-- who is allowed to edit and create new reward inventories?
-- works with player object and player name
reward_inv.may_edit = function(pname)
	return minetest.check_player_privs(pname, {give=true})
end


reward_inv.show_error_msg_fs = function(pname, error_msg)
	local formspec = {"size[10,3]"..
                "label[0.2,0.5;Error:]"..
                "label[0.5,1.0;"}
	table.insert(formspec, minetest.colorize("#FFFF00",
                                        minetest.formspec_escape(
                                                minetest.wrap_text(tostring(error_msg), 80))))
	table.insert(formspec, "]")
	table.insert(formspec, "button[3.5,2.0;2,0.9;back_from_error_msg;Back]")
	minetest.show_formspec(pname, "reward_inv:main", table.concat(formspec, ""))
	return true
end


reward_inv.input_handler = function(player, formname, fields)
	if(not(formname) or formname ~= "reward_inv:main") then
		return false
	end
	local pname = player:get_player_name()

	local reward_data = {}
	if(reward_inv.player_using[pname]) then
		reward_data = reward_inv.get_reward_data(reward_inv.player_using[pname]) or {}
	end
	-- if in edit mode: give items that were added back
	local liste = {}
	if(reward_inv.player_is_editing[pname]) then
		-- make sure we do have a content we can compare with
		if(not(reward_data.content)) then
			reward_data.content = {}
			for i=1, 32 do
				reward_data.content[i] = ""
			end
		end
		local inv_name = reward_inv.reward_inv_get_name(pname)
		-- has the inventory already been created? Then don't create it anew
		local inv = minetest.get_inventory({type="detached", name=inv_name})
		if(inv) then
			-- returns a list of stacks
			liste = inv:get_list("main")
		end
		-- the reason why we return items here is because something complex like
		-- written books or other itemstacks with complex metadata shall not be lost
		local player_inv = player:get_inventory()
		for i, work_stack in pairs(liste) do
			local prev_stack = ItemStack(reward_data.content[i] or "")
			-- there is something or something diffrent in the detached inv now
			if(not(work_stack:equals(prev_stack))) then
				-- is there more in the stack than there used to be?
				if(   work_stack:get_name() == prev_stack:get_name()
				  and work_stack:get_count() > prev_stack:get_count()) then
					local c = work_stack:get_count() - prev_stack:get_count()
					work_stack:set_count(c)
					-- return the leftover parts
					player_inv:add_item("main", work_stack)
				else
					-- diffrent stack (even if only in metadata) - so return all
					player_inv:add_item("main", work_stack)
				end
			end
			liste[i] = liste[i]:to_table()
		end
	end

	if(fields.show_reward_list) then
		reward_inv.show_reward_list_fs(player, reward_inv.player_using[pname])
		return true
	end
	-- any input here is only accepted if the player is allwed to edit this
	if(not(player) or not(fields) or not(reward_inv.may_edit(player))) then
		return false
	end
	if(fields.exit or fields.quit) then
		return true
	end
	if(fields.back_from_error_msg) then
		reward_inv.show_reward_fs(player, reward_inv.player_using[pname])
		return true
	end
	local reward_id = ""
	if(fields.select_reward_id and fields.set_reward_id) then
		reward_id = fields.select_reward_id
		if(not(reward_id) or reward_id == "") then
			return reward_inv.show_error_msg_fs(pname, "Please select a name for the new "..
							"reward ID or enter a new name!")
		end
	elseif(fields.new_reward_id and fields.create_reward_id) then
		reward_id = fields.new_reward_id
		if(string.len(reward_id) < 2 or string.len(reward_id) > 120) then
			return reward_inv.show_error_msg_fs(pname, "The reward ID needs to be between "..
							"2 and 120 characters long.")
		end
	else
		reward_id = reward_inv.player_using[pname]
	end
	if(not(reward_id) or reward_id == "") then
		return reward_inv.show_error_msg_fs(pname, "No reward_id selected.")
	end

	-- if it's a chest make sure reward_id is stored in its metadata
	if(reward_inv.clicked_at_chest[pname]) then
		local meta = minetest.get_meta(reward_inv.clicked_at_chest[pname])
		meta:set_string("reward_id", reward_id)
		-- update infotext as well
		meta:set_string("infotext", "Treasure chest")
	end

