Module:TwitterSnowflake

local p = {}

local Date = require('Module:Date')._Date

function p.snowflakeToDate(frame) local format = frame.args.format or "%B %e, %Y" local epoch = tonumber(frame.args.epoch) or 1288834974 local id_str = frame.args.id_str if type(id_str) ~= "string" then error("bad argument #1 (expected string, got " .. type(id_str) .. ")", 2) end if type(format) ~= "string" then error("bad argument #2 (expected string, got " .. type(format) .. ")", 2) end if type(epoch) ~= "number" then error("bad argument #3 (expected number, got " .. type(epoch) .. ")", 2) end local hi, lo = 0, 0 local hiexp = 1 local two32 = 2^32 for c in id_str:gmatch(".") do		lo = lo * 10 + c		if lo >= two32 then hi, lo = hi * 10^hiexp + math.floor(lo / two32), lo % two32 hiexp = 1 else hiexp = hiexp + 1 end end hi = hi * 10^(hiexp-1) local timestamp = math.floor((hi * 1024 + math.floor(lo / 4194304)) / 1000) + epoch return os.date(format, timestamp) end

function p.getDate(frame) -- just pass frame directly to snowflakeToDate, this wraps it but the args are the same plus if (frame.args.id_str):match("%D") then -- not a number, so return -2 return -2 end frame.args.format = "%B %e, %Y" frame.args.epoch = tonumber(frame.args.epoch) or 1288834974 local epochdate = Date(os.date("%B %e, %Y", frame.args.epoch)) local twitterdate = Date(p.snowflakeToDate(frame)) if twitterdate == epochdate then -- created before epoch, so can't determine the date return -1 end local date = Date(frame.args.date) or 0 -- if we error here, then an input of no date causes an error, which is contrary to the entire way works return date - twitterdate end

local function abs_datediff(x) if type(x) == 'number' then return math.abs(x) end return math.abs(x.age_days) end

function p.datecheck(frame) local args = frame.args if not (args.date and args.id_str) then error('Must define date and id_str, even if they are blank.') end local errors = { args.error1 or 'Date mismatch of two or more days', args.error2 or 'No date, and posted before November 4, 2010', args.error3 or 'Invalid id_str' }	if mw.title.getCurrentTitle:inNamespace(0) and args.error_cat then for i = 1, 3 do errors[i] = errors[i] ..  .. args.error_cat ..  end end if not args.date:match('^%s*$') then -- #if: local testResult = p.getDate{ args = { date = args.date, id_str = args.id_str }} if testResult == -2 then return errors[3] end if abs_datediff(testResult) > 1 then return errors[1] end elseif not args.id_str:match('^%s*$') then local testResult = p.getDate{ args = { id_str = args.id_str }} if testResult == -1 then return errors[2] end if testResult == -2 then return errors[3] end end end

return p