/*
 * Copyright (c) 2021 PANTHEON.tech, s.r.o. and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */
package org.opendaylight.restconf.server.api;

import static java.util.Objects.requireNonNull;

import org.eclipse.jdt.annotation.NonNull;
import org.eclipse.jdt.annotation.Nullable;
import org.opendaylight.restconf.api.QueryParameters;
import org.opendaylight.restconf.api.query.ContentParam;
import org.opendaylight.restconf.api.query.DepthParam;
import org.opendaylight.restconf.api.query.FieldsParam;
import org.opendaylight.restconf.api.query.WithDefaultsParam;

/**
 * Supported query parameters of {@code /data} {@code GET} HTTP operation, as defined in
 * <a href="https://www.rfc-editor.org/rfc/rfc8040#section-4.3">RFC8040 section 4.3</a>.
 */
public record DataGetParams(
        @NonNull ContentParam content,
        @Nullable DepthParam depth,
        @Nullable FieldsParam fields,
        @Nullable WithDefaultsParam withDefaults) {
    public static final @NonNull DataGetParams EMPTY = new DataGetParams(ContentParam.ALL, null, null, null);

    public DataGetParams {
        requireNonNull(content);
    }

    /**
     * Return {@link DataGetParams} for specified query parameters.
     *
     * @param params Parameters and their values
     * @return A {@link DataGetParams}
     * @throws NullPointerException if {@code queryParameters} is {@code null}
     * @throws IllegalArgumentException if the parameters are invalid
     */
    public static @NonNull DataGetParams of(final QueryParameters params) {
        ContentParam content = ContentParam.ALL;
        DepthParam depth = null;
        FieldsParam fields = null;
        WithDefaultsParam withDefaults = null;

        for (var entry : params.asCollection()) {
            final var name = entry.getKey();
            final var value = entry.getValue();

            switch (name) {
                case ContentParam.uriName:
                    content = ContentParam.forUriValue(value);
                    break;
                case DepthParam.uriName:
                    depth = DepthParam.forUriValue(value);
                    break;
                case FieldsParam.uriName:
                    fields = FieldsParam.forUriValue(value);
                    break;
                case WithDefaultsParam.uriName:
                    withDefaults = WithDefaultsParam.forUriValue(value);
                    break;
                default:
                    throw new IllegalArgumentException("Unknown parameter in /data GET: " + name);
            }
        }

        return new DataGetParams(content, depth, fields, withDefaults);
    }
}