/*
 *  wslua_util.c
 *
 * (c) 2006, Luis E. Garcia Ontanon <luis@ontanon.org>
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * 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 "config.h"

/* WSLUA_MODULE Utility Utility Functions */

#include "wslua.h"
#include <math.h>
#include <epan/stat_tap_ui.h>
#include <wsutil/ws_printf.h> /* ws_g_warning */


WSLUA_FUNCTION wslua_get_version(lua_State* L) { /* Gets a string of the Wireshark version. */
    const gchar* str = VERSION;
    lua_pushstring(L,str);
    WSLUA_RETURN(1); /* version string */
}


static gchar* current_plugin_version = NULL;

const gchar* get_current_plugin_version(void) {
    return current_plugin_version ? current_plugin_version : "";
}

void clear_current_plugin_version(void) {
    if (current_plugin_version != NULL) {
        g_free(current_plugin_version);
        current_plugin_version = NULL;
    }
}

WSLUA_FUNCTION wslua_set_plugin_info(lua_State* L) {
    /*  Set a Lua table with meta-data about the plugin, such as version.

        The passed-in Lua table entries need to be keyed/indexed by the following:
         * "version" with a string value identifying the plugin version (required)
         * "description" with a string value describing the plugin (optional)
         * "author" with a string value of the author's name(s) (optional)
         * "repository" with a string value of a URL to a repository (optional)

        Not all of the above key entries need to be in the table. The 'version'
        entry is required, however. The others are not currently used for anything, but
        might be in the future and thus using them might be useful. Table entries keyed
        by other strings are ignored, and do not cause an error.

        Example:
        @code
        local my_info = {
            version = "1.0.1",
            author = "Jane Doe",
            repository = "https://github.com/octocat/Spoon-Knife"
        }

        set_plugin_info(my_info)
        @endcode

        @since 1.99.8
     */
#define WSLUA_ARG_set_plugin_info_TABLE 1 /* The Lua table of information. */

    if ( lua_istable(L,WSLUA_ARG_set_plugin_info_TABLE) ) {
        int top;
        lua_getfield(L, WSLUA_ARG_set_plugin_info_TABLE, "version");
        top = lua_gettop(L);
        if (lua_isstring(L, top)) {
            clear_current_plugin_version();
            current_plugin_version = g_strdup( luaL_checkstring(L, top) );
            /* pop the string */
            lua_pop(L, 1);
        }
        else {
            return luaL_error(L,"the Lua table must have a 'version' key entry with a string value");
        }
    } else {
        return luaL_error(L,"a Lua table with at least a 'version' string entry");
    }

    return 0;
}


WSLUA_FUNCTION wslua_format_date(lua_State* LS) { /* Formats an absolute timestamp into a human readable date. */
#define WSLUA_ARG_format_date_TIMESTAMP 1 /* A timestamp value to convert. */
    lua_Number timestamp = luaL_checknumber(LS,WSLUA_ARG_format_date_TIMESTAMP);
    nstime_t then;
    gchar* str;

    then.secs = (guint32)(floor(timestamp));
    then.nsecs = (guint32) ( (timestamp-(double)(then.secs))*1000000000);
    str = abs_time_to_str(NULL, &then, ABSOLUTE_TIME_LOCAL, TRUE);
    lua_pushstring(LS,str);
    wmem_free(NULL, str);

    WSLUA_RETURN(1); /* A string with the formated date */
}

WSLUA_FUNCTION wslua_format_time(lua_State* LS) { /* Formats a relative timestamp in a human readable form. */
#define WSLUA_ARG_format_time_TIMESTAMP 1 /* A timestamp value to convert. */
    lua_Number timestamp = luaL_checknumber(LS,WSLUA_ARG_format_time_TIMESTAMP);
    nstime_t then;
    gchar* str;

    then.secs = (guint32)(floor(timestamp));
    then.nsecs = (guint32) ( (timestamp-(double)(then.secs))*1000000000);
    str = rel_time_to_str(NULL, &then);
    lua_pushstring(LS,str);
    wmem_free(NULL, str);

