-- Imposing an order on the quest steps is...tricky as best as what will
-- be more important to the players will be the order in which the
-- quest steps have to be solved/done - and not an alphabetical order.
-- But we need an order here for a dropdown menu to select each
-- quest step even if it hasn't been assigned any place in the chain
-- of quest steps yet. So - alphabetical order.
yl_speak_up.get_sorted_quest_step_list = function(pname, q_id)
	local quest_step_list = {}
	if(not(pname) or not(yl_speak_up.speak_to[pname])) then
		return {}
	end
	local q_id = yl_speak_up.speak_to[pname].q_id

	if(q_id and yl_speak_up.quests[q_id] and yl_speak_up.quests[q_id].step_data) then
		for step_id, v in pairs(yl_speak_up.quests[q_id].step_data) do
			table.insert(quest_step_list, step_id)
		end
	end
        table.sort(quest_step_list)
        return quest_step_list
end             


-- helper functions for yl_speak_up.input_fs_manage_quest_steps(..)
-- returns the index of the new quest step
yl_speak_up.input_fs_manage_quest_steps_add_new_entry = function(pname, entry_name)
	local q_id = yl_speak_up.speak_to[pname].q_id
	local res = yl_speak_up.quest_step_add_quest_step(pname, q_id, entry_name)
	-- might make sense to show the error message somewhere
	if(res ~= "OK") then
		return res
	end
	-- the new entry will be somewhere in it
	local quest_step_list = yl_speak_up.get_sorted_quest_step_list(pname)
	return table.indexof(quest_step_list, entry_name)
end


-- helper functions for yl_speak_up.input_fs_manage_quest_steps(..)
-- returns a text describing if deleting the quest worked
yl_speak_up.input_fs_manage_quest_steps_del_old_entry = function(pname, entry_name)
	local q_id = yl_speak_up.speak_to[pname].q_id
	return yl_speak_up.quest_step_del_quest_step(pname, q_id, entry_name)
end


-- helper functions for yl_speak_up.input_fs_manage_quest_steps(..)
-- implements all the functions that are specific to managing quest steps and not part of
-- general item management
yl_speak_up.input_fs_manage_quest_steps_check_fields = function(player, formname, fields, quest_step_name, list_of_entries)
	local pname = player:get_player_name()
	if(not(quest_step_name)) then
		quest_step_name = ""
	end
--[[ TODO: implement some back button functionality?
	if(fields and fields.show_variable) then
		yl_speak_up.show_fs(player, "manage_variables", {var_name = quest_name})
		return
	end
--]]
	-- this function didn't have anything to do
	return "NOTHING FOUND"
end


-- makes use of yl_speak_up.input_fs_manage_general and is thus pretty short
yl_speak_up.input_fs_manage_quest_steps = function(player, formname, fields)
	-- TODO: check if the player is allowed to access that quest
	local pname = player:get_player_name()

	if(fields and fields.change_prev_step) then
		yl_speak_up.show_fs(player, "manage_quest_steps", " change_prev_step")
		return

	end
	if(fields
	  and (fields.add_to_one_needed or fields.add_to_all_needed
	    or fields.insert_after_prev_step or fields.insert_before_next_step)) then
		-- let that function sort out what to do;
		-- yl_speak_up.speak_to[pname].q_id and yl_speak_up.speak_to[pname].quest_step
		-- ought to be set to the current quest and step by now
		yl_speak_up.show_fs(player, "list_quest_steps", {fields=fields})
		return
	end
	local quest_step_list = yl_speak_up.get_sorted_quest_step_list(pname)
	local res = yl_speak_up.input_fs_manage_general(player, formname, fields,
		-- what_is_the_list_about, min_length, max_length, function_add_new_entry,
		"quest step", 2, 70,
		yl_speak_up.input_fs_manage_quest_steps_add_new_entry,
		quest_step_list,
		yl_speak_up.input_fs_manage_quest_steps_del_old_entry,
                yl_speak_up.input_fs_manage_quest_steps_check_fields)
	return true
end


