local S
if minetest.get_translator then
	S = minetest.get_translator("calendar")
else
	S = function(s) return s end
end
local F = minetest.formspec_escape

local COLOR_HOLIDAY = "#00FF00"
local COLOR_DAYBOX = "#00000080"
local COLOR_DAYBOX_TODAY = "#FFFFFF80"

local player_current_calendars = {}

local ORDINAL = false

local function show_calendar(player_name, ordinal, wanted_months, wanted_years)
	local days, months, years = calendar.get_date()
	local total_days = minetest.get_day_count()
	local ddays, dmonths, dyears = calendar.get_date(nil, ordinal)
	local wanted_dmonths, wanted_dyears
	if not wanted_months then
		wanted_months = months
	end
	if not wanted_years then
		wanted_years = years
	end
	wanted_dmonths = wanted_months
	wanted_dyears = wanted_years
	if ordinal then
		wanted_dmonths = wanted_dmonths + 1
		wanted_dyears = wanted_dyears + 1
	end
	local formspec = "formspec_version[3]size["..(calendar.WEEK_DAYS+2)..",10]"
	if ordinal then
		formspec = formspec .. "label[0.5,0.5;"..F(S("@1, year @2", calendar.month_names[wanted_months+1], wanted_dyears)).."]"
	else
		formspec = formspec .. "label[0.5,0.5;"..F(S("@1, @2 years", calendar.month_names[wanted_months+1], wanted_dyears)).."]"
	end
	local start_day, end_day
	local tdays = 0
	tdays = tdays + wanted_years * (calendar.MONTHS * calendar.MONTH_DAYS)
	tdays = tdays + wanted_months * calendar.MONTH_DAYS
	local tdays_start = tdays
	local weekday = calendar.get_weekday(tdays)

	local x, y = 0.75, 1.2
	for w=1, #calendar.weekday_names_short do
		formspec = formspec .. "label["..x..","..y..";"..calendar.weekday_names_short[w].."]"
		x = x + 1.1
	end

	x, y = 0.5, 1.7
	for iday=0, calendar.MONTH_DAYS - 1 do
		weekday = weekday + 1
		if weekday > calendar.WEEK_DAYS then
			weekday = 1
			y = y + 1.1
		end
		x = (weekday*1.1)- 0.5
		local pday = iday
		if ordinal then
			pday = iday + 1
		end
		local day_str = tostring(pday)
		local box_color = COLOR_DAYBOX
		local holidays = calendar.get_holidays(tdays)
		local tooltip_lines = {}
		if #holidays > 0 then
			table.insert(tooltip_lines, minetest.colorize(COLOR_HOLIDAY, holidays[1].name))
			day_str = minetest.colorize(COLOR_HOLIDAY, day_str)
		end
		if tdays == total_days then
			box_color = COLOR_DAYBOX_TODAY
			table.insert(tooltip_lines, S("Today"))
		end
		if #tooltip_lines > 0 then
			formspec = formspec .. "tooltip["..x..","..y..";1,1;"..F(table.concat(tooltip_lines, "\n")).."]"
		end
		day_str = F(day_str)
		formspec = formspec .. "box["..x..","..y..";1,1;"..box_color.."]" ..
		"label["..(x+0.15)..","..(y+0.3)..";"..day_str.."]"
		tdays = tdays + 1
	end
	y = y + 1.1
	if calendar.get_weekday(tdays_start) <= calendar.get_weekday(tdays - 1) then
		y = y + 1.1
	end
	y = y + 0.1
	if wanted_months > 0 or wanted_years > 0 then
		formspec = formspec .. "button[0.5,"..y..";1,1;prev_year;<<]"
		.. "button[1.5,"..y..";1,1;prev_month;<]"
	end
	formspec = formspec .. "button[2.5,"..y..";1,1;next_month;>]"
	.. "button[3.5,"..y..";1,1;next_year;>>]"
	minetest.show_formspec(player_name, "calendar:calendar", formspec)

	player_current_calendars[player_name] = { years = wanted_years, months = wanted_months }
end

minetest.register_on_player_receive_fields(function(player, formname, fields)
	if formname ~= "calendar:calendar" then
		return
	end
	if not player:is_player() then
		return
	end
	local name = player:get_player_name()
	local cur_years, cur_months
	if not player_current_calendars then
		return
	end
	cur_years = player_current_calendars[name].years
	cur_months = player_current_calendars[name].months
	if fields.next_year then
		cur_years = cur_years + 1
		show_calendar(name, ORDINAL, cur_months, cur_years)
	elseif fields.prev_year then
		if cur_years == 0 then
			cur_months = 0
		else
			cur_years = cur_years - 1
		end
		show_calendar(name, ORDINAL, cur_months, cur_years)
	elseif fields.next_month then
		cur_months = cur_months + 1
		if cur_months > calendar.MONTHS - 1 then
			cur_months = 0
			cur_years = cur_years + 1
		end
		show_calendar(name, ORDINAL, cur_months, cur_years)
	elseif fields.prev_month then
		cur_months = cur_months - 1
		if cur_months < 0 then
			if cur_years > 0 then
				cur_months = calendar.MONTHS - 1
				cur_years = cur_years - 1
			end
		end
		show_calendar(name, ORDINAL, cur_months, cur_years)
	end
end)

minetest.register_on_leaveplayer(function(player)
	local name = player:get_player_name()
	player_current_calendars[name] = nil
end)

minetest.register_chatcommand("calendar", {
	param = "",
	description = S("Display calendar"),
	func = function( name, param )
		show_calendar(name, ORDINAL)
	end,
})