	-- the player is working on this reward and editing it (until the Store button is clicked)
	reward_inv.player_using[pname] = reward_id
	reward_inv.player_is_editing[pname] = true

	if(fields.save) then
		-- save the new reward inventory
		reward_data.content = liste
		-- set values for which we got input
		if(fields.input_text_hint) then
			reward_data.hint = fields.input_text_hint
		end
		if(fields.input_text_when_found) then
			reward_data.text_when_found = fields.input_text_when_found
		end
		if(fields.input_refill_after_t_seconds and fields.input_refill_after_t_seconds ~= "") then
			reward_data.refill_after_t_seconds = tonumber(fields.input_refill_after_t_seconds)
		end
		if(reward_inv.clicked_at_chest[pname]) then
			reward_data.pos = reward_inv.clicked_at_chest[pname]
		elseif(minetest.global_exists("yl_speak_up")) then
			reward_data.npc = yl_speak_up.speak_to[pname].n_id
		end
		-- actually save it
		reward_inv.set_inv_data(reward_id, reward_data)
		-- leave edit mode
		reward_inv.player_is_editing[pname] = nil
	end
	reward_inv.show_reward_fs(player, reward_inv.player_using[pname])
	return true
end


-- show the initial formspec for assinging a reward_id
reward_inv.get_fs_set_reward_id = function(player)
	local pname = player:get_player_name()
	local suggested_id = ""
	-- is this for a chest?
	if(reward_inv.clicked_at_chest[pname]) then
		suggested_id = minetest.pos_to_string(reward_inv.clicked_at_chest[pname])
	-- or for an NPC?
	elseif(minetest.global_exists("yl_speak_up")
	  and yl_speak_up.speak_to[pname]) then
		suggested_id = yl_speak_up.speak_to[pname]
	end
	local liste = reward_inv.get_sorted_reward_id_list()
	local formspec = {}
	table.insert(formspec, "size[8,4.5]")
	table.insert(formspec, "label[0,0;Not yet configured. No reward_id set. "..
				"You have the priv to set one.]")
	table.insert(formspec, "label[0,1;Select existing:]")
	table.insert(formspec, "dropdown[2.2,0.9;4.8,1;select_reward_id;")
	table.insert(formspec, table.concat(liste, ","))
	table.insert(formspec, ";1;false]")
	table.insert(formspec, "button[6.8,0.8;1.2,1;set_reward_id;Set]")
	table.insert(formspec, "label[0,2;..or create new:]")
	table.insert(formspec, "field[2.5,2.1;4.7,1;new_reward_id;;")
	table.insert(formspec, minetest.formspec_escape(suggested_id))
	table.insert(formspec, "]")
	table.insert(formspec, "button[6.8,1.8;1.2,1;create_reward_id;Create]")
	table.insert(formspec, "tooltip[new_reward_id;"..
			"The reward_id you store here is needed in order to reference the reward.\n"..
			"If you are adding a treasure chest, just go with the suggested name/pos.\n"..
			"When adding a treasure for an NPC, add some description that will help\n"..
			"you remember what this reward is for.]")
	table.insert(formspec, "tooltip[create_reward_id;Click here to proceed.]")
	table.insert(formspec, "tooltip[select_reward_id;"..
			"You can select an existing reward_id.\n"..
			"Note that this is seldom necessary. It is usually only needed when you\n"..
			"moved a treasure chest a few blocks away and want to keep the data.\n"..
			"Or when you changed the dialog structure of the NPC that hands out the\n"..
			"reward.]")
	table.insert(formspec, "tooltip[set_reward_id;"..
			"Click here to store the selected reward_id. This is seldom needed.\n"..
			"Usually, creating a new one is the better choice.]")
	table.insert(formspec, "label[0,2.6;Note: Select a name which will help you remember "..
				"what this]")
	table.insert(formspec, "label[0,3.0;reward is for and/or where it will be handed out.]")
	table.insert(formspec, "label[0,3.4;In general, just click on \"Create\" to proceed.]")
	table.insert(formspec, "button_exit[3,3.9;2,1;exit;Exit]")
	return table.concat(formspec, "")
end


-- create a formspec with the updated reward inventory for the player
reward_inv.get_reward_fs = function(player, reward_id)
	if(not(player)) then
		return ""
	end
	local pname = player:get_player_name()
	reward_inv.player_using[pname] = reward_id
	-- make the detached inventory contain those items that according to
	-- our stored data are still available to the player
	local inv = reward_inv.update_reward_inv(player, reward_id)
	if(not(inv)) then
		-- nothing to show
		return "size[10,2]"..
			"label[0,0;Internal error: Failed to create detached inventory.]"..
			"button[4,1;2,1;close;Close]"
	end
	-- is the player editing this?
	local edit_mode = reward_inv.player_is_editing[pname]
	-- we use the "give" priv as that seems most fitting
	local has_edit_priv = reward_inv.may_edit(pname, {give=true})
	-- do we need to assign a reward_id here first?
	if(not(reward_id) or reward_id == "") then
		if(not(has_edit_priv)) then
			return "size[6,1]"..
				"label[0,0;No reward assigned. Please come back later!]"..
				"button_exit[2,0.5;2,1;exit;Exit]"
		end
		return reward_inv.get_fs_set_reward_id(player)
	end

