Module:utilities

local export = {}

local headword_data_module = "Module:headword/data"
local languages_module = "Module:languages"
local links_module = "Module:links"
local load_module = "Module:load"
local pages_module = "Module:pages"
local script_utilities_module = "Module:script utilities"
local scripts_module = "Module:scripts"
local string_utilities_module = "Module:string utilities"
local utilities_data_module = "Module:utilities/data"

local mw = mw

local anchor_encode = mw.uri.anchorEncode
local concat = table.concat
local format_categories -- Defined below.
local ipairs = ipairs
local require = require
local type = type
local unstrip = mw.text.unstrip

--[==[
Loaders for functions in other modules, which overwrite themselves with the target function when called. This ensures modules are only loaded when needed, retains the speed/convenience of locally-declared pre-loaded functions, and has no overhead after the first call, since the target functions are called directly in any subsequent calls.]==]
	local function decode_entities(...)
		decode_entities = require(string_utilities_module).decode_entities
		return decode_entities(...)
	end
	
	local function get_script(...)
		get_script = require(scripts_module).getByCode
		return get_script(...)
	end
	
	local function is_content_page(...)
		is_content_page = require(pages_module).is_content_page
		return is_content_page(...)
	end
	
	local function load_data(...)
		load_data = require(load_module).load_data
		return load_data(...)
	end
	
	local function remove_links(...)
		remove_links = require(links_module).remove_links
		return remove_links(...)
	end
	
	local function tag_text(...)
		tag_text = require(script_utilities_module).tag_text
		return tag_text(...)
	end
	
	local function trim(...)
		trim = require(string_utilities_module).trim
		return trim(...)
	end
	
	local function uupper(...)
		uupper = require(string_utilities_module).upper
		return uupper(...)
	end

--[==[
Loaders for objects, which load data (or some other object) into some variable, which can then be accessed as "foo or get_foo()", where the function get_foo sets the object to "foo" and then returns it. This ensures they are only loaded when needed, and avoids the need to check for the existence of the object each time, since once "foo" has been set, "get_foo" will not be called again.]==]
	local catfix_scripts
	local function get_catfix_scripts()
		catfix_scripts, get_catfix_scripts = load_data(utilities_data_module).catfix_scripts, nil
		return catfix_scripts
	end
	
	local current_title
	local function get_current_title()
		current_title, get_current_title = mw.title.getCurrentTitle(), nil
		return current_title
	end
	
	local defaultsort
	local function get_defaultsort()
		defaultsort, get_defaultsort = load_data(headword_data_module).page.pagename_defaultsort, nil
		return defaultsort
	end
	
	local pagename
	local function get_pagename()
		pagename, get_pagename = load_data(headword_data_module).page.encoded_pagename, nil
		return pagename
	end

	local und
	local function get_und()
		und, get_und = require(languages_module).getByCode("und"), nil
		return und
	end


do
	local function handle_url(capture)
		return capture:match("https?://]+%s(]+)") or ""
	end
	
	--[==[
	A helper function to strip wiki markup, giving the plaintext of what is displayed on the page.]==]
	function export.get_plaintext(text)
		text = text
			:gsub("%[%[", "\1")
			:gsub("%]%]", "\2")

		-- Remove strip markers and HTML tags.
		text = unstrip(text):gsub("<+>", "")

		-- Parse internal links for the display text, and remove categories.
		text = remove_links(text)

		-- Remove files.
		text = text:gsub("\1:+\2", "")
			:gsub("\1:+\2", "")

		-- Parse external links for the display text.
		text = text:gsub("%]+)%]", handle_url)
			-- Any remaining square brackets aren't involved in links, but must be escaped to avoid creating new links.
			:gsub("\1", "&#91;&#91;")
			:gsub("\2", "&#93;&#93;")
			:gsub("%[", "&#91;")
			:gsub("]", "&#93;")
			-- Strip bold, italics and soft hyphens.
			:gsub("('*)'''(.-'*)'''", "%1%2")
			:gsub("('*)''(.-'*)''", "%1%2")
			:gsub("­", "")
		
