
/**
 *  \file load.c
 *
 *  This file contains the routines that deal with processing text strings
 *  for options, either from a NUL-terminated string passed in or from an
 *  rc/ini file.
 *
 * @addtogroup autoopts
 * @{
 */
/*
 *  This file is part of AutoOpts, a companion to AutoGen.
 *  AutoOpts is free software.
 *  AutoOpts is Copyright (C) 1992-2018 by Bruce Korb - all rights reserved
 *
 *  AutoOpts is available under any one of two licenses.  The license
 *  in use must be one of these two and the choice is under the control
 *  of the user of the license.
 *
 *   The GNU Lesser General Public License, version 3 or later
 *      See the files "COPYING.lgplv3" and "COPYING.gplv3"
 *
 *   The Modified Berkeley Software Distribution License
 *      See the file "COPYING.mbsd"
 *
 *  These files have the following sha256 sums:
 *
 *  8584710e9b04216a394078dc156b781d0b47e1729104d666658aecef8ee32e95  COPYING.gplv3
 *  4379e7444a0e2ce2b12dd6f5a52a27a4d02d39d247901d3285c88cf0d37f477b  COPYING.lgplv3
 *  13aa749a5b0a454917a944ed8fffc530b784f5ead522b1aacaf4ec8aa55a6239  COPYING.mbsd
 */

static bool
get_realpath(char * buf, size_t b_sz)
{
#if defined(HAVE_CANONICALIZE_FILE_NAME)
    {
        size_t name_len;

        char * pz = canonicalize_file_name(buf);
        if (pz == NULL)
            return false;

        name_len = strlen(pz);
        if (name_len >= (size_t)b_sz) {
            free(pz);
            return false;
        }

        memcpy(buf, pz, name_len + 1);
        free(pz);
    }

#elif defined(HAVE_REALPATH)
    {
        size_t name_len;
        char z[PATH_MAX+1];

        if (realpath(buf, z) == NULL)
            return false;

        name_len = strlen(z);
        if (name_len >= b_sz)
            return false;

        memcpy(buf, z, name_len + 1);
    }
#endif
    return true;
}

/*=export_func  optionMakePath
 * private:
 *
 * what:  translate and construct a path
 * arg:   + char *       + p_buf     + The result buffer +
 * arg:   + int          + b_sz      + The size of this buffer +
 * arg:   + char const * + fname     + The input name +
 * arg:   + char const * + prg_path  + The full path of the current program +
 *
 * ret-type: bool
 * ret-desc: true if the name was handled, otherwise false.
 *           If the name does not start with ``$'', then it is handled
 *           simply by copying the input name to the output buffer and
 *           resolving the name with either
 *           @code{canonicalize_file_name(3GLIBC)} or @code{realpath(3C)}.
 *
 * doc:
 *
 *  This routine will copy the @code{pzName} input name into the
 *  @code{pzBuf} output buffer, not exceeding @code{bufSize} bytes.  If the
 *  first character of the input name is a @code{'$'} character, then there
 *  is special handling:
 *  @*
 *  @code{$$} is replaced with the directory name of the @code{pzProgPath},
 *  searching @code{$PATH} if necessary.
 *  @*
 *  @code{$@} is replaced with the AutoGen package data installation directory
 *  (aka @code{pkgdatadir}).
 *  @*
 *  @code{$NAME} is replaced by the contents of the @code{NAME} environment
 *  variable.  If not found, the search fails.
 *
 *  Please note: both @code{$$} and @code{$NAME} must be at the start of the
 *     @code{pzName} string and must either be the entire string or be followed
 *     by the @code{'/'} (backslash on windows) character.
 *
 * err:  @code{false} is returned if:
 *       @*
 *       @bullet{} The input name exceeds @code{bufSize} bytes.
 *       @*
 *       @bullet{} @code{$$}, @code{$@@} or @code{$NAME} is not the full string
 *                 and the next character is not '/'.
 *       @*
 *       @bullet{} libopts was built without PKGDATADIR defined and @code{$@@}
 *                 was specified.
 *       @*
 *       @bullet{} @code{NAME} is not a known environment variable
 *       @*
 *       @bullet{} @code{canonicalize_file_name} or @code{realpath} return
 *                 errors (cannot resolve the resulting path).
=*/
bool
optionMakePath(char * p_buf, int b_sz, char const * fname, char const * prg_path)
{
    {
        size_t len = strlen(fname);

