/*
 * 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 "key" env variable. */
static int get_trace_fd(const char *key, int *need_close)
{
        char *trace = getenv(key);

        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 %s mean?\n", trace, key);
        fprintf(stderr, "If you want to trace into a file, "
                "then please set %s to an absolute pathname "
                "(starting with /).\n", key);
        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";

static void trace_vprintf(const char *key, const char *fmt, va_list ap)
{
        struct strbuf buf = STRBUF_INIT;

        if (!trace_want(key))
                return;

        set_try_to_free_routine(NULL);  /* is never reset */
        strbuf_vaddf(&buf, fmt, ap);
        trace_strbuf(key, &buf);
        strbuf_release(&buf);
}

__attribute__((format (printf, 2, 3)))
static void trace_printf_key(const char *key, const char *fmt, ...)
{
        va_list ap;
        va_start(ap, fmt);
        trace_vprintf(key, fmt, ap);
        va_end(ap);
}

void trace_printf(const char *fmt, ...)
{
        va_list ap;
        va_start(ap, fmt);
        trace_vprintf("GIT_TRACE", fmt, ap);
        va_end(ap);
}

void trace_strbuf(const char *key, const struct strbuf *buf)
{
        int fd, need_close = 0;

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

        write_or_whine_pipe(fd, buf->buf, buf->len, err_msg);

        if (need_close)
                close(fd);
}

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

        fd = get_trace_fd("GIT_TRACE", &need_close);
        if (!fd)
                return;

        set_try_to_free_routine(NULL);  /* is never reset */
        va_start(ap, fmt);
        strbuf_vaddf(&buf, fmt, ap);
        va_end(ap);

        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)
{
        static const char *key = "GIT_TRACE_SETUP";
        const char *git_work_tree;
        char cwd[PATH_MAX];

        if (!trace_want(key))
                return;

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

        if (!(git_work_tree = get_git_work_tree()))
                git_work_tree = "(null)";

        if (!prefix)
                prefix = "(null)";

        trace_printf_key(key, "setup: git_dir: %s\n", quote_crnl(get_git_dir()));
        trace_printf_key(key, "setup: worktree: %s\n", quote_crnl(git_work_tree));
        trace_printf_key(key, "setup: cwd: %s\n", quote_crnl(cwd));
        trace_printf_key(key, "setup: prefix: %s\n", quote_crnl(prefix));
}

int trace_want(const char *key)
{
        const char *trace = getenv(key);

        if (!trace || !strcmp(trace, "") ||
            !strcmp(trace, "0") || !strcasecmp(trace, "false"))
                return 0;
        return 1;
}