/*
 *------------------------------------------------------------------
 * Copyright (c) 2006-2016 Cisco and/or its affiliates.
 * 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.
 */

/* Break up a delimited string into a vector of substrings */

#include <stdio.h>
#include <vppinfra/clib.h>
#include <vppinfra/vec.h>
#include <vppinfra/hash.h>
#include <stdarg.h>

/*
 * #define UNIT_TESTS 1
 * #define MATCH_TRACE 1
 */

/*
 * delsvec
 * break up an input string into a vector of [null-terminated] u8 *'s
 *
 * Each supplied delimiter character results in a string in the output
 * vector, unless the delimiters occur back-to-back.  When matched,
 * a whitespace character in the delimiter consumes an arbitrary
 * run of whitespace. See the unit tests at the end of this file
 * for a set of examples.
 *
 * Returns a u8 **, or NULL if the input fails to match.  It is assumed
 * that both input and fmt are C strings, not necessarily vectors.
 *
 * Output strings are both vectors and proper C strings.
 */

static u8 **string_cache;
static u8 **svec_cache;

void
delsvec_recycle_this_string (u8 *s)
{
  if (s)
    {
      vec_set_len (s, 0);
      vec_add1 (string_cache, s);
    }
}

void
delsvec_recycle_this_svec (u8 **svec)
{
  if (svec)
    {
      if (svec_cache)
	{
	  vec_free (svec_cache);
	}
      vec_set_len (svec, 0);
      svec_cache = svec;
    }
}

int
pvl (char *a)
{
  return vec_len (a);
}

u8 **
delsvec (void *input_arg, char *fmt)
{
  u8 **rv = 0;
  int input_index = 0;
  u8 *this;
  int dirflag = 0;
  int i;
  u8 *input = input_arg;

  if (svec_cache)
    {
      rv = svec_cache;
      svec_cache = 0;
    }

  while (fmt)
    {
      dirflag = 0;
      if (vec_len (string_cache) > 0)
	{
	  this = string_cache[vec_len (string_cache) - 1];
	  vec_set_len (string_cache, vec_len (string_cache) - 1);
	}
      else
	this = 0;
      /*
       * '*' means one of two things: match the rest of the input,
       * or match as many characters as possible
       */
      if (fmt[0] == '*')
	{
	  fmt++;
	  dirflag = 1;
	  /*
	   * no more format: eat rest of string...
	   */
	  if (!fmt[0])
	    {
	      for (; input[input_index]; input_index++)
		vec_add1 (this, input[input_index]);
	      if (vec_len (this))
		{
		  vec_add1 (this, 0);
#ifdef MATCH_TRACE
		  printf ("final star-match adds: '%s'\n", this);
#endif
		  vec_add1 (rv, this);
		}
	      else
		{
		  vec_add1 (string_cache, this);
		}

	      return (rv);
	    }
	}
      /*
       * Left-to-right scan, adding chars until next delimiter char
       * appears.
       */
      if (!dirflag)
	{
	  while (input[input_index])
	    {
	      if (input[input_index] == fmt[0])
		{
		  /* If we just (exact) matched a whitespace delimiter */
		  if (fmt[0] == ' ')
		    {
		      /* scan forward eating whitespace */
		      while (input[input_index] == ' ' ||
			     input[input_index] == '\t' ||
			     input[input_index] == '\n')
			input_index++;
		      input_index--;
		    }
		  goto found;
		}
	      /* If we're looking for whitespace */
	      if (fmt[0] == ' ')
		{
		  /* and we have whitespace */
		  if (input[input_index] == ' ' ||
		      input[input_index] == '\t' || input[input_index] == '\n')
		    {
		      /* scan forward eating whitespace */
		      while (input[input_index] == ' ' ||
			     input[input_index] == '\t' ||
			     input[input_index] == '\n')
			{
			  input_index++;
			}
		      input_index--;
		      goto found;
		    }
		}
	      /* Not a delimiter, save it */
	      vec_add1 (this, input[input_index]);
	      input_index++;
	    }
	  /*
	   * Fell off the wagon, clean up and bail out
	   */
	bail:

#ifdef MATCH_TRACE
	  printf ("failed, fmt[0] = '%c', input[%d]='%s'\n", fmt[0],
		  input_index, &input[input_index]);
#endif
	  delsvec_recycle_this_string (this);
	  for (i = 0; i < vec_len (rv); i++)
	    delsvec_recycle_this_string (rv[i]);
	  delsvec_recycle_this_svec (rv);
	  return (0);

	found:
	  /*
	   * Delimiter matched
	   */
	  input_index++;
	  fmt++;
	  /*
	   * If we actually accumulated non-delimiter characters,
	   * add them to the result vector
	   */
	  if (vec_len (this))
	    {
	      vec_add1 (this, 0);
#ifdef MATCH_TRACE
	      printf ("match: add '%s'\n", this);
#endif
	      vec_add1 (rv, this);
	    }
	  else
	    {
	      vec_add1 (string_cache, this);
	    }
	}
      else
	{
	  /*
	   * right-to-left scan, '*' not at
	   * the end of the delimiter string
	   */
	  i = input_index;
	  while (input[++i])
	    ; /* scan forward */
	  i--;
	  while (i > input_index)
	    {
	      if (input[i] == fmt[0])
		goto found2;

	      if (fmt[0] == ' ' || fmt[0] == '\t' || fmt[0] == '\n')
		{
		  if (input[i] == ' ' || input[i] == '\t' || input[i] == '\n')
		    goto found2;
		}
	      i--;
	    }
	  goto bail;

	found2:
	  for (; input_index < i; input_index++)
	    {
	      vec_add1 (this, input[input_index]);
	    }
	  input_index++;
	  fmt++;
	  vec_add1 (this, 0);
#ifdef MATCH_TRACE
	  printf ("inner '*' match: add '%s'\n", this);
#endif
	  vec_add1 (rv, this);
	}
    }
  return (rv);
}

