--[[
Re-implementation of `os.date` from the standard lua library
]]

local gettime = require "luatz.gettime".gettime
local new_from_timestamp = require "luatz.timetable".new_from_timestamp
local get_tz = require "luatz.tzcache".get_tz

local function os_date(format_string, timestamp)
	format_string = format_string or "%c"
	timestamp = timestamp or gettime()
	if format_string:sub(1, 1) == "!" then -- UTC
		format_string = format_string:sub(2)
	else -- Localtime
		timestamp = get_tz():localise(timestamp)
	end
	local tt = new_from_timestamp(timestamp)
	if format_string == "*t" then
		return tt
	else
		return tt:strftime(format_string)
	end
end

return os_date