-- IndustrialTest
-- Copyright (C) 2024 mrkubax10

-- This program is free software: you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation, either version 3 of the License, or
-- (at your option) any later version.

-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-- GNU General Public License for more details.

-- You should have received a copy of the GNU General Public License
-- along with this program.  If not, see <http://www.gnu.org/licenses/>.

local function addNodeToNetwork(pos,networkMasterPos)
	local meta=minetest.get_meta(pos)
	local networks={}
	if meta:contains("industrialtest.networks") then
		networks=minetest.deserialize(meta:get_string("industrialtest.networks"))
	end
	for _,network in ipairs(networks) do
		if network.x==networkMasterPos.x and network.y==networkMasterPos.y and network.z==networkMasterPos.z then
			return
		end
	end
	table.insert(networks,networkMasterPos)
	meta:set_string("industrialtest.networks",minetest.serialize(networks))
end

local function clampFlow(pos,flow)
	local def=minetest.registered_nodes[minetest.get_node(pos).name]
	local newFlow
	if def.groups and def.groups._industrialtest_cable then
		newFlow=def._industrialtest_cableFlow
	else
		local meta=minetest.get_meta(pos)
		newFlow=meta:get_int("industrialtest.powerFlow")
	end
	return math.min(flow,newFlow)
end

-- \brief Transfers power from source node to it's network, if sides is set then power will be only transfered to network connected to that sides
-- \param pos Vector with position of source node
-- \param (optional) sides table with Vectors
-- \param (optional) flowOverride number
-- \returns two values: true if any neighbouring node has room for more power, false otherwise
--                      true if any power was transferred, false otherwise
function industrialtest.api.powerFlow(pos,sides,flowOverride)
	local meta=minetest.get_meta(pos)
	-- if machine doesn't have network map then it's not capable of transferring power
	local network=industrialtest.api.getNetwork(meta)
	if not network or #network==0 then
		return false,false
	end
	local endpointCount=0
	for _,endpoint in ipairs(network) do
		local endpointMeta=minetest.get_meta(endpoint.position)
		if not industrialtest.api.isFullyCharged(endpointMeta) and (not sides or sides[endpoint.sourceSide]) then
			endpointCount=endpointCount+1
		end
	end
	if endpointCount==0 then
		return false,false
	end
	local powerDistribution=math.floor((flowOverride and flowOverride or meta:get_int("industrialtest.powerFlow"))/endpointCount)
	local transferred=false
	local roomAvailable=false
	for _,endpoint in ipairs(network) do
		if not sides or sides[endpoint.sourceSide] then
			local endpointMeta=minetest.get_meta(endpoint.position)
			if powerDistribution<=endpoint.flow then
				local transferredPower=industrialtest.api.transferPower(meta,endpointMeta,powerDistribution)
				if transferredPower>0 then
					transferred=true
				end
				local def=minetest.registered_nodes[minetest.get_node(endpoint.position).name]
				if def then
					local updateFormspec=def._industrialtest_updateFormspec
					if updateFormspec then
						updateFormspec(endpoint.position)
					end
					local onPowerFlow=def._industrialtest_onPowerFlow
					if onPowerFlow and transferredPower>0 then
						onPowerFlow(endpoint.position,industrialtest.api.getOppositeSide(endpoint.side),transferredPower)
					end
				end
				minetest.get_node_timer(endpoint.position):start(industrialtest.updateDelay)
				if not industrialtest.api.isFullyCharged(endpointMeta) then
					roomAvailable=true
				end
			else
				minetest.remove_node(endpoint.position)
				industrialtest.internal.explode(endpoint.position,2)
			end
		end
	end
	return roomAvailable,transferred
end

-- \brief Creates network map starting from node at pos, optionally omitting node at omit
-- \param pos vector
-- \param (optional) addCables bool
-- \param (optional) omit Vector
-- \returns table with network map
function industrialtest.api.createNetworkMap(pos,addCables,omit)
	local workers={}
	local map={}
	local connections=industrialtest.api.getConnections(pos,"i")
	if #connections==0 then
		return map
	end
	local sides={
		["-1,0,0"]=1,
		["1,0,0"]=2,
		["0,-1,0"]=3,
		["0,1,0"]=4,
		["0,0,-1"]=5,
		["0,0,1"]=6
	}
	local serializedSourcePos=pos.x..","..pos.y..","..pos.z
	local visitedNodes={[serializedSourcePos]=true}
	for _,conn in ipairs(connections) do
		if not omit or conn.x~=omit.x or conn.y~=omit.y or conn.z~=omit.z then
			visitedNodes[conn.x..","..conn.y..","..conn.z]=true
			addNodeToNetwork(conn,pos)
			local sideVector=vector.subtract(conn,pos)
			local serializedSideVector=sideVector.x..","..sideVector.y..","..sideVector.z
			local def=minetest.registered_nodes[minetest.get_node(conn).name]
			if def.groups._industrialtest_cable then
				table.insert(workers,{
					position=conn,
					targetPosition=conn,
					distance=1,
					flow=def._industrialtest_cableFlow,
					targetFlow=0,
					sourceSide=industrialtest.api.normalizeSide(pos,sides[serializedSideVector])
				})
				if addCables then
					table.insert(map,{
						position=conn,
						distance=0
					})
				end
			else
				local meta=minetest.get_meta(conn)
				table.insert(map,{
					position=conn,
					distance=0,
					flow=meta:get_int("industrialtest.powerFlow"),
					side=sides[serializedSideVector],
					sourceSide=industrialtest.api.normalizeSide(pos,sides[serializedSideVector])
				})
			end
		end
	end
	while #workers>0 do
		for i=1,#workers do
			local worker=workers[i]
			connections=industrialtest.api.getConnections(worker.position,"i")
			if #connections==0 then
				table.remove(workers,i)
				break
			else
				local directionAssigned=false
				local foundNewNode=false
				for _,conn in ipairs(connections) do
					if not omit or conn.x~=omit.x or conn.y~=omit.y or conn.z~=omit.z then
						local serializedPos=conn.x..","..conn.y..","..conn.z
						if not visitedNodes[serializedPos] then
							local def=minetest.registered_nodes[minetest.get_node(conn).name]
							visitedNodes[serializedPos]=true
							foundNewNode=true
							addNodeToNetwork(conn,pos)
							if def.groups._industrialtest_cable then
								if directionAssigned then
									table.insert(workers,{
										position=conn,
										targetPosition=conn,
										distance=worker.distance+1,
										flow=clampFlow(conn,worker.flow),
										targetFlow=0,
										sourceSide=worker.sourceSide
									})
								else
									worker.targetPosition=conn
									worker.distance=worker.distance+1
									worker.targetFlow=clampFlow(conn,worker.flow)
									directionAssigned=true
								end
								if addCables then
									table.insert(map,{
										position=conn,
										distance=worker.distance+1,
									})
								end
							else
								local sideVector=vector.subtract(conn,worker.position)
								table.insert(map,{
									position=conn,
									distance=worker.distance,
									flow=clampFlow(conn,worker.flow),
									side=sides[sideVector.x..","..sideVector.y..","..sideVector.z],
									sourceSide=worker.sourceSide
								})
								if #connections==1 then
									foundNewNode=false
									break
								end
							end
						end
					end
				end
				if not foundNewNode then
					table.remove(workers,i)
					break
				end
				worker.position=worker.targetPosition
				worker.flow=worker.targetFlow
			end
		end
	end
	return map
end

