/*
 * GIT - The information manager from hell
 *
 * Copyright (C) 2000-2002 Michael R. Elkins <me@mutt.org>
 * Copyright (C) 2002-2004 Oswald Buddenhagen <ossi@users.sf.net>
 * Copyright (C) 2004 Theodore Y. Ts'o <tytso@mit.edu>
 * Copyright (C) 2006 Mike McCormack
 * Copyright (C) 2006 Christian Couder
 *
 *  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 "cache.h"
#include "quote.h"

/* Get a trace file descriptor from GIT_TRACE env variable. */
static int get_trace_fd(int *need_close)
{
        char *trace = getenv("GIT_TRACE");

        if (!trace || !strcmp(trace, "") ||
            !strcmp(trace, "0") || !strcasecmp(trace, "false"))
                return 0;
        if (!strcmp(trace, "1") || !strcasecmp(trace, "true"))
                return STDERR_FILENO;
        if (strlen(trace) == 1 && isdigit(*trace))
                return atoi(trace);
        if (is_absolute_path(trace)) {
                int fd = open(trace, O_WRONLY | O_APPEND | O_CREAT, 0666);
                if (fd == -1) {
                        fprintf(stderr,
                                "Could not open '%s' for tracing: %s\n"
                                "Defaulting to tracing on stderr...\n",
                                trace, strerror(errno));
                        return STDERR_FILENO;
                }
                *need_close = 1;
                return fd;
        }

        fprintf(stderr, "What does '%s' for GIT_TRACE mean?\n", trace);
        fprintf(stderr, "If you want to trace into a file, "
                "then please set GIT_TRACE to an absolute pathname "
                "(starting with /).\n");
        fprintf(stderr, "Defaulting to tracing on stderr...\n");

        return STDERR_FILENO;
}

static const char err_msg[] = "Could not trace into fd given by "
        "GIT_TRACE environment variable";

void trace_printf(const char *fmt, ...)
{
        struct strbuf buf;
        va_list ap;
        int fd, len, need_close = 0;

        fd = get_trace_fd(&need_close);
        if (!fd)
                return;

        set_try_to_free_routine(NULL);  /* is never reset */
        strbuf_init(&buf, 64);
        va_start(ap, fmt);
        len = vsnprintf(buf.buf, strbuf_avail(&buf), fmt, ap);
        va_end(ap);
        if (len >= strbuf_avail(&buf)) {
                strbuf_grow(&buf, len - strbuf_avail(&buf) + 128);
                va_start(ap, fmt);
                len = vsnprintf(buf.buf, strbuf_avail(&buf), fmt, ap);
                va_end(ap);
                if (len >= strbuf_avail(&buf))
                        die("broken vsnprintf");
        }
        strbuf_setlen(&buf, len);

        write_or_whine_pipe(fd, buf.buf, buf.len, err_msg);
        strbuf_release(&buf);

        if (need_close)
                close(fd);
}

void trace_argv_printf(const char **argv, const char *fmt, ...)
{
        struct strbuf buf;
        va_list ap;
        int fd, len, need_close = 0;

        fd = get_trace_fd(&need_close);
        if (!fd)
                return;

        set_try_to_free_routine(NULL);  /* is never reset */
        strbuf_init(&buf, 64);
        va_start(ap, fmt);
        len = vsnprintf(buf.buf, strbuf_avail(&buf), fmt, ap);
        va_end(ap);
        if (len >= strbuf_avail(&buf)) {
                strbuf_grow(&buf, len - strbuf_avail(&buf) + 128);
                va_start(ap, fmt);
                len = vsnprintf(buf.buf, strbuf_avail(&buf), fmt, ap);
                va_end(ap);
                if (len >= strbuf_avail(&buf))
                        die("broken vsnprintf");
        }
        strbuf_setlen(&buf, len);

        sq_quote_argv(&buf, argv, 0);
        strbuf_addch(&buf, '\n');
        write_or_whine_pipe(fd, buf.buf, buf.len, err_msg);
        strbuf_release(&buf);

        if (need_close)
                close(fd);
}

static const char *quote_crnl(const char *path)
{
        static char new_path[PATH_MAX];
        const char *p2 = path;
        char *p1 = new_path;

        if (!path)
                return NULL;

        while (*p2) {
                switch (*p2) {
                case '\\': *p1++ = '\\'; *p1++ = '\\'; break;
                case '\n': *p1++ = '\\'; *p1++ = 'n'; break;
                case '\r': *p1++ = '\\'; *p1++ = 'r'; break;
                default:
                        *p1++ = *p2;
                }
                p2++;
        }
        *p1 = '\0';
        return new_path;
}

/* FIXME: move prefix to startup_info struct and get rid of this arg */
void trace_repo_setup(const char *prefix)
{
        char cwd[PATH_MAX];
        char *trace = getenv("GIT_TRACE");

        if (!trace || !strcmp(trace, "") ||
            !strcmp(trace, "0") || !strcasecmp(trace, "false"))
                return;

        if (!getcwd(cwd, PATH_MAX))
                die("Unable to get current working directory");

        trace_printf("setup: git_dir: %s\n", quote_crnl(get_git_dir()));
        trace_printf("setup: worktree: %s\n", quote_crnl(get_git_work_tree()));
        trace_printf("setup: cwd: %s\n", quote_crnl(cwd));
        trace_printf("setup: prefix: %s\n", quote_crnl(prefix));
}