"इस मॉड्यूल हेतु प्रलेख मॉड्यूल:utilities/doc पर बनाया जा सकता है"

local export = {}

local data = mw.loadData("Module:utilities/data")
local notneeded = data.notneeded
local neededhassubpage = data.neededhassubpage

-- A helper function to escape magic characters in a string.
-- Magic characters: ^$()%.[]*+-?
function export.pattern_escape(text)
	if type(text) == "table" then
		text = text.args[1]
	end
	return (text:gsub("([%^$()%%.%[%]*+%-?])", "%%%1"))
end

-- A helper function to resolve HTML entities into plaintext.
-- Iterates over entities in a string, and decodes them into plaintext. We use iteration (instead of decoding the whole string in one go) because it means we can avoid loading the lookup string unnecessarily, as it uses more memory.
function export.get_entities(text)
	local entities
	return (text:gsub("&[#%w]-;", function(entity)
		-- Check if mw.text.decode is able to decode the entity.
		if entity:find("^&#") or
			entity == "<" or
			entity == ">" or
			entity == "&" or
			entity == """ or
			entity == " "
		then
			return mw.text.decode(entity)
		else
			-- [[Module:utilities/data/entities]] is a lookup string of every named HTML entity (except the ones listed above), as they aren't covered by mw.text.decode.
			-- mw.text.decode can decode lots of named entities if the second parameter is true, but around 600 are still not covered, and it's less efficient than doing it this way anyway.
			entities = entities or require("Module:utilities/data/entities")
			local pattern = entity .. "(%Z+)"
			return entities:match(pattern)
		end
	end))
end

-- A helper function to convert plaintext into HTML entities where these match the characters given in set.
-- By default, this resolves any pre-existing entities into plaintext first, to allow mixed input and to avoid accidental double-conversion. This can be turned off with the raw parameter.
function export.make_entities(text, set, raw)
	text = not raw and export.get_entities(text) or text
	return mw.text.encode(text, set)
end

-- A helper function to strip wiki markup, giving the plaintext of what is displayed on the page.
function export.get_plaintext(text)
	local u = mw.ustring.char
	text = text
		:gsub("%[%[", "\1")
		:gsub("%]%]", "\2")
	
	-- Remove strip markers and HTML tags.
	text = mw.text.unstrip(text)
		:gsub("<[^<>\1\2]+>", "")
		
	-- Parse internal links for the display text, and remove categories.
	text = require("Module:links").remove_links(text)
	
	-- Remove files.
	for _, falsePositive in ipairs({"File", "Image"}) do
		text = text:gsub("\1" .. falsePositive .. ":[^\1\2]+\2", "")
	end

	-- Parse external links for the display text.
	text = text:gsub("%[(https?://[^%[%]]+)%]",
		function(capture)
			return capture:match("https?://[^%s%]]+%s([^%]]+)") or ""
		end)
	
	text = text
		:gsub("\1", "[[")
		:gsub("\2", "]]")
	
	-- Any remaining square brackets aren't involved in links, but must be escaped to avoid creating new links.
	text = text:gsub("[%[%]]", mw.text.nowiki)
		
	-- Strip bold, italics and soft hyphens.
	text = text
		:gsub("('*)'''(.-'*)'''", "%1%2")
		:gsub("('*)''(.-'*)''", "%1%2")
		:gsub("­", "")
	
	-- Get any HTML entities.
	-- Note: don't decode URL percent encoding, as it shouldn't be used in display text and may cause problems if % is used.
	text = export.get_entities(text)
	
	return mw.text.trim(text)
end

function export.plain_gsub(text, pattern, replacement)
	local invoked = false
	
	if type(text) == "table" then
		invoked = true
		
		if text.args then
			local frame = text
			
			local params = {
				[1] = {},
				[2] = {},
				[3] = { allow_empty = true },
			}
			
			local args = require("Module:parameters").process(frame.args, params, nil, "utilities", "plain_gsub")
			
			text = args[1]
			pattern = args[2]
			replacement = args[3]
		else
			error("If the first argument to plain_gsub is a table, it should be a frame object.")
		end
	else
		if not ( type(pattern) == "string" or type(pattern) == "number" ) then
			error("The second argument to plain_gsub should be a string or a number.")
		end
		
		if not ( type(replacement) == "string" or type(replacement) == "number" ) then
			error("The third argument to plain_gsub should be a string or a number.")
		end
	end
	
	pattern = export.pattern_escape(pattern)
	
	local gsub = require("Module:string utilities").gsub
	if invoked then
		return (gsub(text, pattern, replacement))
	else
		return gsub(text, pattern, replacement)
	end
end

