--license LGPLv2+

local r_corr = 0.25 --remove a bit more nodes (if shooting diagonal) to let it look like a hole (sth like antialiasing)
local mk1_charge = 40000

local mining_lasers_list = {
--	{<num>, <range of the laser shots>, <max_charge>},
	{"1", 7, mk1_charge},
	{"2", 11, mk1_charge*4},
	{"3", 30, mk1_charge*16},
}

local f_1 = 0.5-r_corr
local f_2 = 0.5+r_corr

-- Taken from the Flowers mod by erlehmann.
local function table_contains(t, v)
	for _,i in ipairs(t) do
		if i == v then
			return true
		end
	end
	return false
end

local function get_used_dir(dir)
	local abs_dir = {x=math.abs(dir.x), y=math.abs(dir.y), z=math.abs(dir.z)}
	local dir_max = math.max(abs_dir.x, abs_dir.y, abs_dir.z)
	if dir_max == abs_dir.x then
		local tab = {"x", {x=1, y=dir.y/dir.x, z=dir.z/dir.x}}
		if dir.x >= 0 then
			tab[3] = "+"
		end
		return tab
	end
	if dir_max == abs_dir.y then
		local tab = {"y", {x=dir.x/dir.y, y=1, z=dir.z/dir.y}}
		if dir.y >= 0 then
			tab[3] = "+"
		end
		return tab
	end
	local tab = {"z", {x=dir.x/dir.z, y=dir.y/dir.z, z=1}}
	if dir.z >= 0 then
		tab[3] = "+"
	end
	return tab
end

local function node_tab(z, d)
	local n1 = math.floor(z*d+f_1)
	local n2 = math.floor(z*d+f_2)
	if n1 == n2 then
		return {n1}
	end
	return {n1, n2}
end

local function laser_node(pos, player)	
	local node = minetest.get_node(pos)
	if table_contains({"air", "ignore", "default:lava_source", "default:lava_flowing"}, node.name) then
		return
	end
	if table_contains({"default:water_source", "default:water_flowing"}, node.name) then
		minetest.remove_node(pos)
		if math.random(300) == 1 then
			minetest.add_particle(pos, {x=0, y=0, z=0}, {x=0, y=0, z=0}, 0.5, 8, false, "smoke_puff.png")
		end
		return
	end
	if player then
		minetest.node_dig(pos, node, player)
	end
end

local function laser_nodes(pos, dir, player, range)
	local t_dir = get_used_dir(dir)
	local dir_typ = t_dir[1]
	if t_dir[3] == "+" then
		f_tab = {0, range}
	else
		f_tab = {-range,0}
	end
	local d_ch = t_dir[2]
	if dir_typ == "x" then
		for d = f_tab[1],f_tab[2],1 do
			local x = d
			local ytab = node_tab(d_ch.y, d)
			local ztab = node_tab(d_ch.z, d)
			for _,y in ipairs(ytab) do
				for _,z in ipairs(ztab) do
					laser_node({x=pos.x+x, y=pos.y+y, z=pos.z+z}, player)
				end
			end
		end
		return
	end
	if dir_typ == "y" then
		for d = f_tab[1],f_tab[2],1 do
			local xtab = node_tab(d_ch.x, d)
			local y = d
			local ztab = node_tab(d_ch.z, d)
			for _,x in ipairs(xtab) do
				for _,z in ipairs(ztab) do
					laser_node({x=pos.x+x, y=pos.y+y, z=pos.z+z}, player)
				end
			end
		end
		return
	end
	for d = f_tab[1],f_tab[2],1 do
		local xtab = node_tab(d_ch.x, d)
		local ytab = node_tab(d_ch.y, d)
		local z = d
		for _,x in ipairs(xtab) do
			for _,y in ipairs(ytab) do
				laser_node({x=pos.x+x, y=pos.y+y, z=pos.z+z}, player)
			end
		end
	end
end

local function laser_shoot(player, range, particle_texture, sound)
	local t1 = os.clock()

	local playerpos=player:getpos()
	local dir=player:get_look_dir()

	local startpos = {x=playerpos.x, y=playerpos.y+1.6, z=playerpos.z}
	local a = {x=dir.x*50, y=dir.y*50, z=dir.z*50}
	local delay = (math.sqrt(1+100*(range+0.4))-1)/50
	minetest.add_particle(startpos, dir, a, delay, 1, false, particle_texture)
	laser_nodes(vector.round(startpos), dir, player, range)
	minetest.sound_play(sound, {pos = playerpos, gain = 1.0, max_hear_distance = range})

	print("[technic] <mining_laser> my shot was calculated after "..tostring(os.clock()-t1).."s")
	return true --Why?
end


for _,m in ipairs(mining_lasers_list) do
	minetest.register_tool("extrablocks:laser_mk"..m[1], {
		description = "Mining Laser MK"..m[1],
		inventory_image = "technic_mining_laser_mk"..m[1]..".png",
		stack_max = 1,
		on_use = function(itemstack, user)
			laser_shoot(user, m[2], "technic_laser_beam_mk"..m[1]..".png", "technic_laser_mk"..m[1])
		end,
	})
end