/* wMUD - Yet another MUD codebase by W00d5t0ck
 * Copyright (C) 2012 - Gergely POLONKAI
 *
 * db.c: database handling routines
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

#include <glib.h>
#include <libgda/libgda.h>
#include <sql-parser/gda-sql-parser.h>

#include "world.h"
#include "main.h"
#include "db.h"
#include "players.h"
#include "configuration.h"
#include "menu.h"
#include "wmudplayer.h"

/**
 * SECTION:db
 * @short_description: Database handling
 * @title: Database handling routines
 *
 * This module handles all the database requests. It currently uses an SQLite3
 * backend, but due to its nature, it could be easily rewritten to use a
 * different (e.g MySQL or PostgreSQL) database.
 */

static GdaConnection *dbh    = NULL;
static GdaSqlParser  *parser = NULL;

GQuark
wmud_db_error_quark()
{
    return g_quark_from_static_string("wmud-db-error");
}

/**
 * wmud_db_init:
 * @err: a GError to put error messages in it
 *
 * Initializes the wMUD database system. Checks and opens database files.
 */
gboolean
wmud_db_init(GError **err)
{
    GError *local_err = NULL;

    g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, "Initializing database");

    gda_init();

    g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,
          "Database DSN is \"%s\"",
          active_config->database_dsn);
    dbh = gda_connection_open_from_string(NULL,
                                          active_config->database_dsn,
                                          NULL,
                                          GDA_CONNECTION_OPTIONS_THREAD_SAFE,
                                          &local_err);

    if (dbh == NULL) {
        g_set_error(err,
                    WMUD_DB_ERROR, WMUD_DB_ERROR_CANTOPEN,
                    "Can not open databsae (%s): %s",
                    active_config->database_dsn,
                    local_err->message);

        return FALSE;
    }

    parser = gda_sql_parser_new();

    g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, "Database initialization finished.");

    return TRUE;
}

/**
 * wmud_db_load_players:
 * @err: a GError to put error messages in it
 *
 * Loads all player records from the database
 */
gboolean
wmud_db_load_players(GError **err)
{
    GdaStatement     *sth = NULL;
    GdaDataModel     *res;
    GdaDataModelIter *iter;
    GError           *local_err = NULL;

    g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, "Loading players");
    if (dbh == NULL) {
        if (err) {
            g_set_error(err,
                        WMUD_DB_ERROR, WMUD_DB_ERROR_NOINIT,
                        "Database backend not initialized");
        }

        return FALSE;
    }

    sth = gda_sql_parser_parse_string(
        parser,
        "SELECT id, login, password, email FROM players",
        NULL,
        NULL);

    /* TODO: error checking! */
    if ((res = gda_connection_statement_execute_select(
             dbh,
             sth,
             NULL,
             &local_err)) == NULL) {
        g_log(G_LOG_DOMAIN, G_LOG_LEVEL_CRITICAL,
              "Unable to load players: %s",
              local_err->message);
        g_set_error(err,
                    WMUD_DB_ERROR, WMUD_DB_ERROR_SELECT_ERROR,
                    "SELECT error: %s",
                    local_err->message);

        return FALSE;
    }

    iter = gda_data_model_create_iter(res);
    gda_data_model_iter_move_next(iter);

    while (gda_data_model_iter_is_valid(iter)) {
        const GValue *val;
        WmudPlayer   *player;

        player = wmud_player_new();

        val = gda_data_model_iter_get_value_at(iter, 0);
        wmud_player_set_id(player, g_value_get_int(val));

        val = gda_data_model_iter_get_value_at(iter, 1);
        wmud_player_set_player_name(player, g_value_get_string(val));

        val = gda_data_model_iter_get_value_at(iter, 2);
        wmud_player_set_cpassword(player, g_value_get_string(val));

        val = gda_data_model_iter_get_value_at(iter, 3);
        wmud_player_set_email(player, g_value_get_string(val));

        g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,
              "Loaded player _%s_",
              wmud_player_get_player_name(player));

        players = g_slist_prepend(players, player);

