--[[

	TechAge
	=======

	Copyright (C) 2019 Joachim Stolberg

	GPL v3
	See LICENSE.txt for more information
	
	TA4 Pipe Inlet

]]--

-- for lazy programmers
local P2S = function(pos) if pos then return minetest.pos_to_string(pos) end end
local S2P = minetest.string_to_pos
local D = techage.Debug
local M = minetest.get_meta
local S = techage.S

local Pipe = techage.LiquidPipe

minetest.register_node("techage:ta4_pipe_inlet", {
	description = S("TA4 Pipe Inlet"),
	tiles = {
		-- up, down, right, left, back, front
		"basic_materials_concrete_block.png",
		"basic_materials_concrete_block.png",
		"basic_materials_concrete_block.png",
		"basic_materials_concrete_block.png",
		"basic_materials_concrete_block.png^techage_tes_inlet.png",
		"basic_materials_concrete_block.png^techage_tes_inlet.png",
	},
	
	paramtype2 = "facedir", -- important!
	on_rotate = screwdriver.disallow, -- important!
	groups = {crumbly = 2, cracky = 2, snappy = 2},
	is_ground_content = false,
	sounds = default.node_sound_metal_defaults(),
})

-- for mechanical pipe connections
techage.power.register_node({"techage:ta4_pipe_inlet"}, {
	conn_sides = {"F", "B"},
	power_network  = Pipe,
})

local Numbers = {
	shell = {
		[2] = 96,  -- 5x5x2 + 3x5x2 + 3x3x2 - 2
		[3] = 216, -- 7x7x2 + 5x7x2 + 5x5x2 - 2
		[4] = 384, -- 9x9x2 + 7x9x2 + 7x7x2 - 2
	},
	filling = {
		[2] = 27,  -- 3x3x3
		[3] = 125, -- 5x5x5
		[4] = 343, -- 7x7x7
	}
}

local function chat(owner, text)
	if owner ~= nil then
		minetest.chat_send_player(owner, string.char(0x1b).."(c@#ff0000)".."[Techage] Error: "..text.."!")
	end
end

local function get_radius(pos, in_dir)
	local dir = tubelib2.Dir6dToVector[in_dir]
	local pos2 = vector.add(pos, vector.multiply(dir, 8))
	local poses = minetest.find_nodes_in_area(pos, pos2, {"techage:ta4_pipe_inlet"})
	if #poses == 2 then
		local radius = vector.distance(poses[1], poses[2]) / 2
		if radius == 2 or radius == 3 or radius == 4 then
			return radius
		end
	end
	return 1
end

local function check_volume(pos, in_dir, owner)
	local radius = get_radius(pos, in_dir)
	if radius then
		local dir = tubelib2.Dir6dToVector[in_dir]
		local cpos = vector.add(pos, vector.multiply(dir, radius))
		-- calculate size
		local pos1 = {x = cpos.x - radius, y = cpos.y - radius, z = cpos.z - radius}
		local pos2 = {x = cpos.x + radius, y = cpos.y + radius, z = cpos.z + radius}
		local _, node_tbl = minetest.find_nodes_in_area(pos1, pos2, 
				{"default:gravel", "techage:ta4_pipe_inlet", 
				"basic_materials:concrete_block", "default:obsidian_glass",
				"techage:glow_gravel"})
		if node_tbl["default:obsidian_glass"] > 1 then 
			chat(owner, "one window maximum")
			return false
		elseif node_tbl["default:obsidian_glass"] + node_tbl["basic_materials:concrete_block"] ~= Numbers.shell[radius] then
			chat(owner, "wrong number of shell nodes")
			return false
		elseif node_tbl["default:gravel"] + node_tbl["techage:glow_gravel"] ~= Numbers.filling[radius] then
			chat(owner, "wrong number of gravel nodes")
			return false
		end
	else
		chat(owner, "wrong diameter (should be 5, 7, or 9)")
		return false
	end
	return true
end

-- provide position behind the obsidian_glass
local function check_window(pos, in_dir)
	local radius = get_radius(pos, in_dir)
	if radius then
		local dir = tubelib2.Dir6dToVector[in_dir]
		local cpos = vector.add(pos, vector.multiply(dir, radius))
		-- calculate size
		local pos1 = {x = cpos.x - radius, y = cpos.y - radius, z = cpos.z - radius}
		local pos2 = {x = cpos.x + radius, y = cpos.y + radius, z = cpos.z + radius}
		local poses,_ = minetest.find_nodes_in_area(pos1, pos2, {"default:obsidian_glass"})
		if #poses == 1 then
			local ndir = vector.direction(poses[1], cpos)
			ndir = vector.normalize(ndir)
			local npos = vector.add(poses[1], ndir)
			return npos
		end
	end
end

-- for logical communication
techage.register_node({"techage:ta4_pipe_inlet"}, {
	on_transfer = function(pos, in_dir, topic, payload)
		if topic == "diameter" then
			return get_radius(pos, in_dir) * 2 - 1
		elseif topic == "volume" then
			return check_volume(pos, in_dir, payload)
		elseif topic == "window" then
			return check_window(pos, in_dir)
		end
		return false
	end
})

minetest.register_craft({
	type = 'shapeless',
	output = "techage:ta4_pipe_inlet",
	recipe = {"basic_materials:concrete_block", "techage:ta4_pipeS"},
})