-- advschem/init.lua

advschem = {}

local path       = minetest.get_worldpath().."/advschem.mt"
local contexts   = {}
local marked     = {}
advschem.markers = {}

---
--- Formspec API
---

local contexts = {}
local tabs = {}
local forms = {}

-- [function] Add form
function advschem.add_form(name, def)
	def.name = name
	forms[name] = def

	if def.tab then
		tabs[#tabs + 1] = name
	end
end

-- [function] Generate tabs
function advschem.generate_tabs(current)
	local retval = "tabheader[0,0;tabs;"
	for _, t in pairs(tabs) do
		local f = forms[t]
		if f.tab ~= false and f.caption then
			retval = retval..f.caption..","

			if type(current) ~= "number" and current == f.name then
				current = _
			end
		end
	end
	retval = retval:sub(1, -2) -- Strip last comma
	retval = retval..";"..current.."]" -- Close tabheader
	return retval
end

-- [function] Handle tabs
function advschem.handle_tabs(pos, name, fields)
	local tab = tonumber(fields.tabs)
	if tab and tabs[tab] and forms[tabs[tab]] then
		advschem.show_formspec(pos, name, forms[tabs[tab]].name)
		return true
	end
end

-- [function] Show formspec
function advschem.show_formspec(pos, player, tab, show, ...)
	if forms[tab] then
		if type(player) == "string" then
			player = minetest.get_player_by_name(player)
		end
		local name = player:get_player_name()

		if show ~= false then
			local form = forms[tab].get(pos, name, ...)
			if forms[tab].tab then
				form = form..advschem.generate_tabs(tab)
			end

			minetest.show_formspec(name, "advschem:"..tab, form)
			contexts[name] = pos

			-- Update player attribute
			if forms[tab].cache_name ~= false then
				player:set_attribute("advschem:tab", tab)
			end
		else
			minetest.close_formspec(pname, "advschem:"..tab)
		end
	end
end

-- [event] On receive fields
minetest.register_on_player_receive_fields(function(player, formname, fields)
	local formname = formname:split(":")

	if formname[1] == "advschem" and forms[formname[2]] then
		local handle = forms[formname[2]].handle
		local name = player:get_player_name()
		if contexts[name] then
			if not advschem.handle_tabs(contexts[name], name, fields) and handle then
				handle(contexts[name], name, fields)
			end
		end
	end
end)

---
--- Formspec Tabs
---

advschem.add_form("main", {
	tab = true,
	caption = "Main",
	get = function(pos, name)
		local meta = minetest.get_meta(pos):to_table().fields
		local strpos = minetest.pos_to_string(pos)

		local border_button
		if meta.schem_border == "true" and advschem.markers[strpos] then
			border_button = "button[3.5,7.5;3,1;border;Hide Border]"
		else
			border_button = "button[3.5,7.5;3,1;border;Show Border]"
		end

		-- TODO: Show information regarding volume, pos1, pos2, etc... in formspec
		return [[
			size[7,8]
			label[0.5,-0.1;Position: ]]..strpos..[[]
			label[3,-0.1;Owner: ]]..name..[[]

			field[0.8,1;5,1;name;Schematic Name:;]]..(meta.schem_name or "")..[[]
			button[5.3,0.69;1.2,1;save_name;Save]
			tooltip[save_name;Save schematic name]
			field_close_on_enter[name;false]

			button[0.5,1.5;6,1;export;Export Schematic]
			label[0.5,2.2;Schematic will be exported as a .mts file and stored in]
			label[0.5,2.45;<minetest dir>/worlds/<worldname>/schems/<name>.mts]

			field[0.8,7;2,1;x;X-Size:;]]..meta.x_size..[[]
			field[2.8,7;2,1;y;Y-Size:;]]..meta.y_size..[[]
			field[4.8,7;2,1;z;Z-Size:;]]..meta.z_size..[[]
			field_close_on_enter[x;false]
			field_close_on_enter[y;false]
			field_close_on_enter[z;false]

			button[0.5,7.5;3,1;save;Save Size]
		]]..
		border_button
	end,
	handle = function(pos, name, fields)
		local realmeta = minetest.get_meta(pos)
		local meta = realmeta:to_table().fields
		local strpos = minetest.pos_to_string(pos)

