/*
 *  This file is part of Player Analytics (Plan).
 *
 *  Plan is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License v3 as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  Plan 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 Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with Plan. If not, see <https://www.gnu.org/licenses/>.
 */
package com.djrapitops.plan.query;

import java.util.Optional;
import java.util.Set;
import java.util.UUID;

/**
 * Class that allows performing most commonly wanted queries.
 * <p>
 * This exists so that SQL does not necessarily need to be written.
 * Obtain an instance from {@link QueryService}.
 *
 * @author AuroraLS3
 */
public interface CommonQueries {

    /**
     * Fetch playtime of a player on a server.
     * <p>
     * Returns 0 for any non existing players or servers.
     *
     * @param playerUUID UUID of the player.
     * @param serverUUID UUID of the Plan server.
     * @param after      Data after this Epoch ms should be fetched
     * @param before     Data before this Epoch ms should be fetched
     * @return Milliseconds the player has played with the defined parameters.
     */
    long fetchPlaytime(UUID playerUUID, UUID serverUUID, long after, long before);

    /**
     * Get playtime of current online session.
     * <p>
     * Requires Capability QUERY_API_ACTIVE_SESSION_PLAYTIME
     *
     * @param playerUUID UUID of the player.
     * @return Milliseconds the player has played during current online session. 0 if player is offline.
     */
    long fetchCurrentSessionPlaytime(UUID playerUUID);

    /**
     * Fetch last seen Epoch ms for a player on a server.
     *
     * @param playerUUID UUID of the player.
     * @param serverUUID UUID of the Plan server.
     * @return Epoch ms the player was last seen, 0 if player has not played on server.
     */
    long fetchLastSeen(UUID playerUUID, UUID serverUUID);

    /**
     * Get the UUIDs of all servers Plan has registered.
     *
     * @return Set of Server UUIDs
     */
    Set<UUID> fetchServerUUIDs();

    /**
     * Fetch UUID of a player by name.
     *
     * @param playerName Name of the player
     * @return UUID if it is found by Plan or empty if not found.
     */
    Optional<UUID> fetchUUIDOf(String playerName);

    /**
     * Fetch name of a player by UUID.
     *
     * @param playerUUID UUID of the player
     * @return Name if it is known by Plan or empty if not.
     */
    Optional<String> fetchNameOf(UUID playerUUID);

    /**
     * Check that schema has table you are using in your queries.
     *
     * @param table Name of the table, e.g. plan_users.
     * @return true if table exists.
     */
    boolean doesDBHaveTable(String table);

    /**
     * Check that schema table has a column you are using in your queries.
     *
     * @param table  Name of the table, e.g. plan_users.
     * @param column Name of the column, e.g. id
     * @return true if table and column exist.
     */
    boolean doesDBHaveTableColumn(String table, String column);

    /**
     * Calculates the activity index for the player at a specific date.
     *
     * @param playerUUID UUID of the player.
     * @param epochMs    Epoch millisecond to use for calculation
     * @return a double between 0.0 and 5.0.
     */
    double fetchActivityIndexOf(UUID playerUUID, long epochMs);

    /**
     * Get a String that represents the Activity group for an index.
     *
     * @param activityIndex a double between 0.0 and 5.0.
     * @return Name of the group (in English) that this activityIndex falls within.
     */
    String getActivityGroupForIndex(double activityIndex);
}