/*

    Copyright (C) 2011  ABRT Team

    Copyright (C) 2011  RedHat inc.

    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.,

    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

*/

#include <satyr/thread.h>

#include <satyr/stacktrace.h>

#include <satyr/distance.h>

#include <satyr/abrt.h>

#include "libabrt.h"

#include <libreport/run_event.h>

/* 70 % similarity */

#define BACKTRACE_DUP_THRESHOLD 0.3

static char *uid = NULL;

static char *uuid = NULL;

static struct sr_stacktrace *corebt = NULL;

static char *type = NULL;

static char *executable = NULL;

static char *crash_dump_dup_name = NULL;

static void dup_corebt_fini(void);

static char* load_backtrace(const struct dump_dir *dd)

{

    const char *filename = FILENAME_BACKTRACE;

    if (strcmp(type, "CCpp") == 0)

    {

        filename = FILENAME_CORE_BACKTRACE;

    }

    return dd_load_text_ext(dd, filename,

        DD_FAIL_QUIETLY_ENOENT|DD_LOAD_TEXT_RETURN_NULL_ON_FAILURE);

}

static int core_backtrace_is_duplicate(struct sr_stacktrace *bt1,

                                       const char *bt2_text)

{

    struct sr_thread *thread1 = sr_stacktrace_find_crash_thread(bt1);

    if (thread1 == NULL)

    {

        log_notice("New stacktrace has no crash thread, disabling core stacktrace deduplicate");

        dup_corebt_fini();

        return 0;

    }

    int result;

    char *error_message;

    struct sr_stacktrace *bt2 = sr_stacktrace_parse(sr_abrt_type_from_type(type),

                                                    bt2_text, &error_message);

    if (bt2 == NULL)

    {

        log_notice("Failed to parse backtrace, considering it not duplicate: %s", error_message);

        free(error_message);

        return 0;

    }

    struct sr_thread *thread2 = sr_stacktrace_find_crash_thread(bt2);

    if (thread2 == NULL)

    {

        log_notice("Failed to get crash thread, considering it not duplicate");

        result = 0;

        goto end;

    }

    int length2 = sr_thread_frame_count(thread2);

    if (length2 <= 0)

    {

        log_notice("Core backtrace has zero frames, considering it not duplicate");

        result = 0;

        goto end;

    }

    float distance = sr_distance(SR_DISTANCE_DAMERAU_LEVENSHTEIN, thread1, thread2);

    log_info("Distance between backtraces: %f", distance);

    result = (distance <= BACKTRACE_DUP_THRESHOLD);

end:

    sr_stacktrace_free(bt2);

    return result;

}

static void dup_uuid_init(const struct dump_dir *dd)

{

    if (uuid)

        return; /* we already loaded it, don't do it again */

    uuid = dd_load_text_ext(dd, FILENAME_UUID,

                            DD_FAIL_QUIETLY_ENOENT + DD_LOAD_TEXT_RETURN_NULL_ON_FAILURE

    );

}

static int dup_uuid_compare(const struct dump_dir *dd)

{

    char *dd_uuid;

    int different;

    if (!uuid)

        return 0;

    /* don't do uuid-based check on crashes that have backtrace available (and

     * nonempty)

     * XXX: this relies on the fact that backtrace is created in the same event

     * as UUID

     */

    if (corebt)

        return 0;

    dd_uuid = dd_load_text_ext(dd, FILENAME_UUID, DD_FAIL_QUIETLY_ENOENT);

    different = strcmp(uuid, dd_uuid);

    free(dd_uuid);

    if (!different)

        log_notice("Duplicate: UUID");

    return !different;

}

static void dup_uuid_fini(void)

{

    free(uuid);

    uuid = NULL;

}

static void dup_corebt_init(const struct dump_dir *dd)

{

    if (corebt)

        return; /* already loaded */

    char *corebt_text = load_backtrace(dd);

    if (!corebt_text)

        return; /* no backtrace */

    enum sr_report_type report_type = sr_abrt_type_from_type(type);

    if (report_type == SR_REPORT_INVALID)

    {

        log_notice("Can't load stacktrace because of unsupported type: %s",

                  type);

        return;

    }

    /* sr_stacktrace_parse moves the pointer */

    char *error_message;

    corebt = sr_stacktrace_parse(report_type, corebt_text, &error_message);

    if (!corebt)

    {

        log_notice("Failed to load core stacktrace: %s", error_message);

        free(error_message);

    }

    free(corebt_text);

}

static int dup_corebt_compare(const struct dump_dir *dd)

{

    if (!corebt)

        return 0;

    int isdup;

    char *dd_corebt = load_backtrace(dd);

    if (!dd_corebt)

        return 0;

    isdup = core_backtrace_is_duplicate(corebt, dd_corebt);

    free(dd_corebt);

    if (isdup)

        log_notice("Duplicate: core backtrace");

    return isdup;

}

static void dup_corebt_fini(void)

{

    sr_stacktrace_free(corebt);

    corebt = NULL;

}

/* This function is run after each post-create event is finished (there may be

 * multiple such events).