        if (((size_t)b_sz <= len) || (len == 0))
            return false;
    }

    /*
     *  IF not an environment variable, just copy the data
     */
    if (*fname != '$') {
        char   const * src = fname;
        char * dst = p_buf;
        int    ct  = b_sz;

        for (;;) {
            if ( (*(dst++) = *(src++)) == NUL)
                break;
            if (--ct <= 0)
                return false;
        }
    }

    /*
     *  IF the name starts with "$$", then it must be "$$" or
     *  it must start with "$$/".  In either event, replace the "$$"
     *  with the path to the executable and append a "/" character.
     */
    else switch (fname[1]) {
    case NUL:
        return false;

    case '$':
        if (! add_prog_path(p_buf, b_sz, fname, prg_path))
            return false;
        break;

    case '@':
        if (program_pkgdatadir[0] == NUL)
            return false;

        if (snprintf(p_buf, (size_t)b_sz, "%s%s",
                     program_pkgdatadir, fname + 2) >= b_sz)
            return false;
        break;

    default:
        if (! add_env_val(p_buf, b_sz, fname))
            return false;
    }

    return get_realpath(p_buf, b_sz);
}

/**
 * convert a leading "$$" into a path to the executable.
 */
static bool
add_prog_path(char * buf, int b_sz, char const * fname, char const * prg_path)
{
    char const *   path;
    char const *   pz;
    int     skip = 2;
    size_t  fname_len;
    size_t  dir_len;  //!< length of the directory portion of the path to the exe

    switch (fname[2]) {
    case DIRCH:
        skip = 3;
    case NUL:
        break;
    default:
        return false;
    }

    /*
     *  See if the path is included in the program name.
     *  If it is, we're done.  Otherwise, we have to hunt
     *  for the program using "pathfind".
     */
    if (strchr(prg_path, DIRCH) != NULL)
        path = prg_path;
    else {
        path = pathfind(getenv("PATH"), (char *)prg_path, "rx");

        if (path == NULL)
            return false;
    }

    pz = strrchr(path, DIRCH);

    /*
     *  IF we cannot find a directory name separator,
     *  THEN we do not have a path name to our executable file.
     */
    if (pz == NULL)
        return false;

    fname    += skip;
    fname_len = strlen(fname) + 1; // + NUL byte
    dir_len   = (pz - path) + 1;   // + dir sep character

    /*
     *  Concatenate the file name to the end of the executable path.
     *  The result may be either a file or a directory.
     */
    if (dir_len + fname_len > (unsigned)b_sz)
        return false;

    memcpy(buf, path, dir_len);
    memcpy(buf + dir_len, fname, fname_len);

    /*
     *  If the "path" path was gotten from "pathfind()", then it was
     *  allocated and we need to deallocate it.
     */
    if (path != prg_path)
        AGFREE(path);
    return true;
}

/**
 * Add an environment variable value.
 */
static bool
add_env_val(char * buf, int buf_sz, char const * name)
{
    char * dir_part = buf;

    for (;;) {
        int ch = (int)*++name;
        if (! IS_VALUE_NAME_CHAR(ch))
            break;
        *(dir_part++) = (char)ch;
    }

    if (dir_part == buf)
        return false;

    *dir_part = NUL;

    dir_part = getenv(buf);

    /*
     *  Environment value not found -- skip the home list entry
     */
    if (dir_part == NULL)
        return false;

    {
        size_t dir_len = strlen(dir_part);
        size_t nm_len  = strlen(name) + 1;
        
        if (dir_len + nm_len >= (unsigned)buf_sz)
            return false;
        memcpy(buf, dir_part, dir_len);
        memcpy(buf + dir_len, name, nm_len);
    }

    return true;
}

/**
 * Trim leading and trailing white space.
 * If we are cooking the text and the text is quoted, then "cook"
 * the string.  To cook, the string must be quoted.
 *
 * @param[in,out] txt  the input and output string
 * @param[in]     mode the handling mode (cooking method)
 */
static void
munge_str(char * txt, tOptionLoadMode mode)
{
    char * end;

    if (mode == OPTION_LOAD_KEEP)
        return;

    if (IS_WHITESPACE_CHAR(*txt)) {
        char * src = SPN_WHITESPACE_CHARS(txt+1);
        size_t l   = strlen(src) + 1;
        memmove(txt, src, l);
        end = txt + l - 1;