-- small helper function for yl_speak_up.get_fs_manage_quest_steps
yl_speak_up.quest_step_show_table = function(formspec, table_specs, liste)
	table.insert(formspec, "tablecolumns[color;text]table[")
	table.insert(formspec, table_specs)
	local tmp = {}
	for k, v in pairs(liste) do
		table.insert(tmp, "#FFFFFF")
		table.insert(tmp, minetest.formspec_escape(v))
	end
	table.insert(formspec, table.concat(tmp, ","))
	table.insert(formspec, ";]")
end


yl_speak_up.get_fs_manage_quest_steps = function(player, param)
	-- small helper function
	local em = function(text)
			return minetest.colorize("#9999FF", text)
		   end

	-- TODO: check if the player is allowed to access that quest
	local pname = player:get_player_name()
	local formspec = {}

	local q_id = yl_speak_up.speak_to[pname].q_id
	local quest = yl_speak_up.quests[q_id]
	local step_data = quest.step_data

	local quest_step_list = yl_speak_up.get_sorted_quest_step_list(pname)
	if(param and param ~= "") then
		local index = table.indexof(quest_step_list, param)
		yl_speak_up.speak_to[pname].tmp_index_general = index + 1
	end
	local idx = yl_speak_up.speak_to[pname].tmp_index_general
	if(idx and idx > 1) then
		yl_speak_up.speak_to[pname].quest_step = quest_step_list[idx - 1]
	end
	table.insert(formspec,	"size[30,12]"..
				"container[6,0;18.5,12]"..
				"label[0.2,1.2;A quest step is a single thing a player may do in a quest - "..
						"like talking to an NPC.\n"..
					"Usually not all quest steps can be done/solved at all times.]")
	local selected = yl_speak_up.get_fs_manage_general(player, param,
				formspec, quest_step_list,
				"Create quest step",
					"Create a new quest step for this quest.",
				"quest step",
				"Enter the name of the new quest step you want to create.\n"..
					"This is an internal text shown only to yourself.\n"..
					"Players cannot see the names of quest steps.",
				"If you click here, the selected quest step will be deleted.\n"..
					"This will only be possible if it's not used anywhere.",
				"1.0")
	table.insert(formspec, "container_end[]")

	if(not(selected) or selected == "" or not(step_data) or not(step_data[selected])) then
		return table.concat(formspec, "")
	end
	-- find out the next quest step
	local required_for = {}
	for s, d in pairs(step_data) do
		if(s and d and d.one_step_required and type(d.one_step_required) == "table"
		  and table.indexof(d.one_step_required, selected) ~= -1) then
			table.insert(required_for, s)
		end
		if(s and d and d.all_steps_required and type(d.all_steps_required) == "table"
		  and table.indexof(d.all_steps_required, selected) ~= -1) then
			table.insert(required_for, s)
		end
	end
	-- left side (previous quest step)
	table.insert(formspec,  "label[0.2,2.0;"..em("Required previous").."]"..
				"label[0.2,2.4;quest step(s):]"..
				"style[change_prev_step,insert_before_next_step,insert_after_prev_step,"..
					"add_to_one_needed,add_to_all_needed;bgcolor=blue;textcolor=yellow]"..
				"button[3.7,1.8;2.0,0.8;change_prev_step;Edit]"..
				"tooltip[change_prev_step;"..
					"Click here to add, set or change the previous\n"..
					"and further required quest steps.]"..
				"container[0.1,2.7;5.6,10.8]"..
				"box[0,0;5.6,8.5;#666666]"..
				"button[4.6,0.0;0.9,0.7;add_to_one_needed;Edit]"..
				"tooltip[add_to_one_needed;Add or remove a quest step to this list.]"..
				"label[0.1,0.5;"..em("One of").." these quest steps:]")
	yl_speak_up.quest_step_show_table(formspec, "0.1,0.7;5.4,2.7;one_step_required;",
				step_data[selected].one_step_required or {})
	table.insert(formspec, "tooltip[one_step_required;"..
				"At least "..em("one of").." these previous quest steps listed "..						"here has to be\n"..
				"achieved by the player who is trying to solve this quest.\n"..
				"Only then can the player try to achieve this current quest\n"..
				"step that you are editing here.\n"..
				"If this is empty, then it's usually the/a first step of the quest.\n"..
				"If there is one entry, then that entry is the previous quest step.\n"..
				"If there are multiple entries, then players have alternate ways\n"..
				"to achieve this current quest step here.]")

