Modul:links

local export = {}

--[=[
	[[Unsupported titles]] and pages with high
	memory usage are listed at [[Modul:links/data]].
	
	Other modules used:
		[[Modul:script utilities]]
		[[Modul:scripts]]
		[[Modul:languages]] and its submodules
		[[Modul:gender and number]]
		[[Modul:utilities]]
		[[Modul:string]]
		[[Modul:debug]]
]=]

-- These are prefixed with u to avoid confusion with the default string methods
-- of the same name.
local usub = mw.ustring.sub

local table_insert = table.insert
local table_concat = table.concat

local ignore_cap = {
	["ko"] = true,
}

local phonetic_extraction = {
	["th"] = "Module:th",
	["km"] = "Module:km",
}

local pos_tags = {
	["a"] = "adjective",
	["adv"] = "adverb",
	["int"] = "interjection",
	["n"] = "noun",
	["pron"] = "pronoun",
	["v"] = "verb",
	["vi"] = "intransitive verb",
	["vt"] = "transitive verb",
	["vti"] = "transitive and intransitive verb",
}

function export.getLinkPage(target, lang)
	if mw.loadData("Module:links/data").unsupported_titles[target] then
		return "Unsupported titles/" .. mw.loadData("Module:links/data").unsupported_titles[target]
	end
	
	-- If the link contains unexpanded template parameters, then don't create a link.
	if target:find("{{{") then
		return nil
	end
	
	if target:sub(1, 1) == ":" or target:sub(1, 2) == "w:" or target:sub(1, 10) == "wikipedia:" then
		return target
	end
	
	-- Remove diacritics from the page name
	target = lang:makeEntryName(target)
	
	if target:sub(1, 1) == "/" then
		return ":" .. target
	
	-- Link to appendix for reconstructed terms and terms in appendix-only languages
	elseif target:sub(1, 1) == "*" and #target > 1 then
		if lang:getCode() == "und" then
			return nil
		end
		
		target = "Reconstruction:" .. lang:getCanonicalName() .. "/" .. usub(target, 2)
	elseif lang:getType() == "reconstructed" then
		error("The specified language " .. lang:getCanonicalName()
			.. " is unattested, while the given word is not marked with '*' to indicate that it is reconstructed")
	elseif lang:getType() == "appendix-constructed" then
		target = "Appendix:" .. lang:getCanonicalName() .. "/" .. target
	end
	
	return target
end

-- Make a language-specific link from given link's parts
local function makeLangLink(link, lang, id, allowSelfLink)
	-- Temporary tracking code
	local langCode = lang:getCode()
	if langCode == "se" or langCode == "sia" or langCode:find("^sm[ajns]$")
			or langCode:find("^sj[dektu]$") then
		if link.display and link.display:find("'") then
			require("Module:debug").track("links/Sami apostrophe display")
		elseif link.target and link.target:find("'") then
			require("Module:debug").track("links/Sami apostrophe target")
		end
	end
	
	-- Find fragments (when link didn't come from parseLink).
	-- Prevents {{l|en|word#Etymology 2|word}} from linking to [[word#Etymology 2#English]].
	if link.fragment == nil then
		-- Replace numeric character references with the corresponding character ( → '),
		-- as they contain #, which causes the numeric character reference to be
		-- misparsed (wa'a → waa → pagename wa&, fragment 29;a).
		link.target = link.target:gsub("&#(%d+);",
			function(number) return mw.ustring.char(tonumber(number)) end)
		local first, second = link.target:match("^([^#]+)#(.+)$")
		if first then
			link.target, link.fragment = first, second
		end
	end
	
	-- If there is no display form, then create a default one
	if not link.display then
		link.display = link.target
		
		-- Strip the prefix from the displayed form
		-- TODO: other interwiki links?
		if link.display:sub(1, 1) == ":" and not mw.loadData("Module:links/data").unsupported_titles[link.display] then
			link.display = link.display:sub(2) -- remove colon from beginning
		else
			local prefix = link.display:match("^([^:]+):")
			local prefixes = {
				w = true,
				wikipedia = true,
			}
			
			if prefixes[prefix] then
				link.display = link.display:sub(#prefix + 2) -- remove prefix plus colon
			end
		end
	end
	
