local m_links = require("Module:links")
local m_utilities = require("Module:utilities")

local export = {}

local u = mw.ustring.char
local rsub = mw.ustring.gsub
local usub = mw.ustring.sub
local ulen = mw.ustring.len
local rfind = mw.ustring.find
local rmatch = mw.ustring.match

-- ABOUT TEMPLATE AND DISPLAY HYPHENS:
--
-- The "template hyphen" is the per-script hyphen character that is used in
-- template calls to indicate that a term is an affix. This is always a single
-- Unicode char, but there may be multiple possible hyphens for a given script.
-- Normally this is just the regular hyphen character "-", but for some
-- non-Latin-script languages (currently only right-to-left languages), it
-- is different.
--
-- The "display hyphen" is the string (which might be an empty string) that
-- is added onto a term as displayed (and linked), to indicate that a term
-- is an affix. Currently this is always either the same as the template
-- hyphen or an empty string, but the code below is written generally enough
-- to handle arbitrary display hyphens. Specifically:
--
-- (1) For East Asian languages, the display hyphen is always blank.
-- (2) For Arabic-script languages, either tatweel (ـ) or ZWNJ (zero-width
--     non-joiner) are allowed as template hyphens, where ZWNJ is supported
--     primarily for Farsi, because some suffixes have non-joining behavior.
--     The display hyphen corresponding to tatweel is also tatweel, but the
--     display hyphen corresponding to ZWNJ is blank (tatweel is also the
--     default display hyphen, for calls to {{prefix}}/{{suffix}}/etc. that
--     don't include an explicit hyphen).

-- List of all Arabic scripts.
local arab_scripts = {
	"Arab",
	-- WTF? Why are there a zillion language-specific variants of the
	-- Arabic script?
	"fa-Arab",
	"kk-Arab",
	"ks-Arab",
	"ku-Arab",
	"ms-Arab",
	"mzn-Arab",
	"ota-Arab",
	"pa-Arab",
	"ps-Arab",
	"sd-Arab",
	"tt-Arab",
	"ug-Arab",
	"ur-Arab",
}

-- Per-script template hyphens. The template hyphen is what appears in the
-- {{affix}}/{{prefix}}/{{suffix}}/etc. template (in the wikicode). See below.
--
-- The value below is a string consisting of one or more hyphen characters.
-- If there is more than one character, a non-default function must be
-- specified for the script in display_hyphens[] so the correct display
-- hyphen will be specified when no template hyphen is given (in {{suffix}}/
-- {{prefix}}/etc.).
--
-- Script detection is normally done when linking, but we need to do it
-- earlier. However, under most circumstances we don't need to do script
-- detection. Specifically, we only need to do script detection for a given
-- language if
--
-- (a) the language has multiple scripts; and
-- (b) at least one of those scripts is listed below or in display_hyphens.

local ZWNJ = u(0x200C) -- zero-width non-joiner
local arab_hyphens = "ـ" .. ZWNJ .. "-"
local template_hyphens = {
	-- Arabic scripts get added below
	["Hebr"] = "־",
	-- FIXME! What about the following right-to-left scripts?
	-- Adlm (Adlam)
	-- Armi (Imperial Aramaic)
	-- Avst (Avestan)
	-- Cprt (Cypriot)
	-- Khar (Kharoshthi)
	-- Mand (Mandaic/Mandaean)
	-- Mani (Manichaean)
	-- Mend (Mende/Mende Kikakui)
	-- Narb (Old North Arabian)
	-- Nbat (Nabataean/Nabatean)
	-- Nkoo (N'Ko)
	-- Orkh (Orkhon runes)
	-- Phli (Inscriptional Pahlavi)
	-- Phlp (Psalter Pahlavi)
	-- Phlv (Book Pahlavi)
	-- Phnx (Phoenician)
	-- Prti (Inscriptional Parthian)
	-- Rohg (Hanifi Rohingya)
	-- Samr (Samaritan)
	-- Sarb (Old South Arabian)
	-- Sogd (Sogdian)
	-- Sogo (Old Sogdian)
	-- Syrc (Syriac)
	-- Thaa (Thaana)
}
for _, script in ipairs(arab_scripts) do
	template_hyphens[script] = arab_hyphens
end

