/*
 * Mini sed implementation for busybox
 *
 *
 * Copyright (C) 1999 by Lineo, inc.
 * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
 *
 * Modifications for addresses and append command have been
 * written by Marco Pantaleoni <panta@prosa.it>, <panta@elasticworld.org>
 * and are:
 * Copyright (C) 1999 Marco Pantaleoni.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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 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, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include "internal.h"
#include "regexp.h"
#include <stdio.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <time.h>
#include <ctype.h>

static const char sed_usage[] =
    "sed [-n] -e script [file...]\n\n"
    "Allowed sed scripts come in the following form:\n"
    "\t'ADDR [!] COMMAND'\n\n"
    "\twhere address ADDR can be:\n"
    "\t  NUMBER    Match specified line number\n"
    "\t  $         Match last line\n"
    "\t  /REGEXP/  Match specified regexp\n"
    "\t  (! inverts the meaning of the match)\n\n"
    "\tand COMMAND can be:\n"
    "\t  s/regexp/replacement/[igp]\n"
    "\t     which attempt to match regexp against the pattern space\n"
    "\t     and if successful replaces the matched portion with replacement.\n\n"
    "\t  aTEXT\n"
    "\t     which appends TEXT after the pattern space\n"
    "Options:\n"
    "-e\tadd the script to the commands to be executed\n"
    "-n\tsuppress automatic printing of pattern space\n\n"
#if defined BB_REGEXP
    "This version of sed matches full regular expresions.\n";
#else
    "This version of sed matches strings (not full regular expresions).\n";
#endif

/* Flags & variables */

typedef enum { f_none, f_replace, f_append } sed_function;

#define NO_LINE		-2
#define LAST_LINE	-1
static int addr_line = NO_LINE;
static char *addr_pattern = NULL;
static int negated = 0;

#define SKIPSPACES(p)		do { while (isspace(*(p))) (p)++; } while (0)

#define BUFSIZE		1024

static inline int at_last(FILE * fp)
{
    int res = 0;

    if (feof(fp))
	return 1;
    else {
	char ch;
	if ((ch = fgetc(fp)) == EOF)
	    res++;
	ungetc(ch, fp);
    }
    return res;
}

static void do_sed_repl(FILE * fp, char *needle, char *newNeedle,
			int ignoreCase, int printFlag, int quietFlag)
{
    int foundOne = FALSE;
    char haystack[BUFSIZE];
    int line = 1, doit;

    while (fgets(haystack, BUFSIZE - 1, fp)) {
	doit = 0;
	if (addr_pattern) {
	    doit = !find_match(haystack, addr_pattern, FALSE);
	} else if (addr_line == NO_LINE)
	    doit = 1;
	else if (addr_line == LAST_LINE) {
	    if (at_last(fp))
		doit = 1;
	} else {
	    if (line == addr_line)
		doit = 1;
	}
	if (negated)
	    doit = 1 - doit;
	if (doit) {
	    foundOne =
		replace_match(haystack, needle, newNeedle, ignoreCase);

	    if (foundOne == TRUE && printFlag == TRUE) {
		fprintf(stdout, haystack);
	    }
	}

	if (quietFlag == FALSE) {
	    fprintf(stdout, haystack);
	}

	line++;
    }
}

static void do_sed_append(FILE * fp, char *appendline, int quietFlag)
{
    char buffer[BUFSIZE];
    int line = 1, doit;

    while (fgets(buffer, BUFSIZE - 1, fp)) {
	doit = 0;
	if (addr_pattern) {
	    doit = !find_match(buffer, addr_pattern, FALSE);
	} else if (addr_line == NO_LINE)
	    doit = 1;
	else if (addr_line == LAST_LINE) {
	    if (at_last(fp))
		doit = 1;
	} else {
	    if (line == addr_line)
		doit = 1;
	}
	if (negated)
	    doit = 1 - doit;
	if (quietFlag == FALSE) {
	    fprintf(stdout, buffer);
	}
	if (doit) {
	    fputs(appendline, stdout);
	    fputc('\n', stdout);
	}

