local set_fs = i3.set_fs

IMPORT("min", "max", "vec_round")
IMPORT("reg_items", "reg_aliases")
IMPORT("sort", "copy", "insert", "remove", "indexof")
IMPORT("S", "random", "translate", "compressible", "ItemStack")
IMPORT("fmt", "find", "match", "sub", "lower", "split", "toupper")
IMPORT("valid_item", "get_stack", "craft_stack", "clean_name", "check_privs", "safe_teleport")
IMPORT("msg", "is_fav", "pos_to_str", "str_to_pos", "add_hud_waypoint", "play_sound", "reset_data")
IMPORT("search", "sort_inventory", "sort_by_category", "get_recipes", "get_detached_inv", "update_inv_size")

local function inv_fields(player, data, fields)
	local name = data.player_name
	local inv = player:get_inventory()

	if fields.dd_sorting_method then
		data.sort = tonumber(fields.dd_sorting_method)
	elseif fields.sb_font_size then
		data.font_size = tonumber(fields.sb_font_size:match"-?%d+$")
	end

	for field in pairs(fields) do
		if sub(field, 1, 4) == "btn_" then
			data.subcat = indexof(i3.categories, sub(field, 5))
			break

		elseif sub(field, 1, 3) == "cb_" then
			local str = sub(field, 4)
			data[str] = false

			if fields[field] == "true" then
				data[str] = true
			end

			if str == "legacy_inventory" then
				update_inv_size(player, data)
			elseif str == "collapse" then
				search(data)
			end

		elseif sub(field, 1, 8) == "setting_" then
			data.show_setting = match(field, "_(%w+)$")

		elseif sub(field, 1, 9) == "skin_btn_" then
			local id = tonumber(field:match("%d+"))
			local _skins = skins.get_skinlist_for_player(name)

			play_sound(name, "i3_skin_change", 0.6)
			skins.set_player_skin(player, _skins[id])

		elseif find(field, "waypoint_%d+") then
			local id, action = match(field, "_(%d+)_(%w+)$")
			      id = tonumber(id)
			local waypoint = data.waypoints[id]
			if not waypoint then return end

			if action == "see" then
				if data.waypoint_see and data.waypoint_see == id then
					data.waypoint_see = nil
				else
					data.waypoint_see = id
				end

			elseif action == "delete" then
				player:hud_remove(waypoint.id)
				remove(data.waypoints, id)

			elseif action == "teleport" then
				local pos = str_to_pos(waypoint.pos)
				safe_teleport(player, pos)
				msg(name, S("Teleported to: @1", waypoint.name))

			elseif action == "refresh" then
				local color = random(0xffffff)
				waypoint.color = color
				player:hud_change(waypoint.id, "number", color)

			elseif action == "hide" then
				if waypoint.hide then
					local new_id = add_hud_waypoint(
						player, waypoint.name, str_to_pos(waypoint.pos), waypoint.color)

					waypoint.id = new_id
					waypoint.hide = nil
				else
					player:hud_remove(waypoint.id)
					waypoint.hide = true
				end
			end

			break
		end
	end

	if fields.quit then
		data.confirm_trash = nil
		data.show_settings = nil
		data.waypoint_see = nil
		data.bag_rename = nil
		data.goto_page = nil

		if data.filter == "" then
			data.enable_search = nil
		end

	elseif fields.trash then
		data.show_settings = nil
		data.confirm_trash = true

	elseif fields.settings then
		if not data.show_settings then
			data.confirm_trash = nil
			data.show_settings = true
		else
			data.show_settings = nil
		end

	elseif fields.confirm_trash_yes or fields.confirm_trash_no then
		if fields.confirm_trash_yes then
			inv:set_list("main", {})
			inv:set_list("craft", {})
		end

		data.confirm_trash = nil

	elseif fields.close_settings then
		data.show_settings = nil

	elseif fields.close_preview then
		data.waypoint_see = nil

	elseif fields.sort then
		sort_inventory(player, data)

	elseif (fields.home or fields.set_home) and not check_privs(name, {home = true}) then
		return msg(name, "'home' privilege missing")

	elseif fields.home then
		if sethome then
			if not sethome.go(name) then
				return msg(name, "No home set")
			end
		elseif not data.home then
			return msg(name, "No home set")
		else
			safe_teleport(player, str_to_pos(data.home))
		end

		msg(name, S"Welcome back home!")