-- Default display-hyphen funct
local function default_display_hyphen(script, hyph)
	if not hyph then
		return template_hyphens[script] or "-"
	end
	return hyph
end

local function no_display_hyphen(script, hyph)
	return ""
end

local function arab_get_display_hyphen(script, hyph)
	if not hyph then
		return "ـ" -- tatweel
	elseif hyph == ZWNJ then
		return ""
	else
		return hyph
	end
end

-- Per-script function to return the correct display hyphen given the
-- script and template hyphen. The function should also handle the case
-- where the passed-in template hyphen is nil, corresponding to the
-- situation in {{prefix}}/{{suffix}}/etc. where no template hyphen is
-- specified.
local display_hyphens = {
	-- Arabic scripts get added below
	["Hani"] = no_display_hyphen,
	-- The following two are mixtures of several scripts. Hopefully
	-- the specs here are correct!
	["Jpan"] = no_display_hyphen,
	["Kore"] = no_display_hyphen,
	["Laoo"] = no_display_hyphen,
	["Nshu"] = no_display_hyphen,
	["Thai"] = no_display_hyphen,
}
for _, script in ipairs(arab_scripts) do
	display_hyphens[script] = arab_get_display_hyphen
end

local function pluralize(pos)
	if pos ~= "nouns" and usub(pos, -5) ~= "verbs" and usub(pos, -4) ~= "ives" then
		if pos:find("[sx]$") then
			pos = pos .. "es"
		else
			pos = pos .. "s"
		end
	end
	return pos
end

local function link_term(terminfo, display_term, lang, sc, sort_key)
	local terminfo_new = require("Module:table").shallowcopy(terminfo)
	local result

	terminfo_new.term = display_term	
	if terminfo_new.lang then
		result = require("Module:etymology").format_borrowed(lang, terminfo_new, sort_key, false, true, "plain")
	else
		terminfo_new.lang = lang
		terminfo_new.sc = terminfo_new.sc or sc
		result = m_links.full_link(terminfo_new, "term", false)
	end
	
	if terminfo_new.q then
		result = result .. " " .. require("Module:qualifier").format_qualifier(terminfo_new.q)
	end
	
	return result
end

-- Figure out the appropriate script for the given affix and language (unless
-- the script is explicitly passed in), and return the values of
-- template_hyphens[] and display_hyphens[] for that script, substituting
-- default values as appropriate. Three values are returned:
--	DETECTED_SCRIPT, TEMPLATE_HYPHEN, DISPLAY_HYPHEN
local function get_template_and_display_hyphens(text, lang, sc)
	local scode
	-- 1. If the script is explicitly passed in, use it.
	if sc then
		scode = sc:getCode()
	else
		lang = require("Module:languages").getNonEtymological(lang)
		-- If we don't call shallowClone here, #possible_scripts always == 0.
		-- Something weird to do with the metatable that's set on the table,
		-- coming from loadData.
		local possible_scripts = require("Module:table").shallowClone(lang:getScriptCodes())
		if #possible_scripts == 0 then
			-- This shouldn't happen; if the language has no script codes,
			-- the list {"None"} should be returned.
			error("Something is majorly wrong! Language " .. lang:getCanonicalName() .. " has no script codes.")
		end
		if #possible_scripts == 1 then
			-- 2. If the language has only one possible script, use it.
			scode = possible_scripts[1]
		else
			-- 3. Check if any of the possible scripts for the language have
			--    non-default values for template_hyphens[] or
			--    display_hyphens[]. If so, we need to do script detection on
			--    the text. If not, just use "Latn", which may not be
			--    technically correct but produces the right results because
			--    Latn has all default values for template_hyphens[] and
			--    display_hyphens[].
			local may_have_nondefault_hyphen = false
			for _, script in ipairs(possible_scripts) do
				if template_hyphens[script] or display_hyphens[script] then
					may_have_nondefault_hyphen = true
					break
				end
			end
			if not may_have_nondefault_hyphen then
				scode = "Latn"
			else
				scode = require("Module:scripts").findBestScript(text, lang):getCode()
			end
		end
	end
	local template_hyphen = template_hyphens[scode] or "-"
	local display_hyphen = display_hyphens[scode] or default_display_hyphen
	return scode, template_hyphen, display_hyphen
end