 *

 * It first checks if there is CORE_BACKTRACE or UUID item in the dump dir

 * we are processing.

 *

 * If there is a CORE_BACKTRACE, it iterates over all other dump

 * directories and computes similarity to their core backtraces (if any).

 * If one of them is similar enough to be considered duplicate, the function

 * saves the path to the dump directory in question and returns 1 to indicate

 * that we have indeed found a duplicate of currently processed dump directory.

 * No more events are processed and program prints the path to the other

 * directory and returns failure.

 *

 * If there is an UUID item (and no core backtrace), the function again

 * iterates over all other dump directories and compares this UUID to their

 * UUID. If there is a match, the path to the duplicate is saved and 1 is returned.

 *

 * If duplicate is not found as described above, the function returns 0 and we

 * either process remaining events if there are any, or successfully terminate

 * processing of the current dump directory.

 */

static int is_crash_a_dup(const char *dump_dir_name, void *param)

{

    int retval = 0; /* defaults to no dup found, "run_event, please continue iterating" */

    struct dump_dir *dd = dd_opendir(dump_dir_name, DD_OPEN_READONLY);

    if (!dd)

        return 0; /* wtf? (error, but will be handled elsewhere later) */

    free(type);

    type = dd_load_text(dd, FILENAME_TYPE);

    free(executable);

    executable = dd_load_text_ext(dd, FILENAME_EXECUTABLE, DD_FAIL_QUIETLY_ENOENT);

    char *container_id = dd_load_text_ext(dd, FILENAME_CONTAINER_ID, DD_FAIL_QUIETLY_ENOENT);

    dup_uuid_init(dd);

    dup_corebt_init(dd);

    dd_close(dd);

    /* dump_dir_name can be relative */

    dump_dir_name = realpath(dump_dir_name, NULL);

    DIR *dir = opendir(g_settings_dump_location);

    if (dir == NULL)

        goto end;

    /* Scan crash dumps looking for a dup */

    //TODO: explain why this is safe wrt concurrent runs

    struct dirent *dent;

    while ((dent = readdir(dir)) != NULL && crash_dump_dup_name == NULL)

    {

        if (dot_or_dotdot(dent->d_name))

            continue; /* skip "." and ".." */

        const char *ext = strrchr(dent->d_name, '.');

        if (ext && strcmp(ext, ".new") == 0)

            continue; /* skip anything named "<dirname>.new" */

        dd = NULL;

        char *tmp_concat_path = concat_path_file(g_settings_dump_location, dent->d_name);

        char *dump_dir_name2 = realpath(tmp_concat_path, NULL);

        if (g_verbose > 1 && !dump_dir_name2)

            perror_msg("realpath(%s)", tmp_concat_path);

        free(tmp_concat_path);

        if (!dump_dir_name2)

            continue;

        char *dd_uid = NULL, *dd_type = NULL;

        char *dd_executable = NULL, *dd_container_id = NULL;

        if (strcmp(dump_dir_name, dump_dir_name2) == 0)

            goto next; /* we are never a dup of ourself */

        int sv_logmode = logmode;

        /* Silently ignore any error in the silent log level. */

        logmode = g_verbose == 0 ? 0 : sv_logmode;

        dd = dd_opendir(dump_dir_name2, /*flags:*/ DD_FAIL_QUIETLY_ENOENT | DD_OPEN_READONLY);

        logmode = sv_logmode;

        if (!dd)

            goto next;

        /* problems from different containers are not duplicates */

        if (container_id != NULL)

        {

            dd_container_id = dd_load_text_ext(dd, FILENAME_CONTAINER_ID, DD_FAIL_QUIETLY_ENOENT);

            if (dd_container_id != NULL && strcmp(container_id, dd_container_id) != 0)

            {

                goto next;

            }

        }

        /* crashes of different users are not considered duplicates */

        dd_uid = dd_load_text_ext(dd, FILENAME_UID, DD_FAIL_QUIETLY_ENOENT);

        if (strcmp(uid, dd_uid))

        {

            goto next;

        }

        /* different crash types are not duplicates */

        dd_type = dd_load_text_ext(dd, FILENAME_TYPE, DD_FAIL_QUIETLY_ENOENT);

        if (strcmp(type, dd_type))

        {

            goto next;

        }

        /* different executables are not duplicates */

        dd_executable = dd_load_text_ext(dd, FILENAME_EXECUTABLE, DD_FAIL_QUIETLY_ENOENT);

        if (     (executable != NULL && dd_executable == NULL)

             ||  (executable == NULL && dd_executable != NULL)

             || ((executable != NULL && dd_executable != NULL)

                  && strcmp(executable, dd_executable) != 0))

