/*      $OpenBSD: rcsutil.c,v 1.48 2023/08/11 05:02:21 guenther Exp $   */
/*
 * Copyright (c) 2005, 2006 Joris Vink <joris@openbsd.org>
 * Copyright (c) 2006 Xavier Santolaria <xsa@openbsd.org>
 * Copyright (c) 2006 Niall O'Higgins <niallo@openbsd.org>
 * Copyright (c) 2006 Ray Lai <ray@openbsd.org>
 * All rights reserved.
 *
 * 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. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED ``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 AUTHOR 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 <sys/stat.h>
#include <sys/time.h>

#include <ctype.h>
#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "rcsprog.h"

/*
 * rcs_get_mtime()
 *
 * Get <filename> last modified time.
 * Returns last modified time on success, or a timespec with tv_nsec
 * set to UTIME_OMIT on failure.
 */
struct timespec
rcs_get_mtime(RCSFILE *file)
{
        struct stat st;
        struct timespec mtime = { .tv_sec = 0, .tv_nsec = UTIME_OMIT };

        if (file->rf_file == NULL)
                return mtime;

        if (fstat(fileno(file->rf_file), &st) == -1) {
                warn("%s", file->rf_path);
                return mtime;
        }

        return st.st_mtim;
}

/*
 * rcs_set_mtime()
 *
 * Set <filename> last modified time to <mtime> if its tv_nsec isn't UTIME_OMIT
 */
void
rcs_set_mtime(RCSFILE *file, struct timespec mtime)
{
        struct timespec ts[2];

        if (file->rf_file == NULL || mtime.tv_nsec == UTIME_OMIT)
                return;

        ts[0] = ts[1] = mtime;

        if (futimens(fileno(file->rf_file), ts) == -1)
                err(1, "utimes");
}

int
rcs_getopt(int argc, char **argv, const char *optstr)
{
        char *a;
        const char *c;
        static int i = 1;
        int opt, hasargument, ret;

        hasargument = 0;
        rcs_optarg = NULL;

        if (i >= argc)
                return (-1);

        a = argv[i++];
        if (*a++ != '-')
                return (-1);

        ret = 0;
        opt = *a;
        for (c = optstr; *c != '\0'; c++) {
                if (*c == opt) {
                        a++;
                        ret = opt;

                        if (*(c + 1) == ':') {
                                if (*(c + 2) == ':') {
                                        if (*a != '\0')
                                                hasargument = 1;
                                } else {
                                        if (*a != '\0') {
                                                hasargument = 1;
                                        } else {
                                                ret = 1;
                                                break;
                                        }
                                }
                        }

                        if (hasargument == 1)
                                rcs_optarg = a;

                        if (ret == opt)
                                rcs_optind++;
                        break;
                }
        }

        if (ret == 0)
                warnx("unknown option -%c", opt);
        else if (ret == 1)
                warnx("missing argument for option -%c", opt);

        return (ret);
}

/*
 * rcs_choosefile()
 *
 * Given a relative filename, decide where the corresponding RCS file
 * should be.  Tries each extension until a file is found.  If no file
 * was found, returns a path with the first extension.
 *
 * Opens and returns file descriptor to RCS file.
 */
int
rcs_choosefile(const char *filename, char *out, size_t len)
{
        int fd;
        struct stat sb;
        char *p, *ext, name[PATH_MAX], *next, *ptr, rcsdir[PATH_MAX],
            *suffixes, rcspath[PATH_MAX];

        /*
         * If `filename' contains a directory, `rcspath' contains that
         * directory, including a trailing slash.  Otherwise `rcspath'
         * contains an empty string.
         */
        if (strlcpy(rcspath, filename, sizeof(rcspath)) >= sizeof(rcspath))
                errx(1, "rcs_choosefile: truncation");

        /* If `/' is found, end string after `/'. */
        if ((ptr = strrchr(rcspath, '/')) != NULL)
                *(++ptr) = '\0';
        else
                rcspath[0] = '\0';

        /* Append RCS/ to `rcspath' if it exists. */
        if (strlcpy(rcsdir, rcspath, sizeof(rcsdir)) >= sizeof(rcsdir) ||
            strlcat(rcsdir, RCSDIR, sizeof(rcsdir)) >= sizeof(rcsdir))
                errx(1, "rcs_choosefile: truncation");

        if (stat(rcsdir, &sb) == 0 && S_ISDIR(sb.st_mode))
                if (strlcpy(rcspath, rcsdir, sizeof(rcspath))
                    >= sizeof(rcspath) ||
                    strlcat(rcspath, "/", sizeof(rcspath)) >= sizeof(rcspath))
                        errx(1, "rcs_choosefile: truncation");

