//
// Copyright 2019 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

syntax = "proto2";

package zetasql;

option java_package = "com.google.zetasql";

// This proto is used as a absl::Status error payload to give the location
// for SQL parsing and analysis errors.
message ErrorLocation {

  // 1-based <line> and <column> offset in the input SQL string.
  // <column> may point to one character off the end of a line when the error
  // occurs at end-of-line.
  //
  // NOTE: <line> is computed assuming lines can be split
  // with \n, \r or \r\n, and <column> is computed assuming tabs
  // expand to eight characters.
  optional int32 line = 1 [default = 1];
  optional int32 column = 2 [default = 1];

  // An optional filename related to the error, if applicable.  May be used
  // to express more general error source information than a filename, for
  // instance if the error comes from a module imported from datascape.
  // ErrorLocation typically gets formatted as 'filename:line:column', so
  // this field content should make sense in this format (i.e., it should
  // probably avoid whitespace).
  optional string filename = 3;

  // An optional list of error source information for the related Status.
  // The last element in this list is the immediate error cause, with
  // the previous element being its cause, etc.  These error sources should
  // normally be displayed in reverse order.
  repeated ErrorSource error_source = 4;
}

// This proto indicates an error that is the source of another error.
// It is expected that all of <error_message>, <error_message_caret_string>,
// and <error_location> are populated in normal use cases.
//
// An example of usage is for deferred, nested resolution of SQL expressions
// related to SQL UDFs inside Modules.  Resolving a SQL UDF (func1) that
// references another SQL UDF (func2) can cause nested resolution, and if the
// resolution of func2 fails then that error information is captured in an
// ErrorSource that is attached to the error Status returned by func1's
// resolution.  The returned Status may also have its own ErrorLocation
// related to func1, while the ErrorSource will be specific to func2's
// resolution.
message ErrorSource {
  // The error message for this ErrorSource.
  optional string error_message = 1;

  // An additional error string added to <error_message> when in
  // ErrorMessageMode ERROR_MESSAGE_MODE_MULTI_LINE_WITH_CARET.  This
  // is constructed as one line of input text, a newline, and then a
  // second line with the caret in the position pointing at the error
  // in the first line.
  optional string error_message_caret_string = 2;

  // The error location indicating a position in the original input file
  // containing the statement with the error.
  // This <error_location> should not itself have <error_source> filled in.
  optional ErrorLocation error_location = 3;
}