	-- Process the target
	link.target = export.getLinkPage(link.target, lang)
	
	if not link.target then
		return link.display
	end
	
	-- If the target is the same as the current page and there is no sense id
	-- and linking to the same page hasn't been turned on, then return a "self-link"
	-- like the software does.
	if not (allowSelfLink or id) and link.target:gsub("^:", "") == mw.title.getCurrentTitle().prefixedText then
		return "<strong class=\"selflink\">" .. link.display .. "</strong>"
	end
	
	--[[
		Add fragment
		Do not add a section link to "Undetermined", as such sections do not exist and are invalid.
		TabbedLanguages handles links without a section by linking to the "last visited" section,
		but adding "Undetermined" would break that feature.
		For localized prefixes that make syntax error, please use the format: ["xyz"] = true,
	]]
	local prefix = link.target:match("^:?([^:]+):")
	local prefixes = {
		w = true,
		wikipedia = true,
		Category = true,
	}
	
	if not prefixes[prefix] then
		if link.fragment or link.target:find("#$") then
			require("Module:debug").track {
				"links/fragment",
				"links/fragment/" .. lang:getCode()
			}
		end
		
		if not link.fragment and lang:getCode() ~= "und" then
			if id then
				link.fragment = require("Module:utilities").make_id(lang, id)
			elseif not mw.ustring.find(link.target, "^Appendix:")
					and not mw.ustring.find(link.target, "^Reconstruction:") then
				link.fragment = lang:getCanonicalName()
			end
		end
		
		-- This allows linking to pages like [[sms:a]] without it being treated weirdly.
		link.target = link.target:gsub(":", "&#x3a;")
	end
	
	return "[[" .. link.target .. (link.fragment and "#" .. link.fragment or "") .. "|" .. link.display .. "]]"
end


-- Split a link into its parts
local function parseLink(linktext)
	local link = { target = linktext }
	local first, second = link.target:match("^([^|]+)|(.+)$")
	
	if first then
		link.target = first
		link.display = second
	else
		link.display = link.target
	end
	
	first, second = link.target:match("^(.+)#(.+)$")
	
	if first then
		link.target = first
		link.fragment = second
	else
		-- So that makeLangLink does not look for a fragment again
		link.fragment = false
	end
	
	return link
end


-- Creates a basic wikilink to the given term. If the text already contains
-- links, these are replaced with links to the correct section.
function export.language_link(data, allowSelfLink, dontLinkRecons)
	if type(data) ~= "table" then
		error("The first argument to the function language_link must be a table. See Module:links/documentation for more information.")
	end
	
	local text = data.term
	
	if ignore_cap[data.lang:getCode()] and text then
		text = text:gsub("%^", "")
	end
	
	-- If the text begins with * and another character,
	-- then act as if each link begins with *
	local allReconstructed = false
	
	if text:find("^*.") then
		allReconstructed = true
	end
	
	-- Do we have embedded wikilinks?
	if text:find("[[", nil, true) then
		--[=[
		[[Xısusi:WhatLinksHere/Template:tracking/links/alt-ignored]]
		[[Xısusi:WhatLinksHere/Template:tracking/links/id-ignored]]
		]=]
		
		if data.alt then
			require("Module:debug").track("links/alt-ignored")
			mw.log("(from Module:links)", "text with embedded wikilinks:", text,
				"ignored alt:", data.alt, "lang:", data.lang:getCode())
		end
		
		if data.id then
			require("Module:debug").track("links/id-ignored")
			mw.log("(from Module:links)", "text with embedded wikilinks:", text,
				"ignored id:", data.id, "lang:", data.lang:getCode())
		end
		
