-- This module implements {{error}}.

local p = {}

local function _error(args)
    local message = args.message or args[1] or error('没有指定的信息', 2)
    message = tostring(message)
    local tag = mw.ustring.lower(tostring(args.tag))

    -- Work out what html tag we should use.
    if not (tag == 'p' or tag == 'span' or tag == 'div') then
        tag = 'strong'
    end

    -- Generate the html.
    local root = mw.html.create(tag)
    root
        :addClass('error')
        :wikitext(message)

    return tostring(root)
end

function p.error(frame)
    local args
    if frame == mw.getCurrentFrame() then
        args = frame.args
    else
        args = frame
    end
    if args.message == "" then
        args.message = nil
    end
    return _error(args)
end

return p