/*      $OpenBSD: tokenizer.c,v 1.21 2016/04/11 21:17:29 schwarze Exp $ */
/*      $NetBSD: tokenizer.c,v 1.28 2016/04/11 18:56:31 christos Exp $  */

/*-
 * Copyright (c) 1992, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Christos Zoulas of Cornell University.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "config.h"

/* We build this file twice, once as NARROW, once as WIDE. */
/*
 * tokenize.c: Bourne shell like tokenizer
 */
#include <stdlib.h>
#include <string.h>

#include "histedit.h"

typedef enum {
        Q_none, Q_single, Q_double, Q_one, Q_doubleone
} quote_t;

#define TOK_KEEP        1
#define TOK_EAT         2

#define WINCR           20
#define AINCR           10

#define IFS             STR("\t \n")

#ifdef NARROWCHAR
#define Char                    char
#define FUN(prefix, rest)       prefix ## _ ## rest
#define TYPE(type)              type
#define STR(x)                  x
#define Strchr(s, c)            strchr(s, c)
#define tok_strdup(s)           strdup(s)
#else
#define Char                    wchar_t
#define FUN(prefix, rest)       prefix ## _w ## rest
#define TYPE(type)              type ## W
#define STR(x)                  L ## x
#define Strchr(s, c)            wcschr(s, c)
#define tok_strdup(s)           wcsdup(s)
#endif

struct TYPE(tokenizer) {
        Char    *ifs;           /* In field separator                    */
        int      argc, amax;    /* Current and maximum number of args    */
        Char   **argv;          /* Argument list                         */
        Char    *wptr, *wmax;   /* Space and limit on the word buffer    */
        Char    *wstart;        /* Beginning of next word                */
        Char    *wspace;        /* Space of word buffer                  */
        quote_t  quote;         /* Quoting state                         */
        int      flags;         /* flags;                                */
};


static void FUN(tok,finish)(TYPE(Tokenizer) *);


/* FUN(tok,finish)():
 *      Finish a word in the tokenizer.
 */
static void
FUN(tok,finish)(TYPE(Tokenizer) *tok)
{

        *tok->wptr = '\0';
        if ((tok->flags & TOK_KEEP) || tok->wptr != tok->wstart) {
                tok->argv[tok->argc++] = tok->wstart;
                tok->argv[tok->argc] = NULL;
                tok->wstart = ++tok->wptr;
        }
        tok->flags &= ~TOK_KEEP;
}


/* FUN(tok,init)():
 *      Initialize the tokenizer
 */
TYPE(Tokenizer) *
FUN(tok,init)(const Char *ifs)
{
        TYPE(Tokenizer) *tok = malloc(sizeof(TYPE(Tokenizer)));

        if (tok == NULL)
                return NULL;
        tok->ifs = tok_strdup(ifs ? ifs : IFS);
        if (tok->ifs == NULL) {
                free(tok);
                return NULL;
        }
        tok->argc = 0;
        tok->amax = AINCR;
        tok->argv = reallocarray(NULL, tok->amax, sizeof(*tok->argv));
        if (tok->argv == NULL) {
                free(tok->ifs);
                free(tok);
                return NULL;
        }
        tok->argv[0] = NULL;
        tok->wspace = reallocarray(NULL, WINCR, sizeof(*tok->wspace));
        if (tok->wspace == NULL) {
                free(tok->argv);
                free(tok->ifs);
                free(tok);
                return NULL;
        }
        tok->wmax = tok->wspace + WINCR;
        tok->wstart = tok->wspace;
        tok->wptr = tok->wspace;
        tok->flags = 0;
        tok->quote = Q_none;

        return tok;
}


/* FUN(tok,reset)():
 *      Reset the tokenizer
 */
void
FUN(tok,reset)(TYPE(Tokenizer) *tok)
{

        tok->argc = 0;
        tok->wstart = tok->wspace;
        tok->wptr = tok->wspace;
        tok->flags = 0;
        tok->quote = Q_none;
}


