-- This module provides a library for formatting file wikilinks.



local yesno = require('Module:Yesno')

local checkType = require('libraryUtil').checkType



local p = {}



function p._main(args)

	checkType('_main', 1, args, 'table')



	-- This is basically libraryUtil.checkTypeForNamedArg, but we are rolling our

	-- own function to get the right error level.

	local function checkArg(key, val, level)

		if type(val) ~= 'string' then

			error(string.format(

				"type error in '%s' parameter of '_main' (expected string, got %s)",

				key, type(val)

			), level)

		end

	end



	local ret = {}



	-- Adds a positional parameter to the buffer.

	local function addPositional(key)

		local val = argskey

		if not val then

			return nil

		end

		checkArg(key, val, 4)

		ret#ret + 1 = val

	end



	-- Adds a named parameter to the buffer. We assume that the parameter name

	-- is the same as the argument key.

	local function addNamed(key)

		local val = argskey

		if not val then

			return nil

		end

		checkArg(key, val, 4)

		ret#ret + 1 = key .. '=' .. val

	end



	-- Filename

	checkArg('file', args.file, 3)

	ret#ret + 1 = 'File:' .. args.file



	-- Format

	if args.format then

		checkArg('format', args.format)

		if args.formatfile then

			checkArg('formatfile', args.formatfile)

			ret#ret + 1 = args.format .. '=' .. args.formatfile

		else

			ret#ret + 1 = args.format

		end

	end



	-- Border

	if yesno(args.border) then

		ret#ret + 1 = 'border'

	end



	addPositional('location')

	addPositional('alignment')

	addPositional('size')

	addNamed('upright')

	addNamed('link')

	addNamed('alt')

	addNamed('page')

	addNamed('class')

	addNamed('lang')

	addNamed('start')

	addNamed('end')

	addNamed('thumbtime')

	addPositional('caption')



	return string.format('[[%s]]', table.concat(ret, '|'))

end



function p.main(frame)

	local origArgs = require('Module:Arguments').getArgs(frame, {

		wrappers = 'Template:File link'

	})

	if not origArgs.file then

		error("'file' parameter missing from [[Template:File link]]", 0)

	end



	-- Copy the arguments that were passed to a new table to avoid looking up

	-- every possible parameter in the frame object.

	local args = {}

	for k, v in pairs(origArgs) do

		-- Make _BLANK a special argument to add a blank parameter. For use in

		-- conditional templates etc. it is useful for blank arguments to be

		-- ignored, but we still need a way to specify them so that we can do

		-- things like [[File:Example.png|link=]].

		if v == '_BLANK' then

			v = ''

		end

		argsk = v

	end

	return p._main(args)

end



return p