		-- Toggle border
		if fields.border then
			if meta.schem_border == "true" and advschem.markers[strpos] then
				advschem.unmark(pos)
				meta.schem_border = "false"
			else
				advschem.mark(pos)
				meta.schem_border = "true"
			end
		end

		local update_positions = false
		-- Save size vector values
		if (fields.save or fields.key_enter_field == "x" or
				fields.key_enter_field == "y" or fields.key_enter_field == "z")
				and (fields.x and fields.y and fields.z and fields.x ~= ""
				and fields.y ~= "" and fields.z ~= "") then
			local x, y, z = tonumber(fields.x), tonumber(fields.y), tonumber(fields.z)

			if x then
				meta.x_size = math.max(x, 1)
			end
			if y then
				meta.y_size = math.max(y, 1)
			end
			if z then
				meta.z_size = math.max(z, 1)
			end

			-- Set positions to be updated
			update_positions = true
		end

		-- Save schematic name
		if fields.save_name or fields.key_enter_field == "name" and fields.name and
				fields.name ~= "" then
			meta.schem_name = fields.name
		end

		-- Export schematic
		if fields.export and meta.schem_name and meta.schem_name ~= "" then
			local pos1, pos2 = advschem.size(pos)
			local path = minetest.get_worldpath().."/schems/"
			minetest.mkdir(path)

			local plist = minetest.deserialize(meta.prob_list)
			local probability_list = {}
			for _, i in pairs(plist) do
				probability_list[#probability_list + 1] = {
					pos = minetest.string_to_pos(_),
					prob = i.prob,
				}
			end

			local filepath = path..meta.schem_name..".mts"
			local res = minetest.create_schematic(pos1, pos2, probability_list, filepath, {})

			if res then
				minetest.chat_send_player(name, minetest.colorize("#00ff00",
						"Exported schematic to "..filepath))
			else
				minetest.chat_send_player(name, minetest.colorize("red",
						"Failed to export schematic to "..filepath))
			end
		end

		-- Save meta before updating visuals
		local inv = realmeta:get_inventory():get_lists()
		realmeta:from_table({fields = meta, inventory = inv})

		-- Update border
		if not fields.border and meta.schem_border == "true" then
			advschem.mark(pos)
		end

		-- Update formspec
		if not fields.quit then
			advschem.show_formspec(pos, minetest.get_player_by_name(name), "main")
		end

		-- Update pos1 and pos2 in marked table (for interaction checking)
		if update_positions then
			local pos1, pos2 = advschem.size(pos)
			pos1, pos2 = advschem.sort_pos(pos1, pos2)
			marked[minetest.pos_to_string(pos)] = {
				pos1 = pos1,
				pos2 = pos2,
			}
		end
	end,
})

advschem.add_form("prob", {
	tab = true,
	caption = "Probability",
	get = function(pos, name)
		local meta = minetest.get_meta(pos)
		local inventory = meta:get_inventory()
		local stack = inventory:get_stack("probability", 1)
		local stringpos = pos.x..","..pos.y..","..pos.z

		local probchange = ""
		if stack:get_name() ~= "" then
			local smeta = stack:get_meta():to_table().fields

			probchange = [[
				field[1.3,0.4;2,1;probability;Probability:;]]..(smeta.advschem_prob or "255")..[[]
				field_close_on_enter[probability;false]
				checkbox[3.1,0.1;force_place;Force Place;]]..(smeta.advschem_force_place or "false")..[[]
				button[5,0.1;1.5,1;rst;Reset]
				button[6.5,0.1;1.5,1;save;Save]
			]]
		else
			probchange = [[
				label[1,0.2;Insert item in slot.]
			]]
		end

		return [[
			size[8,6]
			list[nodemeta:]]..stringpos..[[;probability;0,0;1,1;]
			label[0,1;Probability is a number between 0 and 255.]
			list[current_player;main;0,1.5;8,4;]
			listring[nodemeta:]]..stringpos..[[;probability]
			listring[current_player;main]
		]]..probchange
	end,
	handle = function(pos, name, fields)
		local meta = minetest.get_meta(pos)
		local inventory = meta:get_inventory()
		local stack = inventory:get_stack("probability", 1)
		local smeta = stack:get_meta()

		if stack:get_name() ~= "" then
			if fields.rst then
				smeta:set_string("advschem_prob", nil)
				smeta:set_string("advschem_force_place", nil)