function industrialtest.api.removeNodeFromNetwork(pos,nodePos)
	local meta=minetest.get_meta(pos)
	if not meta:contains("industrialtest.network") then
		return
	end
	local network=minetest.deserialize(meta:get_string("industrialtest.network"))
	local removed=false
	for key,node in ipairs(network) do
		if node.position.x==nodePos.x and node.position.y==nodePos.y and node.position.z==nodePos.z then
			table.remove(network,key)
			removed=true
			break
		end
	end
	if removed then
		meta:set_string("industrialtest.network",minetest.serialize(network))
	end
end

-- \brief Creates network map and writes it to node metadata at pos, optionally omitting node at omit
-- \param pos Vector
-- \param (optional) omit Vector
-- \returns nil
function industrialtest.api.createNetworkMapForNode(pos,omit)
	local meta=minetest.get_meta(pos)
	local network=industrialtest.api.createNetworkMap(pos,false,omit)
	meta:set_string("industrialtest.network",minetest.serialize(network))
end

-- \brief Returns true if meta contains network map, false otherwise
-- \param meta MetaDataRef
-- \returns bool
function industrialtest.api.isNetworkMaster(meta)
	return meta:contains("industrialtest.network")
end

-- \brief Returns network table if node containing meta belongs to any networks, false otherwise
-- \param meta MetaDataRef
-- \returns bool or table
function industrialtest.api.isAttachedToNetwork(meta)
	if not meta:contains("industrialtest.networks") then
		return false
	end
	local networks=minetest.deserialize(meta:get_string("industrialtest.networks"))
	if #networks==0 then
		return false
	end
	return networks
end

-- \brief Returns network master network from it's meta, if meta doesn't contain network map then function returns false
-- \param meta MetaDataRef
-- \returns table or bool
function industrialtest.api.getNetwork(meta)
	if not meta:contains("industrialtest.network") then
		return false
	end
	return minetest.deserialize(meta:get_string("industrialtest.network"))
end

-- \brief Returns connections of node with power storage. If direction is "i" only input connections will be returned, if direction is "o" only output connections
--        will be returned, if it's not provided all connections will be returned.
-- \param pos Vector
-- \param (optional) direction string
-- \returns table
function industrialtest.api.getConnections(pos,direction)
	local result={}
	local neighbourPositions={
		vector.offset(pos,-1,0,0),
		vector.offset(pos,1,0,0),
		vector.offset(pos,0,-1,0),
		vector.offset(pos,0,1,0),
		vector.offset(pos,0,0,-1),
		vector.offset(pos,0,0,1)
	}
	local sourceMeta=minetest.get_meta(pos)
	local sourceDef=minetest.registered_nodes[minetest.get_node(pos).name]
	local directionOutput=(not direction or direction=="o")
	local directionInput=(not direction or direction=="i")
	for key,conn in ipairs(neighbourPositions) do
		local meta=minetest.get_meta(conn)
		local def=minetest.registered_nodes[minetest.get_node(conn).name]
		local normalizedKey=industrialtest.api.normalizeSide(pos,key)
		local powerOutput=(sourceDef.groups._industrialtest_cable or industrialtest.api.isPowerOutput(sourceMeta,normalizedKey))
		local powerInput=(sourceDef.groups._industrialtest_cable or industrialtest.api.isPowerInput(sourceMeta,normalizedKey))
		if def.groups._industrialtest_cable or industrialtest.api.hasPowerStorage(meta) then
			local side=industrialtest.api.normalizeSide(conn,industrialtest.api.getOppositeSide(normalizedKey))
			if (powerOutput and directionInput and (def.groups._industrialtest_cable or industrialtest.api.isPowerInput(meta,side))) or ((def.groups._industrialtest_cable or industrialtest.api.isPowerOutput(meta,side)) and powerInput and directionOutput) then
				table.insert(result,conn)
			end
		end
	end
	return result
end