# Check a JsonArray
# ~~~
# var validator = new ArrayValidator
# assert not validator.validate("""{}""")
# assert validator.validate("""[]""")
# assert validator.validate("""[ "id", 10, {} ]""")
#
# validator = new ArrayValidator(allow_empty=false)
# assert not validator.validate("""[]""")
# assert validator.validate("""[ "id", 10, {} ]""")
#
# validator = new ArrayValidator(length=3)
# assert not validator.validate("""[]""")
# assert validator.validate("""[ "id", 10, {} ]""")
# ~~~
class ArrayValidator
	super DocumentValidator

	# Allow empty arrays (default: true)
	var allow_empty: nullable Bool

	# Check array length (default: no check)
	var length: nullable Int

	redef fun validate(document) do
		super
		var json = document.parse_json
		if json == null then
			validation.add_error("document", "Expected JsonArray got `null`")
			return false
		end
		return validate_json(json)
	end

	# Validate a Serializable input
	fun validate_json(json: Serializable): Bool do
		if not json isa JsonArray then
			validation.add_error("document", "Expected JsonArray got `{json.class_name}`")
			return false
		end
		validation.array = json
		var allow_empty = self.allow_empty
		if json.is_empty and (allow_empty != null and not allow_empty) then
			validation.add_error("document", "Cannot be empty")
			return false
		end
		var length = self.length
		if length != null and json.length != length then
			validation.add_error("document", "Array length must be exactly `{length}`")
			return false
		end

		return true
	end
end