require('strict')
local getArgs = require ('Module:Arguments').getArgs;

local data = mw.loadData ('Module:month translator/data');


--[[--------------------------< _ M O N T H _ X L A T E >------------------------------------------------------

{{#invoke:Month translator|month_xlate|<date>}}

]]

local function _month_xlate (args_t)
	local t = {};
	local day, month, year;
	
	if 'dump' == args_t[1] then													-- args_t[1] = 'dump' to dump <month_names_t> table; 
		return mw.dumpObject (data.month_names_t);
	end
	if not args_t[1] then return nil end
	for i, pattern in ipairs (data.patterns) do									-- spin through the patterns table looking for a match
		local c1, c2, c3;														-- captures in the 'pattern' from the pattern table go here

		c1, c2, c3 = mw.ustring.match (mw.text.trim (args_t[1]), pattern[1]);	-- one or more captures set if source matches patterns[i][1])
		if c1 then																-- c1 always set on match

			t = {
				[pattern[2] or 'x'] = c1,										-- fill the table of captures with the captures
				[pattern[3] or 'x'] = c2,										-- take index names from pattern table and assign sequential captures
				[pattern[4] or 'x'] = c3,										-- index name may be nil in pattern table so "or 'x'" spoofs a name for this index in this table
				};
			day = t.d or '';													-- translate table contents to named variables;
			month = mw.ustring.lower (t.m or '');								-- absent table entries are nil so set unused parts to empty string; lowercase for indexing
			month = data.override_names[month] or data.month_names_t[month];	-- replace non-English name with English name from translation tables
			year= t.y or '';

			if month then
				local df = table.concat ({pattern[2], pattern[3], pattern[4]}, '');	-- extract date format from pattern table (pattern[2], pattern[3], pattern[4])

				if 'dmy' == df then												-- for dmy dates
					return table.concat ({day, month, year}, ' ');				-- assemble an English language dmy date
				elseif 'my' == df then											-- for month year dates
					return table.concat ({month, year}, ' ');					-- assemble an English language dmy date
				elseif 'mdy' == df then											-- for mdy dates
					return string.format ('%s %s, %s', month, day, year);		-- assemble an English language mdy date
				elseif 'm' == df then											-- must be month (only valid option remaining)
					return month;												-- none of the above, return the translated month;
				end
			end
			break;																-- and done; if here found pattern match but did not find non-English month name in <month_names_t>
		end
	end	
	return args_t[1];															-- if here, couldn't translate so return the original date
end


--[[--------------------------< M O N T H _ X L A T E >--------------------------------------------------------

{{#invoke:Month translator|month_xlate|<date>}}

]]

local function month_xlate (frame)
	return _month_xlate (getArgs (frame));
end


--[[--------------------------< E X P O R T E D   F U N C T I O N S >------------------------------------------
]]

return {
	month_xlate = month_xlate,
	_month_xlate = _month_xlate
	};