		-- Begins and ends with a wikilink tag
		if text:find("^%[%[(.+)%]%]$") then
			-- There are no [ ] in between.
			-- This makes the wikilink tag redundant.
			if text:find("^%[%[[^%[%]]+%]%]$") then
				require("Module:debug").track("links/redundant wikilink")
			else
				local temp = text:gsub("^%[%[(.+)%]%]$", "%1")
				temp = temp:gsub("%]%], %[%[", "|")
				
				if not temp:find("[%[%]]") then
					require("Module:debug").track("links/list")
				end
			end
		end
		
		text = text:gsub("%[%[([^%]]+)%]%]",
			function(linktext)
				local link = parseLink(linktext)
				
				if allReconstructed then
					link.target = "*" .. link.target
				end
				
				return makeLangLink(link, data.lang, data.id, allowSelfLink, dontLinkRecons)
			end)
		
		-- Remove the extra * at the beginning if it's immediately followed
		-- by a link whose display begins with * too
		if allReconstructed then
			text = text:gsub("^%*%[%[([^|%]]+)|%*", "[[%1|*")
		end
	else
		-- There is no embedded wikilink, make a link using the parameters.
		text = makeLangLink({ target = text, display = data.alt }, data.lang, data.id, allowSelfLink, dontLinkRecons)
	end
	
	return text
end

function export.mark(text, itemType, face, lang)
	local tag = { "", "" }
	
	if itemType == "gloss" then
		tag = { '<span class="mention-gloss-double-quote">“</span><span class="mention-gloss">',
			'</span><span class="mention-gloss-double-quote">”</span>' }
	elseif itemType == "tr" then
		if face == "term" then
			tag = { '<span lang="' .. lang:getCode() .. '" class="tr mention-tr Latn">',
				'</span>' }
		else
			tag = { '<span lang="' .. lang:getCode() .. '" class="tr Latn">', '</span>' }
		end
	elseif itemType == "ts" then
		tag = { '<span class="ts mention-ts Latn">/', '/</span>' }
	elseif itemType == "annotations" then
		tag = { '<span class="mention-gloss-paren annotation-paren">(</span>',
			'<span class="mention-gloss-paren annotation-paren">)</span>' }
	end
	
	if type(text) == "string" then
		return tag[1] .. text .. tag[2]
	else
		return ""
	end
end

-- Format the annotations (things following the linked term)
function export.format_link_annotations(data, face)
	local output = {}
	
	-- Interwiki link
	if data.interwiki then
		table_insert(output, data.interwiki)
	end
	
	-- Genders
	if type(data.genders) ~= "table" then
		data.genders = { data.genders }
	end
	
	if data.genders and #data.genders > 0 then
		local m_gen = require("Module:gender and number")
		table_insert(output, "&nbsp;" .. m_gen.format_list(data.genders, data.lang))
	end
	
	local annotations = {}
	
	-- Transliteration and transcription
	if data.tr or data.ts then
		local kind
		if face == "term" then
			kind = face
		else
			kind = "default"
		end
		
		if data.tr and data.ts then
			table_insert(annotations,
				require("Module:script utilities").tag_translit(data.tr, data.lang, kind)
				.. " " .. export.mark(data.ts, "ts"))
		elseif data.ts then
			table_insert(annotations, export.mark(data.ts, "ts"))
		else
			table_insert(annotations,
				require("Module:script utilities").tag_translit(data.tr, data.lang, kind))
		end
	end
	
	-- Gloss/translation
	if data.gloss then
		table_insert(annotations, export.mark(data.gloss, "gloss"))
	end
	
	-- Part of speech
	if data.pos then
		-- debug category for pos= containing transcriptions
		if data.pos:find("/[^><]*/") then
			data.pos = data.pos .. "[[Kategori:links likely containing transcriptions in pos]]"
		end

		table_insert(annotations, pos_tags[data.pos] or data.pos)
	end
	
	-- Literal/sum-of-parts meaning
	if data.lit then
		table_insert(annotations, "literally " .. export.mark(data.lit, "gloss"))
	end
	
	if #annotations > 0 then
		table_insert(output, " " .. export.mark(table_concat(annotations, ", "), "annotations"))
	end
	
	return table_concat(output)
end

-- A version of {{l}} or {{m}} that can be called from other modules too
function export.full_link(data, face, allowSelfLink, dontLinkRecons)
	if type(data) ~= "table" then
		error("The first argument to the function full_link must be a table. "
			.. "See Module:links/documentation for more information.")
	end
	