				-- Reset description
				local original_desc = smeta:get_string("original_desc")
				if not original_desc or original_desc == "" then
					original_desc = minetest.registered_items[stack:get_name()].description
				end

				smeta:set_string("description", original_desc)
			elseif fields.force_place or fields.save or
					fields.key_enter_field == "probability" then
				if fields.probability ~= "" then
					local prob = tonumber(fields.probability)
					if prob >= 0 and prob <= 255 then
						smeta:set_string("advschem_prob", fields.probability)
					else
						advschem.show_formspec(pos, minetest.get_player_by_name(name), "prob")
					end
				else
					smeta:set_string("advschem_prob", nil)
				end

				smeta:set_string("advschem_force_place", fields.force_place)

				-- Update description
				local desc = minetest.registered_items[stack:get_name()].description
				local meta_desc = smeta:get_string("description")
				if meta_desc and meta_desc ~= "" then
					desc = meta_desc
				end

				local original_desc = smeta:get_string("original_description")
				if original_desc and original_desc ~= "" then
					desc = original_desc
				else
					smeta:set_string("original_description", desc)
				end

				desc = desc.."\n"..minetest.colorize("grey", "Probability: "..
					fields.probability.."\nForce Place: "..(fields.force_place or "false"))
				smeta:set_string("description", desc)
			end

			-- Update itemstack
			inventory:set_stack("probability", 1, stack)

			-- Refresh formspec
			if fields.rst then
				advschem.show_formspec(pos, minetest.get_player_by_name(name), "prob")
			end
		end
	end,
})

---
--- API
---

-- [function] Load
function advschem.load()
	local res = io.open(path, "r")
	if res then
		marked = minetest.deserialize(res:read("*a"))
		res:close()
	end

	if type(marked) ~= "table" then
		marked = {}
	end
end

-- [function] Save
function advschem.save()
	local res = io.open(path, "w")
	if res then
		res:write(minetest.serialize(marked))
		res:close()
	end
end

--- Copies and modifies positions `pos1` and `pos2` so that each component of
-- `pos1` is less than or equal to the corresponding component of `pos2`.
-- Returns the new positions.
function advschem.sort_pos(pos1, pos2)
	if not pos1 or not pos2 then
		return
	end

	pos1, pos2 = table.copy(pos1), table.copy(pos2)
	if pos1.x > pos2.x then
		pos2.x, pos1.x = pos1.x, pos2.x
	end
	if pos1.y > pos2.y then
		pos2.y, pos1.y = pos1.y, pos2.y
	end
	if pos1.z > pos2.z then
		pos2.z, pos1.z = pos1.z, pos2.z
	end
	return pos1, pos2
end

-- [function] Prepare size
function advschem.size(pos)
	local pos1   = vector.new(pos)
	local meta   = minetest.get_meta(pos)
	local node   = minetest.get_node(pos)
	local param2 = node.param2
	local size   = {
		x = meta:get_int("x_size"),
		y = math.max(meta:get_int("y_size") - 1, 0),
		z = meta:get_int("z_size"),
	}

	if param2 == 1 then
		local new_pos = vector.add({x = size.z, y = size.y, z = -size.x}, pos)
		pos1.x = pos1.x + 1
		new_pos.z = new_pos.z + 1
		return pos1, new_pos
	elseif param2 == 2 then
		local new_pos = vector.add({x = -size.x, y = size.y, z = -size.z}, pos)
		pos1.z = pos1.z - 1
		new_pos.x = new_pos.x + 1
		return pos1, new_pos
	elseif param2 == 3 then
		local new_pos = vector.add({x = -size.z, y = size.y, z = size.x}, pos)
		pos1.x = pos1.x - 1
		new_pos.z = new_pos.z - 1
		return pos1, new_pos
	else
		local new_pos = vector.add(size, pos)
		pos1.z = pos1.z + 1
		new_pos.x = new_pos.x - 1
		return pos1, new_pos
	end
end

