-- register LV machines here
local LV_machines = {}
function register_LV_machine(string1,string2)
   LV_machines[string1] = string2
end

power_tools ={}
registered_power_tools_count=0

function register_power_tool (string1,max_charge)
   registered_power_tools_count=registered_power_tools_count+1
   power_tools[registered_power_tools_count]={}
   power_tools[registered_power_tools_count].tool_name=string1
   power_tools[registered_power_tools_count].max_charge=max_charge
end

register_power_tool ("technic:battery",10000)
register_power_tool ("technic:red_energy_crystal",100000)
register_power_tool ("technic:green_energy_crystal",250000)
register_power_tool ("technic:blue_energy_crystal",500000)

minetest.register_craft({
			   output = 'technic:battery 1',
			   recipe = {
			      {'default:wood', 'default:copper_ingot', 'default:wood'},
			      {'default:wood', 'moreores:tin_ingot', 'default:wood'},
			      {'default:wood', 'default:copper_ingot', 'default:wood'},
			   }
			})

minetest.register_craft({
			   output = 'technic:battery_box 1',
			   recipe = {
			      {'technic:battery', 'default:wood', 'technic:battery'},
			      {'technic:battery', 'moreores:copper_ingot', 'technic:battery'},
			      {'default:steel_ingot', 'default:steel_ingot', 'default:steel_ingot'},
			   }
			})


minetest.register_tool("technic:battery",
		       {description = "RE Battery",
			inventory_image = "technic_battery.png",
			tool_capabilities = {load=0,max_drop_level=0, groupcaps={fleshy={times={}, uses=10000, maxlevel=0}}}})

minetest.register_craftitem("technic:battery_box", {
			       description = "Battery box",
			       stack_max = 99,
			    })



battery_box_formspec =
	"invsize[8,9;]"..
	"image[1,1;1,2;technic_power_meter_bg.png]"..
	"list[current_name;src;3,1;1,1;]"..
	"list[current_name;dst;5,1;1,1;]"..
	"label[0,0;LV Battery Box]"..
	"label[3,0;Charge]"..
	"label[5,0;Discharge]"..
	"label[1,3;Power level]"..
	"list[current_player;main;0,5;8,4;]"..
	"background[-0.19,-0.25;8.4,9.75;ui_form_bg.png]"..
	"background[0,0;8,4;ui_lv_battery_box.png]"..
	"background[0,5;8,4;ui_main_inventory.png]"

minetest.register_node(
   "technic:battery_box", {
      description = "LV Battery Box",
      tiles = {"technic_battery_box_top.png", "technic_battery_box_bottom.png", "technic_battery_box_side0.png",
	       "technic_battery_box_side0.png", "technic_battery_box_side0.png", "technic_battery_box_side0.png"},
      groups = {snappy=2,choppy=2,oddly_breakable_by_hand=2},
      sounds = default.node_sound_wood_defaults(),
      drop="technic:battery_box",
      on_construct = function(pos)
			     if pos == nil then return end
			     local meta = minetest.env:get_meta(pos)
			     local inv = meta:get_inventory()
			     meta:set_string("infotext", "Battery box")
			     meta:set_float("technic_power_machine", 1)
			     meta:set_string("formspec", battery_box_formspec)
			     meta:set_float("internal_EU_buffer", 0)
			     meta:set_float("internal_EU_buffer_size", 60000)
			     inv:set_size("src", 1)
			     inv:set_size("dst", 1)
			  end,
      can_dig = function(pos,player)
			if pos == nil then return end
			local meta = minetest.env:get_meta(pos);
			local inv = meta:get_inventory()
			if not inv:is_empty("dst") then
			   return false
			elseif not inv:is_empty("src") then
			   return false
			end
			return true
		     end,
   })


