/*
 * Copyright 2020, TeamDev. All rights reserved.
 *
 * Redistribution and use in source and/or binary forms, with or without
 * modification, must retain the above copyright notice and the following
 * disclaimer.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package io.spine.server.delivery;

import com.google.common.base.Joiner;
import com.google.common.collect.ImmutableSet;
import io.spine.type.TypeUrl;
import org.checkerframework.checker.nullness.qual.Nullable;

import java.util.Set;

/**
 * An exception telling that the projection catch-up cannot be started, since some of the requested
 * entities are already catching up.
 */
public final class CatchUpAlreadyStartedException extends IllegalStateException {

    private static final long serialVersionUID = 0L;

    private final TypeUrl projectionStateType;
    private final @Nullable ImmutableSet<Object> requestedIds;

    CatchUpAlreadyStartedException(TypeUrl type, @Nullable Set<?> ids) {
        super();
        projectionStateType = type;
        requestedIds = ids == null ? null : ImmutableSet.copyOf(ids);
    }

    @Override
    public String getMessage() {
        String message = String.format(
                "Cannot start the catch-up for the `%s` Projection, `%s`. " +
                        "Another catch-up is already in progress.",
                projectionStateType, targetsAsString());
        return message;
    }

    public TypeUrl projectionStateType() {
        return projectionStateType;
    }

    public ImmutableSet<Object> requestedIds() {
        return requestedIds == null? ImmutableSet.of() : requestedIds;
    }

    private String targetsAsString() {
        if (requestedIds == null) {
            return "[all instances]";
        }
        return Joiner.on(',')
                     .join(requestedIds);
    }
}

@@ -2165,89 +2165,379 @@
     
-public TypeUrl projectionStateType() %7B%0A        return projectionStateType;%0A    %7D%0A
+/**%0A     * Returns the type URL of the projection for which the catch-up was requested.%0A     */%0A    public TypeUrl projectionStateType() %7B%0A        return projectionStateType;%0A    %7D%0A%0A    /**%0A     * Returns the IDs of the targets which were asked to catch up.%0A     *%0A     * %3Cp%3EIf all the projection entities were specified as a target, returns an empty %7B@code Set%7D.%0A     */
 %0A   

Document the exception.