-- Find the type of affix ("prefix", "infix", "suffix", "circumfix" or nil
-- for non-affix). Return the affix type and the displayed/linked equivalent
-- of the part (normally the same as the part but will be different for some
-- East Asian languages that use a regular hyphen as an affix-signaling
-- hyphen but have no display hyphen).
local function get_affix_type(lang, sc, part)
	if not part then
		return nil, nil
	end
	
	local scode, thyph, dhyph = get_template_and_display_hyphens(part, lang, sc)
	thyph = "([" .. thyph .. "])"
	local hyphen_space_hyphen = thyph .. " " .. thyph

	if part:find("^%^") then
		-- If part begins with ^, it's not an affix no matter what.
		-- Strip off the ^ and return "no affix".
		return nil, usub(part, 2)
	end

	-- Remove an asterisk if the morpheme is reconstructed and add it in the end.
	local reconstructed = ""
	if part:find("^%*") then 
		reconstructed = "*"
		part = part:gsub("^%*", "")
	end

	local affix_type = nil

	local beginning_hyphen = rmatch(part, "^" .. thyph .. ".*$")
	local ending_hyphen = rmatch(part, "^.*" .. thyph .. "$")
	local beginning_dhyph = dhyph(scode, beginning_hyphen)
	local ending_dhyph = dhyph(scode, ending_hyphen)

	if rfind(part, hyphen_space_hyphen) then
		affix_type = "circumfix"
		-- FIXME! Change to display hyphens?
	elseif beginning_hyphen and ending_hyphen then
		affix_type = "infix"
		-- Don't do anything if the part is a single hyphen.
		-- This is probably correct.
		if (beginning_hyphen ~= beginning_dhyph or
			ending_hyphen ~= ending_dhyph) and ulen(part) > 1 then
			part = beginning_dhyph .. rsub(part, "^.(.-).$", "%1") .. ending_dhyph
		end
	elseif ending_hyphen then
		affix_type = "prefix"
		if ending_hyphen ~= ending_dhyph then
			part = rsub(part, "^(.-).$", "%1") .. ending_dhyph
		end
	elseif beginning_hyphen then
		affix_type = "suffix"
		if beginning_hyphen ~= beginning_dhyph then
			part = beginning_dhyph .. usub(part, 2)
		end
	end

	part = reconstructed .. part
	return affix_type, part
end


-- Iterate an array up to the greatest integer index found.
local function ipairs_with_gaps(t)
	local max_index = math.max(unpack(require("Module:table").numKeys(t)))
	local i = 0
	return function()
		while i < max_index do
			i = i + 1
			return i, t[i]
		end
	end
end

export.ipairs_with_gaps = ipairs_with_gaps


function export.show_affixes(lang, sc, parts, pos, sort_key, nocat)
	pos = pos or "word"
	
	pos = pluralize(pos)
	
	-- Process each part
	local parts_formatted = {}
	local categories_formatted = {}
	local whole_words = 0
	
	for i, part in ipairs_with_gaps(parts) do
		part = part or {}
		local part_lang = part.lang or lang
		local part_sc = part.sc or sc
		
		-- Is it an affix, and if so, what type of affix?
		local affix_type, display_term = get_affix_type(part_lang, part_sc, part.term)
		
		-- Make a link for the part
		if display_term == "" then
			-- If a bare ^ was specified, then insert a blank string. A + will still
			-- appear next to it. This lets us directly convert things such as
			-- {{suffix|mul||idae}} to {{affix|mul|^|-idae}}.
			table.insert(parts_formatted, "")
		else
			table.insert(parts_formatted, link_term(part, display_term, lang, sc, sort_key))
		end
		
		if affix_type then
			-- Make a sort key
			-- For the first part, use the second part as the sort key
			local part_sort_base = nil
			local part_sort = part.sort or sort_key
			
			if i == 1 and parts[2] and parts[2].term then
				local part2_lang = parts[2].lang or lang
				local part2_sc = parts[2].sc or sc
				local part2_affix_type, part2_display_term = get_affix_type(part2_lang, part2_sc, parts[2].term)
				part_sort_base = part2_lang:makeEntryName(part2_display_term)
			end
			
			if affix_type == "infix" then affix_type = "interfix" end
			
			if part.pos and rfind(part.pos, "patronym") then
				table.insert(categories_formatted, m_utilities.format_categories({lang:getCanonicalName() .. " patronymics"}, lang, part_sort, part_sort_base))
			end
			