	-- Create the link
	local output = {}
	local categories = {}
	local link = ""
	local annotations
	
	--local m_utilities = require("Module:utilities")
	
	-- Is there any text to show?
	if (data.term or data.alt) then
		-- Try to detect the script if it was not provided
		if not data.sc then
			data.sc = require("Module:scripts").findBestScript(data.alt or data.term, data.lang)
		else
			-- Track uses of sc parameter
			local best = require("Module:scripts").findBestScript(data.alt or data.term, data.lang)
			require("Module:debug").track("links/sc")
			
			if data.sc:getCode() == best:getCode() then
				require("Module:debug").track("links/sc/redundant")
				require("Module:debug").track("links/sc/redundant/" .. data.sc:getCode())
			else
				require("Module:debug").track("links/sc/needed")
				require("Module:debug").track("links/sc/needed/" .. data.sc:getCode())
			end
		end
		
		local class = ""
		
		if data.accel then
			local accel
			if type(data.accel) == "table" then
				local form, gender, translit, lemma, lemma_translit, no_store
				form = data.accel.form and data.accel.form .. "-form-of" or ""
				gender = data.accel.gender and "gender-" .. data.accel.gender or ""
				translit = data.accel.translit and "transliteration-" .. data.accel.translit or ""
				-- This is decoded again by [[WT:ACCEL]].
				lemma = data.accel.lemma and "origin-" .. data.accel.lemma:gsub("%%", "."):gsub(" ", "_") or "" 
				lemma_translit = data.accel.lemma_translit and "origin-transliteration-" .. data.accel.lemma_translit or ""
				no_store = data.accel.no_store and "form-of-nostore" or ""
				
				accel =
					form .. " " ..
					gender .. " " ..
					translit .. " " ..
					lemma .. " " ..
					lemma_translit .. " " ..
					no_store .. " "
			else
				accel = data.accel
				require("Module:debug").track("links/accel not table")
				require("Module:debug").track("links/accel not table/" .. data.lang:getCode())
			end
			
			class = "form-of lang-" .. data.lang:getCode() .. " " .. accel
		end
		
		-- Only make a link if the term has been given, otherwise just show the alt text without a link
		link = require("Module:script utilities").tag_text(
			data.term and export.language_link(data, allowSelfLink, dontLinkRecons)
			or data.alt, data.lang, data.sc, face, class)
	else
		--[[	No term to show.
				Is there at least a transliteration we can work from?	|	No term to show.
				Is there at least a transliteration we can work from?	]]
		link = require("Module:script utilities").request_script(data.lang, data.sc)
		
		if link == "" or not data.tr or data.tr == "-" then
			-- No link to show, and no transliteration either. Show a term request.
			local category = ""
			
			if mw.title.getCurrentTitle().nsText ~= "Şablon" then
				table_insert(categories, "[[Kategori:Waştışê çekuyan be " .. data.lang:getCanonicalName() .. "]]")
			end
			
			link = "<small>[Çekuye?]</small>"
		end
	end
	
	table_insert(output, link)
	
	if data.tr == "" or data.tr == "-" then
		data.tr = nil
	
	elseif phonetic_extraction[data.lang:getCode()] then
		local m_phonetic = require(phonetic_extraction[data.lang:getCode()])
		data.tr = data.tr or m_phonetic.getTranslit(export.remove_links(data.term))
	
	elseif (data.term or data.alt) and not data.sc:getCode():find("Lati?n") then
		
		-- Try to generate a transliteration, unless transliteration has been
		-- supplied and we are in a high-memory entry.
		if not (data.tr and mw.loadData("Module:links/data").high_memory_entries[mw.title.getCurrentTitle().text]) then
			local automated_tr = data.lang:transliterate(export.remove_links(data.alt or data.term), data.sc)
			
			if automated_tr then
				local manual_tr = data.tr
				
				if (not manual_tr) or data.lang:overrideManualTranslit() then
					data.tr = automated_tr
				end
			end
		end
	end
	