        /* Name of file without path. */
        if ((ptr = strrchr(filename, '/')) == NULL) {
                if (strlcpy(name, filename, sizeof(name)) >= sizeof(name))
                        errx(1, "rcs_choosefile: truncation");
        } else {
                /* Skip `/'. */
                if (strlcpy(name, ptr + 1, sizeof(name)) >= sizeof(name))
                        errx(1, "rcs_choosefile: truncation");
        }

        /* Name of RCS file without an extension. */
        if (strlcat(rcspath, name, sizeof(rcspath)) >= sizeof(rcspath))
                errx(1, "rcs_choosefile: truncation");

        /*
         * If only the empty suffix was given, use existing rcspath.
         * This ensures that there is at least one suffix for strsep().
         */
        if (strcmp(rcs_suffixes, "") == 0) {
                if (strlcpy(out, rcspath, len) >= len)
                        errx(1, "rcs_choosefile: truncation");
                fd = open(rcspath, O_RDONLY);
                return (fd);
        }

        /*
         * Cycle through slash-separated `rcs_suffixes', appending each
         * extension to `rcspath' and testing if the file exists.  If it
         * does, return that string.  Otherwise return path with first
         * extension.
         */
        suffixes = xstrdup(rcs_suffixes);
        for (next = suffixes; (ext = strsep(&next, "/")) != NULL;) {
                char fpath[PATH_MAX];

                if ((p = strrchr(rcspath, ',')) != NULL) {
                        if (!strcmp(p, ext)) {
                                if ((fd = open(rcspath, O_RDONLY)) == -1)
                                        continue;

                                if (fstat(fd, &sb) == -1)
                                        err(1, "%s", rcspath);

                                if (strlcpy(out, rcspath, len) >= len)
                                        errx(1, "rcs_choosefile: truncation");

                                free(suffixes);
                                return (fd);
                        }

                        continue;
                }

                /* Construct RCS file path. */
                if (strlcpy(fpath, rcspath, sizeof(fpath)) >= sizeof(fpath) ||
                    strlcat(fpath, ext, sizeof(fpath)) >= sizeof(fpath))
                        errx(1, "rcs_choosefile: truncation");

                /* Don't use `filename' as RCS file. */
                if (strcmp(fpath, filename) == 0)
                        continue;

                if ((fd = open(fpath, O_RDONLY)) == -1)
                        continue;

                if (fstat(fd, &sb) == -1)
                        err(1, "%s", fpath);

                if (strlcpy(out, fpath, len) >= len)
                        errx(1, "rcs_choosefile: truncation");

                free(suffixes);
                return (fd);
        }

        /*
         * `suffixes' should now be NUL separated, so the first
         * extension can be read just by reading `suffixes'.
         */
        if (strlcat(rcspath, suffixes, sizeof(rcspath)) >= sizeof(rcspath))
                errx(1, "rcs_choosefile: truncation");

        free(suffixes);

        if (strlcpy(out, rcspath, len) >= len)
                errx(1, "rcs_choosefile: truncation");

        fd = open(rcspath, O_RDONLY);

        return (fd);
}

/*
 * Set <str> to <new_str>.  Print warning if <str> is redefined.
 */
void
rcs_setrevstr(char **str, char *new_str)
{
        if (new_str == NULL)
                return;
        if (*str != NULL)
                warnx("redefinition of revision number");
        *str = new_str;
}

/*
 * Set <str1> or <str2> to <new_str>, depending on which is not set.
 * If both are set, error out.
 */
void
rcs_setrevstr2(char **str1, char **str2, char *new_str)
{
        if (new_str == NULL)
                return;
        if (*str1 == NULL)
                *str1 = new_str;
        else if (*str2 == NULL)
                *str2 = new_str;
        else
                errx(1, "too many revision numbers");
}

/*
 * Get revision from file.  The revision can be specified as a symbol or
 * a revision number.
 */
RCSNUM *
rcs_getrevnum(const char *rev_str, RCSFILE *file)
{
        RCSNUM *rev;

        /* Search for symbol. */
        rev = rcs_sym_getrev(file, rev_str);