for i=1,8,1 do
   minetest.register_node(
      "technic:battery_box"..i, {
	 description = "LV Battery Box",
	 tiles = {"technic_battery_box_top.png", "technic_battery_box_bottom.png", "technic_battery_box_side0.png^technic_power_meter"..i..".png",
		  "technic_battery_box_side0.png^technic_power_meter"..i..".png", "technic_battery_box_side0.png^technic_power_meter"..i..".png", "technic_battery_box_side0.png^technic_power_meter"..i..".png"},
	 groups = {snappy=2,choppy=2,oddly_breakable_by_hand=2,not_in_creative_inventory=1},
	 sounds = default.node_sound_wood_defaults(),
	 drop="technic:battery_box",
	 on_construct = function(pos)
			     if pos == nil then return end
			     local meta = minetest.env:get_meta(pos)
			     local inv = meta:get_inventory()
			     meta:set_string("infotext", "Battery box")
			     meta:set_float("technic_power_machine", 1)
			     meta:set_string("formspec", battery_box_formspec)
			     meta:set_float("internal_EU_buffer", 0)
			     meta:set_float("internal_EU_buffer_size", 60000)
			     inv:set_size("src", 1)
			     inv:set_size("dst", 1)
			  end,
	 can_dig = function(pos,player)
			if pos == nil then return end
			local meta = minetest.env:get_meta(pos);
			local inv = meta:get_inventory()
			if not inv:is_empty("dst") then
			   return false
			elseif not inv:is_empty("src") then
			   return false
			end
			return true
		     end,
      })
end

function get_RE_item_load (load1,max_load)
   if load1==0 then load1=65535 end
   local temp = 65536-load1
   temp= temp/65535*max_load
   return math.floor(temp + 0.5)
end

function set_RE_item_load (load1,max_load)
   if load1 == 0 then return 65535 end
   local temp=load1/max_load*65535
   temp=65536-temp
   return math.floor(temp)
end

function set_RE_wear (item_stack,load1,max_load)
   local temp=65536-math.floor(load1/max_load*65535)
   item_stack["wear"]=tostring(temp)
   return item_stack
end

minetest.register_abm(
   {nodenames = {"technic:battery_box","technic:battery_box1","technic:battery_box2","technic:battery_box3","technic:battery_box4",
		 "technic:battery_box5","technic:battery_box6","technic:battery_box7","technic:battery_box8"},
    interval = 1,
    chance = 1,
    action = function(pos, node, active_object_count, active_object_count_wider)
		local meta       = minetest.env:get_meta(pos)
		local max_charge = 60000 -- Set maximum charge for the device here
		local charge     = meta:get_int("internal_EU_buffer")

		-- Select node textures
		local i=math.ceil((charge/max_charge)*8)
		if i > 8 then i = 8 end
		local j = meta:get_float("last_side_shown")
		if i~=j then
		   if i>0 then hacky_swap_node(pos,"technic:battery_box"..i)
		   elseif i==0 then hacky_swap_node(pos,"technic:battery_box") end
		   meta:set_float("last_side_shown",i)
		end
		
		--charge registered power tools
		local inv = meta:get_inventory()
		if inv:is_empty("src")==false  then
		   local srcstack = inv:get_stack("src", 1)
		   local src_item=srcstack:to_table()
		   local src_meta=get_item_meta(src_item["metadata"])
		   
		   local item_max_charge=nil
		   for i=1,registered_power_tools_count,1 do
		      if power_tools[i].tool_name==src_item["name"] then
			 src_meta=get_item_meta(src_item["metadata"])
			 if src_meta==nil then
			    src_meta={}
			    src_meta["technic_power_tool"]=true
			    src_meta["charge"]=0
			 else
			    if src_meta["technic_power_tool"]==nil then
			       src_meta["technic_power_tool"]=true
			       src_meta["charge"]=0
			    end
			 end
			 -- Do the charging
			 local item_max_charge = power_tools[i].max_charge
			 local load1           = src_meta["charge"]
			 local load_step       = 1000 -- how much to charge per tick
			 if load1<item_max_charge and charge>0 then
			    if charge-load_step<0 then load_step=charge end
			    if load1+load_step>item_max_charge then load_step=item_max_charge-load1 end
			    load1=load1+load_step
			    charge=charge-load_step
			    set_RE_wear(src_item,load1,item_max_charge)
			    src_meta["charge"]=load1
			    src_item["metadata"]=set_item_meta(src_meta)
			    inv:set_stack("src", 1, src_item)
			 end
			 meta:set_int("internal_EU_buffer",charge)
			 break
		      end
		   end
		end
		
