/*
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 2021 Gerald Combs
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

#include "config.h"
#include "wslog.h"

#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <stdarg.h>
#include <ws_attributes.h>

#include <wsutil/ws_assert.h>
#include <wsutil/time_util.h>

#define LOGBUFSIZE  256

#define LOGENVVAR "WS_LOG_LEVEL"


/* TODO: Add filtering by domain. */

static enum ws_log_level current_log_level = LOG_LEVEL_MESSAGE;

static ws_log_writer_t *current_log_writer = ws_log_default_writer;

static void *current_log_writer_data = NULL;

static ws_log_writer_free_data_t *current_log_writer_data_free = NULL;

static FILE *custom_log = NULL;


static void ws_log_cleanup(void);


static void
log_default_writer_do_work(FILE *fp, const char *message)
{
    ws_assert(message);
    fputs(message, fp);
    fputc('\n', fp);
    fflush(fp);
}


void
ws_log_default_writer(const char *message,
                       enum ws_log_domain domain _U_,
                       enum ws_log_level level _U_,
                       void *user_data _U_)
{
    log_default_writer_do_work(stderr, message);
}


const char *ws_log_level_to_string(enum ws_log_level level)
{
    switch (level) {
        case LOG_LEVEL_NONE:
            return "(none)";
        case LOG_LEVEL_ERROR:
            return "ERROR";
        case LOG_LEVEL_CRITICAL:
            return "CRITICAL";
        case LOG_LEVEL_WARNING:
            return "WARNING";
        case LOG_LEVEL_MESSAGE:
            return "MESSAGE";
        case LOG_LEVEL_INFO:
            return "INFO";
        case LOG_LEVEL_DEBUG:
            return "DEBUG";
        default:
            return "(BOGUS LOG LEVEL)";
    }
}


const char *ws_log_domain_to_string(enum ws_log_domain domain)
{
    switch (domain) {
        case LOG_DOMAIN_DEFAULT:
            return "Default";
        case LOG_DOMAIN_MAIN:
            return "Main";
        case LOG_DOMAIN_CAPTURE:
            return "Capture";
        case LOG_DOMAIN_CAPCHILD:
            return "CapChild";
        case LOG_DOMAIN_WIRETAP:
            return "Wiretap";
        case LOG_DOMAIN_EPAN:
            return "Epan";
        case LOG_DOMAIN_WSUTIL:
            return "Util";
        case LOG_DOMAIN_QTUI:
            return "GUI";
        default:
            return "(BOGUS LOG DOMAIN)";
    }
}


gboolean ws_log_level_is_active(enum ws_log_level level)
{
    return level <= current_log_level;
}


enum ws_log_level ws_log_get_level(void)
{
    return current_log_level;
}


enum ws_log_level ws_log_set_level(enum ws_log_level log_level)
{
    ws_assert(log_level > LOG_LEVEL_NONE && log_level < _LOG_LEVEL_LAST);

    current_log_level = log_level;
    return current_log_level;
}


enum ws_log_level ws_log_set_level_str(const char *str_level)
{
    enum ws_log_level level;

    if (!str_level)
        return LOG_LEVEL_NONE;

    if (g_ascii_strcasecmp(str_level, "debug") == 0)
        level = LOG_LEVEL_DEBUG;
    else if (g_ascii_strcasecmp(str_level, "info") == 0)
        level = LOG_LEVEL_INFO;
    else if (g_ascii_strcasecmp(str_level, "message") == 0)
        level = LOG_LEVEL_MESSAGE;
    else if (g_ascii_strcasecmp(str_level, "warning") == 0)
        level = LOG_LEVEL_WARNING;
    else if (g_ascii_strcasecmp(str_level, "critical") == 0)
        level = LOG_LEVEL_CRITICAL;
    else if (g_ascii_strcasecmp(str_level, "error") == 0)
        level = LOG_LEVEL_ERROR;
    else
        return LOG_LEVEL_NONE;

    current_log_level = level;
    return current_log_level;
}


static const char *set_level_and_prune_argv(int count, char **ptr, int prune_extra,
                                const char *optarg, int *ret_argc)
{
    if (optarg && ws_log_set_level_str(optarg) != LOG_LEVEL_NONE)
        optarg = NULL; /* success */

    /*
     * We found a "--log-level" option. We will remove it from
     * the argv by moving up the other strings in the array. This is
     * so that it doesn't generate an unrecognized option
     * error further along in the initialization process.
     */

    /* Include the terminating NULL in the memmove. */
    memmove(ptr, ptr + 1 + prune_extra, (count - prune_extra) * sizeof(*ptr));
    *ret_argc -= (1 + prune_extra);
    return optarg;
}

const char *ws_log_set_level_args(int *argc_ptr, char *argv[])
{
    char **p;
    int c;
    const char *opt = "--log-level";
    size_t len = strlen(opt);
    const char *optarg;

    for (p = argv, c = *argc_ptr; *p != NULL; p++, c--) {
        if (strncmp(*p, opt, len) == 0) {
            optarg = *p + len;
            /* Two possibilities:
             *      --log_level <level>
             * or
             *      --log-level=<level>
             */
            if (optarg[0] == '\0') {
                /* value is separated with blank space */
                optarg = *(p + 1);