    WSLUA_RETURN(1); /* A string with the formated time */
}

WSLUA_FUNCTION wslua_report_failure(lua_State* LS) { /* Reports a failure to the user. */
#define WSLUA_ARG_report_failure_TEXT 1 /* Message text to report. */
    const gchar* s = luaL_checkstring(LS,WSLUA_ARG_report_failure_TEXT);
    report_failure("%s",s);
    return 0;
}

static int wslua_log(lua_State* L, GLogLevelFlags log_level) {
    GString* str = g_string_new("");
    int n = lua_gettop(L);  /* Number of arguments */
    int i;

    lua_getglobal(L, "tostring");
    for (i=1; i<=n; i++) {
        const char *s;
        lua_pushvalue(L, -1);  /* function to be called */
        lua_pushvalue(L, i);   /* value to print */
        lua_call(L, 1, 1);
        s = lua_tostring(L, -1);  /* get result */
        if (s == NULL)
            return luaL_error(L, "`tostring' must return a string");

        if (i>1) g_string_append(str,"\t");
        g_string_append(str,s);

        lua_pop(L, 1);  /* pop result */
    }

    g_log(LOG_DOMAIN_LUA, log_level, "%s\n", str->str);
    g_string_free(str,TRUE);

    return 0;
}

WSLUA_FUNCTION wslua_critical( lua_State* L ) { /* Will add a log entry with critical severity. */
/* WSLUA_MOREARGS critical objects to be printed    */
    wslua_log(L,G_LOG_LEVEL_CRITICAL);
    return 0;
}
WSLUA_FUNCTION wslua_warn( lua_State* L ) { /* Will add a log entry with warn severity. */
/* WSLUA_MOREARGS warn objects to be printed    */
    wslua_log(L,G_LOG_LEVEL_WARNING);
    return 0;
}
WSLUA_FUNCTION wslua_message( lua_State* L ) { /* Will add a log entry with message severity. */
/* WSLUA_MOREARGS message objects to be printed    */
    wslua_log(L,G_LOG_LEVEL_MESSAGE);
    return 0;
}
WSLUA_FUNCTION wslua_info( lua_State* L ) { /* Will add a log entry with info severity. */
/* WSLUA_MOREARGS info objects to be printed    */
    wslua_log(L,G_LOG_LEVEL_INFO);
    return 0;
}
WSLUA_FUNCTION wslua_debug( lua_State* L ) { /* Will add a log entry with debug severity. */
/* WSLUA_MOREARGS debug objects to be printed    */
    wslua_log(L,G_LOG_LEVEL_DEBUG);
    return 0;
}

/* The returned filename is g_malloc()'d so the caller must free it */
/* except when NULL is returned if file doesn't exist               */
char* wslua_get_actual_filename(const char* fname) {
    char fname_clean[256];
    char* f;
    char* filename;

    g_strlcpy(fname_clean,fname,255);
    fname_clean[255] = '\0';

    for(f = fname_clean; *f; f++) {
        switch(*f) {
            case '/': case '\\':
                *f = *(G_DIR_SEPARATOR_S);
                break;
            default:
                break;
        }
    }

    if ( file_exists(fname_clean) ) {
        return g_strdup(fname_clean);
    }

    filename = get_persconffile_path(fname_clean,FALSE);

    if ( file_exists(filename) ) {
        return filename;
    }
    g_free(filename);

    /*
     * Try to look in global data directory, nothing extraordinary for normal
     * installations. For executions from the build dir, it will look for files
     * copied to DATAFILE_DIR (cmake). In case autotools was used, files were
     * not copied to that directory, so the next line will return a non-existing
     * file.
     */
    filename = get_datafile_path(fname_clean);
    if ( file_exists(filename) ) {
        return filename;
    }
    g_free(filename);

