Dealing cards on selected table color

Turn "Deal to table" button to drop down menu of colors if
table has multiple colors.

init.lua

@@ -64,6 +64,9 @@ local cardnames = {}
 -- Prefix of all individual card node names.
 local cardprefix="deck:card_"
 local cardprefixlen=string.len(cardprefix)
+-- Prefix of cardtable types
+local tableprefix="deck:cardtable_"
+local tableprefixlen=string.len(tableprefix)
 
 -- Table of card descriptions. Key is minetest node name, value is
 -- verbose card name, for example deck:card_ah -> Ace of hearts
@@ -524,7 +527,7 @@ local function cardtable_try_add_card(pos,cardname)
 end
 
 -- Adds card to cardtable. Return true if card was added or false if cardtable was full.
-local function cardtable_add_card(pos,cardname)
+local function cardtable_add_card(pos,cardname,color)
    local above={x=pos.x,y=pos.y+1,z=pos.z}
    if cardtable_try_add_card(above,cardname) then return true end
    local positions=cardtable_get_positions(pos)
@@ -586,9 +589,8 @@ local function inventory_to_cardtable(list,pos,sender,which)
 end
 
 local function is_cardtable(pos)
-      local prefix="deck:cardtable_"
       local n=minetest.get_node(pos)
-      if string.sub(n.name,1,string.len(prefix)) == prefix then
+      if string.sub(n.name,1,string.len(tableprefix)) == tableprefix then
 	 return true
       end
       return false
@@ -638,7 +640,7 @@ local function deal_card_to_table(pos,formname,fields,sender)
 	 log("out of cards")
 	 return false
       end
-      if cardtable_add_card(below,stack:get_name()) then
+      if cardtable_add_card(below,stack:get_name(),fields.deal_card_to_table) then
 	 return true
       else
 	 log("Card did not fit on table.")
@@ -887,6 +889,23 @@ local function after_dig_cardtable(pos, oldnode, oldmeta, digger)
    end
 end
 
+-- return array of strings that contain colors of cardtable at pos. Each color is returned only once.
+local function cardtable_get_colors(pos)
+   local tablepositions=cardtable_get_positions(pos)
+   local colors={}
+   local colortable={}
+   local offset=tableprefixlen+1
+   for i,p in ipairs(tablepositions) do
+      local n=minetest.get_node(p)
+      local color=string.sub(n.name,offset)
+      if colortable[color] == nil then
+	 table.insert(colors,color)
+	 colortable[color]=1
+      end
+   end
+   return colors
+end
+
 -- Chestpile is a pile of cards that player can use like a chest.
 minetest.register_node("deck:chestpile", {
 	description = "Card pile that user has full access to. Works also like a minetest chest.",
@@ -926,13 +945,25 @@ minetest.register_node("deck:stockpile", {
 	on_construct = function(pos)
 	   pile_inv_setup(pos)
 	   local meta=minetest.get_meta(pos)
+	   local below={x=pos.x,y=pos.y-1,z=pos.z}
+	   local colors=cardtable_get_colors(below)
+	   local dealmenu
+	   if table.getn(colors) == 1 then
+	      dealmenu="button[10,0;2,1;deal_to_table;Deal to table]"
+	   else
+	      dealmenu="dropdown[10,0;2;deal_to_table;"
+	      for key,value in ipairs(colors) do
+		 dealmenu=dealmenu..value..","
+	      end
+	      dealmenu=dealmenu..";1]"
+	   end
 	   meta:set_string("formspec","size[13,6]"..
 			      "button[0,0;2,1;draw;Draw]"..
 			      "button[2,0;2,1;drawall;Draw all]"..
 			      "button[4,0;2,1;alltopile;Add all to pile]"..
 			      "button[6,0;2,1;shuffle;Shuffle cards]"..
 			      "button[8,0;2,1;deal;Deal cards]"..
-			      "button[10,0;2,1;deal_to_table;Deal to table]"..
+			      dealmenu..
 			      "list[current_player;main;0,1;13,5;]"
 	   )
 	end,
@@ -947,7 +978,7 @@ minetest.register_node("deck:stockpile", {
 log(table.getn(dye.dyes).." cardtable colors")
 for _, row in ipairs(dye.dyes) do
    local color = row[1]
-   local name = "deck:cardtable_"..color
+   local name = tableprefix..color
    local colorize = tablecolorize[color]
    if colorize == nil then colorize = color end
    local tile = "deck_table_g.png^[colorize:"..colorize..":127"
@@ -1014,13 +1045,13 @@ minetest.register_craft({
 
 -- card table pieces can be crafted from 2x2 grid of wood
 minetest.register_craft({
-      output = "deck:cardtable_white 99",
+      output = tableprefix.."white 99",
       recipe = {{ "group:wood", "group:wood"},{"group:wood","group:wood"}}
 })
 
 for _, row in ipairs(dye.dyes) do
    local color = row[1]
-   local name = "deck:cardtable_"..color
+   local name = tableprefix..color
    local outputstring = name.." 99"
    local dyetype = "group:dye,color_white"
    log("registering craft for '"..outputstring.."' and dyetype "..dyetype)