/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
** File:          plgetopt.c
** Description:   utilities to parse argc/argv
*/

#include "prmem.h"
#include "prlog.h"
#include "prerror.h"
#include "plstr.h"
#include "plgetopt.h"

#include <string.h>

static char static_Nul = 0;

struct PLOptionInternal {
  const char* options;       /* client options list specification */
  PRIntn argc;               /* original number of arguments */
  char** argv;               /* vector of pointers to arguments */
  PRIntn xargc;              /* which one we're processing now */
  const char* xargv;         /* where within *argv[xargc] */
  PRIntn minus;              /* do we already have the '-'? */
  const PLLongOpt* longOpts; /* Caller's array */
  PRBool endOfOpts;          /* have reached a "--" argument */
  PRIntn optionsLen;         /* is strlen(options) */
};

/*
** Create the state in which to parse the tokens.
**
** argc        the sum of the number of options and their values
** argv        the options and their values
** options    vector of single character options w/ | w/o ':
*/
PR_IMPLEMENT(PLOptState*)
PL_CreateOptState(PRIntn argc, char** argv, const char* options) {
  return PL_CreateLongOptState(argc, argv, options, NULL);
} /* PL_CreateOptState */

PR_IMPLEMENT(PLOptState*)
PL_CreateLongOptState(PRIntn argc, char** argv, const char* options,
                      const PLLongOpt* longOpts) {
  PLOptState* opt = NULL;
  PLOptionInternal* internal;

  if (NULL == options) {
    PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
    return opt;
  }

  opt = PR_NEWZAP(PLOptState);
  if (NULL == opt) {
    PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
    return opt;
  }

  internal = PR_NEW(PLOptionInternal);
  if (NULL == internal) {
    PR_DELETE(opt);
    PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
    return NULL;
  }

  opt->option = 0;
  opt->value = NULL;
  opt->internal = internal;
  opt->longOption = 0;
  opt->longOptIndex = -1;

  internal->argc = argc;
  internal->argv = argv;
  internal->xargc = 0;
  internal->xargv = &static_Nul;
  internal->minus = 0;
  internal->options = options;
  internal->longOpts = longOpts;
  internal->endOfOpts = PR_FALSE;
  internal->optionsLen = PL_strlen(options);

  return opt;
} /* PL_CreateLongOptState */

/*
** Destroy object created by CreateOptState()
*/
PR_IMPLEMENT(void) PL_DestroyOptState(PLOptState* opt) {
  PR_DELETE(opt->internal);
  PR_DELETE(opt);
} /* PL_DestroyOptState */

PR_IMPLEMENT(PLOptStatus) PL_GetNextOpt(PLOptState* opt) {
  PLOptionInternal* internal = opt->internal;

  opt->longOption = 0;
  opt->longOptIndex = -1;
  /*
  ** If the current xarg points to nul, advance to the next
  ** element of the argv vector. If the vector index is equal
  ** to argc, we're out of arguments, so return an EOL.
  ** Note whether the first character of the new argument is
  ** a '-' and skip by it if it is.
  */
  while (0 == *internal->xargv) {
    internal->xargc += 1;
    if (internal->xargc >= internal->argc) {
      opt->option = 0;
      opt->value = NULL;
      return PL_OPT_EOL;
    }
    internal->xargv = internal->argv[internal->xargc];
    internal->minus = 0;
    if (!internal->endOfOpts && ('-' == *internal->xargv)) {
      internal->minus++;
      internal->xargv++; /* and consume */
      if ('-' == *internal->xargv && internal->longOpts) {
        internal->minus++;
        internal->xargv++;
        if (0 == *internal->xargv) {
          internal->endOfOpts = PR_TRUE;
        }
      }
    }
  }

  /*
  ** If we already have a '-' or '--' in hand, xargv points to the next
  ** option. See if we can find a match in the list of possible
  ** options supplied.
  */
  if (internal->minus == 2) {
    char* foundEqual = strchr(internal->xargv, '=');
    PRIntn optNameLen =
        foundEqual ? (foundEqual - internal->xargv) : strlen(internal->xargv);
    const PLLongOpt* longOpt = internal->longOpts;
    PLOptStatus result = PL_OPT_BAD;

    opt->option = 0;
    opt->value = NULL;

    for (; longOpt->longOptName; ++longOpt) {
      if (strncmp(longOpt->longOptName, internal->xargv, optNameLen)) {
        continue; /* not a possible match */
      }
      if (strlen(longOpt->longOptName) != optNameLen) {
        continue; /* not a match */
      }
      /* option name match */
      opt->longOptIndex = longOpt - internal->longOpts;
      opt->longOption = longOpt->longOption;
      /* value is part of the current argv[] element if = was found */
      /* note: this sets value even for long options that do not
       * require option if specified as --long=value */
      if (foundEqual) {
        opt->value = foundEqual + 1;
      } else if (longOpt->valueRequired) {
        /* value is the next argv[] element, if any */
        if (internal->xargc + 1 < internal->argc) {
          opt->value = internal->argv[++(internal->xargc)];
        }
        /* missing value */
        else {
          break; /* return PL_OPT_BAD */
        }
      }
      result = PL_OPT_OK;
      break;
    }
    internal->xargv = &static_Nul; /* consume this */
    return result;
  }
  if (internal->minus) {
    PRIntn cop;
    PRIntn eoo = internal->optionsLen;
    for (cop = 0; cop < eoo; ++cop) {
      if (internal->options[cop] == *internal->xargv) {
        opt->option = *internal->xargv++;
        opt->longOption = opt->option & 0xff;
        /*
        ** if options indicates that there's an associated
        ** value, it must be provided, either as part of this
        ** argv[] element or as the next one
        */
        if (':' == internal->options[cop + 1]) {
          /* value is part of the current argv[] element */
          if (0 != *internal->xargv) {
            opt->value = internal->xargv;
          }
          /* value is the next argv[] element, if any */
          else if (internal->xargc + 1 < internal->argc) {
            opt->value = internal->argv[++(internal->xargc)];
          }
          /* missing value */
          else {
            return PL_OPT_BAD;
          }

          internal->xargv = &static_Nul;
          internal->minus = 0;
        } else {
          opt->value = NULL;
        }
        return PL_OPT_OK;
      }
    }
    internal->xargv += 1; /* consume that option */
    return PL_OPT_BAD;
  }

  /*
  ** No '-', so it must be a standalone value. The option is nul.
  */
  opt->value = internal->argv[internal->xargc];
  internal->xargv = &static_Nul;
  opt->option = 0;
  return PL_OPT_OK;
} /* PL_GetNextOpt */

/* plgetopt.c */