--- This module gets the effective protection level of a page.
-- Based on https://en.wikipedia.org/wiki/Module:Effective_protection_level
-- @module Effective protection level

local p = {}

-- Returns the permission required to perform a given action on a given title.
-- If no title is specified, the title of the page being displayed is used.
function p._main(action, pagename)
	local title
	if type(pagename) == 'table' and pagename.prefixedText then
		title = pagename
	elseif pagename then
		title = mw.title.new(pagename)
	else
		title = mw.title.getCurrentTitle()
	end
	pagename = title.prefixedText
	if title.namespace == 8 then -- MediaWiki namespace
		return 'sysop'
	elseif title.namespace == 2 and title.isSubpage then
		if title.contentModel == 'javascript' or title.contentModel == 'css' or title.contentModel == 'json' then -- CSS/JS/JSON
			return 'sysop'
		end
	end
	if action == 'undelete' then
		return 'sysop'
	end
	local level = title.protectionLevels[action] and title.protectionLevels[action][1]
	if level == 'sysop' or level == 'editprotected' then
		return 'content-moderator'
	elseif title.cascadingProtection.restrictions[action] and title.cascadingProtection.restrictions[action][1] then -- used by a cascading-protected page
		return 'content-moderator'
	elseif action == 'move' then
		local blacklistentry = mw.ext.TitleBlacklist.test('edit', pagename) -- Testing action edit is correct, since this is for the source page. The target page name gets tested with action move.
		if blacklistentry and not blacklistentry.params.autoconfirmed then
			return 'sysop'
		elseif title.namespace == 6 then
			return 'filemover'
		else
			return 'autoconfirmed'
		end
	end
	local blacklistentry = mw.ext.TitleBlacklist.test(action, pagename)
	if blacklistentry then
		if not blacklistentry.params.autoconfirmed then
			return 'sysop'
		else
			return 'autoconfirmed'
		end
	elseif level == 'editsemiprotected' then -- create-semiprotected pages return this for some reason
		return 'autoconfirmed'
	elseif level then
		return level
	else
		return '*'
	end
end

setmetatable(p, { __index = function(t, k)
	return function(frame)
		return t._main(k, frame.args[1])
	end
end })

return p