# Module:Portal

--[==[ This module is a Lua implementation of the old template. As of February 2019 it is used on nearly 7,900,000 articles.  
-- Please take care when updating it! It outputs two functions: p.portal, which generates a list of portals, and p.image, which  
-- produces the image name for an individual portal.  

-- The portal image data is kept in submodules of Module:Portal/images, listed below:  
-- Module:Portal/images/a - for portal names beginning with "A".  
-- Module:Portal/images/b - for portal names beginning with "B".  
-- Module:Portal/images/c - for portal names beginning with "C".  
-- Module:Portal/images/d - for portal names beginning with "D".  
-- Module:Portal/images/e - for portal names beginning with "E".  
-- Module:Portal/images/f - for portal names beginning with "F".  
-- Module:Portal/images/g - for portal names beginning with "G".  
-- Module:Portal/images/h - for portal names beginning with "H".  
-- Module:Portal/images/i - for portal names beginning with "I".  
-- Module:Portal/images/j - for portal names beginning with "J".  
-- Module:Portal/images/k - for portal names beginning with "K".  
-- Module:Portal/images/l - for portal names beginning with "L".  
-- Module:Portal/images/m - for portal names beginning with "M".  
-- Module:Portal/images/n - for portal names beginning with "N".  
-- Module:Portal/images/o - for portal names beginning with "O".  
-- Module:Portal/images/p - for portal names beginning with "P".  
-- Module:Portal/images/q - for portal names beginning with "Q".  
-- Module:Portal/images/r - for portal names beginning with "R".  
-- Module:Portal/images/s - for portal names beginning with "S".  
-- Module:Portal/images/t - for portal names beginning with "T".  
-- Module:Portal/images/u - for portal names beginning with "U".  
-- Module:Portal/images/v - for portal names beginning with "V".  
-- Module:Portal/images/w - for portal names beginning with "W".  
-- Module:Portal/images/x - for portal names beginning with "X".  
-- Module:Portal/images/y - for portal names beginning with "Y".  
-- Module:Portal/images/z - for portal names beginning with "Z".  
-- Module:Portal/images/other - for portal names beginning with any other letters. This includes numbers,  
-- letters with diacritics, and letters in non-Latin alphabets.  
-- Module:Portal/images/aliases - for adding aliases for existing portal names. Use this page for variations  
-- in spelling and diacritics, etc., no matter what letter the portal begins with.  
---
-- The images data pages are separated by the first letter to reduce server load when images are added, changed, or removed.  
-- Previously all the images were on one data page at Module:Portal/images, but this had the disadvantage that all  
-- 5,000,000 pages using this module needed to be refreshed every time an image was added or removed.  
]==]  

local p = {}  

local trackingEnabled = true  

local templatestyles = 'Module:Portal/styles.css'  

local yesno = require('Module:Yesno')  

-- Check whether to do tracking in this namespace  
-- Returns true unless the page is one of the banned namespaces  
local function checkTrackingNamespace  
local thisPage = mw.title.getCurrentTitle  
if (thisPage.namespace == 1) -- Talk  
or (thisPage.namespace == 2) -- User  
or (thisPage.namespace == 3) -- User talk  
or (thisPage.namespace == 5) -- Wikipedia talk  
or (thisPage.namespace == 7) -- File talk  
or (thisPage.namespace == 11) -- Template talk  
or (thisPage.namespace == 15) -- Category talk  
or (thisPage.namespace == 101) -- Portal talk  
or (thisPage.namespace == 109) -- Book talk  
or (thisPage.namespace == 118) -- Draft  
or (thisPage.namespace == 119) -- Draft talk  
or (thisPage.namespace == 829) -- Module talk  
then  
return false  
end  
return true  
end  

-- Check whether to do tracking on this pagename  
-- Returns false if the page title matches one of the banned strings  
-- Otherwise returns true  
local function checkTrackingPagename  
local thisPage = mw.title.getCurrentTitle  
local thisPageLC = mw.ustring.lower(thisPage.text)  
if (string.match(thisPageLC, "/archive") ~= nil) then  
return false  
end  
if (string.match(thisPageLC, "/doc") ~= nil) then  
return false  
end  
if (string.match(thisPageLC, "/test") ~= nil) then  
return false  
end  
return true  
end  

local function matchImagePage(s)  
-- Finds the appropriate image subpage given a lower-case  
-- portal name plus the first letter of that portal name.  
if type(s) ~= 'string' or #s < 1 then return end  
local firstLetter = mw.ustring.sub(s, 1, 1)  
local imagePage  
if mw.ustring.find(firstLetter, '^[a-z]') then  
imagePage = 'Module:Portal/images/' .. firstLetter  
else  
imagePage = 'Module:Portal/images/other'  
end  
return mw.loadData(imagePage)[s]  
end  

local function getAlias(s)  
-- Gets an alias from the image alias data page.  
local aliasData = mw.loadData('Module:Portal/images/aliases')  
for portal, aliases in pairs(aliasData) do  
for _, alias in ipairs(aliases) do  
if alias == s then  
return portal  
end  
end  
end  
end  

local function getImageName(s)  
-- Gets the image name for a given string.  
local default = 'Portal-puzzle.svg|link=|alt='  
if type(s) ~= 'string' or #s < 1 then  
return default  
end  
s = mw.ustring.lower(s)  
return matchImagePage(s) or matchImagePage(getAlias(s)) or default  
end  

local function checkPortalExists(portal)  
return not (mw.title.makeTitle(100, portal).id == 0)  
end  

function p._portal(portals, args)  
-- This function builds the portal box used by the template.  
local root = mw.html.create('div')  
:attr('role', 'navigation')  
:attr('aria-label', 'Portals')  
:addClass('noprint portal plainlist')  
:addClass(args. and 'tleft' or 'tright')  
:css('margin', args.margin or nil)  
:newline  

-- Tracking is on by default.  
-- It is disabled if any of the following is true  
-- 1/ the parameter "tracking" is set to 'no, 'n', or 'false'  
-- 2/ the current page fails the namespace tests in checkTrackingNamespace  
-- 3/ the current page fails the pagename tests in checkTrackingPagename  
trackingEnabled = yesno(args.tracking, trackingEnabled)  
if (checkTrackingNamespace == false) then  
trackingEnabled = false  
end  
if (checkTrackingPagename == false) then  
trackingEnabled = false  
end  

-- If no portals have been specified, display an error and add the page to a tracking category.  
if not portals[1] then  
if yesno(args.nominimum) then  
-- if nominimum as been set to yes (or similar), omit the warning  

else  
root:wikitext('<strong>No portals specified: please specify at least one portal</strong>')  
end  
if (trackingEnabled) then  
root:wikitext('')  
end  
return tostring(root)  
end  

-- scan for nonexistent portals, if they exist remove them from the portals table. If redlinks=yes, then don't remove  
local portallen = #portals  
-- traverse the list backwards to ensure that no portals are missed (table.remove also moves down the portals in the list, so that the next portal isn't checked if going fowards.  
-- going backwards allows us to circumvent this issue  
for i=portallen,1,-1 do  
-- the use of pcall here catches any errors that may occour when attempting to locate pages when the page name is invalid  
-- if pcall returns true, then rerun the function to find if the page exists  
if not pcall(checkPortalExists, portals[i]) or not checkPortalExists(portals[i]) then  
-- Getting here means a redlinked portal has been found  
if yesno(args.redlinks) or (args.redlinks == 'include') then  
-- if redlinks as been set to yes (or similar), add the cleanup category and then break the loop before the portal is removed from the list  
if (trackingEnabled) then  
root:wikitext('')  
end  
break  
end  
-- remove the portal (this does not happen if redlinks=yes)  
table.remove(portals,i)  
end  
end  

-- if the length of the table is different, then rows were removed from the table, so portals were removed. If this is the case add the cleanup category  
if not (portallen == #portals) then  
if (trackingEnabled) then  
if #portals == 0 then  
return ''  
else  
root:wikitext('')  
end  
end  
end  

-- Start the list. This corresponds to the start of the wikitext table in the old Template:Portal.  
local listroot = root:tag('ul')  
:css('width', type(args.boxsize) == 'string' and (args.boxsize .. 'px') or nil)  

-- Display the portals specified in the positional arguments.  
for _, portal in ipairs(portals) do  
local image = getImageName(portal)  

-- Generate the html for the image and the portal name.  
listroot  
:newline  
:tag('li')  
:tag('span')  
:wikitext(string.format('', image))  
:done  
:tag('span')  
:wikitext(string.format('%s%sவலைவாசல்', portal, portal, args['break'] and '  
' or ' '))  
end  
return tostring(root)  
end  

function p._image(portals)  
-- Wrapper function to allow getImageName to be accessed through #invoke.  
local name = getImageName(portals[1])  
return name:match('^(.-)|') or name -- FIXME: use a more elegant way to separate borders etc. from the image name  
end  

local function getAllImageTables  
-- Returns an array containing all image subpages (minus aliases) as loaded by mw.loadData.  
local images = {}  
for i, subpage in ipairs{'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'other'} do  
images[i] = mw.loadData('Module:Portal/images/' .. subpage)  
end  
return images  
end  

function p._displayAll(portals, args)  
-- This function displays all portals that have portal images. This function is for maintenance purposes and should not be used in  
-- articles, for two reasons: 1) there are over 1500 portals with portal images, and 2) the module doesn't record how the portal  
-- names are capitalized, so the portal links may be broken.  
local lang = mw.language.getContentLanguage  
local count = 1  
for _, imageTable in ipairs(getAllImageTables) do  
for portal in pairs(imageTable) do  
portals[count] = lang:ucfirst(portal)  
count = count + 1  
end  
end  
return p._portal(portals, args)  
end  

function p._imageDupes  
-- This function searches the image subpages to find duplicate images. If duplicate images exist, it is not necessarily a bad thing,  
-- as different portals might just happen to choose the same image. However, this function is helpful in identifying images that  
-- should be moved to a portal alias for ease of maintenance.  
local exists, dupes = {}, {}  
for _, imageTable in ipairs(getAllImageTables) do  
for portal, image in pairs(imageTable) do  
if not exists[image] then  
exists[image] = portal  
else  
table.insert(dupes, string.format('The image "" is used for both portals "%s" and "%s".', image, image, exists[image], portal))  
end  
end  
end  
if #dupes < 1 then  
return 'No duplicate images found.'  
else  
return 'The following duplicate images were found:\n* ' .. table.concat(dupes, '\n* ')  
end  
end  

local function processPortalArgs(args)  
-- This function processes a table of arguments and returns two tables: an array of portal names for processing by ipairs, and a table of  
-- the named arguments that specify style options, etc. We need to use ipairs because we want to list all the portals in the order  
-- they were passed to the template, but we also want to be able to deal with positional arguments passed explicitly, for example  
-- . The behaviour of ipairs is undefined if nil values are present, so we need to make sure they are all removed.  
args = type(args) == 'table' and args or {}  
local portals = {}  
local namedArgs = {}  
for k, v in pairs(args) do  
if type(k) == 'number' and type(v) == 'string' then -- Make sure we have no non-string portal names.  
table.insert(portals, k)  
elseif type(k) ~= 'number' then  
namedArgs[k] = v  
end  
end  
table.sort(portals)  
for i, v in ipairs(portals) do  
portals[i] = args[v]  
end  
return portals, namedArgs  
end  

local function makeWrapper(funcName)  
-- Processes external arguments and sends them to the other functions.  
return function  
-- If called via #invoke, use the args passed into the invoking  
-- template, or the args passed to #invoke if any exist. Otherwise  
-- assume args are being passed directly in from the debug console  
-- or from another Lua module.  
local origArgs  
if type(.getParent) == 'function' then  
origArgs = :getParent.args  
for k, v in pairs(.args) do  
origArgs = .args  
break  
end  
else  
origArgs =  
end  
-- Trim whitespace and remove blank arguments.  
local args = {}  
for k, v in pairs(origArgs) do  
if type(v) == 'string' then  
v = mw.text.trim(v)  
end  
if v ~= '' then  
args[k] = v  
end  
end  

local results = ''  
if funcName == '_portal' or funcName == '_displayAll' then  
results = :extensionTag{ name = 'templatestyles', args = { src = templatestyles} }  
end  
return results .. p[funcName](processPortalArgs(args)) -- passes two tables to func: an array of portal names, and a table of named arguments.  
end  
end  

for _, funcName in ipairs{'portal', 'image', 'imageDupes', 'displayAll'} do  
p[funcName] = makeWrapper('_' .. funcName)  
end  

return p