		-- discharging registered power tools
		if inv:is_empty("dst") == false then
		   srcstack = inv:get_stack("dst", 1)
		   src_item=srcstack:to_table()
		   local src_meta=get_item_meta(src_item["metadata"])
		   local item_max_charge=nil
		   for i=1,registered_power_tools_count,1 do
		      if power_tools[i].tool_name==src_item["name"] then
			 src_meta=get_item_meta(src_item["metadata"])
			 if src_meta==nil then
			    src_meta={}
			    src_meta["technic_power_tool"]=true
			    src_meta["charge"]=0
			 else
			    if src_meta["technic_power_tool"]==nil then
			       src_meta["technic_power_tool"]=true
			       src_meta["charge"]=0
			    end
			 end
			 local item_max_charge = power_tools[i].max_charge
			 local load1           = src_meta["charge"]
			 local load_step       = 4000 -- how much to discharge per tick
			 if load1>0 and charge<max_charge then
			    if charge+load_step>max_charge then load_step=max_charge-charge end
			    if load1-load_step<0 then load_step=load1 end
			    load1=load1-load_step
			    charge=charge+load_step
			    set_RE_wear(src_item,load1,item_max_charge)
			    src_meta["charge"]=load1
			    src_item["metadata"]=set_item_meta(src_meta)
			    inv:set_stack("dst", 1, src_item)
			 end
			 meta:set_int("internal_EU_buffer",charge)
			 break
		      end
		   end
		end

		local load = math.floor(charge/60000 * 100)
		meta:set_string("formspec",
				battery_box_formspec..
				   "image[1,1;1,2;technic_power_meter_bg.png^[lowpart:"..
				   (load)..":technic_power_meter_fg.png]"
			     )

		-- Next index the surrounding network the get the producers and receivers on the power grid
		local pos1={}
		pos1.y=pos.y-1
		pos1.x=pos.x
		pos1.z=pos.z

		meta1 = minetest.env:get_meta(pos1)
		if meta1:get_float("cablelike")~=1 then return end

		local LV_nodes = {}
		local PR_nodes = {}
		local RE_nodes = {}
		local BA_nodes = {}

		LV_nodes[1]={}
		LV_nodes[1].x=pos1.x
		LV_nodes[1].y=pos1.y
		LV_nodes[1].z=pos1.z
		LV_nodes[1].visited=false

		local table_index=1
		repeat
		   check_LV_node(PR_nodes,RE_nodes,BA_nodes,LV_nodes,table_index)
		   table_index=table_index+1
		   if LV_nodes[table_index]==nil then break end
		until false


		-- Get power from all connected producers
		local pr_pos
                for _,pr_pos in ipairs(PR_nodes) do
		   local meta1              = minetest.env:get_meta(pr_pos)
		   local internal_EU_buffer = meta1:get_float("internal_EU_buffer")
		   local charge_to_take     = 200
		   if charge<max_charge then
		      if internal_EU_buffer-charge_to_take<=0 then
			 charge_to_take=internal_EU_buffer
		      end
		      if charge_to_take>0 then
			 charge=charge+charge_to_take
			 internal_EU_buffer=internal_EU_buffer-charge_to_take
			 meta1:set_float("internal_EU_buffer",internal_EU_buffer)
		      end
		   end
		end