                /* If the option value after the blank is missing or stars with '-' just ignore it.
                 * But we should probably signal an error (missing required value). */
                if (optarg == NULL || !*optarg || *optarg == '-') {
                    return set_level_and_prune_argv(c, p, 0, NULL, argc_ptr);
                }
                return set_level_and_prune_argv(c, p, 1, optarg, argc_ptr);
            }
            else if (optarg[0] == '=') {
                /* value is after equals */
                optarg += 1;
                return set_level_and_prune_argv(c, p, 0, optarg, argc_ptr);
            }
            /* we didn't find what we want */
        }
    }
    return NULL; /* No log-level option, ignore and return success. */
}


void ws_log_init(ws_log_writer_t *_writer)
{
    if (_writer) {
        current_log_writer = _writer;
    }

    const char *env = g_getenv(LOGENVVAR);
    if (env && ws_log_set_level_str(env) == LOG_LEVEL_NONE) {
        fprintf(stderr, "Ignoring invalid environment value %s=\"%s\"\n", LOGENVVAR, env);
    }

    atexit(ws_log_cleanup);
}


void ws_log_init_with_data(ws_log_writer_t *writer, void *user_data,
                              ws_log_writer_free_data_t *free_user_data)
{
    current_log_writer_data = user_data;
    current_log_writer_data_free = free_user_data;
    ws_log_init(writer);
}


static inline const char *_level_to_string(enum ws_log_level level)
{
    switch (level) {
        case LOG_LEVEL_NONE:       return "NUL";
        case LOG_LEVEL_ERROR:      return "ERR";
        case LOG_LEVEL_CRITICAL:   return "CRI";
        case LOG_LEVEL_WARNING:    return "WRN";
        case LOG_LEVEL_MESSAGE:    return "MSG";
        case LOG_LEVEL_INFO:       return "NFO";
        case LOG_LEVEL_DEBUG:      return "DBG";
        default:
            return "(BOGUS LOG LEVEL)";
    }
}


static inline const char *_domain_to_string(enum ws_log_domain domain)
{
    switch (domain) {
        case LOG_DOMAIN_DEFAULT:   return "Dflt";
        case LOG_DOMAIN_MAIN:      return "Main";
        case LOG_DOMAIN_CAPTURE:   return "Capt";
        case LOG_DOMAIN_CAPCHILD:  return "CChd";
        case LOG_DOMAIN_WIRETAP:   return "Wtap";
        case LOG_DOMAIN_EPAN:      return "Epan";
        case LOG_DOMAIN_WSUTIL:    return "Util";
        case LOG_DOMAIN_QTUI:      return "Qtui";
        default:
            return "(BOGUS LOG DOMAIN)";
    }
}


static void ws_log_writev(enum ws_log_domain domain, enum ws_log_level level,
                            const char *location, const char *format, va_list ap)
{
    char timestamp[sizeof("00:00:00.000")];
    char user_string[LOGBUFSIZE];
    char message[LOGBUFSIZE*2];
    time_t curr;
    struct tm *today;

    /* create a "timestamp" */
    time(&curr);
    today = localtime(&curr);
    guint64 microseconds = create_timestamp();
    if (today != NULL) {
        snprintf(timestamp, sizeof(timestamp), "%02d:%02d:%02d.%03" G_GUINT64_FORMAT,
                    today->tm_hour, today->tm_min, today->tm_sec,
                    microseconds % 1000000 / 1000);
    }
    else {
        snprintf(timestamp, sizeof(timestamp), "(notime)");
    }

    vsnprintf(user_string, sizeof(user_string), format, ap);

    snprintf(message, sizeof(message), "%s %s-%s %s : %s",
                timestamp,
                _domain_to_string(domain),
                _level_to_string(level),
                location ? location : "(nofile)",
                user_string);

    /* Call the registered writer, or the default if one wasn't registered. */
    current_log_writer(message, domain, level, current_log_writer_data);

    /* If we have a custom file, write to it _also_. */
    if (custom_log) {
        log_default_writer_do_work(custom_log, message);
    }

    if (level == LOG_LEVEL_ERROR) {
        G_BREAKPOINT();
        ws_assert_not_reached();
    }
}


void ws_logv(enum ws_log_domain domain, enum ws_log_level level,
                    const char *format, va_list ap)
{
    if (!ws_log_level_is_active(level))
        return;

    ws_log_writev(domain, level, NULL, format, ap);
}


void ws_log(enum ws_log_domain domain, enum ws_log_level level,
                    const char *format, ...)
{
    va_list ap;

    if (!ws_log_level_is_active(level))
        return;

    va_start(ap, format);
    ws_log_writev(domain, level, NULL, format, ap);
    va_end(ap);
}


void ws_log_full(enum ws_log_domain domain, enum ws_log_level level,
                    const char *file, int line, const char *func,
                    const char *format, ...)
{
    va_list ap;
    char location[LOGBUFSIZE];

    if (!ws_log_level_is_active(level))
        return;

    if (func)
        snprintf(location, sizeof(location), "%s(%d) %s()", file, line, func);
    else
        snprintf(location, sizeof(location), "%s(%d)", file, line);

    va_start(ap, format);
    ws_log_writev(domain, level, location, format, ap);
    va_end(ap);
}


static void ws_log_cleanup(void)
{
    if (current_log_writer_data_free) {
        current_log_writer_data_free(current_log_writer_data);
        current_log_writer_data = NULL;
    }
    if (custom_log) {
        fclose(custom_log);
        custom_log = NULL;
    }
}


void ws_log_add_custom_file(FILE *fp)
{
        if (custom_log != NULL) {
            fclose(custom_log);
            custom_log = NULL;
        }
        if (fp != NULL) {
            custom_log = fp;
        }
}