	-- get general information about the reward as such
	local reward_data = reward_inv.get_reward_data(reward_id)
	if(not(reward_data)) then
		if(not(has_edit_priv)) then
			return "size[6,1]"..
				"label[0,0;Not yet filled. Please come back later!]"..
				"button_exit[2,0.5;2,1;exit;Exit]"
		end
		-- no data yet - force entering edit mode so that we get data
		reward_inv.player_is_editing[pname] = true
		edit_mode = true
		reward_data = {}
	end

	-- for showing the player when and how much he/she took
	local access_data = reward_inv.get_access_data(pname, reward_id) or {0, 0, {}, 0}

	-- create the formspec
	local formspec = {"size[12,11]"}

	local text = "Congratulations! You've "
	local error_msg = ""
	if(edit_mode) then
		text = "You are in edit mode and editing this reward with ID \""..
			minetest.formspec_escape(reward_id).."\""
	elseif(not(reward_data)) then
		text = text.."found something not yet ready to use"
		-- TODO: add assign reward_id button?
	elseif(reward_data.pos) then
		text = text.."found this treasure chest at "..
			minetest.formspec_escape(minetest.pos_to_string(reward_data.pos))
	elseif(reward_data.npc_name) then
		text = text.."been awarded this reward by "..
			table.insert(formspec, minetest.formspec_escape(reward_data.npc_name))
	else
		text = text.."found this treasure"
	end
	table.insert(formspec, "label[1,-0.3;")
	table.insert(formspec, text)
	table.insert(formspec, ":]")

	-- provide information about how to identify this reward
	local text_hint       = reward_data.hint
	local text_when_found = reward_data.text_when_found
	if(text_hint and (not(text_when_found) or text_when_found=="")) then
		text_when_found = text_hint
	end
	table.insert(formspec, "container[0.2,0.2]")
	table.insert(formspec, "label[0,0;The hint that was supposed to lead you here was:]")
	table.insert(formspec, "label[0,1;Now this will be listed like this when you type \"/rewards\":]")
	text_hint       = minetest.formspec_escape(text_hint or "")
	text_when_found = minetest.formspec_escape(text_when_found or "")
	if(edit_mode) then
		table.insert(formspec, "field[0.5,0.6;7.6,1.0;input_text_hint;;")
		table.insert(formspec, text_hint)
		table.insert(formspec, "]")
		table.insert(formspec, "field[0.5,1.6;7.6,1.0;input_text_when_found;;")
		table.insert(formspec, text_when_found)
		table.insert(formspec, "]")
		table.insert(formspec, "label[8.0,0;Refill reward after t seconds:]")
		table.insert(formspec, "field[8.5,0.6;3.7,1.0;input_refill_after_t_seconds;;")
		table.insert(formspec, minetest.formspec_escape(reward_data.refill_after_t_seconds or 0))
		table.insert(formspec, "]")
		table.insert(formspec, "tooltip[input_text_hint;"..
					"This hint will be shown to players who have not found or not\n"..
					"been awarded this reward yet. The hint ought to help players\n"..
					"locate the general area where to search, i.e.\n"..
					"\tTavern \"The Lion's Inn\" in Capital City "..
					minetest.formspec_escape("[Area ID 1234]")..
					"\nor something like:\n"..
					"\tTalk to shopkeeper in the village Lone Valley\n"..
					"If no text is set, then this reward will not show up in /rewards.]")
		table.insert(formspec, "tooltip[input_text_when_found;"..
					"This text will be shown to players who have found or been\n"..
					"awarded this reward.\n"..
					"If nothing is set here, the hint text will be shown.]")
		table.insert(formspec, "tooltip[input_refill_after_t_secons;"..
					"If this value is higher than 0, players can claim this reward\n"..
					"again if more than this many seconds have passed since they\n"..
					"last took something from this reward.\n"..
					"Hour: 3600 s, day: 86400 s, week: 604800 s, month: 18144000 s\n"..
					"Leave it at 0 in order to hand each reward out only once.]")
	else
		if(text_hint == "") then
			text_hint = "- none -"
		end
		if(text_when_found == "") then
			text_when_found = "- not listed -"
		end
		table.insert(formspec, "label[0.5,0.5;")
		table.insert(formspec, minetest.colorize("#CCCCFF", text_hint))
		table.insert(formspec, "]")
		table.insert(formspec, "label[0.5,1.5;")
		table.insert(formspec, minetest.colorize("#00FF00", text_when_found))
		table.insert(formspec, "]")
	end
	if(reward_data
	  and reward_data.refill_after_t_seconds
	  and reward_data.refill_after_t_seconds > 0) then
		table.insert(formspec, "label[8.0,6;This treasure refills sometimes.]")
		table.insert(formspec, "label[8.0,6.3;")
		table.insert(formspec, minetest.colorize("#FFFF00", "Might be worth comming back!"))
		table.insert(formspec, "]")
	else
		table.insert(formspec, "label[8.0,6;But beware: There is no refill.]")
		table.insert(formspec, "label[8.0,6.3;You will get this only once.]")
	end
	table.insert(formspec, "container_end[]")