--[[
Format the categories with the appropriate sort key. CATEGORIES is a list of
categories.
	-- LANG is an object encapsulating a language; if nil, the object for
	   language code 'und' (undetermined) will be used.
	-- SORT_KEY is placed in the category invocation, and indicates how the
	   page will sort in the respective category. Normally this should be nil,
	   and a default sort key based on the subpage name (the part after the
	   colon) will be used.
	-- SORT_BASE lets you override the default sort key used when SORT_KEY is
	   nil. Normally, this should be nil, and a language-specific default sort
	   key is computed from the subpage name (e.g. for Russian this converts
	   Cyrillic ё to a string consisting of Cyrillic е followed by U+10FFFF,
	   so that effectively ё sorts after е instead of the default Wikimedia
	   sort, which (I think) is based on Unicode sort order and puts ё after я,
	   the last letter of the Cyrillic alphabet.
	-- FORCE_OUTPUT forces normal output in all namespaces. Normally, nothing
	   is output if the page isn't in the main, Appendix:, Reconstruction: or
	   Citations: namespaces.
]]
function export.format_categories(categories, lang, sort_key, sort_base, force_output, sc)
	if type(lang) == "table" and not lang.getCode then
		error("The second argument to format_categories should be a language object.")
	end

	local title_obj = mw.title.getCurrentTitle()	
	local allowedNamespaces = {
		[0] = true, [100] = true, [114] = true, [118] = true -- (main), Appendix, Citations, Reconstruction
	}

	if force_output or allowedNamespaces[title_obj.namespace] or title_obj.prefixedText == "Wiktionary:Sandbox" then
		local PAGENAME = title_obj.text
		local SUBPAGENAME = title_obj.subpageText
		
		if not lang then
			lang = require("Module:languages").getByCode("und")
		end
		
		-- Generate a default sort key.
		local upper = require("Module:string utilities").upper
		if sort_key ~= "-" then
			-- Determine the intended title if the page is an unsupported title.
			local unsupported; SUBPAGENAME, unsupported = SUBPAGENAME:gsub("^Unsupported titles/", "")
			if unsupported > 0 then
				for title, page in pairs(mw.loadData("Module:links/data").unsupported_titles) do
					if page == SUBPAGENAME then
						SUBPAGENAME = title
						break
					end
				end
			end
			sort_base = (lang:makeSortKey(sort_base or SUBPAGENAME, sc))
			if sort_key and sort_key ~= "" then
				-- Gather some statistics regarding sort keys
				if upper(sort_key) == sort_base then
					table.insert(categories, "Sort key tracking/redundant")
				end
			else
				sort_key = sort_base
			end
			-- If the sortkey is empty, remove it.
			-- Leave the sortkey if it is equal to PAGENAME, because it still
			-- might be different from DEFAULTSORT and therefore have an effect; see
			-- [[Wiktionary:Grease pit/2020/April#Module:utilities#format categories]].
			if sort_key == "" then
				sort_key = nil
			end
		-- If the sort key is "-", bypass the process of generating a sort key altogether. This is desirable when categorising (e.g.) translation requests, as the pages to be categorised are always in English/Translingual.
		else
			sort_key = upper(sort_base or SUBPAGENAME)
		end
		
		local out_categories = {}
		for key, cat in ipairs(categories) do
			out_categories[key] = "[[Category:" .. cat .. (sort_key and "|" .. sort_key or "") .. "]]"
		end
		
		return table.concat(out_categories, "")
	else
		return ""
	end
end

function export.catfix(lang, sc)
	if not lang then
		require("Module:debug").track("catfix/no lang")
		return nil
	elseif type(lang) ~= "table" then
		require("Module:debug").track("catfix/lang not table")
		return nil
	end
	local canonicalName = lang:getCanonicalName() or error('The first argument to the function "catfix" should be a language object from Module:languages.')
	
	if sc and not sc.getCode then
		error('The second argument to the function "catfix" should be a script object from Module:scripts.')
	end
	