        gda_data_model_iter_move_next(iter);
    }

    g_object_unref(iter);
    g_object_unref(sth);
    g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, "Finished loading players");

    return TRUE;
}

/**
 * wmud_db_save_player:
 * @player: the player record to save
 * @err: a GError to put error messages in it
 *
 * Saves a player record to the database backend.
 *
 * Return value: %TRUE on success. Upon failure, %FALSE is returned, and err is
 *               set accordingly.
 */
gboolean
wmud_db_save_player(WmudPlayer *player, GError **err)
{
    GError *local_err = NULL;
    GValue *login_value,
           *email_value;

    g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, "Saving player");
    if (dbh == NULL) {
        if (err) {
            g_set_error(err,
                        WMUD_DB_ERROR, WMUD_DB_ERROR_NOINIT,
                        "Database backend not initialized");
        }

        return FALSE;
    }

    login_value = gda_value_new_from_string(
        wmud_player_get_player_name(player),
        G_TYPE_STRING);
    email_value = gda_value_new_from_string(
        wmud_player_get_email(player),
        G_TYPE_STRING);

    if (!gda_connection_insert_row_into_table(dbh,
                                              "players",
                                              &local_err,
                                              "id", NULL,
                                              "login", login_value,
                                              "password", NULL,
                                              "email", email_value,
                                              NULL)) {
        g_set_error(err,
                    WMUD_DB_ERROR, WMUD_DB_ERROR_BADQUERY,
                    "Error saving player: %s",
                    local_err->message);

        return FALSE;
    }

    return TRUE;
}

gboolean
wmud_db_update_player_password(WmudPlayer *player,
                               gchar      *crypted_password,
                               GError     **err)
{
    GValue *cpw,
           *player_id;
    GError *local_err = NULL;

    g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,
          "Saving player password for %s",
          wmud_player_get_player_name(player));

    if (dbh == NULL) {
        g_set_error(err,
                    WMUD_DB_ERROR, WMUD_DB_ERROR_NOINIT,
                    "Database backend not initialized");

        return FALSE;
    }

    player_id = gda_value_new(G_TYPE_UINT);
    g_value_set_uint(player_id, wmud_player_get_id(player));
    cpw = gda_value_new_from_string(crypted_password, G_TYPE_STRING);

    if (!gda_connection_update_row_in_table(dbh,
                                            "players",
                                            "id", player_id,
                                            &local_err,
                                            "password", cpw,
                                            NULL)) {
        g_set_error(err,
                    WMUD_DB_ERROR, WMUD_DB_ERROR_BADQUERY,
                    "Error saving player password: %s",
                    local_err->message);

        return FALSE;
    }

    return TRUE;
}

gboolean
wmud_db_load_planes(GSList **planes, GError **err)
{
    GdaStatement     *sth = NULL;
    GdaDataModel     *res = NULL;
    GdaDataModelIter *iter;

    g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, "Loading planes");
    if (dbh == NULL) {
        if (err) {
            g_set_error(err,
                        WMUD_DB_ERROR, WMUD_DB_ERROR_NOINIT,
                        "Database backend not initialized");
        }

        return FALSE;
    }

    sth = gda_sql_parser_parse_string(parser,
                                      "SELECT id, name FROM planes",
                                      NULL,
                                      NULL);
    res  = gda_connection_statement_execute_select(dbh, sth, NULL, NULL);
    iter = gda_data_model_create_iter(res);
    gda_data_model_iter_move_next(iter);

    while (gda_data_model_iter_is_valid(iter)) {
        const GValue *val;
        wmudPlane    *plane;

        plane = g_new0(wmudPlane, 1);

        val       = gda_data_model_iter_get_value_at(iter, 0);
        plane->id = g_value_get_int(val);

        val         = gda_data_model_iter_get_value_at(iter, 1);
        plane->name = g_strdup(g_value_get_string(val));

        g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,
              "Loaded plane _%s_",
              plane->name);