        {

            goto next;

        }

        if (dup_uuid_compare(dd)

         || dup_corebt_compare(dd)

        ) {

            crash_dump_dup_name = dump_dir_name2;

            dump_dir_name2 = NULL;

            retval = 1; /* "run_event, please stop iterating" */

            /* sonce crash_dump_dup_name != NULL now, we exit the loop */

        }

next:

        free(dump_dir_name2);

        dd_close(dd);

        free(dd_uid);

        free(dd_type);

        free(dd_container_id);

    }

    closedir(dir);

end:

    free((char*)dump_dir_name);

    free(container_id);

    return retval;

}

static char *do_log(char *log_line, void *param)

{

    /* We pipe output of events to our log.

     * Otherwise, errors on post-create result in

     * "Corrupted or bad dump DIR, deleting" without adequate explanation why.

     */

    log_warning("%s", log_line);

    return log_line;

}

int main(int argc, char **argv)

{

    /* I18n */

    setlocale(LC_ALL, "");

#if ENABLE_NLS

    bindtextdomain(PACKAGE, LOCALEDIR);

    textdomain(PACKAGE);

#endif

    abrt_init(argv);

    const char *program_usage_string = _(

        "& [-v -i -n INCREMENT] -e|--event EVENT DIR..."

        );

    char *event_name = NULL;

    int interactive = 0; /* must be _int_, OPT_BOOL expects that! */

    int nice_incr = 0;

    struct options program_options[] = {

        OPT__VERBOSE(&g_verbose),

        OPT_STRING('e', "event" , &event_name, "EVENT",  _("Run EVENT on DIR")),

        OPT_BOOL('i', "interactive" , &interactive, _("Communicate directly to the user")),

        OPT_INTEGER('n',     "nice" , &nice_incr,   _("Increment the nice value by INCREMENT")),

        OPT_END()

    };

    parse_opts(argc, argv, program_options, program_usage_string);

    argv += optind;

    if (!*argv || !event_name)

        show_usage_and_die(program_usage_string, program_options);

    load_abrt_conf();

    const char *const opt_env_nice = getenv("ABRT_EVENT_NICE");

    if (opt_env_nice != NULL && opt_env_nice[0] != '\0')

    {

        log_debug("Using ABRT_EVENT_NICE=%s to increment the nice value", opt_env_nice);

        nice_incr = xatoi(opt_env_nice);

    }

    if (nice_incr != 0)

    {

        log_debug("Incrementing the nice value by %d", nice_incr);

        const int ret = nice(nice_incr);

        if (ret == -1)

            perror_msg_and_die("Failed to increment the nice value");

    }

    bool post_create = (strcmp(event_name, "post-create") == 0);

    char *dump_dir_name = NULL;

    while (*argv)

    {

        dump_dir_name = xstrdup(*argv++);

        int i = strlen(dump_dir_name);

        while (--i >= 0)

            if (dump_dir_name[i] != '/')

                break;

        dump_dir_name[++i] = '\0';

        struct dump_dir *dd = dd_opendir(dump_dir_name, /*flags:*/ DD_OPEN_READONLY);

        if (!dd)

            return 1;

        uid = dd_load_text_ext(dd, FILENAME_UID, DD_FAIL_QUIETLY_ENOENT);

        dd_close(dd);

        struct run_event_state *run_state = new_run_event_state();

        if (!interactive)

            make_run_event_state_forwarding(run_state);

        run_state->logging_callback = do_log;

        if (post_create)

            run_state->post_run_callback = is_crash_a_dup;

        int r = run_event_on_dir_name(run_state, dump_dir_name, event_name);

        const bool no_action_for_event = (r == 0 && run_state->children_count == 0);

        free_run_event_state(run_state);

        /* Needed only if is_crash_a_dup() was called, but harmless

         * even if it wasn't:

         */

        dup_uuid_fini();

        dup_corebt_fini();

        if (no_action_for_event)

            error_msg_and_die("No actions are found for event '%s'", event_name);

//TODO: consider this case:

// new dump is created, post-create detects that it is a dup,

// but then load_crash_info(dup_name) *FAILS*.

// In this case, we later delete damaged dup_name (right?)

// but new dump never gets its FILENAME_COUNT set!

        /* Is crash a dup? (In this case, is_crash_a_dup() should have

         * aborted "post-create" event processing as soon as it saw uuid

         * and determined that there is another crash with same uuid.

         * In this case it sets crash_dump_dup_name)

         */

        if (crash_dump_dup_name)

            error_msg_and_die("DUP_OF_DIR: %s", crash_dump_dup_name);

        /* Was there error on one of processing steps in run_event? */

        if (r != 0)

            return r; /* yes */

        free(dump_dir_name);

        dump_dir_name = NULL;

    }

    /* exit 0 means, that there is no duplicate of dump-dir */

    return 0;

}