#ifdef UNIT_TESTS

typedef struct utest_
{
  char *string;
  char *fmt;
} utest_t;

utest_t tests[] = {
#ifdef NOTDEF
  { "Dec  7 08:56", "  :*" },
  { "Dec 17 08:56", "  :*" },
  { "Dec  7 08:56:41.239 install/inst_repl 0/9/CPU0 t1  [40989] File "
    "List:Successfully blobbified file list. Took 1 milliseconds",
    "  ::. / //  [] *" },
  { "RP/0/9/CPU0:Dec  7 08:55:28.550 : sam_server[291]: SAM backs up digest "
    "list to memory file",
    "///:  ::. : []: *" },
  /* Expected to fail */
  { "Dec  7 08:56:41.239 install/inst_repl 0/9/CPU0 t1  [40989] File "
    "List:Successfully blobbified file list. Took 1 milliseconds",
    "///:  ::. : : *" },
  /* Expected to fail */
  { "RP/0/9/CPU0:Dec  7 08:55:28.550 : sam_server[291]: SAM backs up digest "
    "list to memory file",
    "  ::. / //  [] *" },
  { "THIS that and + theother", "*+ *" },
  { "Dec 12 15:33:07.103 ifmgr/errors 0/RP0/CPU0 3# t2  Failed to open IM "
    "connection: No such file or directory",
    "  ::. / //   *" },
  { "Dec 16 21:43:47.328 ifmgr/bulk 0/3/CPU0 t8  Bulk DPC async download "
    "complete. Partitions 1, node_count 1, total_out 0, out_offset 0, "
    "out_expected 0: No error",
    "  ::. / //  *" },
  { "t:0x53034bd6 CPU:00 PROCESS :PROCCREATE_NAME", ": :  :*" },
  { "                       pid:1", " *" },
  { "t:0x53034cbb CPU:00 THREAD  :THCREATE      pid:1 tid:1",
    ": :  : pid: tid:*" },
  { "t:0x5303f950 CPU:00 COMM    :REC_PULSE     scoid:0x40000003 pid:364659",
    ": :  : *" },
  { "/hfr-base-3.3.85/lib/libttyconnection.dll 0xfc000000 0x0000306c "
    "0xfc027000 0x000001c8    1",
    "     *" },
  { "Feb 28 02:38:26.123 seqtrace 0/1/CPU0 t8  "
    ":msg_receive:ifmgr/t8:IMC_MSG_MTU_UPDATE:ppp_ma/t1",
    "  ::.  //  ::::*" },

  { "Feb 28 02:38:26.123 seqtrace 0/1/CPU0 t8  "
    ":msg_send_event:call:ifmgr/t8:124/0:cdp/t1",
    "  ::.  //  :msg_send_event::::*" },

  { "Feb 28 02:38:26.125 seqtrace 0/1/CPU0 t1  "
    ":msg_receive_event:cdp/t1:124/0",
    "  ::.  //  :msg_receive_event::*" } {
    "t:0x645dd86d CPU:00 USREVENT:EVENT:100, d0:0x00000002 d1:0x00000000",
    ": : USREVENT:EVENT:, d0: *" } {
    "t:0x5303f950 CPU:00 COMM    :REC_PULSE     scoid:0x40000003 pid:364659",
    ": :  : *" },
  { "t:0x2ccf9f5a CPU:00 INT_ENTR:0x80000000 (-2147483648)       "
    "IP:0x002d8b18",
    ": : INT_ENTR:  IP:*" } {
    "t:0xd473951c CPU:00 KER_EXIT:SCHED_GET/88 ret_val:2 sched_priority:10",
    ": : KER_EXIT:SCHED_GET : sched_priority:*" } {
    "t:0x00000123 CPU:01 SYSTEM  :FUNC_ENTER thisfn:0x40e62048 "
    "call_site:0x00000000",
    ": : SYSTEM :FUNC_ thisfn: *" },
  { "t:0x5af8de95 CPU:00 INT_HANDLER_ENTR:0x0000004d (77)       PID:8200 "
    "IP:0x00000000 AREA:0x0bf9b290",
    ": : INT_HANDLER_*" },
#endif
  { "t:0x6d1ff92f CPU:00 CONTROL: BUFFER sequence = 1053, num_events = 714",
    ": : CONTROL*" },
  { "t:0x6d1ff92f CPU:00 CONTROL :TIME msb:0x0000003c lsb(offset):0x6d1ff921",
    ": : CONTROL*" },
};

int
main (int argc, char **argv)
{
  int i, j;
  u8 **svec;

  for (j = 0; j < ARRAY_LEN (tests); j++)
    {
      printf ("input string: '%s'\n", tests[j].string);
      printf ("delimiter arg: '%s'\n", tests[j].fmt);
      printf ("parse trace:\n");
      svec = delsvec (tests[j].string, tests[j].fmt);
      if (!svec)
	{
	  printf ("index %d failed\n", j);
	  continue;
	}
      printf ("%d substring vectors\n", vec_len (svec));
      for (i = 0; i < vec_len (svec); i++)
	{
	  printf ("[%d]: '%s'\n", i, svec[i]);
	}
      printf ("-------------------\n");
    }
  exit (0);
}
#endif