-- construct the questlog
function quests.create_formspec(playername, tab)
	local queststringlist = {}
	local questlist = {}
	quests.formspec_lists[playername] = quests.formspec_lists[playername] or {}
	quests.formspec_lists[playername].id = 1
	quests.formspec_lists[playername].list = {}
	tab = tab or quests.formspec_lists[playername].tab or "1"
	if (tab == "1") then
		questlist = quests.active_quests[playername] or {}
	elseif (tab == "2") then
		questlist = quests.successfull_quests[playername] or {}
	elseif (tab == "3") then
		questlist = quests.failed_quests[playername] or {}
	end
	quests.formspec_lists[playername].tab = tab
		
	local no_quests = true
	for questname,questspecs in pairs(questlist) do
		if (questspecs.finished == nil) then
			local queststring = quests.registered_quests[questname]["title"]
			if (questspecs["count"] and questspecs["count"] > 1) then
				queststring = queststring .. " - " .. questspecs["count"]
			elseif(not questspecs["count"] and quests.registered_quests[questname]["max"] ~= 1) then
				queststring = queststring .. " - (" .. quests.round(questspecs["value"], 2) .. "/" .. quests.registered_quests[questname]["max"] .. ")"
			end
			table.insert(queststringlist, queststring)
			table.insert(quests.formspec_lists[playername].list, questname)
			no_quests = false
		end
	end
	local formspec = "size[7,10]"..
			"tabheader[0,0;header;Open quests,Finished quests,Failed quests;" .. tab .. "]"
	if (no_quests) then
		formspec = formspec .. "label[0.25,0.25;There are no quests in this category.]"
	else
		formspec = formspec .. "textlist[0.25,0.25;6.5,7.5;questlist;"..table.concat(queststringlist, ",") .. ";1;false]"
	end
	if (quests.formspec_lists[playername].tab == "1") then
		formspec = formspec .."button[0.25,8;3,.7;abort;Abort quest]"
	end
	formspec = formspec .. "button[3.75,8;3,.7;config;Configure]"..
			"button[.25,9;3,.7;info;Info]"..
			"button_exit[3.75,9;3,.7;exit;Exit]"
	return formspec
end

-- construct the configuration
function quests.create_config(playername)
	local formspec = "size[7,3]" .. 
			"checkbox[.25,.25;enable;Enable HUD;" 
	if(quests.hud[playername] ~= nil) then 
		formspec = formspec .. "true"
	else
		formspec = formspec ..  "false"
	end 
	formspec = formspec .. "]"..
			"button[.25,1.25;3,.7;return;Return]"
	return formspec
end

-- construct the info formspec
function quests.create_info(playername, questname)
	local formspec = "size[7,6.5]" ..
			 "label[0.5,0.5;" 

	if (questname) then
		formspec = formspec .. quests.registered_quests[questname].title .. "]" ..
				 "textarea[.5,1.5;6,4.5;description;;" .. quests.registered_quests[questname].description .. "]"

		if (quests.formspec_lists[playername].tab == "1") then
			formspec = formspec .. "button[.5,6;3,.7;abort;Abort quest]"
		end
	else
		formspec = formspec .. "No quest specified.]"
	end
	formspec = formspec .. "button[3.25,6;3,.7;return;Return]"
	return formspec
end

-- show the player playername his/her questlog
function quests.show_formspec(playername) 
	minetest.show_formspec(playername, "quests:questlog", quests.create_formspec(playername))
end

-- chatcommand to see a full list of quests:
minetest.register_chatcommand("quests", {
	params = "",
	description = "Show all open quests",
	func = function(name, param)
		minetest.show_formspec(name, "quests:questlog", quests.create_formspec(name))
		return true
	end
})

-- Handle the return fields of the questlog
minetest.register_on_player_receive_fields(function(player, formname, fields)
	if (player == nil) then
		return
	end
	local playername = player:get_player_name();
	if (playername == "") then
		return
	end
	if (formname == "quests:questlog") then
		if (fields["header"]) then
			minetest.show_formspec(playername, "quests:questlog", quests.create_formspec(playername, fields["header"]))
			return
		end
		if (fields["questlist"]) then
			local event = minetest.explode_textlist_event(fields["questlist"])
			if (event.type == "CHG") then
				quests.formspec_lists[playername].id = event.index
			end
		end
		if (fields["abort"]) then
			if (quests.formspec_lists[playername].id == nil) then
				return
			end
			quests.abort_quest(playername, quests.formspec_lists[playername]["list"][quests.formspec_lists[playername].id]) 
			minetest.show_formspec(playername, "quests:questlog", quests.create_formspec(playername))
		end
		if (fields["config"]) then
			minetest.show_formspec(playername, "quests:config", quests.create_config(playername))
		end
		if (fields["info"]) then
			minetest.show_formspec(playername, "quests:info", quests.create_info(playername, quests.formspec_lists[playername].list[quests.formspec_lists[playername].id]))
		end
	end
	if (formname == "quests:config") then
		if (fields["enable"]) then
			if (fields["enable"] == "true") then	
				quests.show_hud(playername)
			else
				quests.hide_hud(playername)
			end
		end
		if (fields["return"]) then
			minetest.show_formspec(playername, "quests:questlog", quests.create_formspec(playername))
		end
	end
	if (formname == "quests:info") then
		if (fields["abort"]) then
			if (quests.formspec_lists[playername].id == nil) then
				return
			end
			quests.abort_quest(playername, quests.formspec_lists[playername]["list"][quests.formspec_lists[playername].id]) 
			minetest.show_formspec(playername, "quests:questlog", quests.create_formspec(playername))
		end
		if (fields["return"]) then
			minetest.show_formspec(playername, "quests:questlog", quests.create_formspec(playername))
		end
	end
end)