local p = {}



function p.decide_migration(args)

	if args'migration' then

		return args'migration'

	end

	local licsense_migration_data = mw.loadJsonData( 'Module:Self/license_migration_data.json')

	for _, template_name in ipairs(args) do

		local migration_data = licsense_migration_datastring.lower(template_name)]

		if migration_data == 'redundant' then

			return migration_data

		end

	end

	return ''

end



function p.setup_template_params(template_name, frame,  args, migration)

	local title =  mw.title.new(template_name, 10)

	if not title.exists then

		return {

			txt='',

			errors=('<span class="error scribunto-error">The license "' .. template_name ..  '" does not exist.</span>' ..

					'[[Category:Wikipedia dual licensed files with invalid licenses]]'

			)

		}

	end



	return { txt=(frame:expandTemplate({

		title = template_name,

		args = {

			dw= (args'dw' or 'no'),

			date= (args'date'  or ''),

			migration= (migration)

	 } })), errors='' }

end



function p.more_than_one(args)

	local c  = 0

	for _, __ in ipairs(args) do

		c = c + 1

		if c == 2 then

			return true

		end

	end

	return false

end



function p.start_line(args)

	local more_than_one = p.more_than_one(args)

	return mw.ustring.format(

		'\'\'\'\'\'%s, the copyright holder of this work,\'\'\' hereby publish%s it under the following license%s:\'\'',

		args'author' or 'I',

		args'author' and 'es' or '',

		more_than_one and 's' or ''

	)

end



function p.categories(args)

	local currentTitle = mw.title.getCurrentTitle()

	local is_in_file_namespace = currentTitle.nsText == 'File'

	if not is_in_file_namespace then

		return ''

	end



	if args'author' then

		return mw.ustring.format('[[Category:Files licensed by third parties|%s]]', currentTitle.fullText)

	else

		return mw.ustring.format('[[Category:Self-published work|%s]]', currentTitle.fullText)

	end

end



function p.main(frame)

	local args = frame:getParent().args

	local tstyles = frame:extensionTag( 'templatestyles', '', { src = 'Module:Self/styles.css' } )

	local fmt_string_tmpl = '<div class="wp-tmpl-self-license-wrapper">' ..

	'<div class="center">%s</div><div class="center">%s</div>%s</div>%s'

	local initial_text = p.start_line(args)

	local final_line = p.more_than_one(args) and "<div class='center'>''You may select the license of your choice.''</div>" or ''

	local categories = p.categories(args)

	local templates = ''

	local errors = ''

	local migration = p.decide_migration(args)

	for _, template_name in ipairs(args) do

		tmpl_with_args = p.setup_template_params(template_name, frame, args, migration)

		templates = templates .. tmpl_with_args.txt

		errors = errors .. tmpl_with_args.errors

	end

	return tstyles .. mw.ustring.format(fmt_string_tmpl, initial_text, templates, final_line, categories) .. errors

end



return p

-- </nowiki>