        *planes = g_slist_prepend(*planes, plane);

        gda_data_model_iter_move_next(iter);
    }

    g_object_unref(iter);
    g_object_unref(sth);

    return TRUE;
}

gboolean
wmud_db_load_planets(GSList **planets, GError **err)
{
    GdaStatement     *sth = NULL;
    GdaDataModel     *res = NULL;
    GdaDataModelIter *iter;

    g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, "Loading planets");
    if (dbh == NULL) {
        if (err) {
            g_set_error(err,
                        WMUD_DB_ERROR, WMUD_DB_ERROR_NOINIT,
                        "Database backend not initialized");
        }

        return FALSE;
    }

    sth = gda_sql_parser_parse_string(parser,
                                      "SELECT id, name FROM planets",
                                      NULL,
                                      NULL);
    res  = gda_connection_statement_execute_select(dbh, sth, NULL, NULL);
    iter = gda_data_model_create_iter(res);
    gda_data_model_iter_move_next(iter);

    while (gda_data_model_iter_is_valid(iter)) {
        const GValue *val;
        wmudPlanet   *planet;

        planet = g_new0(wmudPlanet, 1);

        val        = gda_data_model_iter_get_value_at(iter, 0);
        planet->id = g_value_get_int(val);

        val          = gda_data_model_iter_get_value_at(iter, 1);
        planet->name = g_strdup(g_value_get_string(val));

        g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,
              "Loaded planet _%s_",
              planet->name);

        *planets = g_slist_prepend(*planets, planet);

        gda_data_model_iter_move_next(iter);
    }

    g_object_unref(iter);
    g_object_unref(sth);

    return TRUE;
}

gboolean
wmud_db_load_directions(GSList **directions, GError **err)
{
    GdaStatement     *sth = NULL;
    GdaDataModel     *res = NULL;
    GdaDataModelIter *iter;
    GError           *local_err = NULL;

    g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, "Loading directions");

    if (dbh == NULL) {
        if (err) {
            g_set_error(err,
                        WMUD_DB_ERROR, WMUD_DB_ERROR_NOINIT,
                        "Database backend not initialized");
        }

        return FALSE;
    }

    sth = gda_sql_parser_parse_string(
        parser,
        "SELECT id, short_name, name FROM directions",
        NULL,
        NULL);

    if ((res = gda_connection_statement_execute_select(
             dbh, sth,
             NULL, &local_err)) == NULL) {
        g_set_error(err,
                    WMUD_DB_ERROR, WMUD_DB_ERROR_SELECT_ERROR,
                    "Unable to load directions: %s",
                    local_err->message);

        return FALSE;
    }

    iter = gda_data_model_create_iter(res);
    gda_data_model_iter_move_next(iter);

    while (gda_data_model_iter_is_valid(iter)) {
        const GValue  *val;
        wmudDirection *dir;

        dir = g_new0(wmudDirection, 1);

        val     = gda_data_model_iter_get_value_at(iter, 0);
        dir->id = g_value_get_int(val);

        val             = gda_data_model_iter_get_value_at(iter, 1);
        dir->short_name = g_strdup(g_value_get_string(val));

        val       = gda_data_model_iter_get_value_at(iter, 2);
        dir->name = g_strdup(g_value_get_string(val));

        g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,
              "Loaded direction _%s_",
              dir->name);

        *directions = g_slist_prepend(*directions, dir);

        gda_data_model_iter_move_next(iter);
    }

    g_object_unref(iter);
    g_object_unref(sth);

    return TRUE;
}

gboolean
wmud_db_load_areas(GSList **areas, GError **err)
{
    GdaStatement     *sth = NULL;
    GdaDataModel     *res = NULL;
    GdaDataModelIter *iter;

    g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, "Loading areas");
    if (dbh == NULL) {
        if (err) {
            g_set_error(err,
                        WMUD_DB_ERROR, WMUD_DB_ERROR_NOINIT,
                        "Database backend not initialized");
        }

        return FALSE;
    }

    sth = gda_sql_parser_parse_string(
        parser,
        "SELECT id, name FROM areas",
        NULL,
        NULL);
    res  = gda_connection_statement_execute_select(dbh, sth, NULL, NULL);
    iter = gda_data_model_create_iter(res);
    gda_data_model_iter_move_next(iter);

    while (gda_data_model_iter_is_valid(iter)) {
        const GValue *val;
        wmudArea     *area;

        area = g_new0(wmudArea, 1);

        val      = gda_data_model_iter_get_value_at(iter, 0);
        area->id = g_value_get_int(val);

        val        = gda_data_model_iter_get_value_at(iter, 1);
        area->name = g_strdup(g_value_get_string(val));

        g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, "Loaded area _%s_", area->name);