	-- Link to the transliteration entry for languages that require this
	if data.tr and data.lang:link_tr() then
		data.tr = export.language_link { lang = data.lang, term = data.tr }
	end
	
	table_insert(output, export.format_link_annotations(data, face))
	
	return table_concat(output) .. table_concat(categories)
end


--[[	Strips links: deletes category links,
		the targets of piped links,
		and all double square brackets.			]]
function export.remove_links(text)
	if type(text) == "table" then
		text = text.args[1]
	end
	
	if not text or text == "" then
		return ""
	end
	
	text = mw.ustring.gsub(text, "%[%[Kategori:[^|%]]-|?[^|%]]-%]%]", "")
	text = text:gsub("%[%[[^|%]]-|", "")
	text = text:gsub("%[%[", "")
	text = text:gsub("%]%]", "")
	
	return text
end

function export.english_links(text)
	local lang = require("Module:languages").getByCode("en")
	
	-- Parentheses around function call to remove second return value, the
	-- number of replacements.
	return (text:gsub("%[%[([^%]]+)%]%]",
		function(linktext)
			local link = parseLink(linktext)
			return makeLangLink(link, lang, nil, true, false)
		end))
end

function export.light_link(data)
	local language_names = mw.loadData("Module:languages/code to canonical name")
	local script_codes = mw.loadData("Module:scripts/codes")
	
	if data.langCode then
		data.langName = language_names[data.langCode] or error('The language code "' .. data.langCode .. '" is not recognized.')
	else
		error('Language code is required.')
	end
	
	if not data.term then
		error('Term to link to is required.')
	end
	
	if data.scCode then
		if not script_codes[data.scCode] then
			error('The script code "' .. data.sc .. '" is not recognized.')
		end
	else
		error("The function light_link requires a script code.")
	end
	
	local fragment
	if data.id then
		fragment = data.langName .. "-" .. mw.uri.encode(data.id, "WIKI")
	else
		fragment = data.langName
	end
	
	return table_concat {
		'<span class="', data.scCode, '" lang="', data.langCode,
		'">[[', data.term, "#", fragment, "|", (data.alt or data.term), "]]</span>"
	}
end

--[=[
	For example, Norwegian_Bokm.C3.A5l → Norwegian_Bokmål. 0xC3 and 0xA5 are the
	hexadecimal-base representation of the two bytes used to encode the character
	å in the UTF-8 encoding:
		11000011 10100101
	
	Note that the bytes used to represent a character are actually different from
	the Unicode codepoint. For å, the codepoint is 0xE5. The bits (digits) that
	actually spell the codepoint are found in the brackets: 110[00011] 10[100101].
	For further explanation, see [[w:UTF-8#Description]].
]=]

-- The character class %x should not be used, as it includes the characters a-f,
-- which do not occur in these anchor encodings.
local capitalHex = "[0-9A-F]"

local function decodeAnchor(anchor)
	return (anchor:gsub("%.(" .. capitalHex .. capitalHex .. ")",
		function(hexByte)
			return string.char(tonumber(hexByte, 16))
		end))
end

function export.section_link(link)
	if type(link) ~= "string" then
		error("The first argument to section_link was a " .. type(link) .. ", but it should be a string.")
	end
	
	link = link:gsub("_", " ")
	
	local numberSigns = require("Module:string").count(link, "#")
	
	if numberSigns > 1 then
		error("The section link should only contain one number sign (#).")
	end
	
	local page, section = link:match("^([^#]+)#(.+)$")
	
	if page and section then
		section = decodeAnchor(section)
		
		-- URI-encode (percent-encode) section to allow square brackets, [],
		-- in section name. If not percent-encoded, they prevent the parser from
		-- recognizing the link.
		return table_concat { "[[", page, "#", mw.uri.encode(section, "WIKI"), "|", page, " § ", section, "]]" }
	else
		error('The function "' .. section_link .. '" could not find a number sign marking a section name.')
	end
end

return export