模組:FeaturedTopicSum

-- This module implements {{FeaturedTopicSum}}.

local p = {}

local function pagesInCategory(category)
    -- Gets the number of pages in a category. Counting pages in a category is
    -- expensive, so use pcall in case we are being used on pages with lots of
    -- expensive function calls.
    local success, noPages = pcall(mw.site.stats.pagesInCategory, category, 'pages')
    return success and noPages or 0
end

function p.status(topic)
    if not topic then
        error('未指定话题', 2)
    end
    local baseCategory = '维基百科典范话题' .. topic
    local noGood = pagesInCategory(baseCategory .. '优良内容')
    local noFeatured = pagesInCategory(baseCategory .. '典范内容')
    local noOther = pagesInCategory(baseCategory)

    -- For a topic to be featured:
    -- 1) it must contain at least two featured articles, and
    -- 2) 50% or more of its articles must be featured.
    -- If either of these criteria are not met, the topic is assumed to be a
    -- good topic.
    if noFeatured >= 2 and noFeatured >= (noGood + noOther) then
        return 'FT'
    else
        return 'GT'
    end
end

function p._main(args)
    local status = p.status(args[1])
    if status == 'FT' then
        return args[2]
    else
        return args[3]
    end
end

function p.main(frame)
    local args = require('Module:Arguments').getArgs(frame, { wrappers = 'Template:FeaturedTopicSum' })
    return p._main(args)
end

return p