require('strict')

local p = {}
local function checkPortalExists(portal)
	return not (mw.title.makeTitle.id == 0)
end
local getImageName = require( 'Module:Portal' ).image
local yesno = require( 'Module:Yesno' )

local trackingInThisNamespace = false

local function checkNamespace
	local thisPage = mw.title.getCurrentTitle
	if (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 == 829) -- Module talk
		then
		trackingInThisNamespace = true
		return true
	end
	trackingInThisNamespace = false
	return false
end

-- Builds the portal bar used by .
function p._main
	
	if #portals < 1 then return '' end -- Don't display a blank navbox if no portals were specified.
	
	local nav = mw.html.create( 'div' )
	if yesno( args.border ) == false then
		nav
	else
		nav
	end
	
	checkNamespace

	-- 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 or not checkPortalExists(portals[i]) then
			-- Getting here means a redlinked portal has been found
			if (args.redlinks == 'yes') or (args.redlinks == 'y') or (args.redlinks == 'true') 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 not (trackingInThisNamespace) then
					nav:wikitext('분류:깨진 포털이 있는 포털 틀') -- Category:Portal templates with redlinked portals
				end
				break
			end
			-- remove the portal (this does not happen if redlinks=yes)
			table.remove
		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 #portals == 0 then
 	if not (trackingInThisNamespace) then
				return '분류:깨진 포털이 있는 포털 틀' -- Category:Portal templates with all redlinked portals
			else
				return ""
			end
 end
		if not (trackingInThisNamespace) then
			nav:wikitext('분류:깨진 포털이 있는 포털 틀') -- Category:Portal templates with redlinked portals
		end
	end
	
	local list = mw.html.create( 'ul' )
	for _, portal in ipairs( portals ) do
		list
	end
	
	nav
	
	return tostring( nav )
end

-- Processes external arguments and sends them to the other functions.
function p.main( 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 type( frame.getParent ) == 'function' then
		origArgs = frame:getParent.args
		for k, v in pairs( frame.args ) do
			origArgs = frame.args
			break
		end
	else
		origArgs = frame
	end
	-- Process the args to make an array of portal names that can be used with ipairs. 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.
	local portals, args = {}, {}
	for k, v in pairs( origArgs ) do
		if type( k ) == 'number' and type( v ) == 'string' then -- Make sure we have no non-string portal names.
			if mw.ustring.find then -- Remove blank values.
				table.insert
				end
			elseif type( k ) ~= 'number' then -- Separate named arguments from portals.
			if type( v ) == 'string' then
				v = mw.text.trim( v )
			end
			args[ k ] = v
		end
	end
	table.sort( portals )
	for i, v in ipairs( portals ) do
		portals[ i ] = mw.text.trim( origArgs[ v ] ) -- Swap keys with values, trimming whitespace.
	end
	return p._main
end