        /* Search for revision number. */
        if (rev == NULL)
                rev = rcsnum_parse(rev_str);

        return (rev);
}

/*
 * Prompt for and store user's input in an allocated string.
 *
 * Returns the string's pointer.
 */
char *
rcs_prompt(const char *prompt, int flags)
{
        BUF *bp;
        size_t len;
        char *buf;

        if (!(flags & INTERACTIVE) && isatty(STDIN_FILENO))
                flags |= INTERACTIVE;

        bp = buf_alloc(0);
        if (flags & INTERACTIVE)
                (void)fprintf(stderr, "%s", prompt);
        if (flags & INTERACTIVE)
                (void)fprintf(stderr, ">> ");
        clearerr(stdin);
        while ((buf = fgetln(stdin, &len)) != NULL) {
                /* The last line may not be EOL terminated. */
                if (buf[0] == '.' && (len == 1 || buf[1] == '\n'))
                        break;
                else
                        buf_append(bp, buf, len);

                if (flags & INTERACTIVE)
                        (void)fprintf(stderr, ">> ");
        }
        buf_putc(bp, '\0');

        return (buf_release(bp));
}

u_int
rcs_rev_select(RCSFILE *file, const char *range)
{
        int i;
        u_int nrev;
        const char *ep;
        char *lstr, *rstr;
        struct rcs_delta *rdp;
        struct rcs_argvector *revargv, *revrange;
        RCSNUM lnum, rnum;

        nrev = 0;
        (void)memset(&lnum, 0, sizeof(lnum));
        (void)memset(&rnum, 0, sizeof(rnum));

        if (range == NULL) {
                TAILQ_FOREACH(rdp, &file->rf_delta, rd_list)
                        if (rcsnum_cmp(rdp->rd_num, file->rf_head, 0) == 0) {
                                rdp->rd_flags |= RCS_RD_SELECT;
                                return (1);
                        }
                return (0);
        }

        revargv = rcs_strsplit(range, ",");
        for (i = 0; revargv->argv[i] != NULL; i++) {
                revrange = rcs_strsplit(revargv->argv[i], ":");
                if (revrange->argv[0] == NULL)
                        /* should not happen */
                        errx(1, "invalid revision range: %s", revargv->argv[i]);
                else if (revrange->argv[1] == NULL)
                        lstr = rstr = revrange->argv[0];
                else {
                        if (revrange->argv[2] != NULL)
                                errx(1, "invalid revision range: %s",
                                    revargv->argv[i]);
                        lstr = revrange->argv[0];
                        rstr = revrange->argv[1];
                        if (strcmp(lstr, "") == 0)
                                lstr = NULL;
                        if (strcmp(rstr, "") == 0)
                                rstr = NULL;
                }

                if (lstr == NULL)
                        lstr = RCS_HEAD_INIT;
                if (rcsnum_aton(lstr, &ep, &lnum) == 0 || (*ep != '\0'))
                        errx(1, "invalid revision: %s", lstr);

                if (rstr != NULL) {
                        if (rcsnum_aton(rstr, &ep, &rnum) == 0 || (*ep != '\0'))
                                errx(1, "invalid revision: %s", rstr);
                } else
                        rcsnum_cpy(file->rf_head, &rnum, 0);

                rcs_argv_destroy(revrange);

                TAILQ_FOREACH(rdp, &file->rf_delta, rd_list)
                        if (rcsnum_cmp(rdp->rd_num, &lnum, 0) <= 0 &&
                            rcsnum_cmp(rdp->rd_num, &rnum, 0) >= 0 &&
                            !(rdp->rd_flags & RCS_RD_SELECT)) {
                                rdp->rd_flags |= RCS_RD_SELECT;
                                nrev++;
                        }
        }
        rcs_argv_destroy(revargv);

        free(lnum.rn_id);
        free(rnum.rn_id);

        return (nrev);
}

/*
 * Load description from <in> to <file>.
 * If <in> starts with a `-', <in> is taken as the description.
 * Otherwise <in> is the name of the file containing the description.
 * If <in> is NULL, the description is read from stdin.
 * Returns 0 on success, -1 on failure, setting errno.
 */
int
rcs_set_description(RCSFILE *file, const char *in, int flags)
{
        BUF *bp;
        char *content;
        const char *prompt =
            "enter description, terminated with single '.' or end of file:\n"
            "NOTE: This is NOT the log message!\n";

