/*
 *      Copyright (C) 2012-2015 DataStax Inc.
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 */
package com.datastax.driver.core.exceptions;

import java.net.InetAddress;
import java.net.InetSocketAddress;

/**
 * Exception thrown when a query attempts to create a keyspace or table that already exists.
 */
public class AlreadyExistsException extends QueryValidationException implements CoordinatorException {

    private static final long serialVersionUID = 0;

    private final InetSocketAddress address;
    private final String keyspace;
    private final String table;

    public AlreadyExistsException(String keyspace, String table) {
        this(null, keyspace, table);
    }

    public AlreadyExistsException(InetSocketAddress address, String keyspace, String table) {
        super(makeMsg(keyspace, table));
        this.address = address;
        this.keyspace = keyspace;
        this.table = table;
    }

    private AlreadyExistsException(InetSocketAddress address, String msg, Throwable cause, String keyspace, String table) {
        super(msg, cause);
        this.address = address;
        this.keyspace = keyspace;
        this.table = table;
    }

    private static String makeMsg(String keyspace, String table) {
        if (table.isEmpty())
            return String.format("Keyspace %s already exists", keyspace);
        else
            return String.format("Table %s.%s already exists", keyspace, table);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public InetAddress getHost() {
        return address.getAddress();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public InetSocketAddress getAddress() {
        return address;
    }

    /**
     * Returns whether the query yielding this exception was a table creation
     * attempt.
     *
     * @return {@code true} if this exception is raised following a table
     * creation attempt, {@code false} if it was a keyspace creation attempt.
     */
    public boolean wasTableCreation() {
        return !table.isEmpty();
    }

    /**
     * The name of keyspace that either already exists or is home to the table
     * that already exists.
     *
     * @return a keyspace name that is either the keyspace whose creation
     * attempt failed because a keyspace of the same name already exists (in
     * that case, {@link #table} will return {@code null}), or the keyspace of
     * the table creation attempt (in which case {@link #table} will return the
     * name of said table).
     */
    public String getKeyspace() {
        return keyspace;
    }

    /**
     * If the failed creation was a table creation, the name of the table that already exists.
     *
     * @return the name of table whose creation attempt failed because a table
     * of this name already exists, or {@code null} if the query was a keyspace
     * creation query.
     */
    public String getTable() {
        return table.isEmpty() ? null : table;
    }

    @Override
    public DriverException copy() {
        return new AlreadyExistsException(getAddress(), getMessage(), this, keyspace, table);
    }

    /**
     * Create a copy of this exception with a nicer stack trace, and including the coordinator
     * address that caused this exception to be raised.
     * <p/>
     * This method is mainly intended for internal use by the driver and exists mainly because:
     * <ol>
     * <li>the original exception was decoded from a response frame
     * and at that time, the coordinator address was not available; and</li>
     * <li>the newly-created exception will refer to the current thread in its stack trace,
     * which generally yields a more user-friendly stack trace that the original one.</li>
     * </ol>
     *
     * @param address The full address of the host that caused this exception to be thrown.
     * @return a copy/clone of this exception, but with the given host address instead of the original one.
     */
    public AlreadyExistsException copy(InetSocketAddress address) {
        return new AlreadyExistsException(address, getMessage(), this, keyspace, table);
    }

}