Editing Module:Sandbox/Ste1la/Dates

-- Ste1la Google Code-in, Date formatting

local p = {}

p.formatDate = function(frame)
	local date = frame.args.date or ""
	local format = frame.args.format or ""
	local circa 
	local epoca = nil
	local out = ""
	local monthList = {"jan", "january", "feb", "february", "feb", "mar", "march",
		"apr", "april", "may", "jun", "june", "jul", "july", "aug", "august", 
		"sep", "september", "oct", "october", "nov", "november", "dec", "december"}
	local obtain = 0
	
	--> extracting dates
	--check if is uncertain and if epoca exists
	--[[ = date:find("uncertain")
	if circa == nil then
		circa = date:find("sometime")
	end
	if circa == nil then
		circa = date:find("around")
	end
	if circa ~= nil then
		out = out .. "circa "
	end]]
	if date:find("uncertain") or date:find("sometime") or date:find("around") then
		out = out .. "circa "
	end
	
	epoca = date:find("AD")
    if epoca ~= nil then
		epoca = "AD"
	elseif epoca == nil then
    epoca = date:find("BCE")
    if epoca ~= nil then
      epoca = "BCE"
    elseif epoca == nil then
      epoca = date:find("BC")
      if epoca ~= nil then
        epoca = "BC"
      elseif epoca == nil then
          epoca = date:find("CE")
          if epoca ~= nil then
            epoca = "CE"
          end
        end
      end
    end
	
	--dmy
	local day, month, year = date:match("(%d+) (%w+) (%d+)")
	if day ~= nil and month ~= nil and year ~= nil then
		obtain = 1
		inputFormat = "dmy"
	end
	
	--mdy
	if obtain == 0 then
		month, day, year = date:match("(%w+) (%d+), (%d+)")

		if day ~= nil and month ~= nil and year ~= nil then
			obtain = 1
			inputFormat = "mdy"
		end
	end
	--three number cases
	if obtain == 0 then
		day, month, year = date:match("(%d+)/(%d+)/(%d+)")
		if day ~= nil and month ~= nil and year ~= nil then
			obtain = 1
			inputFormat = "iso"
		end
	end
	
	if obtain == 0 then
		day, month, year = date:match("(%d+)-(%d+)-(%d+)")
		if day ~= nil and month ~= nil and year ~= nil then
			obtain = 1
			inputFormat = "iso"
		end
	end
	-- not any above, gets two numbers and checks for month
	if obtain == 0 then
		local i, j = date:find("%d+")
		if i ~= nil then
			year = date:sub(i, j) or 0
			inputFormat = "year"
			if i ~= nil then
				i, j = date:find("%d+", j + 1)
				if i ~= nil then
					day = date:sub(i, j) or 0
					inputFormat = "day"
				end
			end
		end
		
		for i = 1, 23 do
			local temp = date:lower()
			if temp:match(monthList[i]) ~= nil then
    			month = temp:match(monthList[i])
    			if inputFormat == "year" then
    				
    				inputFormat = "month and year"
    			elseif inputFormat == "day" then
    				inputFormat = "all"
    			end
    			
			end
		i = i + 1
		end
		
		if month == nil then
			month = ""
		end
		if day == nil then
			day = 0
		end
		if year == nil then
			year = 0
		end
		
	end

	if (day == "" or day == 0) and (year == "" or year == 0) then
		return "Invalid entry"
	end
	
	
	if inputFormat == "day" then
      inputFormat = "year"
    end
    
	--converts month to number
	if tonumber(month) == nil then
		monthChange = 1
		month = month:lower()
		if month:match("jan") then
			month = 1
		elseif month:match("feb") then
			month = 2
		elseif month:match("mar") then
			month = 3
		elseif month:match("apr") then
			month = 4
		elseif month:match("may") then
			month = 5
		elseif month:match("jun") then
			month = 6
		elseif month:match("jul") then
			month = 7
		elseif month:match("aug") then
			month = 8
		elseif month:match("sep") then
			month = 9
		elseif month:match("oct") then
			month = 10
		elseif month:match("nov") then
			month = 11
		elseif month:match("dec") then
			month = 12
		else 
			month = 0
		end
	end
	
	-->switches variables
	-- sets year
	day = tonumber(day)
	month = tonumber(month)
	if day > 31 then
	  local temp = year
	  year = day
	  day = temp
	elseif month > 31 then
	  local temp = year
	  year = month
	  month = temp
	end

	if month > 12 then
	  local temp = day
	  day = month
	  month = temp
	end	

	--checks leap year
	if month == 2 and day > 29 then
		return "Invalid entry"
	end
	if month == 2 and day == 29 then 	
		local leap = year % 4
		if leap ~= 0 then
			return "Invalid entry"
		end
	end
	
	--OUTPUTS DATAAAAAAAAAAA!!!
	-->reformat data if necessary
	if format ~= "" then
		inputFormat = ""
	end
	
	if format == "dmy" or format == "mdy" or format == "month and year" or 
		inputFormat == "dmy" or inputFormat == "mdy" or inputFormat == "month and year" or
		inputFormat == "all" then
		if month == 1 then
			month = "January"
		elseif month == 2 then
			month = "February"
		elseif month == 3 then
			month = "March"	
		elseif month == 4 then
			month = "April"
		elseif month == 5 then
			month = "May"
		elseif month == 6 then
			month = "June"
		elseif month == 7 then
			month = "July"
		elseif month == 8 then
			month = "August"
		elseif month == 9 then
			month = "September"
		elseif month == 10 then
			month = "October"
		elseif month == 11 then
			month = "November"
		elseif month == 12 then
			month = "December"
		end
	end
	
	if day == 0 then
		day = ""
	end
	if month == 0 then
		month = ""
	end
	if year == 0 then
		year = ""
	end

	
	if format == "dmy" then
		if day < 31 and year < 31 and month == "" then
			return "Invalid entry"
		end
		out = out .. day .. " " .. month .. " " .. year
	elseif format == "mdy" then
		out = out .. month .. " " .. day .. ", " .. year
	elseif format == "iso" then
		if month < 10 then
			month = "0" .. month
		end
		out = out .. year .. "-" .. month .. "-" .. day
	elseif format == "year" then
		out = out .. year
	elseif format == "month and year" then
		out = out .. month .. " " .. year
	elseif inputFormat == "dmy" then
		if tonumber(day) < 31 and tonumber(year) < 31 and month == "" then
			return "Invalid entry"
		end
		out = out .. day .. " " .. month .. " " .. year	
	elseif inputFormat == "mdy" then
		out = out .. month .. " " .. day .. ", " .. year
	elseif inputFormat == "iso" then
		if month < 10 then
			month = "0" .. month
		end
		out = out .. year .. "-" .. month .. "-" .. day
	elseif inputFormat == "year" then
		out = out .. year
	elseif inputFormat == "month and year" then
		out = out .. year .. " " .. month
	else
		if day ~= "" or day ~= nil then
			out = out .. day .. " "
		end
		if month ~= "" or month ~= nil then
			out = out .. month .. " "
		end
		if year ~= "" or year ~= nil then
			out = out .. year
		end
	end
	
	if epoca ~= nil then
		out = out .. " " .. epoca
	end
	
	return out .. "<br>"
end

return p