/* FUN(tok,end)():
 *      Clean up
 */
void
FUN(tok,end)(TYPE(Tokenizer) *tok)
{

        free(tok->ifs);
        free(tok->wspace);
        free(tok->argv);
        free(tok);
}



/* FUN(tok,line)():
 *      Bourne shell (sh(1)) like tokenizing
 *      Arguments:
 *              tok     current tokenizer state (setup with FUN(tok,init)())
 *              line    line to parse
 *      Returns:
 *              -1      Internal error
 *               3      Quoted return
 *               2      Unmatched double quote
 *               1      Unmatched single quote
 *               0      Ok
 *      Modifies (if return value is 0):
 *              argc    number of arguments
 *              argv    argument array
 *              cursorc if !NULL, argv element containing cursor
 *              cursorv if !NULL, offset in argv[cursorc] of cursor
 */
int
FUN(tok,line)(TYPE(Tokenizer) *tok, const TYPE(LineInfo) *line,
    int *argc, const Char ***argv, int *cursorc, int *cursoro)
{
        const Char *ptr;
        int cc, co;

        cc = co = -1;
        ptr = line->buffer;
        for (ptr = line->buffer; ;ptr++) {
                if (ptr >= line->lastchar)
                        ptr = STR("");
                if (ptr == line->cursor) {
                        cc = tok->argc;
                        co = (int)(tok->wptr - tok->wstart);
                }
                switch (*ptr) {
                case '\'':
                        tok->flags |= TOK_KEEP;
                        tok->flags &= ~TOK_EAT;
                        switch (tok->quote) {
                        case Q_none:
                                tok->quote = Q_single;  /* Enter single quote
                                                         * mode */
                                break;

                        case Q_single:  /* Exit single quote mode */
                                tok->quote = Q_none;
                                break;

                        case Q_one:     /* Quote this ' */
                                tok->quote = Q_none;
                                *tok->wptr++ = *ptr;
                                break;

                        case Q_double:  /* Stay in double quote mode */
                                *tok->wptr++ = *ptr;
                                break;

                        case Q_doubleone:       /* Quote this ' */
                                tok->quote = Q_double;
                                *tok->wptr++ = *ptr;
                                break;

                        default:
                                return -1;
                        }
                        break;

                case '"':
                        tok->flags &= ~TOK_EAT;
                        tok->flags |= TOK_KEEP;
                        switch (tok->quote) {
                        case Q_none:    /* Enter double quote mode */
                                tok->quote = Q_double;
                                break;

                        case Q_double:  /* Exit double quote mode */
                                tok->quote = Q_none;
                                break;

                        case Q_one:     /* Quote this " */
                                tok->quote = Q_none;
                                *tok->wptr++ = *ptr;
                                break;

                        case Q_single:  /* Stay in single quote mode */
                                *tok->wptr++ = *ptr;
                                break;

                        case Q_doubleone:       /* Quote this " */
                                tok->quote = Q_double;
                                *tok->wptr++ = *ptr;
                                break;

                        default:
                                return -1;
                        }
                        break;

                case '\\':
                        tok->flags |= TOK_KEEP;
                        tok->flags &= ~TOK_EAT;
                        switch (tok->quote) {
                        case Q_none:    /* Quote next character */
                                tok->quote = Q_one;
                                break;

                        case Q_double:  /* Quote next character */
                                tok->quote = Q_doubleone;
                                break;

                        case Q_one:     /* Quote this, restore state */
                                *tok->wptr++ = *ptr;
                                tok->quote = Q_none;
                                break;

                        case Q_single:  /* Stay in single quote mode */
                                *tok->wptr++ = *ptr;
                                break;

                        case Q_doubleone:       /* Quote this \ */
                                tok->quote = Q_double;
                                *tok->wptr++ = *ptr;
                                break;

                        default:
                                return -1;
                        }
                        break;

                case '\n':
                        tok->flags &= ~TOK_EAT;
                        switch (tok->quote) {
                        case Q_none:
                                goto tok_line_outok;

