/*
 * Copyright (c) 2018, PostgreSQL Global Development Group
 * See the LICENSE file in the project root for more information.
 */

package org.postgresql.core;

import org.postgresql.util.GT;
import org.postgresql.util.PSQLException;
import org.postgresql.util.PSQLState;

Parses oid and rows from a CommandComplete (B) message (end of Execute). /**
 * Parses {@code oid} and {@code rows} from a {@code CommandComplete (B)} message (end of Execute).
 */
public final class CommandCompleteParser {
  private long oid;
  private long rows;

  public CommandCompleteParser() {
  }

  public long getOid() {
    return oid;
  }

  public long getRows() {
    return rows;
  }

  void set(long oid, long rows) {
    this.oid = oid;
    this.rows = rows;
  }

  
Parses CommandComplete (B) message. Status is in the format of "COMMAND OID ROWS" where both 'OID' and 'ROWS' are optional and COMMAND can have spaces within it, like CREATE TABLE. 
Params:
status – COMMAND OID ROWS message
Throws:
PSQLException – in case the status cannot be parsed/**
   * Parses {@code CommandComplete (B)} message.
   * Status is in the format of "COMMAND OID ROWS" where both 'OID' and 'ROWS' are optional
   * and COMMAND can have spaces within it, like CREATE TABLE.
   *
   * @param status COMMAND OID ROWS message
   * @throws PSQLException in case the status cannot be parsed
   */
  public void parse(String status) throws PSQLException {
    // Assumption: command neither starts nor ends with a digit
    if (!Parser.isDigitAt(status, status.length() - 1)) {
      set(0, 0);
      return;
    }

    // Scan backwards, while searching for a maximum of two number groups
    //   COMMAND OID ROWS
    //   COMMAND ROWS
    long oid = 0;
    long rows = 0;
    try {
      int lastSpace = status.lastIndexOf(' ');
      // Status ends with a digit => it is ROWS
      if (Parser.isDigitAt(status, lastSpace + 1)) {
        rows = Parser.parseLong(status, lastSpace + 1, status.length());

        if (Parser.isDigitAt(status, lastSpace - 1)) {
          int penultimateSpace = status.lastIndexOf(' ', lastSpace - 1);
          if (Parser.isDigitAt(status, penultimateSpace + 1)) {
            oid = Parser.parseLong(status, penultimateSpace + 1, lastSpace);
          }
        }
      }
    } catch (NumberFormatException e) {
      // This should only occur if the oid or rows are out of 0..Long.MAX_VALUE range
      throw new PSQLException(
          GT.tr("Unable to parse the count in command completion tag: {0}.", status),
          PSQLState.CONNECTION_FAILURE, e);
    }
    set(oid, rows);
  }

  @Override
  public String toString() {
    return "CommandStatus{"
        + "oid=" + oid
        + ", rows=" + rows
        + '}';
  }

  @Override
  public boolean equals(Object o) {
    if (this == o) {
      return true;
    }
    if (o == null || getClass() != o.getClass()) {
      return false;
    }

    CommandCompleteParser that = (CommandCompleteParser) o;

    if (oid != that.oid) {
      return false;
    }
    return rows == that.rows;
  }

  @Override
  public int hashCode() {
    int result = (int) (oid ^ (oid >>> 32));
    result = 31 * result + (int) (rows ^ (rows >>> 32));
    return result;
  }
}