Editing Module:SDC tracking

--[[  
  __  __           _       _        ____  ____   ____    _                  _    _             
 |  \/  | ___   __| |_   _| | ___ _/ ___||  _ \ / ___|  | |_ _ __ __ _  ___| | _(_)_ __   __ _ 
 | |\/| |/ _ \ / _` | | | | |/ _ (_)___ \| | | | |      | __| '__/ _` |/ __| |/ / | '_ \ / _` |
 | |  | | (_) | (_| | |_| | |  __/_ ___) | |_| | |___   | |_| | | (_| | (__|   <| | | | | (_| |
 |_|  |_|\___/ \__,_|\__,_|_|\___(_)____/|____/ \____|___\__|_|  \__,_|\___|_|\_\_|_| |_|\__, |
                                                    |_____|                              |___/ 
This module is intended to be the engine behind "Template:SDC_tracking".

Please do not modify this code without applying the changes first at
"Module:SDC_tracking/sandbox" and testing at "Module:SDC_tracking/testcases".

Authors and maintainers:
* User:Jarekt - original version 
]]


-- =======================================
-- === Dependencies ======================
-- =======================================
require('strict') -- used for debugging purposes as it detects cases of unintended global variables

-- =======================================
-- === Local Functions ===================
-- =======================================

local function getArgs(frame)
	-- switch to lowercase parameters to make them case independent
	local args = {}
	for name, value in pairs( frame.args ) do 
		if value ~= '' then -- nuke empty strings
			args[string.lower(name)] = value
		end
	end
	
	local page  = mw.title.getCurrentTitle()
	
	if mw.wikibase then
	    if page.namespace == 6 then
	        args.entity = mw.wikibase.getEntity()
	    elseif args.item then
	        args.entity = mw.wikibase.getEntity(args.item)
	    end
	end
	
	return args
end

-----------------------------------------------------------------------
local function Category(catName)
	if catName then
		return '[[Category:' .. catName .. ']]'
	else
		return ''
	end
end

-- ==================================================
-- === External functions ===========================
-- ==================================================
local p = {}

-- ===========================================================================
-- === Version of the function to be called from other LUA codes
-- ===========================================================================

function p._statement_exist(entity, property, positive, negative)
	-- check if statement exist
	if entity and entity.statements and entity.statements[property] then
		return positive
	else
		return negative
	end
end

-----------------------------------------------------------------------
function p._statement_has_value(entity, property, value, matching, mismatching, missing)
	value = value or ''
	if entity and entity.statements and entity.statements[property] then
		for _, statement in pairs( entity:getAllStatements( property )) do
			if (statement.mainsnak.snaktype == "value") then 
				local val = statement.mainsnak.datavalue.value
				if val.id then 
					val = val.id
				elseif val.text then
					val = val.text
				end
				if val==value then
					return matching
				end				
			end
		end
		return mismatching
	else
		return missing
	end
end

-- ===========================================================================
-- === Versions of the function to be called from template namespace
-- ===========================================================================

function p.SDC_statement_exist(frame)
	local args   = getArgs(frame)
	
	-- skip if we are not in file namespace
	local page = mw.title.getCurrentTitle()
	if not (page.namespace==6 or page.namespace==args.namespace or args.namespace=='all') then
		return ''
	end	
	
	local output = p._statement_exist(args.entity, args.property, args.positive_category, args.negative_category)
	return Category(output)
end

-----------------------------------------------------------------------
function p.SDC_statement_has_value (frame)
	local args   = getArgs(frame)
		
	-- skip if we are not in file namespace
	local page = mw.title.getCurrentTitle()
	if not (page.namespace==6 or page.namespace==args.namespace or args.namespace=='all') then
		return ''
	end	
	
	local output = p._statement_has_value(args.entity, args.property, args.value, 
					args.matching_category, args.mismatching_category, args.missing_category)
	return Category(output)
end

return p