# Module:Unsubst

local checkType = require('libraryUtil').checkType  
local p = {}  
local BODY_PARAM = '$B'  
local specialParams = {
['$params'] = 'parameter list',
['$aliases'] = 'parameter aliases',
['$flags'] = 'flags',
['$B'] = 'template content',
['$template-name'] = 'template invocation name override',
}  
function p.main(, body)
-- If we are substing, this function returns a template invocation, and if
-- not, it returns the template body. The template body can be specified in
-- the body parameter, or in the template parameter defined in the
-- BODY_PARAM variable. This function can be called from Lua or from
-- #invoke.  
-- Return the template body if we aren't substing.
if not mw.isSubsting then
if body ~= nil then
return body
elseif .args[BODY_PARAM] ~= nil then
return .args[BODY_PARAM]
else
error(string.format(
"no template content specified (use parameter '%s' from #invoke)",
BODY_PARAM
), 2)
end
end  
-- Sanity check for the object.
if type ~= 'table'
or type(.getParent) ~= 'function'
or not :getParent
then
error(
"argument #1 to 'main' must be a object with a parent " ..
" available",
2
end  
-- Find the invocation name.
local mTemplateInvocation = require('Module:Template invocation')
local name  
if .args['$template-name'] and '' ~= .args['$template-name'] then
name = .args['$template-name'] -- override whatever the template name is with this name
else
name = mTemplateInvocation.name(:getParent:getTitle)
end  
-- Combine passed args with passed defaults
local args = {}
if string.find( ','..(.args['$flags'] or '')..',', ',%s*override%s*,' ) then
for k, v in pairs( :getParent.args ) do
args[k] = v
end
for k, v in pairs( .args ) do
if not specialParams[k] then
if v == '__DATE__' then
v = mw.getContentLanguage:formatDate( 'F Y' )
end
args[k] = v
end
end
else
for k, v in pairs( .args ) do
if not specialParams[k] then
if v == '__DATE__' then
v = mw.getContentLanguage:formatDate( 'F Y' )
end
args[k] = v
end
end
for k, v in pairs( :getParent.args ) do
args[k] = v
end
end  
-- Trim parameters, if not specified otherwise
if not string.find( ','..(.args['$flags'] or '')..',', ',%s*keep%-whitespace%s*,' ) then
for k, v in pairs( args ) do args[k] = mw.ustring.match(v, '^%s*(.*)%s*$') or '' end
end  
-- Pull information from parameter aliases
local aliases = {}
if .args['$aliases'] then
local list = mw.text.split( .args['$aliases'], '%s*,%s*' )
for k, v in ipairs( list ) do
local tmp = mw.text.split( v, '%s*>%s*' )
aliases[tonumber(mw.ustring.match(tmp[1], '^[1-9][0-9]*$')) or tmp[1]] = ((tonumber(mw.ustring.match(tmp[2], '^[1-9][0-9]*$'))) or tmp[2])
end
end
for k, v in pairs( aliases ) do
if args[k] and ( not args[v] or args[v] == '' ) then
args[v] = args[k]
end
args[k] = nil
end  
-- Remove empty parameters, if specified
if string.find( ','..(.args['$flags'] or '')..',', ',%s*remove%-empty%s*,' ) then
local tmp = 0
for k, v in ipairs( args ) do
if v ~= * or ( args[k+1] and args[k+1] ~= * ) or ( args[k+2] and args[k+2] ~= '' ) then
tmp = k
else
break
end
end
for k, v in pairs( args ) do
if v == '' then
if not (type(k) == 'number' and k < tmp) then args[k] = nil end
end
end
end  
-- Order parameters
if .args['$params'] then
local params, tmp = mw.text.split( .args['$params'], '%s*,%s*' ), {}
for k, v in ipairs(params) do
v = tonumber(mw.ustring.match(v, '^[1-9][0-9]*$')) or v
if args[v] then tmp[v], args[v] = args[v], nil end
end
for k, v in pairs(args) do tmp[k], args[k] = args[k], nil end
args = tmp
end  
return mTemplateInvocation.invocation(name, args)
end  
p[''] = p.main -- For backwards compatibility  
return p