class GraphQL::StaticValidation::LiteralValidator

def ensure_array(value)
  value.is_a?(Array) ? value : [value]
end

def present_input_field_values_are_valid(type, ast_node)
  fields = type.input_fields
  ast_node.arguments.all? do |value|
    field = fields[value.name]
    field ? validate(value.value, field.type) : true
  end
end

def required_input_fields_are_present(type, ast_node)
  required_field_names = type.input_fields
    .values
    .select { |f| f.type.kind.non_null? }
    .map(&:name)
  present_field_names = ast_node.arguments.map(&:name)
  missing_required_field_names = required_field_names - present_field_names
  missing_required_field_names.none?
end

def validate(ast_value, type)
  if type.kind.non_null?
    (!ast_value.nil?) && validate(ast_value, type.of_type)
  elsif type.kind.list?
    item_type = type.of_type
    ensure_array(ast_value).all? { |val| validate(val, item_type) }
  elsif type.kind.scalar? && !ast_value.is_a?(GraphQL::Language::Nodes::AbstractNode) && !ast_value.is_a?(Array)
    type.valid_input?(ast_value)
  elsif type.kind.enum? && ast_value.is_a?(GraphQL::Language::Nodes::Enum)
    type.valid_input?(ast_value.name)
  elsif type.kind.input_object? && ast_value.is_a?(GraphQL::Language::Nodes::InputObject)
    required_input_fields_are_present(type, ast_value) &&
      present_input_field_values_are_valid(type, ast_value)
  elsif ast_value.is_a?(GraphQL::Language::Nodes::VariableIdentifier)
    true
  else
    false
  end
end