			if pos ~= "words" and part.pos and rfind(part.pos, "diminutive") then
				table.insert(categories_formatted, m_utilities.format_categories({lang:getCanonicalName() .. " diminutive " .. pos}, lang, part_sort, part_sort_base))
			end
			
			table.insert(categories_formatted, m_utilities.format_categories({lang:getCanonicalName() .. " " .. pos .. " " .. affix_type .. "ed with " .. part_lang:makeEntryName(display_term) .. (part.id and " (" .. part.id .. ")" or "")}, lang, part_sort, part_sort_base))
		else
			whole_words = whole_words + 1
			
			if whole_words == 2 then
				table.insert(categories_formatted, m_utilities.format_categories({lang:getCanonicalName() .. " compound " .. pos}, lang, sort_key))
			end
		end
	end
	
	-- If there are no categories, then there were no actual affixes, only regular words.
	-- This function does not support compounds (yet?), so show an error.
	if #categories_formatted == 0 then
		error("The parameters did not include any affixes, and the word is not a compound. Please provide at least one affix.")
	end
	
	return table.concat(parts_formatted, " +&lrm; ") .. (nocat and "" or table.concat(categories_formatted))
end


function export.show_compound(lang, sc, parts, pos, sort_key, nocat)
	pos = pos or "words"
	local parts_formatted = {}
	local categories_formatted = {}
	table.insert(categories_formatted, m_utilities.format_categories({lang:getCanonicalName() .. " compound words"}, lang, sort_key))
	
	-- Make links out of all the parts
	local whole_words = 0
	for i, part in ipairs(parts) do
		local part_lang = part.lang or lang
		local part_sc = part.sc or sc
		local affix_type, display_term = get_affix_type(part_lang, part_sc, part.term)

		-- If the word is an infix, recognize it as such (which means
		-- e.g. that we will display the word without hyphens for
		-- East Asian languages). Otherwise, ignore the fact that it
		-- looks like an affix and display as specified in the template
		-- (but pay attention to the detected affix type for certain
		-- tracking purposes)
		if affix_type == "infix" then
			table.insert(categories_formatted, m_utilities.format_categories({lang:getCanonicalName() .. " " .. pos .. " interfixed with " .. part_lang:makeEntryName(display_term)}, lang, part.sort or sort_key))
		else
			display_term = part.term
			if affix_type then
				require("Module:debug").track{
					"compound",
					"compound/" .. affix_type,
					"compound/" .. affix_type .. "/lang/" .. lang:getCode()
				}
			else
				whole_words = whole_words + 1
			end
		end
		table.insert(parts_formatted, link_term(part, display_term, lang, sc, sort_key))
	end

	if whole_words == 1 then
		require("Module:debug").track("compound/one whole word")
	elseif whole_words == 0 then
		require("Module:debug").track("compound/looks like confix")
	end
	
	return table.concat(parts_formatted, " +&lrm; ") .. (nocat and "" or table.concat(categories_formatted))
end


function export.show_compound_like(lang, sc, parts, sort_key, text, oftext, cat)
	local parts_formatted = {}
	local categories_formatted = {}

	if cat then	
		table.insert(categories_formatted, m_utilities.format_categories({lang:getCanonicalName() .. " " .. cat}, lang, sort_key))
	end
	
	-- Make links out of all the parts
	for i, part in ipairs(parts) do
		table.insert(parts_formatted, link_term(part, part.term, lang, sc, sort_key))
	end

	local text_sections = {}
	if text then
		table.insert(text_sections, text)
	end
	if #parts > 0 and oftext then
		table.insert(text_sections, " ")
		table.insert(text_sections, oftext)
		table.insert(text_sections, " ")
	end
	table.insert(text_sections, table.concat(parts_formatted, " +&lrm; "))
	table.insert(text_sections, table.concat(categories_formatted, ""))
	return table.concat(text_sections, "")
end


