/*
 * Copyright (C) 2018, Google LLC. and others
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0 which is available at
 * https://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */
package org.eclipse.jgit.transport;

import static java.util.Objects.requireNonNull;

import java.util.List;
import java.util.Set;

import org.eclipse.jgit.annotations.NonNull;
import org.eclipse.jgit.annotations.Nullable;
import org.eclipse.jgit.lib.ObjectId;

/**
 * Common fields between v0/v1/v2 fetch requests.
 */
abstract class FetchRequest {

	final Set<ObjectId> wantIds;

	final int depth;

	final Set<ObjectId> clientShallowCommits;

	final FilterSpec filterSpec;

	final Set<String> clientCapabilities;

	final int deepenSince;

	final List<String> deepenNotRefs;

	@Nullable
	final String agent;

	/**
	 * Initialize the common fields of a fetch request.
	 *
	 * @param wantIds
	 *            list of want ids
	 * @param depth
	 *            how deep to go in the tree
	 * @param clientShallowCommits
	 *            commits the client has without history
	 * @param filterSpec
	 *            the filter spec
	 * @param clientCapabilities
	 *            capabilities sent in the request
	 * @param deepenNotRefs
	 *            Requests that the shallow clone/fetch should be cut at these
	 *            specific revisions instead of a depth.
	 * @param deepenSince
	 *            Requests that the shallow clone/fetch should be cut at a
	 *            specific time, instead of depth
	 * @param agent
	 *            agent as reported by the client in the request body
	 */
	FetchRequest(@NonNull Set<ObjectId> wantIds, int depth,
			@NonNull Set<ObjectId> clientShallowCommits,
			@NonNull FilterSpec filterSpec,
			@NonNull Set<String> clientCapabilities, int deepenSince,
			@NonNull List<String> deepenNotRefs, @Nullable String agent) {
		this.wantIds = requireNonNull(wantIds);
		this.depth = depth;
		this.clientShallowCommits = requireNonNull(clientShallowCommits);
		this.filterSpec = requireNonNull(filterSpec);
		this.clientCapabilities = requireNonNull(clientCapabilities);
		this.deepenSince = deepenSince;
		this.deepenNotRefs = requireNonNull(deepenNotRefs);
		this.agent = agent;
	}

	/**
	 * @return object ids in the "want" (and "want-ref") lines of the request
	 */
	@NonNull
	Set<ObjectId> getWantIds() {
		return wantIds;
	}

	/**
	 * @return the depth set in a "deepen" line. 0 by default.
	 */
	int getDepth() {
		return depth;
	}

	/**
	 * Shallow commits the client already has.
	 *
	 * These are sent by the client in "shallow" request lines.
	 *
	 * @return set of commits the client has declared as shallow.
	 */
	@NonNull
	Set<ObjectId> getClientShallowCommits() {
		return clientShallowCommits;
	}

	/**
	 * @return the filter spec given in a "filter" line
	 */
	@NonNull
	FilterSpec getFilterSpec() {
		return filterSpec;
	}

	/**
	 * Capabilities that the client wants enabled from the server.
	 *
	 * Capabilities are options that tune the expected response from the server,
	 * like "thin-pack", "no-progress" or "ofs-delta". This list should be a
	 * subset of the capabilities announced by the server in its first response.
	 *
	 * These options are listed and well-defined in the git protocol
	 * specification.
	 *
	 * The agent capability is not included in this set. It can be retrieved via
	 * {@link #getAgent()}.
	 *
	 * @return capabilities sent by the client (excluding the "agent"
	 *         capability)
	 */
	@NonNull
	Set<String> getClientCapabilities() {
		return clientCapabilities;
	}

	/**
	 * The value in a "deepen-since" line in the request, indicating the
	 * timestamp where to stop fetching/cloning.
	 *
	 * @return timestamp in seconds since the epoch, where to stop the shallow
	 *         fetch/clone. Defaults to 0 if not set in the request.
	 */
	int getDeepenSince() {
		return deepenSince;
	}

	/**
	 * @return refs received in "deepen-not" lines.
	 */
	@NonNull
	List<String> getDeepenNotRefs() {
		return deepenNotRefs;
	}

	/**
	 * @return string identifying the agent (as sent in the request body by the
	 *         client)
	 */
	@Nullable
	String getAgent() {
		return agent;
	}
}