    } else
        end = txt + strlen(txt);

    end  = SPN_WHITESPACE_BACK(txt, end);
    *end = NUL;

    if (mode == OPTION_LOAD_UNCOOKED)
        return;

    switch (*txt) {
    default: return;
    case '"':
    case '\'': break;
    }

    switch (end[-1]) {
    default: return;
    case '"':
    case '\'': break;
    }

    (void)ao_string_cook(txt, NULL);
}

static char *
assemble_arg_val(char * txt, tOptionLoadMode mode)
{
    char * end = strpbrk(txt, ARG_BREAK_STR);
    int    space_break;

    /*
     *  Not having an argument to a configurable name is okay.
     */
    if (end == NULL)
        return txt + strlen(txt);

    /*
     *  If we are keeping all whitespace, then the  modevalue starts with the
     *  character that follows the end of the configurable name, regardless
     *  of which character caused it.
     */
    if (mode == OPTION_LOAD_KEEP) {
        *(end++) = NUL;
        return end;
    }

    /*
     *  If the name ended on a white space character, remember that
     *  because we'll have to skip over an immediately following ':' or '='
     *  (and the white space following *that*).
     */
    space_break = IS_WHITESPACE_CHAR(*end);
    *(end++) = NUL;

    end = SPN_WHITESPACE_CHARS(end);
    if (space_break && ((*end == ':') || (*end == '=')))
        end = SPN_WHITESPACE_CHARS(end+1);

    return end;
}

static char *
trim_quotes(char * arg)
{
    switch (*arg) {
    case '"':
    case '\'':
        ao_string_cook(arg, NULL);
    }
    return arg;
}

/**
 * See if the option is to be processed in the current scan direction
 * (-1 or +1).
 */
static bool
direction_ok(opt_state_mask_t f, int dir)
{
    if (dir == 0)
        return true;

    switch (f & (OPTST_IMM|OPTST_DISABLE_IMM)) {
    case 0:
        /*
         *  The selected option has no immediate action.
         *  THEREFORE, if the direction is PRESETTING
         *  THEN we skip this option.
         */
        if (PRESETTING(dir))
            return false;
        break;

    case OPTST_IMM:
        if (PRESETTING(dir)) {
            /*
             *  We are in the presetting direction with an option we handle
             *  immediately for enablement, but normally for disablement.
             *  Therefore, skip if disabled.
             */
            if ((f & OPTST_DISABLED) == 0)
                return false;
        } else {
            /*
             *  We are in the processing direction with an option we handle
             *  immediately for enablement, but normally for disablement.
             *  Therefore, skip if NOT disabled.
             */
            if ((f & OPTST_DISABLED) != 0)
                return false;
        }
        break;

    case OPTST_DISABLE_IMM:
        if (PRESETTING(dir)) {
            /*
             *  We are in the presetting direction with an option we handle
             *  immediately for disablement, but normally for handling.
             *  Therefore, skip if NOT disabled.
             */
            if ((f & OPTST_DISABLED) != 0)
                return false;
        } else {
            /*
             *  We are in the processing direction with an option we handle
             *  immediately for disablement, but normally for handling.
             *  Therefore, skip if disabled.
             */
            if ((f & OPTST_DISABLED) == 0)
                return false;
        }
        break;

    case OPTST_IMM|OPTST_DISABLE_IMM:
        /*
         *  The selected option is always for immediate action.
         *  THEREFORE, if the direction is PROCESSING
         *  THEN we skip this option.
         */
        if (PROCESSING(dir))
            return false;
        break;
    }
    return true;
}