		if charge>max_charge then charge=max_charge end

		-- Provide power to all connected receivers
		local re_pos
                for _,re_pos in ipairs(RE_nodes) do
		   local meta1                   = minetest.env:get_meta(re_pos)
		   local internal_EU_buffer      = meta1:get_float("internal_EU_buffer")
		   local internal_EU_buffer_size = meta1:get_float("internal_EU_buffer_size")
		   local charge_to_give          = math.min(200, charge/table.getn(RE_nodes))
		   if internal_EU_buffer+charge_to_give>internal_EU_buffer_size then
		      charge_to_give=internal_EU_buffer_size-internal_EU_buffer
		   end
		   if charge-charge_to_give<0 then charge_to_give=charge end

		   internal_EU_buffer=internal_EU_buffer+charge_to_give
		   meta1:set_float("internal_EU_buffer",internal_EU_buffer)
		   charge=charge-charge_to_give;
		end
		charge=math.floor(charge)
		meta:set_string("infotext", "LV Battery box: "..charge.."/"..max_charge);
		meta:set_int("internal_EU_buffer",charge)
	     end
 })

-- Register as a battery type
-- Battery type machines function as power reservoirs and can both receive and give back power
register_LV_machine("technic:battery_box","BA")
for i=1,8,1 do
   register_LV_machine("technic:battery_box"..i,"BA")
end

function add_new_cable_node (LV_nodes,pos1)
   if LV_nodes == nil then return true end
   local i=1
   repeat
      if LV_nodes[i]==nil then break end
      if pos1.x==LV_nodes[i].x and pos1.y==LV_nodes[i].y and pos1.z==LV_nodes[i].z then return false end
      i=i+1
   until false
   LV_nodes[i]={}
   LV_nodes[i].x=pos1.x
   LV_nodes[i].y=pos1.y
   LV_nodes[i].z=pos1.z
   return true
end

function check_LV_node(PR_nodes,RE_nodes,BA_nodes,LV_nodes,i)
   local pos1={}
   pos1.x=LV_nodes[i].x
   pos1.y=LV_nodes[i].y
   pos1.z=LV_nodes[i].z

   pos1.x=pos1.x+1
   check_LV_node_subp (PR_nodes,RE_nodes,BA_nodes,LV_nodes,pos1)
   pos1.x=pos1.x-2
   check_LV_node_subp (PR_nodes,RE_nodes,BA_nodes,LV_nodes,pos1)
   pos1.x=pos1.x+1

   pos1.y=pos1.y+1
   check_LV_node_subp (PR_nodes,RE_nodes,BA_nodes,LV_nodes,pos1)
   pos1.y=pos1.y-2
   check_LV_node_subp (PR_nodes,RE_nodes,BA_nodes,LV_nodes,pos1)
   pos1.y=pos1.y+1

   pos1.z=pos1.z+1
   check_LV_node_subp (PR_nodes,RE_nodes,BA_nodes,LV_nodes,pos1)
   pos1.z=pos1.z-2
   check_LV_node_subp (PR_nodes,RE_nodes,BA_nodes,LV_nodes,pos1)
   pos1.z=pos1.z+1
   return new_node_added
end

function check_LV_node_subp (PR_nodes,RE_nodes,BA_nodes,LV_nodes,pos1)
   local meta = minetest.env:get_meta(pos1)
   local name = minetest.env:get_node(pos1).name
   if meta:get_float("cablelike")==1 then
      add_new_cable_node(LV_nodes,pos1)
   elseif LV_machines[name] then
      --print(name.." is a "..LV_machines[name])
      if     LV_machines[name] == "PR" then
	 add_new_cable_node(PR_nodes,pos1)
      elseif LV_machines[name] == "RE" then
	 add_new_cable_node(RE_nodes,pos1)
      elseif LV_machines[name] == "BA" then
	 add_new_cable_node(BA_nodes,pos1)
      end
   end
end