		-- Get any HTML entities and trim.
		-- Note: don't decode URL percent encoding, as it shouldn't be used in display text and may cause problems if % is used.
		return trim(decode_entities(text))
	end
end

do
	local function generate_sortkey(lang, sc, sort_key, sort_base)
		-- If the sort key is "-", treat the language as undetermined (the default). This is desirable when categorising (e.g.) translation requests, as the pages to be categorised are always in English/Translingual.
		if sort_key == "-" then
			lang, sort_key = und or get_und(), nil
		elseif not lang then
			lang = und or get_und()
		end
		-- Generate the automatic sort key.
		local auto = lang:makeSortKey(sort_base or pagename or get_pagename(), sc)
		-- Use the page defaultsort if necessary.
		if not auto or auto == "" then
			auto = defaultsort or get_defaultsort()
		end
		-- If not sort key specified, use the automatic one.
		if not sort_key or sort_key == "" then
			return auto
		-- Otherwise, if the language is not "und", categorize the manual sort key as either redundant or non-redundant.
		-- FIXME: we should do this for "und" as well, but "Undetermined terms..." does not make sense for translations etc.
		elseif lang:getCode() ~= "und" then
			return sort_key, "[[Category:" .. lang:getFullName() .. " terms with " .. (
				uupper(sort_key) == auto and "redundant" or
				"non-redundant non-automated"
			) .. " sortkeys|" .. sort_key .. "]]"
		end
		return sort_key
	end

	--[==[
	Format the categories with the appropriate sort key.
	* `cat` can take two forms:
	  ** A string (the full category, minus the {"Category:"} prefix);
	  ** A list of categories. Each category in the list can be either:
	  *** A string in the same format as above;
	  *** An object with the fields:
	  **** `cat`: a string in the same format as above (required);
	  **** `lang`: an optional language object to override the overall `lang`;
	  **** `sc`: an optional script object to override the overall `sc`.
	  **** `sort_key`: an optional sort key to override the overall `sort_key`;
	  **** `sort_base`: an optional sort base to override the overall `sort_base`;
	* `lang` is an object encapsulating a language; if {nil}, the object for language code {"und"} (undetermined) will
	  be used. `lang` is used when computing the sort key (either from the subpage name or sort base).
	* `sort_key` is placed in the category invocation, and indicates how the page will sort in the respective category.
	  Normally '''do not use this'''. Instead, leave it {nil}, and if you need to a control the sort order, use
	  {sort_base}, so that language-specific normalization is applied on top of the specified sort base. If neither
	  {sort_key} nor {sort_base} is specified, the default is to apply language-specific normalization to the subpage
	  name; see below.
	* `sort_base` lets you override the default sort key while still maintaining appropriate language-specific
	  normalization. If {nil} is specified, this defaults to the subpage name, which is the portion of the full pagename
	  after subtracting the namespace prefix (and, in certain namespaces such as {User:}, but notably not in the
	  mainspace, after subtracting anything up through the final slash). The actual sort key is derived from the sort
	  base approximately by lowercasing, applying language-specific normalization and then uppercasing; note that the
	  same process is applied in deriving the sort key when no sort base is specified. For example, for French, Spanish,
	  etc. the normalization process maps accented letters to their unaccented equivalents, so that e.g. in French,
	  {{m|fr|ça}} sorts after {{m|fr|ca}} (instead of after the default Wikimedia sort order, which is approximately
	  based on Unicode sort order and places ç after z) and {{m|fr|côté}} sorts after {{m|fr|coté}} (instead of between
	  c and d). Similarly, in Russian the normalization process 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)
	  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:, Thesaurus:, Reconstruction: or Citations: namespaces.
	* `sc` is a script object; if nil, the default will be derived from the sort base (or its default value, the
	  subpage name) by calling {lang:findBestScript()}. The value of `sc` is used during the sort base normalization
	  process; for example, languages with multiple scripts will often have script-specific normalization processes.]==]
	function export.format_categories(cat, lang, sort_key, sort_base, force_output, sc)
		if not (
			force_output or
			is_content_page(current_title or get_current_title()) or
			current_title.prefixedText == "Wiktionary:Sandbox"
		) then
			return ""
		elseif type(cat) == "string" then
			local this_sort_key, extra = generate_sortkey(lang, sc, sort_key, sort_base)
			return "]" .. (extra or "")
		end
		local ret, i, n, default = {}, 0, 0
		-- Iterate over all categories in `cat`.
		while true do
			i = i + 1
			local category = cat
			if category == nil then
				return concat(ret)
			end
			local this_sort_key, extra
			-- If the category type is a table, use any custom options in it.
			if type(category) == "table" then
				category, this_sort_key, extra = category.cat, generate_sortkey(
					category.lang or lang,
					category.sc or sc,
					category.sort_key or sort_key,
					category.sort_base or sort_base
				)
			-- If `default` has already been determined, use it.
			elseif default then
				this_sort_key = default
			-- Otherwise, calculate `default` and use it.
			else
				this_sort_key, extra = generate_sortkey(lang, sc, sort_key, sort_base)
				default = this_sort_key
			end
			n = n + 1
			ret = "]" .. (extra or "")
		end
	end
	format_categories = export.format_categories
end