	-- show some simple access data to all
	table.insert(formspec, "container[8.2,2]")
	table.insert(formspec, "box[-0.2,0.3;3.9,2.9;#000000]")
	table.insert(formspec, "label[1,0.5;Statistic:]")
	table.insert(formspec, "label[0,2.5;Found by:]")
	table.insert(formspec, "label[2,2.5;")
	table.insert(formspec, tostring(reward_data.anz_found or 0))
	table.insert(formspec, " people]")
	table.insert(formspec, "label[0,1.0;First found:]")
	table.insert(formspec, "label[0,1.5;Last found:]")
	table.insert(formspec, "label[0,2.0;Last taken:]")
	-- player-specific information
	table.insert(formspec, "box[-0.2,4.9;3.9,2.1;#000000]")
	table.insert(formspec, "label[1,5.0;Your data:]")
	table.insert(formspec, "label[0,5.5;First found:]")
	table.insert(formspec, "label[0,6.0;Last taken:]")
	table.insert(formspec, "label[0,6.5;Items taken:]")
	local offset = 0.5
	local dates = {reward_data.first_found or 0,
			reward_data.last_found or 0,
			reward_data.last_taken or 0,
			access_data[1] or 0,
			access_data[4] or 0}
	for i, date in ipairs(dates) do
		local txt = "- never -"
		if(date and date > 0) then
			txt = os.date("%m/%d/%y %H:%M", date)
		end
		table.insert(formspec, "label[1.6,")
		table.insert(formspec, tostring(offset + (0.5 * i)))
		table.insert(formspec, ";")
		table.insert(formspec, minetest.formspec_escape(txt))
		table.insert(formspec, "]")
		-- for the "Your data:" part
		if(i==3) then
			offset = 3.5
		end
	end
	table.insert(formspec, "label[2,6.5;")
	table.insert(formspec, tostring(access_data[5]))
	table.insert(formspec, "]")

	table.insert(formspec, "button_exit[-0.2,-0.5;4.1,1;show_reward_list;Show reward list]")
	table.insert(formspec, "button_exit[-0.2,8.2;4.1,1;exit;Close]")
	if(edit_mode) then
		table.insert(formspec, "button[-0.2,3.4;4.1,1;save;Save changes]")
	else
		table.insert(formspec, "button[-0.2,3.4;4.1,1;start_edit;Edit]")
	end
	table.insert(formspec, "container_end[]")

	-- add a short text in the space between the two inventories
	if(edit_mode) then
		table.insert(formspec, "label[0.5,6.15;Fill this inventory with what you want the "..
					"reward to be.]")
		table.insert(formspec, "label[0.5,6.45;Each player may then take out one copy of it.]")
	else
		table.insert(formspec, "label[0.5,6.15;Don't worry if you can't carry it all.]")
		table.insert(formspec, "label[0.5,6.45;You can come back any time later and claim the rest.]")
	end

	local reward_inv_name = reward_inv.reward_inv_get_name(pname)
	table.insert(formspec, "container[0,2]")
--	table.insert(formspec, "background[0,0;8,9;default_gold_block.png;true]")
--	table.insert(formspec, "background[0,0;8,9;default_chest_top.png;true]")

	table.insert(formspec, "list[current_player;main;0,4.95;8,1;]")
	table.insert(formspec, "list[current_player;main;0,6.08;8,3;8]")
	table.insert(formspec, "list[detached:")
	table.insert(formspec, reward_inv_name)
	table.insert(formspec, ";main;0,0.3;8,4;]")
	table.insert(formspec, "listring[detached:")
	table.insert(formspec, reward_inv_name)
	table.insert(formspec, ";main]")
	table.insert(formspec, "listring[current_player;main]")
	table.insert(formspec, "container_end[]")
	return table.concat(formspec, "")
end


-- show a formspec with the updated reward inventory to the player
reward_inv.show_reward_fs = function(player, reward_id)
	if(not(player)) then
		return
	end
	local pname = player:get_player_name()
	-- create the formspec
	local formspec = reward_inv.get_reward_fs(player, reward_id)
	-- actually show the reward formspec to the player
	minetest.show_formspec(pname, "reward_inv:main", formspec)
end