	table.insert(formspec, "label[0.1,4.0;"..em("All of").." these quest steps:]"..
				"button[4.6,3.5;0.9,0.7;add_to_all_needed;Edit]"..
				"tooltip[add_to_all_needed;Add or remove a quest step to this list.]")
	yl_speak_up.quest_step_show_table(formspec, "0.1,4.2;5.4,4.0;all_steps_required;",
				step_data[selected].all_steps_required or {})
	table.insert(formspec, "tooltip[all_steps_required;"..
				"Sometimes there may not be a particular order in which\n"..
				"quest steps ought to be solved. Imagine for example getting\n"..
				"indigrents for a cake and delivering them to an NPC.\n"..
				"The quest steps listed here can be done in "..em("any order")..".\n"..
				"They have "..em("all").." to be achieved first in order for this current\n"..
				"quest step to become available.\n"..
				"Usually this list is empty.]")
	table.insert(formspec, "container_end[]")


	-- right side (next quest step)
	table.insert(formspec,  "label[24.2,2.0;Achieving this quest step]"..
				"label[24.2,2.4;"..em("helps").." the quester to:]"..
				"container[24.2,2.7;5.6,10.8]"..
				"box[0,0;5.6,8.5;#666666]"..
				"label[0.1,0.5;get these quest step(s) "..em("next")..":]")
	yl_speak_up.quest_step_show_table(formspec, "0.1,0.7;5.4,7.7;next_steps_show;",
				needed_for or {})
	table.insert(formspec, "tooltip[next_steps_show;"..
				"Once the current quest step has been achieved by the\n"..
				"player, the player can strive to achieve these next\n"..
				"quest step(s).\n"..
				"If this is empty, then it's either the/a last step (quest\n"..
				"solved!) - or the quest is not properly set up.]")
	table.insert(formspec, "container_end[]")

	-- middle (this quest step)
	table.insert(formspec, "container[6,2.7;12,10.8]"..
				"label[0.2,0.5;This quest step:]"..
				"dropdown[0.7,0.7;17,0.7;curr_step_show;")
	table.insert(formspec, minetest.formspec_escape(selected))
	table.insert(formspec, ";1;]")
	table.insert(formspec, "container_end[]")

	-- add buttons for inserting steps between this and the prev/next one
	if(not(step_data[selected].one_step_required) or #step_data[selected].one_step_required==1) then
		table.insert(formspec,
				"button[3.0,11.3;6.0,0.6;insert_after_prev_step;"..
					"+ Insert step *before* this one]"..
				"tooltip[insert_after_prev_step;"..
					"Insert a new quest step between the *previous* step\n"..
					"and the *current* (displayed here) step.\n"..
					"Note: This only makes sense if there's just one\n"..
					"      previous step.]")
	end
	if(#required_for <= 1) then
		table.insert(formspec,
				"button[21.0,11.3;6.0,0.6;insert_before_next_step;"..
					"Insert step *after* this one +]"..
				"tooltip[insert_before_next_step;"..
					"Insert a new quest step between this, the *currently*\n"..
					"displayed step, and the *next one*.\n"..
					"Note: This only makes sense if there's just one\n"..
					"      next step.]")
	end

	return table.concat(formspec, "")
end