-- Make a given part into an affix of a specific type. For example, if the desired affix type
-- is "suffix", this will (in general) add a hyphen onto the beginning of the term, alt, tr and ts
-- components of the part if not already present. The hyphen that's added is the "display hyphen"
-- (see above) and may be language-specific. In the case of East Asian languages, the display
-- hyphen is an empty string whereas the template hyphen is the regular hyphen, meaning that any
-- regular hyphen at the beginning of the part will be effectively removed.
local function make_part_affix(part, lang, sc, affix_type)
	local part_lang = part.lang or lang
	local part_sc = part.sc or sc

	part.term = export.make_affix(part.term, part_lang, part_sc, affix_type)
	part.alt = export.make_affix(part.alt, part_lang, part_sc, affix_type)
	part.tr = export.make_affix(part.tr, part_lang, require("Module:scripts").getByCode("Latn"), affix_type)
	part.ts = export.make_affix(part.ts, part_lang, require("Module:scripts").getByCode("Latn"), affix_type)
end


local function track_wrong_affix_type(template, part, lang, sc, expected_affix_type, part_name)
	if part then
		local affix_type = get_affix_type(part.lang or lang, part.sc or sc, part.term)
		if affix_type ~= expected_affix_type then
			require("Module:debug").track{
				template,
				template .. "/" .. part_name,
				template .. "/" .. part_name .. "/" .. (affix_type or "none"),
				template .. "/" .. part_name .. "/" .. (affix_type or "none") .. "/lang/" .. lang:getCode()
			}
		end
	end
end


local function insert_affix_category(categories, lang, pos, affix_type, part)
	if part.term then
		local part_lang = part.lang or lang
		table.insert(categories, lang:getCanonicalName() .. " " .. pos .. " " .. affix_type .. "ed with " .. part_lang:makeEntryName(part.term) .. (part.id and " (" .. part.id .. ")" or ""))
	end
end


function export.show_circumfix(lang, sc, prefix, base, suffix, pos, sort_key, nocat)
	local categories = {}
	pos = pos or "word"
	
	pos = pluralize(pos)
	
	-- Hyphenate the affixes
	make_part_affix(prefix, lang, sc, "prefix")
	make_part_affix(suffix, lang, sc, "suffix")
	
	track_wrong_affix_type("circumfix", prefix, lang, sc, "prefix", "prefix")
	track_wrong_affix_type("circumfix", base, lang, sc, nil, "base")
	track_wrong_affix_type("circumfix", suffix, lang, sc, "suffix", "suffix")
	
	-- Create circumfix term
	local circumfix = nil
	
	if prefix.term and suffix.term then
		circumfix = prefix.term .. " " .. suffix.term
		prefix.alt = prefix.alt or prefix.term
		suffix.alt = suffix.alt or suffix.term
		prefix.term = circumfix
		suffix.term = circumfix
	end
	
	-- Make links out of all the parts
	local parts_formatted = {}
	local sort_base = (base.lang or lang):makeEntryName(base.term)
	
	table.insert(parts_formatted, link_term(prefix, prefix.term, lang, sc, sort_key))
	table.insert(parts_formatted, link_term(base, base.term, lang, sc, sort_key))
	table.insert(parts_formatted, link_term(suffix, suffix.term, lang, sc, sort_key))
	
	-- Insert the categories
	table.insert(categories, lang:getCanonicalName() .. " " .. pos .. " circumfixed with " .. (prefix.lang or lang):makeEntryName(circumfix))
	
	return table.concat(parts_formatted, " +&lrm; ") .. (nocat and "" or m_utilities.format_categories(categories, lang, sort_key, sort_base))
end


function export.show_confix(lang, sc, prefix, base, suffix, pos, sort_key, nocat)
	pos = pos or "word"
	
	pos = pluralize(pos)
	
	-- Hyphenate the affixes
	make_part_affix(prefix, lang, sc, "prefix")
	make_part_affix(suffix, lang, sc, "suffix")
	
	track_wrong_affix_type("confix", prefix, lang, sc, "prefix", "prefix")
	track_wrong_affix_type("confix", base, lang, sc, nil, "base")
	track_wrong_affix_type("confix", suffix, lang, sc, "suffix", "suffix")
	