	elseif fields.set_home then
		if sethome then
			sethome.set(name, player:get_pos())
		else
			data.home = pos_to_str(player:get_pos(), 1)
		end

	elseif fields.bag_rename then
		data.bag_rename = true

	elseif fields.confirm_rename then
		local bag = get_detached_inv("bag", name)
		local bagstack = bag:get_stack("main", 1)
		local meta = bagstack:get_meta()
		local desc = translate(data.lang_code, bagstack:get_description())
		local fill = split(desc, "(")[2]
		local newname = fields.bag_newname:gsub("([%(%)])", "")
		      newname = toupper(newname:trim())

		if fill then
			newname = fmt("%s (%s", newname, fill)
		end

		meta:set_string("description", newname)
		bag:set_stack("main", 1, bagstack)

		data.bag = bagstack:to_string()
		data.bag_rename = nil

	elseif fields.waypoint_add then
		local max_waypoints = i3.settings.max_waypoints

		if #data.waypoints >= max_waypoints then
			play_sound(name, "i3_cannot", 0.8)
			return msg(name, fmt("Waypoints limit reached (%u)", max_waypoints))
		end

		local pos = player:get_pos()

		for _, v in ipairs(data.waypoints) do
			if vec_round(pos) == vec_round(str_to_pos(v.pos)) then
				play_sound(name, "i3_cannot", 0.8)
				return msg(name, S"You already have set a waypoint at this position")
			end
		end

		local waypoint = fields.waypoint_name

		if fields.waypoint_name == "" then
			waypoint = "Waypoint"
		end

		local color = random(0xffffff)
		local id = add_hud_waypoint(player, waypoint, pos, color)

		insert(data.waypoints, {
			name  = waypoint,
			pos   = pos_to_str(pos, 1),
			color = color,
			id    = id,
		})

		data.scrbar_inv += 1000

	elseif fields.hide_debug_grid then
		data.hide_debug_grid = not data.hide_debug_grid
	end
end

local function select_item(player, data, fields)
	local item

	for field in pairs(fields) do
		if find(field, ":") then
			item = field
			break
		end
	end

	if not item then return end

	if compressible(item, data) then
		local idx

		for i = 1, #data.items do
			local it = data.items[i]
			if it == item then
				idx = i
				break
			end
		end

		if data.expand ~= "" then
			data.alt_items = nil

			if item == data.expand then
				data.expand = nil
				return
			end
		end

		if idx and item ~= data.expand then
			data.alt_items = copy(data.items)
			data.expand = item

			if i3.compress_groups[item] then
				local items = copy(i3.compress_groups[item])
				insert(items, fmt("_%s", item))

				sort(items, function(a, b)
					if a:sub(1, 1) == "_" then
						a = a:sub(2)
					end

					return a < b
				end)

				local i = 1

				for _, v in ipairs(items) do
					if valid_item(reg_items[clean_name(v)]) then
						insert(data.alt_items, idx + i, v)
						i++
					end
				end
			end
		end
	else
		if sub(item, 1, 1) == "_" then
			item = sub(item, 2)
		elseif sub(item, 1, 6) == "group!" then
			item = match(item, "([%w:_]+)$")
		end

		item = reg_aliases[item] or item
		if not reg_items[item] then return end

		if core.is_creative_enabled(data.player_name) then
			local stack = ItemStack(item)
			local stackmax = stack:get_stack_max()
			      stack = fmt("%s %s", item, stackmax)

			return get_stack(player, stack)
		end

		if item == data.query_item then return end
		local recipes, usages = get_recipes(player, item)

		data.query_item   = item
		data.recipes      = recipes
		data.usages       = usages
		data.rnum         = 1
		data.unum         = 1
		data.scrbar_rcp   = 1
		data.scrbar_usg   = 1
		data.crafting_rcp = nil
		data.crafting_usg = nil
	end
end

local function rcp_fields(player, data, fields)
	local sb_rcp, sb_usg = fields.scrbar_rcp, fields.scrbar_usg

	if not data.hide_tabs and fields.filter and fields.filter == "" then
		data.enable_search = nil
	end

	if fields.cancel then
		reset_data(data)

	elseif fields.exit then
		data.query_item = nil

	elseif fields.enable_search then
		if data.hide_tabs then
			data.enable_search = not data.enable_search
		else
			data.enable_search = true
		end

	elseif fields.filter and (fields.key_enter_field == "filter" or fields.search) then
		if fields.filter == "" then
			reset_data(data)
			return set_fs(player)
		end

		local str = lower(fields.filter)
		if data.filter == str then return end

		data.filter = str
		data.pagenum = 1

		search(data)

