class GraphQL::Tracing::PlatformTracing

def self.use(schema_defn, options = {})
  tracer = self.new(options)
  schema_defn.instrument(:field, tracer)
  schema_defn.tracer(tracer)
end

def initialize(options = {})
  @options = options
  @platform_keys = self.class.platform_keys
  @trace_scalars = options.fetch(:trace_scalars, false)
end

def instrument(type, field)
  return_type = field.type.unwrap
  case return_type
  when GraphQL::ScalarType, GraphQL::EnumType
    if field.trace || (field.trace.nil? && @trace_scalars)
      trace_field(type, field)
    else
      field
    end
  else
    trace_field(type, field)
  end
end

def trace(key, data)
  case key
  when "lex", "parse", "validate", "analyze_query", "analyze_multiplex", "execute_query", "execute_query_lazy", "execute_multiplex"
    platform_key = @platform_keys.fetch(key)
    platform_trace(platform_key, key, data) do
      yield
    end
  when "execute_field", "execute_field_lazy"
    if (platform_key = data[:context].field.metadata[:platform_key])
      platform_trace(platform_key, key, data) do
        yield
      end
    else
      yield
    end
  else
    # it's a custom key
    yield
  end
end

def trace_field(type, field)
  new_f = field.redefine
  new_f.metadata[:platform_key] = platform_field_key(type, field)
  new_f
end