        *areas = g_slist_prepend(*areas, area);

        gda_data_model_iter_move_next(iter);
    }

    g_object_unref(iter);
    g_object_unref(sth);

    return TRUE;
}

gboolean
wmud_db_load_rooms(GSList **rooms, GError **err)
{
    GdaStatement     *sth = NULL;
    GdaDataModel     *res = NULL;
    GdaDataModelIter *iter;

    g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, "Loading rooms");
    if (dbh == NULL) {
        if (err) {
            g_set_error(err,
                        WMUD_DB_ERROR, WMUD_DB_ERROR_NOINIT,
                        "Database backend not initialized");
        }

        return FALSE;
    }

    sth = gda_sql_parser_parse_string(
        parser,
        "SELECT id, area, name, distant_description, close_description FROM rooms",
        NULL,
        NULL);
    res  = gda_connection_statement_execute_select(dbh, sth, NULL, NULL);
    iter = gda_data_model_create_iter(res);
    gda_data_model_iter_move_next(iter);

    while (gda_data_model_iter_is_valid(iter)) {
        const GValue *val;
        wmudRoom     *room;

        room = g_new0(wmudRoom, 1);

        val      = gda_data_model_iter_get_value_at(iter, 0);
        room->id = g_value_get_int(val);

        val           = gda_data_model_iter_get_value_at(iter, 1);
        room->area_id = g_value_get_int(val);

        val        = gda_data_model_iter_get_value_at(iter, 2);
        room->name = g_strdup(g_value_get_string(val));

        val                       = gda_data_model_iter_get_value_at(iter, 3);
        room->distant_description = g_strdup(g_value_get_string(val));

        val                     = gda_data_model_iter_get_value_at(iter, 4);
        room->close_description = g_strdup(g_value_get_string(val));

        g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,
              "Loaded room %d/_%s_",
              room->area_id,
              room->name);

        *rooms = g_slist_prepend(*rooms, room);

        gda_data_model_iter_move_next(iter);
    }

    g_object_unref(iter);
    g_object_unref(sth);

    return TRUE;
}

gboolean
wmud_db_load_exits(GSList **exits, GError **err)
{
    GdaStatement     *sth = NULL;
    GdaDataModel     *res = NULL;
    GdaDataModelIter *iter;

    g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, "Loading exits");
    if (dbh == NULL) {
        if (err) {
            g_set_error(err,
                        WMUD_DB_ERROR, WMUD_DB_ERROR_NOINIT,
                        "Database backend not initialized");
        }

        return FALSE;
    }

    sth = gda_sql_parser_parse_string(
        parser,
        "SELECT room_id, direction, other_side FROM room_exits",
        NULL,
        NULL);
    res  = gda_connection_statement_execute_select(dbh, sth, NULL, NULL);
    iter = gda_data_model_create_iter(res);
    gda_data_model_iter_move_next(iter);

    while (gda_data_model_iter_is_valid(iter)) {
        const GValue *val;
        wmudExit     *room_exit;

        room_exit = g_new0(wmudExit, 1);

        val                       = gda_data_model_iter_get_value_at(iter, 0);
        room_exit->source_room_id = g_value_get_int(val);

        val                     = gda_data_model_iter_get_value_at(iter, 1);
        room_exit->direction_id = g_value_get_int(val);

        val                            = gda_data_model_iter_get_value_at(iter, 2);
        room_exit->destination_room_id = g_value_get_int(val);

        g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,
              "Loaded exit %d =%d=> %d",
              room_exit->source_room_id,
              room_exit->direction_id,
              room_exit->destination_room_id);