/**
 *  Load an option from a block of text.  The text must start with the
 *  configurable/option name and be followed by its associated value.
 *  That value may be processed in any of several ways.  See "tOptionLoadMode"
 *  in autoopts.h.
 *
 * @param[in,out] opts       program options descriptor
 * @param[in,out] opt_state  option processing state
 * @param[in,out] line       source line with long option name in it
 * @param[in]     direction  current processing direction (preset or not)
 * @param[in]     load_mode  option loading mode (OPTION_LOAD_*)
 */
static void
load_opt_line(tOptions * opts, tOptState * opt_state, char * line,
              tDirection direction, tOptionLoadMode load_mode )
{
    /*
     * When parsing a stored line, we only look at the characters after
     * a hyphen.  Long names must always be at least two characters and
     * short options are always exactly one character long.
     */
    line = SPN_LOAD_LINE_SKIP_CHARS(line);

    {
        char * arg = assemble_arg_val(line, load_mode);

        if (IS_OPTION_NAME_CHAR(line[1])) {

            if (! SUCCESSFUL(opt_find_long(opts, line, opt_state)))
                return;

        } else if (! SUCCESSFUL(opt_find_short(opts, *line, opt_state)))
            return;

        if ((! CALLED(direction)) && (opt_state->flags & OPTST_NO_INIT))
            return;

        opt_state->pzOptArg = trim_quotes(arg);
    }

    if (! direction_ok(opt_state->flags, direction))
        return;

    /*
     *  Fix up the args.
     */
    if (OPTST_GET_ARGTYPE(opt_state->pOD->fOptState) == OPARG_TYPE_NONE) {
        if (*opt_state->pzOptArg != NUL)
            return;
        opt_state->pzOptArg = NULL;

    } else if (opt_state->pOD->fOptState & OPTST_ARG_OPTIONAL) {
        if (*opt_state->pzOptArg == NUL)
             opt_state->pzOptArg = NULL;
        else {
            AGDUPSTR(opt_state->pzOptArg, opt_state->pzOptArg, "opt arg");
            opt_state->flags |= OPTST_ALLOC_ARG;
        }

    } else {
        if (*opt_state->pzOptArg == NUL)
             opt_state->pzOptArg = zNil;
        else {
            AGDUPSTR(opt_state->pzOptArg, opt_state->pzOptArg, "opt arg");
            opt_state->flags |= OPTST_ALLOC_ARG;
        }
    }

    {
        tOptionLoadMode sv = option_load_mode;
        option_load_mode = load_mode;
        handle_opt(opts, opt_state);
        option_load_mode = sv;
    }
}

/*=export_func  optionLoadLine
 *
 * what:  process a string for an option name and value
 *
 * arg:   tOptions *,   opts,  program options descriptor
 * arg:   char const *, line,  NUL-terminated text
 *
 * doc:
 *
 *  This is a client program callable routine for setting options from, for
 *  example, the contents of a file that they read in.  Only one option may
 *  appear in the text.  It will be treated as a normal (non-preset) option.
 *
 *  When passed a pointer to the option struct and a string, it will find
 *  the option named by the first token on the string and set the option
 *  argument to the remainder of the string.  The caller must NUL terminate
 *  the string.  The caller need not skip over any introductory hyphens.
 *  Any embedded new lines will be included in the option
 *  argument.  If the input looks like one or more quoted strings, then the
 *  input will be "cooked".  The "cooking" is identical to the string
 *  formation used in AutoGen definition files (@pxref{basic expression}),
 *  except that you may not use backquotes.
 *
 * err:   Invalid options are silently ignored.  Invalid option arguments
 *        will cause a warning to print, but the function should return.
=*/
void
optionLoadLine(tOptions * opts, char const * line)
{
    tOptState st = OPTSTATE_INITIALIZER(SET);
    char *    pz;
    proc_state_mask_t sv_flags = opts->fOptSet;
    opts->fOptSet &= ~OPTPROC_ERRSTOP;
    AGDUPSTR(pz, line, "opt line");
    load_opt_line(opts, &st, pz, DIRECTION_CALLED, OPTION_LOAD_COOKED);
    AGFREE(pz);
    opts->fOptSet = sv_flags;
}
/** @}
 *
 * Local Variables:
 * mode: C
 * c-file-style: "stroustrup"
 * indent-tabs-mode: nil
 * End:
 * end of autoopts/load.c */
