local export = {}

local m_links = require("Module:links")
local m_str_utils = require("Module:string utilities")

local sub = m_str_utils.sub
local gsub = m_str_utils.gsub
local match = m_str_utils.match
local u = m_str_utils.char

local PAGENAME = mw.loadData("Module:headword/data").pagename
local lang = require("Module:languages").getByCode("pra")

local genders = {
	["m"] = "陽性", ["f"] = "陰性", ["n"] = "中性",
}

export.orjoiner = " <small style=\"color:888\">或</small> " -- Share for testing


local cases = {
	"主格", "賓格", "工具格", "與格", "離格",
	"屬格", "位格", "呼格"
}

local diaeresis = {i = "ï", u = "ü"}

function ending(tr)
	return sub(tr, -1, -1)
end


function export.joinSuffix(frame, stem, suffixes, etc)

	local output = ""
	local term

	local function to_Brah(tr)
		local is = require("Module:typing-aids").interpret_shortcuts
		return is(tr, "pra")
	end

	local function to_Deva(tr)
		local is = require("Module:typing-aids").interpret_shortcuts
		return is(tr, "sa")
	end

	local function to_Knda(tr)
		local is = require("Module:typing-aids").interpret_shortcuts
		return is(tr, "pra-Knda")
	end
	
	local function asis(tr) return tr end
	
	local sc = etc and etc.sc or error("Script not provided.")
	local converter = etc and etc.converter
	if not converter then
		converters = {Brah = to_Brah, Deva = to_Deva, Knda = to_Knda}
		converter = converters[sc:getCode()] or asis
		if etc then etc.converter = converter end
	end
	for _,suffix in ipairs(suffixes) do
		if match(suffix, "^⌫⌫") then --backspace
			term = sub(stem, 1, -3) .. "Ⓙ" .. sub(suffix, 3, -1)
		elseif match(suffix, "^⌫") then --backspace
			term = sub(stem, 1, -2) .. "Ⓙ" .. sub(suffix, 2, -1)
		else
			term = stem .. "Ⓙ" .. suffix
		end
-- May need a diaeresis at the join.
		term = gsub(term, "aⒿⒿ?([iu])", function(x) return "a" .. diaeresis[x] end)
		term = gsub(term, "Ⓙ", "")
		
		if output ~= "" then
			output = output .. export.orjoiner
		end
		output = output .. m_links.full_link({
			lang = lang,
			sc = sc,
			term = converter(term)})
	end
	
	if output == "" then
		output = "—"
	end

	return output

end

function export.select(dialect, word, g, etc)
	-- This is a function rather than inline so as to facilitate testing.
	-- sc is not yet used, but will be in later forms, and will be script object.
	local dn = "Module:pra-decl/noun/" .. dialect
	local data = mw.loadData(dn) or error("Could not load data module "..dn)
	if not etc then error("Argument etc not provided.") end
	if not etc.sc then
		error("Argument etc lacks field sc")
--	else error("Argument etc provides script "..etc.sc:getCode())
	end
	toler_other = false
	local word_tr = (lang:transliterate(word, etc.sc)) or toler_other and word
	if not word_tr then
		if etc.sc:getCode() == "None" then
			error(word.." is not in a script registered for Prakrit.")
		else
			error("Unknown transliteration error for "..word)
		end
	end
-- Special handling for explicit combining diaeresis.
	if sub(word_tr, -1, -1) == u(0x0308) then
		stem = sub(word_tr, 1, -3) .. "Ⓙ"  .. sub(word_tr, -2, -2)
	else
		stem = word_tr
	end
	local the_ending = ending(stem)
	return data[the_ending] and data[the_ending][g], stem
end

function export.show(frame, dialect)
	local args = frame:getParent().args
	local g = args[1]
	local word = args[2] or PAGENAME
	
	if PAGENAME == "pra-mah-decl-noun" or PAGENAME == "pra-sau-decl-noun" or PAGENAME == "pra-ard-decl-noun" or PAGENAME == "pra-mag-decl-noun" then
		g = "m"
		word = "𑀧𑀼𑀢𑁆𑀢"
	end
	local sc = lang:findBestScript(word)
	local etc = {sc = sc}
	
	local m_lang = require("Module:languages").getByCode(dialect, true, "allow etym")
	-- 4th argument is to be supplied when it comes to be used.
	local selected_data, word_tr = export.select(dialect, word, g, etc)
	
	local output = {nil,nil,nil,nil,nil,nil,nil,nil,nil,nil,nil,nil,nil,nil,nil,nil,nil,nil,nil,nil,nil,nil,nil,nil,nil,nil,nil}
	local output_i = 0
	local function insert(s)
		output_i = output_i + 1
		output[output_i] = s
	end
	insert([=[
{| class="inflection-table vsSwitcher" data-toggle-category="inflection" style="background:#FEFEFE; text-align:center; border: 1px solid #CCC;"
|- style="background: #d9ebff;"
! class="vsToggleElement" style="text-align: left;" colspan="3" |]=])
	insert(sub(m_lang:getCanonicalName(), 1, -9))
	insert(word)
	insert [=[ 的變格 ]=]
	insert(" (" .. genders[g] .. ")")

	insert [=[

|- class="vsHide"
! style="background:#eff7ff" | 
! style="background:#eff7ff" | 單數
! style="background:#eff7ff" | 複數
	]=]

	for i,v in ipairs(cases) do
		insert("\n|- class=\"vsHide\"\n! style=\"background-color:#eff7ff;\" | ")
		insert(v)
		insert("\n| ")
		insert(export.joinSuffix(frame, word_tr, selected_data[2 * i - 1], etc))
		insert("\n| ")
		insert(export.joinSuffix(frame, word_tr, selected_data[2 * i], etc))
	end

	insert "\n|}"
	return table.concat(output)
	
end

function export.pra_mah(frame)
	return export.show(frame, "pra-mah")
end

function export.pra_sau(frame)
	return export.show(frame, "pra-sau")
end

function export.pra_ard(frame)
	return export.show(frame, "pra-ard")
end

function export.pra_mag(frame)
	return export.show(frame, "pra-mag")
end

return export