                        case Q_single:
                        case Q_double:
                                *tok->wptr++ = *ptr;    /* Add the return */
                                break;

                        case Q_doubleone:   /* Back to double, eat the '\n' */
                                tok->flags |= TOK_EAT;
                                tok->quote = Q_double;
                                break;

                        case Q_one:     /* No quote, more eat the '\n' */
                                tok->flags |= TOK_EAT;
                                tok->quote = Q_none;
                                break;

                        default:
                                return 0;
                        }
                        break;

                case '\0':
                        switch (tok->quote) {
                        case Q_none:
                                /* Finish word and return */
                                if (tok->flags & TOK_EAT) {
                                        tok->flags &= ~TOK_EAT;
                                        return 3;
                                }
                                goto tok_line_outok;

                        case Q_single:
                                return 1;

                        case Q_double:
                                return 2;

                        case Q_doubleone:
                                tok->quote = Q_double;
                                *tok->wptr++ = *ptr;
                                break;

                        case Q_one:
                                tok->quote = Q_none;
                                *tok->wptr++ = *ptr;
                                break;

                        default:
                                return -1;
                        }
                        break;

                default:
                        tok->flags &= ~TOK_EAT;
                        switch (tok->quote) {
                        case Q_none:
                                if (Strchr(tok->ifs, *ptr) != NULL)
                                        FUN(tok,finish)(tok);
                                else
                                        *tok->wptr++ = *ptr;
                                break;

                        case Q_single:
                        case Q_double:
                                *tok->wptr++ = *ptr;
                                break;


                        case Q_doubleone:
                                *tok->wptr++ = '\\';
                                tok->quote = Q_double;
                                *tok->wptr++ = *ptr;
                                break;

                        case Q_one:
                                tok->quote = Q_none;
                                *tok->wptr++ = *ptr;
                                break;

                        default:
                                return -1;

                        }
                        break;
                }

                if (tok->wptr >= tok->wmax - 4) {
                        size_t size = tok->wmax - tok->wspace + WINCR;
                        Char *s = reallocarray(tok->wspace, size, sizeof(*s));
                        if (s == NULL)
                                return -1;

                        if (s != tok->wspace) {
                                int i;
                                for (i = 0; i < tok->argc; i++) {
                                    tok->argv[i] =
                                        (tok->argv[i] - tok->wspace) + s;
                                }
                                tok->wptr = (tok->wptr - tok->wspace) + s;
                                tok->wstart = (tok->wstart - tok->wspace) + s;
                                tok->wspace = s;
                        }
                        tok->wmax = s + size;
                }
                if (tok->argc >= tok->amax - 4) {
                        Char **p;
                        tok->amax += AINCR;
                        p = reallocarray(tok->argv, tok->amax, sizeof(*p));
                        if (p == NULL) {
                                tok->amax -= AINCR;
                                return -1;
                        }
                        tok->argv = p;
                }
        }
 tok_line_outok:
        if (cc == -1 && co == -1) {
                cc = tok->argc;
                co = (int)(tok->wptr - tok->wstart);
        }
        if (cursorc != NULL)
                *cursorc = cc;
        if (cursoro != NULL)
                *cursoro = co;
        FUN(tok,finish)(tok);
        *argv = (const Char **)tok->argv;
        *argc = tok->argc;
        return 0;
}

/* FUN(tok,str)():
 *      Simpler version of tok_line, taking a NUL terminated line
 *      and splitting into words, ignoring cursor state.
 */
int
FUN(tok,str)(TYPE(Tokenizer) *tok, const Char *line, int *argc,
    const Char ***argv)
{
        TYPE(LineInfo) li;

        memset(&li, 0, sizeof(li));
        li.buffer = line;
        li.cursor = li.lastchar = Strchr(line, '\0');
        return FUN(tok,line)(tok, &li, argc, argv, NULL, NULL);
}