	line++;
    }
}

extern int sed_main(int argc, char **argv)
{
    FILE *fp;
    char *needle = NULL, *newNeedle = NULL;
    char *name;
    char *cp;
    int ignoreCase = FALSE;
    int printFlag = FALSE;
    int quietFlag = FALSE;
    int stopNow;
    char *line_s = NULL, saved;
    char *appendline = NULL;
    char *pos;
    sed_function sed_f = f_none;

    argc--;
    argv++;
    if (argc < 1) {
	usage(sed_usage);
    }

    if (**argv == '-') {
	argc--;
	cp = *argv++;
	stopNow = FALSE;

	while (*++cp && stopNow == FALSE) {
	    switch (*cp) {
	    case 'n':
		quietFlag = TRUE;
		break;
	    case 'e':
		if (*(cp + 1) == 0 && --argc < 0) {
		    usage(sed_usage);
		}
		if (*++cp != 's')
		    cp = *argv++;

		/* Read address if present */
		SKIPSPACES(cp);
		if (*cp == '$') {
		    addr_line = LAST_LINE;
		    cp++;
		} else {
		    if (isdigit(*cp)) {	/* LINE ADDRESS   */
			line_s = cp;
			while (isdigit(*cp))
			    cp++;
			if (cp > line_s) {
			    /* numeric line */
			    saved = *cp;
			    *cp = '\0';
			    addr_line = atoi(line_s);
			    *cp = saved;
			}
		    } else if (*cp == '/') {	/* PATTERN ADDRESS */
			pos = addr_pattern = cp + 1;
			pos = strchr(pos, '/');
			if (!pos)
			    usage(sed_usage);
			*pos = '\0';
			cp = pos + 1;
		    }
		}

		SKIPSPACES(cp);
		if (*cp == '!') {
		    negated++;
		    cp++;
		}

		/* Read command */

		SKIPSPACES(cp);
		switch (*cp) {
		case 's':	/* REPLACE */
		    if (strlen(cp) <= 3 || *(cp + 1) != '/')
			break;
		    sed_f = f_replace;

		    pos = needle = cp + 2;

		    for (;;) {
			pos = strchr(pos, '/');
			if (pos == NULL) {
			    usage(sed_usage);
			}
			if (*(pos - 1) == '\\') {
			    pos++;
			    continue;
			}
			break;
		    }
		    *pos = 0;
		    newNeedle = ++pos;
		    for (;;) {
			pos = strchr(pos, '/');
			if (pos == NULL) {
			    usage(sed_usage);
			}
			if (*(pos - 1) == '\\') {
			    pos++;
			    continue;
			}
			break;
		    }
		    *pos = 0;
		    if (pos + 2 != 0) {
			while (*++pos) {
			    switch (*pos) {
			    case 'i':
				ignoreCase = TRUE;
				break;
			    case 'p':
				printFlag = TRUE;
				break;
			    case 'g':
				break;
			    default:
				usage(sed_usage);
			    }
			}
		    }
		    cp = pos;
		    /* fprintf(stderr, "replace '%s' with '%s'\n", needle, newNeedle); */
		    break;

		case 'a':	/* APPEND */
		    if (strlen(cp) < 2)
			break;
		    sed_f = f_append;
		    appendline = ++cp;
		    /* fprintf(stderr, "append '%s'\n", appendline); */
		    break;
		}

		stopNow = TRUE;
		break;

	    default:
		usage(sed_usage);
	    }
	}
    }

    if (argc == 0) {
	switch (sed_f) {
	case f_none:
	    break;
	case f_replace:
	    do_sed_repl(stdin, needle, newNeedle, ignoreCase, printFlag,
			quietFlag);
	    break;
	case f_append:
	    do_sed_append(stdin, appendline, quietFlag);
	    break;
	}
    } else {
	while (argc-- > 0) {
	    name = *argv++;

	    fp = fopen(name, "r");
	    if (fp == NULL) {
		perror(name);
		continue;
	    }

	    switch (sed_f) {
	    case f_none:
		break;
	    case f_replace:
		do_sed_repl(fp, needle, newNeedle, ignoreCase, printFlag,
			    quietFlag);
		break;
	    case f_append:
		do_sed_append(fp, appendline, quietFlag);
		break;
	    }

	    if (ferror(fp))
		perror(name);

	    fclose(fp);
	}
    }
    exit(TRUE);
}


/* END CODE */