	-- Make links out of all the parts
	local parts_formatted = {}
	local prefix_sort_base
	if suffix.term then
		prefix_sort_base = (suffix.lang or lang):makeEntryName(suffix.term)
	end
	local prefix_categories = {}
	local suffix_categories = {}
	
	table.insert(parts_formatted, link_term(prefix, prefix.term, lang, sc, sort_key))
	insert_affix_category(prefix_categories, lang, pos, "prefix", prefix)
	
	if base then
		if base.term then
			prefix_sort_base = (base.lang or lang):makeEntryName(base.term)
		end
		table.insert(parts_formatted, link_term(base, base.term, lang, sc, sort_key))
	end
	
	table.insert(parts_formatted, link_term(suffix, suffix.term, lang, sc, sort_key))
	insert_affix_category(suffix_categories, lang, pos, "suffix", suffix)
	
	return table.concat(parts_formatted, " +&lrm; ") .. (nocat and "" or m_utilities.format_categories(prefix_categories, lang, sort_key, prefix_sort_base) .. m_utilities.format_categories(suffix_categories, lang, sort_key))
end


function export.show_infix(lang, sc, base, infix, pos, sort_key, nocat)
	local categories = {}
	pos = pos or "word"
	
	pos = pluralize(pos)
	
	-- Hyphenate the affixes
	make_part_affix(infix, lang, sc, "infix")
	
	track_wrong_affix_type("infix", base, lang, sc, nil, "base")
	track_wrong_affix_type("infix", infix, lang, sc, "infix", "infix")
	
	-- Make links out of all the parts
	local parts_formatted = {}
	
	table.insert(parts_formatted, link_term(base, base.term, lang, sc, sort_key))
	table.insert(parts_formatted, link_term(infix, infix.term, lang, sc, sort_key))
	
	-- Insert the categories
	insert_affix_category(categories, lang, pos, "infix", infix)
	
	return table.concat(parts_formatted, " +&lrm; ") .. (nocat and "" or m_utilities.format_categories(categories, lang, sort_key))
end


function export.show_prefixes(lang, sc, prefixes, base, pos, sort_key, nocat)
	pos = pos or "word"
	
	pos = pluralize(pos)
	
	-- Hyphenate the affixes
	for i, prefix in ipairs(prefixes) do
		make_part_affix(prefix, lang, sc, "prefix")
	end
	
	for i, prefix in ipairs(prefixes) do
		track_wrong_affix_type("prefix", prefix, lang, sc, "prefix", "prefix")
	end

	track_wrong_affix_type("prefix", base, lang, sc, nil, "base")

	-- Make links out of all the parts
	local parts_formatted = {}
	local first_sort_base = nil
	local categories = {}
	
	for i, prefix in ipairs(prefixes) do
		table.insert(parts_formatted, link_term(prefix, prefix.term, lang, sc, sort_key))
		insert_affix_category(categories, lang, pos, "prefix", prefix)
		
		if i > 1 and first_sort_base == nil then
			first_sort_base = (prefix.lang or lang):makeEntryName(prefix.term)
		end
	end
	
	if base then
		if first_sort_base == nil then
			first_sort_base = (base.lang or lang):makeEntryName(base.term)
		end
		
		table.insert(parts_formatted, link_term(base, base.term, lang, sc, sort_key))
	else
		table.insert(parts_formatted, "")
	end
	
	local first_category = table.remove(categories, 1)
	return table.concat(parts_formatted, " +&lrm; ") .. (nocat and "" or m_utilities.format_categories({first_category}, lang, sort_key, first_sort_base) .. m_utilities.format_categories(categories, lang, sort_key))
end


function export.show_suffixes(lang, sc, base, suffixes, pos, sort_key, nocat)
	local categories = {}
	pos = pos or "word"
	
	pos = pluralize(pos)
	
	-- Hyphenate the affixes
	for i, suffix in ipairs(suffixes) do
		make_part_affix(suffix, lang, sc, "suffix")
	end
	
	track_wrong_affix_type("suffix", base, lang, sc, nil, "base")

	for i, suffix in ipairs(suffixes) do
		track_wrong_affix_type("suffix", suffix, lang, sc, "suffix", "suffix")
	end
	
	-- Make links out of all the parts
	local parts_formatted = {}
	
	if base then
		table.insert(parts_formatted, link_term(base, base.term, lang, sc, sort_key))
	else
		table.insert(parts_formatted, "")
	end
	
	for i, suffix in ipairs(suffixes) do
		table.insert(parts_formatted, link_term(suffix, suffix.term, lang, sc, sort_key))
	end
	