        *exits = g_slist_prepend(*exits, room_exit);

        gda_data_model_iter_move_next(iter);
    }

    g_object_unref(iter);
    g_object_unref(sth);

    return TRUE;
}

gboolean
wmud_db_load_planet_planes(GSList **planet_planes, GError **err)
{
    GdaStatement     *sth = NULL;
    GdaDataModel     *res = NULL;
    GdaDataModelIter *iter;

    g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,
          "Loading planet<->plane associations");
    if (dbh == NULL) {
        if (err) {
            g_set_error(err,
                        WMUD_DB_ERROR, WMUD_DB_ERROR_NOINIT,
                        "Database backend not initialized");
        }

        return FALSE;
    }

    sth = gda_sql_parser_parse_string(
        parser,
        "SELECT planet_id, plane_id FROM planet_planes",
        NULL,
        NULL);
    res  = gda_connection_statement_execute_select(dbh, sth, NULL, NULL);
    iter = gda_data_model_create_iter(res);
    gda_data_model_iter_move_next(iter);

    while (gda_data_model_iter_is_valid(iter)) {
        const GValue         *val;
        wmudPlanetPlaneAssoc *planet_plane;

        planet_plane = g_new0(wmudPlanetPlaneAssoc, 1);

        val                     = gda_data_model_iter_get_value_at(iter, 0);
        planet_plane->planet_id = g_value_get_int(val);

        val                    = gda_data_model_iter_get_value_at(iter, 1);
        planet_plane->plane_id = g_value_get_int(val);

        g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,
              "Loaded planet-plane association %d <> %d",
              planet_plane->planet_id,
              planet_plane->plane_id);

        *planet_planes = g_slist_prepend(*planet_planes, planet_plane);

        gda_data_model_iter_move_next(iter);
    }

    g_object_unref(iter);
    g_object_unref(sth);

    return TRUE;
}

gboolean
wmud_db_load_menu(GSList **menu_items, GError **err)
{
    GdaStatement     *sth = NULL;
    GdaDataModel     *res = NULL;
    GdaDataModelIter *iter;

    g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, "Loading menu items");
    if (dbh == NULL) {
        if (err) {
            g_set_error(err,
                        WMUD_DB_ERROR, WMUD_DB_ERROR_NOINIT,
                        "Database backend not initialized");
        }

        return FALSE;
    }

    sth = gda_sql_parser_parse_string(
        parser,
        "SELECT id, menuchar, need_active_char, placement, display_text, fnctn FROM menu ORDER BY placement",
        NULL,
        NULL);
    res  = gda_connection_statement_execute_select(dbh, sth, NULL, NULL);
    iter = gda_data_model_create_iter(res);
    gda_data_model_iter_move_next(iter);

    while (gda_data_model_iter_is_valid(iter)) {
        const GValue *val;
        wmudMenu     *menu_item;

        menu_item = g_new0(wmudMenu, 1);

        val           = gda_data_model_iter_get_value_at(iter, 0);
        menu_item->id = g_value_get_int(val);

        val                 = gda_data_model_iter_get_value_at(iter, 1);
        menu_item->menuchar = *(g_value_get_string(val));

        val                         = gda_data_model_iter_get_value_at(iter, 2);
        menu_item->need_active_char = g_value_get_boolean(val);

        val                  = gda_data_model_iter_get_value_at(iter, 3);
        menu_item->placement = g_value_get_int(val);

        val             = gda_data_model_iter_get_value_at(iter, 4);
        menu_item->text = g_strdup(g_value_get_string(val));

        val             = gda_data_model_iter_get_value_at(iter, 5);
        menu_item->func = g_strdup(g_value_get_string(val));

        g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,
              "Loaded menu item %d: %s(%c)",
              menu_item->id, menu_item->text,
              menu_item->menuchar);

        *menu_items = g_slist_prepend(*menu_items, menu_item);

        gda_data_model_iter_move_next(iter);
    }

    g_object_unref(iter);
    g_object_unref(sth);

    return TRUE;
}