    /*
     * Fallback for autotools: assume that this is not an autogenerated file
     * (like init.lua) but something that is available in the source tree (e.g.
     * epan/wslua/console.lua). Assume that get_datafile_dir() returns the path
     * to the source tree (TOP_SRCDIR).
     */
    if (running_in_build_directory()) {
        filename = g_strdup_printf("%s" G_DIR_SEPARATOR_S "epan" G_DIR_SEPARATOR_S "wslua"
                                   G_DIR_SEPARATOR_S "%s", get_datafile_dir(), fname_clean);
        if ( file_exists(filename) ) {
            return filename;
        }
        g_free(filename);
    }

    return NULL;
}

WSLUA_FUNCTION wslua_loadfile(lua_State* L) {
    /* Lua's loadfile() has been modified so that if a file does not exist
    in the current directory it will look for it in wireshark's user and system directories. */
#define WSLUA_ARG_loadfile_FILENAME 1 /* Name of the file to be loaded. */
    const char *given_fname = luaL_checkstring(L, WSLUA_ARG_loadfile_FILENAME);
    char* filename;

    filename = wslua_get_actual_filename(given_fname);

    if (!filename) {
        WSLUA_ARG_ERROR(loadfile,FILENAME,"file does not exist");
        return 0;
    }

    if (luaL_loadfile(L, filename) == 0) {
        g_free(filename);
        return 1;
    } else {
        g_free(filename);
        lua_pushnil(L);
        lua_insert(L, -2);
        return 2;
    }
}

WSLUA_FUNCTION wslua_dofile(lua_State* L) {
    /* Lua's dofile() has been modified so that if a file does not exist
    in the current directory it will look for it in wireshark's user and system directories. */
#define WSLUA_ARG_dofile_FILENAME 1 /* Name of the file to be run. */
    const char *given_fname = luaL_checkstring(L, WSLUA_ARG_dofile_FILENAME);
    char* filename = wslua_get_actual_filename(given_fname);
    int n;

    if (!filename) {
        WSLUA_ARG_ERROR(dofile,FILENAME,"file does not exist");
        return 0;
    }

    n = lua_gettop(L);
    if (luaL_loadfile(L, filename) != 0) lua_error(L);
    g_free(filename);
    lua_call(L, 0, LUA_MULTRET);
    return lua_gettop(L) - n;
}


typedef struct _statcmd_t {
    lua_State* L;
    int func_ref;
} statcmd_t;

static int statcmd_init_cb_error_handler(lua_State* L _U_) {
    return 0;
}

static void statcmd_init(const char *opt_arg, void* userdata) {
    statcmd_t* sc = (statcmd_t *)userdata;
    lua_State* L = sc->L;

    lua_settop(L,0);
    lua_pushcfunction(L,statcmd_init_cb_error_handler);
    lua_rawgeti(L, LUA_REGISTRYINDEX, sc->func_ref);

    lua_pushstring(L,opt_arg);

    switch ( lua_pcall(L,1,0,1) ) {
        case 0:
            break;
        case LUA_ERRRUN:
            ws_g_warning("Runtime error while calling statcmd callback");
            break;
        case LUA_ERRMEM:
            ws_g_warning("Memory alloc error while calling statcmd callback");
            break;
        default:
            g_assert_not_reached();
            break;
    }

}

WSLUA_FUNCTION wslua_register_stat_cmd_arg(lua_State* L) {
    /*  Register a function to handle a `-z` option */
#define WSLUA_ARG_register_stat_cmd_arg_ARGUMENT 1 /* Argument */
#define WSLUA_OPTARG_register_stat_cmd_arg_ACTION 2 /* Action */
    const char* arg = luaL_checkstring(L,WSLUA_ARG_register_stat_cmd_arg_ARGUMENT);
    statcmd_t* sc = (statcmd_t *)g_malloc0(sizeof(statcmd_t)); /* XXX leaked */
    stat_tap_ui ui_info;

    sc->L = L;
    lua_pushvalue(L, WSLUA_OPTARG_register_stat_cmd_arg_ACTION);
    sc->func_ref = luaL_ref(L, LUA_REGISTRYINDEX);
    lua_remove(L,1);

    ui_info.group = REGISTER_STAT_GROUP_UNSORTED;  /* XXX - need group for CLI-only? */
    ui_info.title = NULL;
    ui_info.cli_string = arg;
    ui_info.tap_init_cb = statcmd_init;
    ui_info.nparams = 0;
    ui_info.params = NULL;
    register_stat_tap_ui(&ui_info, sc);
    return 0;
}

/*
 * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 4
 * tab-width: 8
 * indent-tabs-mode: nil
 * End:
 *
 * vi: set shiftwidth=4 tabstop=8 expandtab:
 * :indentSize=4:tabSize=8:noTabs=true:
 */