-- [function] Mark region
function advschem.mark(pos)
	advschem.unmark(pos)

	local id = minetest.pos_to_string(pos)
	local owner = minetest.get_meta(pos):get_string("owner")
	local pos1, pos2 = advschem.size(pos)
	pos1, pos2 = advschem.sort_pos(pos1, pos2)

	local thickness = 0.2
	local sizex, sizey, sizez = (1 + pos2.x - pos1.x) / 2, (1 + pos2.y - pos1.y) / 2, (1 + pos2.z - pos1.z) / 2
	local m = {}

	-- XY plane markers
	for _, z in ipairs({pos1.z - 0.5, pos2.z + 0.5}) do
		local marker = minetest.add_entity({x = pos1.x + sizex - 0.5, y = pos1.y + sizey - 0.5, z = z}, "advschem:display")
		if marker ~= nil then
			marker:set_properties({
				visual_size={x=sizex * 2, y=sizey * 2},
				collisionbox = {-sizex, -sizey, -thickness, sizex, sizey, thickness},
			})
			marker:get_luaentity().id = id
			marker:get_luaentity().owner = owner
			table.insert(m, marker)
		end
	end

	-- YZ plane markers
	for _, x in ipairs({pos1.x - 0.5, pos2.x + 0.5}) do
		local marker = minetest.add_entity({x = x, y = pos1.y + sizey - 0.5, z = pos1.z + sizez - 0.5}, "advschem:display")
		if marker ~= nil then
			marker:set_properties({
				visual_size={x=sizez * 2, y=sizey * 2},
				collisionbox = {-thickness, -sizey, -sizez, thickness, sizey, sizez},
			})
			marker:set_yaw(math.pi / 2)
			marker:get_luaentity().id = id
			marker:get_luaentity().owner = owner
			table.insert(m, marker)
		end
	end

	advschem.markers[id] = m
	return true
end

-- [function] Unmark region
function advschem.unmark(pos)
	local id = minetest.pos_to_string(pos)
	if advschem.markers[id] then
		local retval
		for _, entity in ipairs(advschem.markers[id]) do
			entity:remove()
			retval = true
		end
		return retval
	end
end

---
--- Registrations
---

-- [event] Save data on shut down
minetest.register_on_shutdown(advschem.save)

-- [event] Transfer probabilities and force place on place node
minetest.register_on_placenode(function(pos, newnode, player, oldnode, itemstack)
	local smeta = itemstack:get_meta():to_table().fields

	if smeta.advschem_prob and tonumber(smeta.advschem_prob) then
		local px, py, pz = pos.x, pos.y, pos.z
		for strpos, r in pairs(marked) do
			local ap1, ap2 = r.pos1, r.pos2
			if (px >= ap1.x and px <= ap2.x) and
					(py >= ap1.y and py <= ap2.y) and
					(pz >= ap1.z and pz <= ap2.z) then
				local realpos = minetest.string_to_pos(strpos)
				local node = minetest.get_node_or_nil(realpos)

				if node and node.name == "advschem:creator" then
					local meta = minetest.get_meta(realpos)
					local prob_list = minetest.deserialize(meta:get_string("prob_list"))

					local force_place = false
					if smeta.advschem_force_place == "true" then
						force_place = true
					end

					local ostrpos = minetest.pos_to_string(pos)
					prob_list[ostrpos] = {
						pos = pos,
						prob = tonumber(smeta.advschem_prob),
						force_place = force_place,
					}
					meta:set_string("prob_list", minetest.serialize(prob_list))
				end
			end
		end
	end
end)

