Module:Smyth

local export = {}

local function Smyth(section, part)
	if not part then
		part = "smythp"
	end
	local Part, url
	if section == "" or section == nil then
		url, Part = "No number provided", "No number provided"
	else
		sectionNumber = tonumber(section)
		if sectionNumber == nil then
			Part = ""
		else
			if sectionNumber < 189 then
				Part = "Part I: Letters, Sounds, Syllables, Accent"
			elseif sectionNumber < 822 then
				Part = "Part II: Inflection"
			elseif sectionNumber < 900 then
				Part = "Part III: Formation of Words"
			elseif sectionNumber < 3049 then
				Part = "Part IV: Syntax"
			else
				error("The largest valid section number is 3048")
			end
		end
		section = mw.uri.encode(section, "PATH")
		url = "http://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0007:" .. part .. "=" .. section
	end
	return { url = url, Part = Part }
end

function export.SmythSection(frame)
	local sectionParameter = frame.args[1]
	local output, sign = "", ""
	local sections, postscripts, separators = {}, {}, {}
	local part = frame.args[2]
	if sectionParameter then
		n = 1
		if mw.ustring.find(sectionParameter, "[^%d%s]") then
			for number, postscript, separator in mw.ustring.gmatch(sectionParameter, "(%d+ ?%u?)(%.?[%l%d]?)(%p?[^%d]*)") do
				sections[n], postscripts[n], separators[n] = number, postscript, separator
				if sections[n] == "" or sections[n] == nil then
					break
				end
				n = n + 1
			end
		else
			sections[1], separators[1] = mw.ustring.match(sectionParameter, "(%d+)"), ""
		end
	else
		error("SmythSection wants input in the first parameter")
	end
	if #sections == nil then
		error("No numbers in the text provided to SmythSection")
	elseif sections[2] == "" or sections[2] == nil then
		sign = "§"
	else
		sign = "§§"
	end
	for i = 1, #sections do
		if sections[i] == "" or sections[i] == nil then -- Does gmatch return nil or an empty string when it finds no match?
			break
		else
			if not postscripts[i] then postscripts[i] = "" end
			if not separators[i] then separators[i] = "" end
			output = output .. "[" .. Smyth(sections[i]).url .. " "
			if i == 1 then
				output = output .. sign .. "&nbsp;"
			end
			output = output .. sections[i] .. postscripts[i] .. "]" ..  separators[i]
		end
	end
	return output
end

function export.SmythPart(frame)
	local sectionParameter = frame.args[1]
	local section = mw.ustring.match(sectionParameter, "(%d+)")
	return Smyth(section).Part
end

return export