	-- Insert the categories
	for i, suffix in ipairs(suffixes) do
		if suffix.term then
			insert_affix_category(categories, lang, pos, "suffix", suffix)
		end
		
		if suffix.pos and rfind(suffix.pos, "patronym") then
			table.insert(categories, lang:getCanonicalName() .. " patronymics")
		end
	end
	
	return table.concat(parts_formatted, " +&lrm; ") .. (nocat and "" or m_utilities.format_categories(categories, lang, sort_key))
end


function export.show_transfix(lang, sc, base, transfix, pos, sort_key, nocat)
	local categories = {}
	pos = pos or "word"
	
	pos = pluralize(pos)
	
	-- Hyphenate the affixes
	make_part_affix(transfix, lang, sc, "transfix")
	
	-- Make links out of all the parts
	local parts_formatted = {}
	
	table.insert(parts_formatted, link_term(base, base.term, lang, sc, sort_key))
	table.insert(parts_formatted, link_term(transfix, transfix.term, lang, sc, sort_key))
	
	-- Insert the categories
	insert_affix_category(categories, lang, pos, "transfix", transfix)
	
	return table.concat(parts_formatted, " +&lrm; ") .. (nocat and "" or m_utilities.format_categories(categories, lang, sort_key))
end


-- Add a hyphen to a word in the appropriate place, based on the specified
-- affix type. For example, if `affix_type` == "prefix", we'll add a hyphen
-- onto the end if it's not already there. In general, if the template and
-- display hyphens are the same and the appropriate hyphen is already
-- present, we leave it, else we strip off the template hyphen if present
-- and add the display hyphen.
function export.make_affix(term, lang, sc, affix_type)
	if not (affix_type == "prefix" or affix_type == "suffix" or
		affix_type == "circumfix" or affix_type == "infix" or
		affix_type == "interfix" or affix_type == "transfix") then
		error("Internal error: Invalid affix type " .. (affix_type or "(nil)"))
	end
	
	if not term then
		return nil
	end

	-- If the term begins with ^, leave it exactly as-is except for removing the ^.
	if usub(term, 1, 1) == "^" then
		return usub(term, 2)
	end
		
	if affix_type == "circumfix" or affix_type == "transfix" then
		return term
	elseif affix_type == "interfix" then
		affix_type = "infix"
	end
	
	local scode, thyph, dhyph = get_template_and_display_hyphens(term, lang, sc)
	thyph = "([" .. thyph .. "])"
	
	-- Remove an asterisk if the morpheme is reconstructed and add it in the end.
	local reconstructed = ""
	if term:find("^%*") then 
		reconstructed = "*"
		term = term:gsub("^%*", "")
	end
	
	local beginning_hyphen = rmatch(term, "^" .. thyph .. ".*$")
	local ending_hyphen = rmatch(term, "^.*" .. thyph .. "$")
	local beginning_dhyph = dhyph(scode, beginning_hyphen)
	local ending_dhyph = dhyph(scode, ending_hyphen)

	if affix_type == "suffix" then
		if beginning_hyphen and beginning_hyphen == beginning_dhyph then
			-- leave term alone
		else
			local term_no_hyphen = beginning_hyphen and usub(term, 2) or term
			term = beginning_dhyph .. term_no_hyphen
		end
	elseif affix_type == "prefix" then
		if ending_hyphen and ending_hyphen == ending_dhyph then
			-- leave term alone
		else
			local term_no_hyphen = ending_hyphen and rsub(term, "^(.-).$", "%1") or term
			term = term_no_hyphen .. ending_dhyph
		end
	elseif affix_type == "infix" then
		if (beginning_hyphen and ending_hyphen and
			beginning_hyphen == beginning_dhyph and
			ending_hyphen == ending_dhyph) then
			-- leave term alone
		elseif term == beginning_hyphen or term == ending_hyphen then
			-- term is a single hyphen; should probably leave alone
		else
			local term_no_hyphen = beginning_hyphen and usub(term, 2) or term
			term_no_hyphen = ending_hyphen and rsub(term_no_hyphen, "^(.-).$", "%1") or term_no_hyphen
			term = beginning_dhyph .. term_no_hyphen .. ending_dhyph
		end
	else
		error("Internal error: Bad affix type " .. affix_type)
	end
	
	return reconstructed .. term
end

return export

-- For Vim, so we get 4-space tabs
-- vim: set ts=4 sw=4 noet: