View source for Portal

--[==[ This module is a Lua implementation of the old {{Portal}} template. As of August 2013 it is used on nearly 5,000,000 articles.
-- Please take care when updating it! It outputs two functions: p.portal, which generates a table 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 htmlBuilder = require( 'Module:HtmlBuilder' )

-- Finds the appropriate image subpage given a lower-case
-- portal name plus the first letter of that portal name.
local function matchImagePage( s )
    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
    local images = mw.loadData( imagePage )
    local image = images[ s ]
    if image then
        return image
    end
end

-- Gets the image name for a given string.
local function getImageName( s )
    if type( s ) ~= 'string' or #s < 1 then
        return 'Portal-puzzle.svg'
    end
    s = mw.ustring.lower( s )
    local image = matchImagePage( s )
    if image then
        return image
    else
        local aliases = mw.loadData( 'Module:Portal/images/aliases' )
        local alias = aliases[ s ]
        image = matchImagePage( alias )
        if image then
            return image
        else
            return 'Portal-puzzle.svg'
        end
    end
end

-- This function builds the portal box used by the {{portal}} template.
local function _portal( portals, args )
    local root = htmlBuilder.create( 'div' )
    root
        .addClass( 'noprint' )
        .addClass( args.left and 'tleft' or 'tright' )
        .addClass( 'portal' )
        .css( 'border', 'solid #aaa 1px' )
        .css( 'margin', args.margin or ( args.left == 'yes' and '0.5em 1em 0.5em 0' ) or '0.5em 0 0.5em 1em')
        .newline()

    -- Start the table. This corresponds to the start of the wikitext table in the old [[Template:Portal]].
    local tableroot = root.tag( 'table' )
        .css( 'background', '#f9f9f9' )
        .css( 'font-size', '85%' )
        .css( 'line-height', '110%' )
        .css( 'max-width', '175px' )
        .css( 'width', type( args.boxsize ) == 'string' and ( args.boxsize .. 'px' ) )
    
    -- If no portals have been specified, display an error and add the page to a tracking category.
    if not portals[ 1 ] then
        tableroot.wikitext( '<strong class="error">No portals specified: please specify at least one portal</strong>[[Category:Portal templates without a parameter]]' )
    end

    -- Display the portals specified in the positional arguments.
    for i, portal in ipairs( portals ) do
        local image = getImageName( portal )
        
        -- Generate the html for the image and the portal name.
        tableroot
            .newline()
            .tag( 'tr' )
                .attr( 'valign', 'middle' )
                .tag( 'td' )
                    .css( 'text-align', 'center' )
                    .wikitext( mw.ustring.format( '[[File:%s|32x28px|alt=Portal icon]]', image ) )
                    .done()
                .tag( 'td' )
                    .css( 'padding', '0 0.2em' )
                    .css( 'vertical-align', 'middle' )
                    .css( 'font-style', 'italic' )
                    .css( 'font-weight', 'bold' )
                    .wikitext(mw.ustring.format( '[[Portal:%s|%s%sportal]]', portal, portal, args[ 'break' ] and '<br />' or ' ' ) )
    end
    return tostring( root )
end

-- Wrapper function to allow getImageName() to be accessed through #invoke.
local function _image( portals )
    return getImageName( portals[ 1 ] )
end

-- Returns an array containing all image subpages (minus aliases) as loaded by mw.loadData.
local function getAllImageTables()
    local images = {}
    local subpages = { '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' }
    for i, subpage in ipairs( subpages ) do
        table.insert( images, mw.loadData( 'Module:Portal/images/' .. subpage ) )
    end
    return images
end

-- 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 function _displayAll( portals, args )
    local lang = mw.language.getContentLanguage()
    local images = getAllImageTables()
    local count = 1
    for i, imageTable in ipairs( images ) do
        for portal in pairs( imageTable ) do
            portals[ count ] = lang:ucfirst( portal )
            count = count + 1
        end
    end
    return _portal( portals, args )
end

-- 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 function _findImageDupes()
    local exists, dupes = {}, {}
    local images = getAllImageTables()
    for i, imageTable in ipairs( images ) do
        for portal, image in pairs( imageTable ) do
            if not exists[ image ] then
                exists[ image ] = portal
            else
                table.insert( dupes, mw.ustring.format( 'The image "[[:File:%s|%s]]" 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
	
-- 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
-- {{portal|2=Politics}}. The behaviour of ipairs is undefined if nil values are present, so we need to make sure they are all removed.
local function processPortalArgs( args )
    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

-- Processes external arguments and sends them to the other functions.
local function makeWrapper( func )
    return function ( frame )
        -- 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 frame == mw.getCurrentFrame() then
            origArgs = frame:getParent().args
            for k, v in pairs( frame.args ) do
                origArgs = frame.args
                break
            end
        else
            origArgs = frame
        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
        return func( processPortalArgs( args ) ) -- passes two tables to func: an array of portal names, and a table of named arguments.
    end
end

return {
    portal = makeWrapper( _portal ),
    image = makeWrapper( _image ),
    imageDupes = makeWrapper( _findImageDupes ),
    displayAll = makeWrapper( _displayAll )
}