--[==[
Add a "catfix", which is used on language-specific category pages to add language attributes and often script
classes to all entry names. The addition of language attributes and script classes makes the entry names display
better (using the language- or script-specific styles specified in ]), which is particularly
important for non-English languages that do not have consistent font support in browsers.

Language attributes are added for all languages, but script classes are only added for languages with one script
listed in their data file, or for languages that have a default script listed in the {catfix_script} list in
]. Some languages clearly have a default script, but still have other scripts listed in
their data file. If those other scripts are not simply scripts like {{cd|Brai}} (Braille), their default script
needs to be specified. Others do not have a default script.

* Serbo-Croatian is regularly written in both the Latin and Cyrillic scripts. Because it uses two scripts,
  Serbo-Croatian cannot have a script class applied to entries in its category pages, as only one script class
  can be specified at a time.
* German is usually written in the Latin script ({{cd|Latn}}), but Fraktur ({{cd|Latf}}) is also listed in
  its data file. So German needs an entry in the {catfix_script} list, so that the {{cd|Latn}} (Latin) script
  class will be applied to entries in its category pages.

To find the scripts listed for a language, go to ] and use the search box to find the data file
for the language. To find out what a script code means, search the script code in ].]==]
function export.catfix(lang, sc)
	if not lang or not lang.getCanonicalName then
		error('The first argument to the function "catfix" should be a language object from ] or ].')
	end
	if sc and not sc.getCode then
		error('The second argument to the function "catfix" should be a script object from ].')
	end

	-- To add script classes to links on pages created by category boilerplate templates.
	if not sc then
		local code = (catfix_scripts or get_catfix_scripts()) or catfix_scripts
		if code then
			sc = get_script(code)
		end
	end

	-- If the language only has a single valid candidate script, apply it as the default.
	if not sc then
		local scripts = lang:getScripts()
		if #scripts == 1 then
			sc = scripts
		else
			-- Iterate over scripts. If there is only one when ignoring
			-- scripts like Brai, then pick that one.
			for _, script in ipairs(scripts) do
				if script:getCode() ~= "Brai" then
					if sc then
						-- Multiple candidates - fail.
						sc = nil
						break
					else
						sc = script
					end
				end
			end
		end
	end
	
	-- Hack: using a <ul> tag prevents the parser from automatically generating a <p> tag around the catfix element.
	return "<ul class=\"catfix\" data-anchor=\"" ..
		anchor_encode(lang:getFullName()) .. "\">" ..
		tag_text("", lang, sc) .. "</ul>" ..
		format_categories("Pages using catfix", nil, nil, nil, true)
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, ...)
	if ... == nil then
		if noErr then
			return false
		end
		error("Must provide at least one object to check.", 2)
	end
	for _, obj in ipairs{...} do
		if type(obj) ~= "table" or type(obj.hasType) ~= "function" then
			if noErr then
				return false
			end
			error("Function expected a " .. typ .. " object, but received a " .. type(obj) .. " instead.", 2)
		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
					if noErr then
						return false
					end
					error("Function expected a " .. typ .. " object, but received a " .. wrong_type .. " object instead.", 2)
				end
			end
			if noErr then
				return false
			end
			error("Function expected a " .. typ .. " object, but received another type of object instead.", 2)
		end
	end
	return true
end

return export