Moduuli:Cs:Wikidata/Tree

---

local p = {}

local lib = require 'Module:cs:Wikidata/lib'

p.instance_prop = 'P31'
p.abovetaxa_prop = 'P171'
p.class_prop = 'P279'

function p.GoInTree(item, prop, level, holder, callback)
	if level == 0 then
		return holder
	end
	local entity = mw.wikibase.getEntity(item)
	local Statements = entity:getBestStatements(prop)
	for i, statement in pairs(Statements) do
		local new_holder, ok = callback(holder, Statements, i)
		if ok and lib.IsSnakValue(statement.mainsnak) then
			local item = lib.getEntityIdFromValue(statement.mainsnak.datavalue.value)
			return p.GoInTree(item, prop, level - 1, new_holder, callback)
		end
	end
	return holder
end

function p.IsInTree(item, root, prop, level, item_cache)
	if item == root then
		return true
	end
	if level == 0 then
		return false
	end
	local entity = mw.wikibase.getEntity(item)
	local Statements = entity:getBestStatements(prop)
	for _, statement in pairs(Statements) do
		if lib.IsSnakValue(statement.mainsnak) then
			local item = lib.getEntityIdFromValue(statement.mainsnak.datavalue.value)
			if not item_cache[item] then
				item_cache[item] = item
				if p.IsInTree(item, root, prop, level - 1, item_cache) then
					return true
				end
			end
		end
	end
	return false
end

function p.IsInstance(item, options)
	local Classes = lib.textToTable(options.instance:upper())
	local entity = mw.wikibase.getEntity(item)
	local Statements = entity:getBestStatements(p.instance_prop)
	local level = tonumber(options.level) or 10
	for _, class in pairs(Classes) do
		for _, statement in pairs(Statements) do
			if lib.IsSnakValue(statement.mainsnak) then
				local item = lib.getEntityIdFromValue(statement.mainsnak.datavalue.value)
				if p.IsInTree(item, class, p.class_prop, level, {}) then
					return true
				end
			end
		end
	end
	return false
end

return p