	-- To add script classes to links on pages created by category boilerplate templates.
	if not sc then
		sc = data.catfix_scripts[lang:getCode()]
		if sc then
			sc = require("Module:scripts").getByCode(sc)
		end
	end
	
	return "<span id=\"catfix\" style=\"display:none;\" class=\"CATFIX-" .. mw.uri.anchorEncode(canonicalName) .. "\">" ..
		require("Module:script utilities").tag_text("&nbsp;", lang, sc, nil) ..
		"</span>"
end

function export.catfix_template(frame)
	local params = {
		[1] = {},
		[2] = { alias_of = "sc" },
		["sc"] = {},
	}
	
	local args = require("Module:parameters").process(frame:getParent().args, params, nil, "utilities", "catfix_template")
	
	local lang = require("Module:languages").getByCode(args[1]) or require("Module:languages").err(args[1], 1)
	
	local sc = args.sc
	if sc then
		sc = require("Module:scripts").getByCode(sc) or error('The script code "' .. sc .. '", provided in the second parameter, is not valid.')
	end
	
	return export.catfix(lang, sc)
end

-- Not exporting because it is not used yet.
local function getDateTense(frame) 
	local name_num_mapping = {["January"] = 1, ["February"] = 2, ["March"] = 3, ["April"] = 4, ["May"] = 5, ["June"] = 6, 
		["July"] = 7, ["August"] = 8, ["September"] = 9, ["October"] = 10, ["November"] = 11, ["December"] = 12, 
		[1] = 1, [2] = 2, [3] = 3, [4] = 4, [5] = 5, [6] = 6, [7] = 7, [8] = 8, [9] = 9, [10] = 10, [11] = 11, [12] = 12}
	local month = name_num_mapping[frame.args[2]]
	local date = os.time({year = frame.args[1], day = frame.args[3], month = month})
	local today = os.time() -- 12 AM/PM
	local diff = os.difftime(date, today)
	local daylength = 24 * 3600
	
	if diff < -daylength / 2 then return "past"
	else 
		if diff > daylength / 2  then return "future"
		else return "present" end
	end
end

function export.make_id(lang, str)
	--[[	If called with invoke, first argument is a frame object.
			If called by a module, first argument is a language object. ]]
	local invoked = false
	
	if type(lang) == "table" then
		if lang.args then
			invoked = true
			
			local frame = lang
			
			local params = {
				[1] = {},
				[2] = {},
			}
			
			local args = require("Module:parameters").process(frame:getParent().args, params, nil, "utilities", "make_id")
			
			local langCode = args[1]
			str = args[2]
			
			local m_languages = require("Module:languages")
			
			lang = m_languages.getByCode(langCode) or m_languages.err(langCode, 1)
		elseif not lang.getCanonicalName then
			error("The first argument to make_id should be a language object.")
		end
	end

	if not ( type(str) == "string" or type(str) == "number" ) then
		error("The second argument to make_id should be a string or a number.")
	end
	
	local id = require("Module:senseid").anchor(lang, str)
	
	if invoked then
		return '<li class="senseid" id="' .. id .. '">'
	else
		return id
	end
end

-- Given a type (as a string) and an arbitrary number of entities, checks whether all of those entities are language, family, script, writing system or Wikimedia language objects. Useful for error handling in functions that require one of these kinds of object.
-- If noErr is set, the function returns false instead of throwing an error, which allows customised error handling to be done in the calling function.
function export.check_object(typ, noErr, ...)
	local function fail(message)
		if noErr then
			return false
		else
			error(message, 3)
		end
	end
	
	local objs = {...}
	if #objs == 0 then
		return fail("Must provide at least one object to check.")
	end
	for _, obj in ipairs{...} do
		if type(obj) ~= "table" or type(obj.hasType) ~= "function" then
			return fail("Function expected a " .. typ .. " object, but received a " .. type(obj) .. " instead.")
		elseif not (typ == "object" or obj:hasType(typ)) then
			for _, wrong_type in ipairs{"family", "language", "script", "Wikimedia language", "writing system"} do
				if obj:hasType(wrong_type) then
					return fail("Function expected a " .. typ .. " object, but received a " .. wrong_type .. " object instead.")
				end
			end
			return fail("Function expected a " .. typ .. " object, but received another type of object instead.")
		end
	end
	return true
end

return export