-- [event] Remove probability on break node
minetest.register_on_dignode(function(pos, oldnode, player)
	local original_strpos = minetest.pos_to_string(pos)
	local px, py, pz = pos.x, pos.y, pos.z
	for strpos, r in pairs(marked) do
		local ap1, ap2 = r.pos1, r.pos2
		if (px >= ap1.x and px <= ap2.x) and
				(py >= ap1.y and py <= ap2.y) and
				(pz >= ap1.z and pz <= ap2.z) then
			local realpos = minetest.string_to_pos(strpos)
			local meta = minetest.get_meta(realpos)
			local prob_list = minetest.deserialize(meta:get_string("prob_list"))

			for _, i in pairs(prob_list) do
				if _ == original_strpos then
					prob_list[_] = nil
				end
			end

			meta:set_string("prob_list", minetest.serialize(prob_list))
		end
	end
end)

-- [priv] schematic_override
minetest.register_privilege("schematic_override", {
	description = "Allows you to access advschem nodes not owned by you",
	give_to_singleplayer = false,
})

-- [node] Schematic creator
minetest.register_node("advschem:creator", {
	description = "Schematic Creator",
	tiles = {"advschem_creator_top.png", "advschem_creator_bottom.png",
			"advschem_creator_sides.png"},
	groups = {cracky = 3},
	paramtype2 = "facedir",

	after_place_node = function(pos, player)
		local name = player:get_player_name()
		local meta = minetest.get_meta(pos)

		meta:set_string("owner", name)
		meta:set_string("infotext", "Schematic Creator\n(owned by "..name..")")
		meta:set_string("prob_list", minetest.serialize({}))

		local node = minetest.get_node(pos)
		local dir  = minetest.facedir_to_dir(node.param2)

		meta:set_int("x_size", 1)
		meta:set_int("y_size", 1)
		meta:set_int("z_size", 1)

		local inv = meta:get_inventory()
		inv:set_size("probability", 1)

		local pos1, pos2 = advschem.size(pos)
		marked[minetest.pos_to_string(pos)] = {
			pos1 = pos1,
			pos2 = pos2,
		}

		-- Don't take item from itemstack
		return true
	end,
	can_dig = function(pos, player)
		local name = player:get_player_name()
		local meta = minetest.get_meta(pos)
		if meta:get_string("owner") == name or
				minetest.check_player_privs(player, "schematic_override") == true then
			return true
		end

		return false
	end,
	on_rightclick = function(pos, node, player)
		local meta = minetest.get_meta(pos)
		local name = player:get_player_name()
		if meta:get_string("owner") == name or
				minetest.check_player_privs(player, "schematic_override") == true then
			-- Get player attribute
			local tab = player:get_attribute("advschem:tab")
			if not forms[tab] then
				tab = "main"
			end

			advschem.show_formspec(pos, player, tab, true)
		end
	end,
	after_destruct = function(pos)
		advschem.unmark(pos)
	end,

	-- Update formspec when items are added to or taken from the probability inventory
	on_metadata_inventory_put = function(pos, listname, index, stack, player)
		if listname == "probability" then
			advschem.show_formspec(pos, player, "prob", true)
		end
	end,
	on_metadata_inventory_take = function(pos, listname, index, stack, player)
		if listname == "probability" then
			advschem.show_formspec(pos, player, "prob", true)
		end
	end,
})

-- [entity] Display
minetest.register_entity("advschem:display", {
	initial_properties = {
		visual = "upright_sprite",
		visual_size = {x=1.1, y=1.1},
		textures = {"advschem_border.png"},
		visual_size = {x=10, y=10},
		physical = false,
	},
	on_step = function(self, dtime)
		if not self.id then
			self.object:remove()
		elseif not advschem.markers[self.id] then
			self.object:remove()
		end
	end,
	on_punch = function(self, hitter)
		local pos = minetest.string_to_pos(self.id)
		local meta = minetest.get_meta(pos)
		if meta:get_string("owner") == hitter:get_player_name() or
				minetest.check_player_privs(hitter, "schematic_override") == true then
			advschem.unmark(pos)
			meta:set_string("schem_border", "false")
		end
	end,
	on_activate = function(self)
		self.object:set_armor_groups({immortal = 1})
	end,
})

---
--- Load Data
---

advschem.load()