local export = {}

local gsub = mw.ustring.gsub

function format_def (term, definition)
	local anchor = gsub(term, "%[%[([^%]]+)%]%]", "%1") -- Remove wikilinks
	anchor = gsub(anchor, "^%w+:", "") -- Remove interwiki prefixes
	
	return "; <span id=\""..anchor.."\">"..term.."</span>\n: "..definition
end

function format_anchor (anchor)
	anchor = gsub(anchor, " +", "_") -- spaces to underscores
	return anchor
end

function export.def (frame)
	local params = {
		[1] = { required = true, default = "", },
		[2] = { required = true, default = "", },
	}
	
	local args = require("Module:parameters").process(frame:getParent().args, params)
	
	local term = args[1]
	local definition = args[2]
	
	return format_def (term, definition)
end

function export.link(frame)
	local args = frame:getParent().args
	for k, v in pairs(args) do
		if not (k == 1 or k == 2) then
			require "Module:debug".track "glossary/invalid argument"
			require "Module:debug".track("glossary/invalid argument/" .. k)
			mw.log("invalid argument in {{glossary}}: " .. k)
		end
	end
	
	local anchor, text = args[1] or "", args[2]
	if text and text:match "^%s*$" then
		text = nil
	end
	
	-- This won't work if the initial letter is non-ASCII.
	local lower_anchor = anchor:lower()
	
	local data = mw.loadData("Module:glossary/data")
	if data[format_anchor(anchor)] then
		return "[[ภาคผนวก:อภิธานศัพท์#" .. format_anchor(anchor) .. "|" .. (text or anchor) .. "]]"
	else
		local link = "[[ภาคผนวก:อภิธานศัพท์#" .. format_anchor(lower_anchor) .. "|" .. (text or anchor) .. "]]"
		if data[format_anchor(lower_anchor)] or lower_anchor:find "^%s*$" then
			return link
		else
			mw.log("The anchor " .. lower_anchor
				.. (lower_anchor ~= anchor and " or " .. anchor or "")
				.. " does not exist in Appendix:Glossary.")
			return link
				.. "[[Category:Pages linking to anchors not found in Appendix:Glossary|"
				.. lower_anchor .. "]]"
		end
	end
end

return export