein')
	end
	turtle.turnRight()
	turtle.turnRight()
	local block_right = is_stone(turtle.inspect())
	if block_right ~= "" then
		print('found: ', block_right)
		dig_vein(1, {}, false)
		print('end of vein')
	end
	turtle.turnLeft()
end

function dig_up_down()
	local block_up = is_stone(turtle.inspectUp())
	local block_down = is_stone(turtle.inspectDown())
	if block_up ~= "" then
		print('found: ', block_up)
		dig_vein(1, {}, false)
		print('end of vein')
	end
	if block_down ~= "" then
		print('found: ', block_down)
		dig_vein(1, {}, false)
		print('end of vein')
	end
end

function dig_shaft()
	for i = 1, 4 do
		if turtle.detect() then
			turtle.dig()
		end
		for x=0,20 do
			if not turtle.forward() then
				turtle.dig()
			else
				break
			end
		end
		if i ~= 1 then
			dig_sides()
		end
		dig_up_down()
	end
	for i = 1, 4 do
		turtle.back()
	end
end

function dig_vein(i, path, moving_back)
	if path[i] == nil then
		path[i] = {}
	end
	--check up down and forward first,
	if not moving_back then
		if #path[i] == 0 then
			local block_up = is_stone(turtle.inspectUp())
			if block_up ~= "" then
				path[i][#path[i]+1] = 0
			end
			local block_down = is_stone(turtle.inspectDown())
			if block_down ~= "" then
				path[i][#path[i]+1] = 1
			end
			for j = 1, 4 do--forward, left, back, right
				local block = is_stone(turtle.inspect())
				if block ~= "" then
					path[i][#path[i]+1] = 1 + j
				end
				turtle.turnLeft()
			end
			--print("len: " .. #path[i])
		end
		if #path[i] == 0 then--go back from the path you started
			return dig_vein(i, path, true)
		else
			local dir = path[i][1]
			--print("dir: " .. dir)
			if dir == 0 then
				turtle.digUp()
				for x=0,20 do
					if not turtle.up() then
						turtle.digUp()
					else
						break
					end
				end
			elseif dir == 1 then
				turtle.digDown()
				turtle.down()
			elseif dir == 2 then
				turtle.dig()
				for x=0,20 do
					if not turtle.forward() then
						turtle.dig()
					else
						break
					end
				end
			elseif dir == 3 then
				turtle.turnLeft()
				turtle.dig()
				for x=0,20 do
					if not turtle.forward() then
						turtle.dig()
					else
						break
					end
				end
			elseif dir == 4 then
				turtle.turnLeft()
				turtle.turnLeft()
				turtle.dig()
				for x=0,20 do
					if not turtle.forward() then
						turtle.dig()
					else
						break
					end
				end
			elseif dir == 5 then
				turtle.turnRight()
				turtle.dig()
				for x=0,20 do
					if not turtle.forward() then
						turtle.dig()
					else
						break
					end
				end
			end
			i = i + 1
			return dig_vein(i, path, false)
		end
	else--moving back
		i = i - 1
		if i == 0 then
			return 0
		elseif #path[i] > 0 then
			local dir = path[i][1]
			if dir == 0 then
				turtle.down()
			elseif dir == 1 then
				for x=0,20 do
					if not turtle.up() then
						turtle.digUp()
					else
						break
					end
				end
			elseif dir == 2 then
				turtle.back()
			elseif dir == 3 then
				turtle.back()
				turtle.turnRight()
			elseif dir == 4 then
				turtle.back()
				turtle.turnLeft()
				turtle.turnLeft()
			elseif dir == 5 then
				turtle.back()
				turtle.turnLeft()
			end
			table.remove(path[i], 1)
			if #path[i] > 0 then
				return dig_vein(i, path, false)
			else
				return dig_vein(i, path, true)
			end
		end
	end
end

function refuel(f)
	for k = 1, 16 do
		turtle.select(k)
		if turtle.refuel(f) then
			return true
		end
	end
end

function dropAll()
	for k = 1, 16 do
		turtle.select(k)
		turtle.dropDown()
	end
end

function hasSpace()
    for slot=1,16 do
        if turtle.getItemDetail(slot) == nil then
        	return true
        end
    end
    return false
end

function mine(length)
	for i=1,length do
		if i == 100 then
			break
		end
		if turtle.getFuelLevel() < (length*1.2) then
			if not refuel(2) then
				return false
			end
		end
		if not hasSpace() then
			for k = 2, i do
				turtle.back()
			end
			refuel(5)
			dropAll()
			if turtle.getFuelLevel() < (i*1.2) then
				return false
			end
			for k = 2, i do
				for x=0,20 do
					if not turtle.forward() then
						turtle.dig()
					else
						break
					end
				end
			end
		end
		if turtle.detect() then
			turtle.dig()
		end
		for x=0,20 do
			if not turtle.forward() then
				turtle.dig()
			else
				break
			end
		end
		dig_up_down()
		dig_sides()
		if turtle.detectDown() then
			turtle.digDown()
		end
		turtle.down()
		dig_sides()
		dig_up_down()
		for x=0,20 do
			if not turtle.up() then
				turtle.digUp()
			else
				break
			end
		end
	end
	turtle.turnLeft()
	turtle.turnLeft()
	for i = 2, length do
		for x=0,20 do
			if not turtle.forward() then
				turtle.dig()
			else
				break
			end
		end
		if turtle.getFuelLevel() == 0 then
			return false
		end
	end
	return true
end

if mine(100) then
	dropAll()
	print('complete!!!')
else
	print('ran out of fuel')
end