		if data.itab > 1 then
			sort_by_category(data)
		end

	elseif fields.pagenum then
		data.goto_page = not data.goto_page

	elseif fields.goto_page then
		local pagenum = tonumber(fields.goto_page)
		data.pagenum = max(1, min(data.pagemax, pagenum or data.pagenum))
		data.goto_page = nil

	elseif fields.prev_page or fields.next_page then
		if data.pagemax == 1 then return end
		data.pagenum -= (fields.prev_page and 1 or -1)

		if data.pagenum > data.pagemax then
			data.pagenum = 1
		elseif data.pagenum == 0 then
			data.pagenum = data.pagemax
		end

	elseif fields.prev_skin or fields.next_skin then
		if data.skin_pagemax == 1 then return end
		data.skin_pagenum -= (fields.prev_skin and 1 or -1)

		if data.skin_pagenum > data.skin_pagemax then
			data.skin_pagenum = 1
		elseif data.skin_pagenum == 0 then
			data.skin_pagenum = data.skin_pagemax
		end

	elseif fields.prev_recipe or fields.next_recipe then
		local num = data.rnum + (fields.prev_recipe and -1 or 1)
		data.rnum = data.recipes[num] and num or (fields.prev_recipe and #data.recipes or 1)
		data.crafting_rcp = nil
		data.scrbar_rcp = 1

	elseif fields.prev_usage or fields.next_usage then
		local num = data.unum + (fields.prev_usage and -1 or 1)
		data.unum = data.usages[num] and num or (fields.prev_usage and #data.usages or 1)
		data.crafting_usg = nil
		data.scrbar_usg = 1

	elseif fields.fav then
		local fav = is_fav(data)

		if #data.favs < i3.settings.max_favs and not fav then
			insert(data.favs, data.query_item)
		elseif fav then
			remove(data.favs, fav)
		end

	elseif fields.crafting_rcp or fields.crafting_usg then
		if fields.crafting_rcp then
			data.crafting_rcp = not data.crafting_rcp

			if not data.crafting_rcp then
				data.scrbar_rcp = 1
			end
		else
			data.crafting_usg = not data.crafting_usg

			if not data.crafting_usg then
				data.scrbar_usg = 1
			end
		end

	elseif (sb_rcp and sub(sb_rcp, 1, 3) == "CHG") or (sb_usg and sub(sb_usg, 1, 3) == "CHG") then
		data.scrbar_rcp = sb_rcp and tonumber(match(sb_rcp, "%d+"))
		data.scrbar_usg = sb_usg and tonumber(match(sb_usg, "%d+"))

	elseif fields.craft_rcp or fields.craft_usg then
		craft_stack(player, data, fields.craft_rcp)

		if fields.craft_rcp then
			data.crafting_rcp = nil
			data.scrbar_rcp = 1
		else
			data.crafting_usg = nil
			data.scrbar_usg = 1
		end
	else
		select_item(player, data, fields)
	end
end

core.register_on_player_receive_fields(function(player, formname, fields)
	local name = player:get_player_name()

	if formname == "i3_outdated" then
		return false, core.kick_player(name, S"Your Minetest client needs updating (www.minetest.net)")
	elseif formname ~= "" then
		return false
	end

--	No-op buttons
	if fields.player_name or fields.awards or fields.home_pos or fields.no_item or
	   fields.no_rcp or fields.select_sorting or fields.sort_method or fields.bg_content or
	   fields.quick_crafting then
		return false
	end

--	print(dump(fields))
	local data = i3.data[name]
	if not data then return end

	local sb_inv = fields.scrbar_inv
	if sb_inv and sub(sb_inv, 1, 3) == "CHG" then
		data.scrbar_inv = tonumber(match(sb_inv, "%d+"))
		return
	end

	for f in pairs(fields) do
		if sub(f, 1, 4) == "tab_" then
			local tabname = sub(f, 5)
			i3.set_tab(player, tabname)
			break
		elseif sub(f, 1, 5) == "itab_" then
			data.pagenum = 1
			data.itab = tonumber(f:sub(-1))
			sort_by_category(data)
			break
		end
	end

	rcp_fields(player, data, fields)

	local tab = i3.tabs[data.tab]
	if tab then
		if tab.slots then
			inv_fields(player, data, fields)
		end

		if tab.fields then
			local ret = tab.fields(player, data, fields)
			if ret == false then return end
		end
	end

	return true, set_fs(player)
end)