        /* Description is in file <in>. */
        if (in != NULL && *in != '-') {
                if ((bp = buf_load(in)) == NULL)
                        return (-1);
                buf_putc(bp, '\0');
                content = buf_release(bp);
        /* Description is in <in>. */
        } else if (in != NULL)
                /* Skip leading `-'. */
                content = xstrdup(in + 1);
        /* Get description from stdin. */
        else
                content = rcs_prompt(prompt, flags);

        rcs_desc_set(file, content);
        free(content);
        return (0);
}

/*
 * Split the contents of a file into a list of lines.
 */
struct rcs_lines *
rcs_splitlines(u_char *data, size_t len)
{
        u_char *c, *p;
        struct rcs_lines *lines;
        struct rcs_line *lp;
        size_t i, tlen;

        lines = xcalloc(1, sizeof(*lines));
        TAILQ_INIT(&(lines->l_lines));

        lp = xcalloc(1, sizeof(*lp));
        TAILQ_INSERT_TAIL(&(lines->l_lines), lp, l_list);


        p = c = data;
        for (i = 0; i < len; i++) {
                if (*p == '\n' || (i == len - 1)) {
                        tlen = p - c + 1;
                        lp = xmalloc(sizeof(*lp));
                        lp->l_line = c;
                        lp->l_len = tlen;
                        lp->l_lineno = ++(lines->l_nblines);
                        TAILQ_INSERT_TAIL(&(lines->l_lines), lp, l_list);
                        c = p + 1;
                }
                p++;
        }

        return (lines);
}

void
rcs_freelines(struct rcs_lines *lines)
{
        struct rcs_line *lp;

        while ((lp = TAILQ_FIRST(&(lines->l_lines))) != NULL) {
                TAILQ_REMOVE(&(lines->l_lines), lp, l_list);
                free(lp);
        }

        free(lines);
}

BUF *
rcs_patchfile(u_char *data, size_t dlen, u_char *patch, size_t plen,
    int (*p)(struct rcs_lines *, struct rcs_lines *))
{
        struct rcs_lines *dlines, *plines;
        struct rcs_line *lp;
        BUF *res;

        dlines = rcs_splitlines(data, dlen);
        plines = rcs_splitlines(patch, plen);

        if (p(dlines, plines) < 0) {
                rcs_freelines(dlines);
                rcs_freelines(plines);
                return (NULL);
        }

        res = buf_alloc(1024);
        TAILQ_FOREACH(lp, &dlines->l_lines, l_list) {
                if (lp->l_line == NULL)
                        continue;
                buf_append(res, lp->l_line, lp->l_len);
        }

        rcs_freelines(dlines);
        rcs_freelines(plines);
        return (res);
}

/*
 * rcs_yesno()
 *
 * Read a char from standard input, returns defc if the
 * user enters an equivalent to defc, else whatever char
 * was entered.  Converts input to lower case.
 */
int
rcs_yesno(int defc)
{
        int c, ret;

        fflush(stderr);
        fflush(stdout);

        clearerr(stdin);
        if (isalpha(c = getchar()))
                c = tolower(c);
        if (c == defc || c == '\n' || (c == EOF && feof(stdin)))
                ret = defc;
        else
                ret = c;

        while (c != EOF && c != '\n')
                c = getchar();

        return (ret);
}

/*
 * rcs_strsplit()
 *
 * Split a string <str> of <sep>-separated values and allocate
 * an argument vector for the values found.
 */
struct rcs_argvector *
rcs_strsplit(const char *str, const char *sep)
{
        struct rcs_argvector *av;
        size_t i = 0;
        char *cp, *p;

        cp = xstrdup(str);
        av = xmalloc(sizeof(*av));
        av->str = cp;
        av->argv = xmalloc(sizeof(*(av->argv)));

        while ((p = strsep(&cp, sep)) != NULL) {
                av->argv[i++] = p;
                av->argv = xreallocarray(av->argv,
                    i + 1, sizeof(*(av->argv)));
        }
        av->argv[i] = NULL;

        return (av);
}

/*
 * rcs_argv_destroy()
 *
 * Free an argument vector previously allocated by rcs_strsplit().
 */
void
rcs_argv_destroy(struct rcs_argvector *av)
{
        free(av->str);
        free(av->argv);
        free(av);
}

/*
 * Strip suffix from filename.
 */
void
rcs_strip_suffix(char *filename)
{
        char *p, *suffixes, *next, *ext;

        if ((p = strrchr(filename, ',')) != NULL) {
                suffixes = xstrdup(rcs_suffixes);
                for (next = suffixes; (ext = strsep(&next, "/")) != NULL;) {
                        if (!strcmp(p, ext)) {
                                *p = '\0';
                                break;
                        }
                }
                free(suffixes);
        }
}