/* Copyright (c) 2010, 2023, Oracle and/or its affiliates.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License, version 2.0, for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA */


#include <stdlib.h>
#include <errno.h>
#include <ctype.h>
#include <string.h>
#include "sql_bootstrap.h"

int read_bootstrap_query(char *query, size_t *query_length,
                         fgets_input_t input, fgets_fn_t fgets_fn, int *error)
{
  char line_buffer[MAX_BOOTSTRAP_LINE_SIZE];
  const char *line;
  size_t len;
  size_t query_len= 0;
  int fgets_error= 0;
  *error= 0;

  for ( ; ; )
  {
    line= (*fgets_fn)(line_buffer, sizeof(line_buffer), input, &fgets_error);
    
    if (error)
      *error= fgets_error;

    if (fgets_error != 0)
      return READ_BOOTSTRAP_ERROR;
      
    if (line == NULL)
      return (query_len == 0) ? READ_BOOTSTRAP_EOF : READ_BOOTSTRAP_ERROR;

    len= strlen(line);

    /*
      Remove trailing whitespace characters.
      This assumes:
      - no multibyte encoded character can be found at the very end of a line,
      - whitespace characters from the "C" locale only.
     which is sufficient for the kind of queries found
     in the bootstrap scripts.
    */
    while (len && (isspace(line[len - 1])))
      len--;
    /*
      Cleanly end the string, so we don't have to test len > x
      all the time before reading line[x], in the code below.
    */
    line_buffer[len]= '\0';

    /* Skip blank lines */
    if (len == 0)
      continue;

    /* Skip # comments */
    if (line[0] == '#')
      continue;
    
    /* Skip -- comments */
    if ((line[0] == '-') && (line[1] == '-'))
      continue;

    /* Skip delimiter, ignored. */
    if (strncmp(line, "delimiter", 9) == 0)
      continue;

    /* Append the current line to a multi line query. If the new line will make
       the query too long, preserve the partial line to provide context for the
       error message.
    */
    if (query_len + len + 1 >= MAX_BOOTSTRAP_QUERY_SIZE)
    {
      size_t new_len= MAX_BOOTSTRAP_QUERY_SIZE - query_len - 1;
      if ((new_len > 0) && (query_len < MAX_BOOTSTRAP_QUERY_SIZE))
      {
        memcpy(query + query_len, line, new_len);
        query_len+= new_len;
      }
      query[query_len]= '\0';
      *query_length= query_len;
      return READ_BOOTSTRAP_QUERY_SIZE;
    }

    if (query_len != 0)
    {
      /*
        Append a \n to the current line, if any,
        to preserve the intended presentation.
       */
      query[query_len++]= '\n';
    }
    memcpy(query + query_len, line, len);
    query_len+= len;

    if (line[len - 1] == ';')
    {
      /*
        The last line is terminated by ';'.
        Return the query found.
      */
      query[query_len]= '\0';
      *query_length= query_len;
      return READ_BOOTSTRAP_SUCCESS;
    }
  }
}