/*
 * 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.nb.rfc8040.databind.jaxrs;

import static java.util.Objects.requireNonNull;

import com.google.common.annotations.Beta;
import com.google.common.annotations.VisibleForTesting;
import java.util.List;
import java.util.Map.Entry;
import java.util.Set;
import java.util.function.Function;
import javax.ws.rs.core.UriInfo;
import org.eclipse.jdt.annotation.NonNull;
import org.eclipse.jdt.annotation.Nullable;
import org.opendaylight.restconf.common.context.InstanceIdentifierContext;
import org.opendaylight.restconf.common.errors.RestconfDocumentedException;
import org.opendaylight.restconf.common.errors.RestconfError;
import org.opendaylight.restconf.nb.rfc8040.ContentParam;
import org.opendaylight.restconf.nb.rfc8040.DepthParam;
import org.opendaylight.restconf.nb.rfc8040.FieldsParam;
import org.opendaylight.restconf.nb.rfc8040.FilterParam;
import org.opendaylight.restconf.nb.rfc8040.InsertParam;
import org.opendaylight.restconf.nb.rfc8040.LeafNodesOnlyParam;
import org.opendaylight.restconf.nb.rfc8040.NotificationQueryParams;
import org.opendaylight.restconf.nb.rfc8040.PointParam;
import org.opendaylight.restconf.nb.rfc8040.PrettyPrintParam;
import org.opendaylight.restconf.nb.rfc8040.ReadDataParams;
import org.opendaylight.restconf.nb.rfc8040.SkipNotificationDataParam;
import org.opendaylight.restconf.nb.rfc8040.StartTimeParam;
import org.opendaylight.restconf.nb.rfc8040.StopTimeParam;
import org.opendaylight.restconf.nb.rfc8040.WithDefaultsParam;
import org.opendaylight.restconf.nb.rfc8040.WriteDataParams;
import org.opendaylight.restconf.nb.rfc8040.legacy.QueryParameters;
import org.opendaylight.restconf.nb.rfc8040.utils.parser.NetconfFieldsTranslator;
import org.opendaylight.restconf.nb.rfc8040.utils.parser.WriterFieldsTranslator;
import org.opendaylight.yangtools.yang.common.ErrorTag;
import org.opendaylight.yangtools.yang.common.ErrorType;

@Beta
public final class QueryParams {
    private static final Set<String> KNOWN_PARAMS = Set.of(
        // Read data
        ContentParam.uriName, DepthParam.uriName, FieldsParam.uriName, WithDefaultsParam.uriName,
        PrettyPrintParam.uriName,
        // Modify data
        InsertParam.uriName, PointParam.uriName,
        // Notifications
        FilterParam.uriName, StartTimeParam.uriName, StopTimeParam.uriName,
        LeafNodesOnlyParam.uriName, SkipNotificationDataParam.uriName);

    private QueryParams() {
        // Utility class
    }

    public static @NonNull NotificationQueryParams newNotificationQueryParams(final UriInfo uriInfo) {
        StartTimeParam startTime = null;
        StopTimeParam stopTime = null;
        FilterParam filter = null;
        LeafNodesOnlyParam leafNodesOnly = null;
        SkipNotificationDataParam skipNotificationData = null;

        for (Entry<String, List<String>> entry : uriInfo.getQueryParameters().entrySet()) {
            final String paramName = entry.getKey();
            final List<String> paramValues = entry.getValue();

            try {
                switch (paramName) {
                    case FilterParam.uriName:
                        filter = optionalParam(FilterParam::forUriValue, paramName, paramValues);
                        break;
                    case StartTimeParam.uriName:
                        startTime = optionalParam(StartTimeParam::forUriValue, paramName, paramValues);
                        break;
                    case StopTimeParam.uriName:
                        stopTime = optionalParam(StopTimeParam::forUriValue, paramName, paramValues);
                        break;
                    case LeafNodesOnlyParam.uriName:
                        leafNodesOnly = optionalParam(LeafNodesOnlyParam::forUriValue, paramName, paramValues);
                        break;
                    case SkipNotificationDataParam.uriName:
                        skipNotificationData = optionalParam(SkipNotificationDataParam::forUriValue, paramName,
                            paramValues);
                        break;
                    default:
                        throw unhandledParam("notification", paramName);
                }
            } catch (IllegalArgumentException e) {
                throw new RestconfDocumentedException("Invalid " + paramName + " value: " + e.getMessage(),
                    ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE, e);
            }
        }

        try {
            return NotificationQueryParams.of(startTime, stopTime, filter, leafNodesOnly, skipNotificationData);
        } catch (IllegalArgumentException e) {
            throw new RestconfDocumentedException("Invalid query parameters: " + e.getMessage(), e);
        }
    }

    public static QueryParameters newQueryParameters(final ReadDataParams params,
            final InstanceIdentifierContext identifier) {
        final var fields = params.fields();
        if (fields == null) {
            return QueryParameters.of(params);
        }

        return identifier.getMountPoint() != null
            ? QueryParameters.ofFieldPaths(params, NetconfFieldsTranslator.translate(identifier, fields))
                : QueryParameters.ofFields(params, WriterFieldsTranslator.translate(identifier, fields));
    }

    /**
     * Parse parameters from URI request and check their types and values.
     *
     * @param uriInfo    URI info
     * @return {@link ReadDataParams}
     */
    public static @NonNull ReadDataParams newReadDataParams(final UriInfo uriInfo) {
        ContentParam content = ContentParam.ALL;
        DepthParam depth = null;
        FieldsParam fields = null;
        WithDefaultsParam withDefaults = null;
        PrettyPrintParam prettyPrint = null;
        boolean tagged = false;

        for (Entry<String, List<String>> entry : uriInfo.getQueryParameters().entrySet()) {
            final String paramName = entry.getKey();
            final List<String> paramValues = entry.getValue();

            try {
                switch (paramName) {
                    case ContentParam.uriName:
                        content = optionalParam(ContentParam::forUriValue, paramName, paramValues);
                        break;
                    case DepthParam.uriName:
                        final String depthStr = optionalParam(paramName, paramValues);
                        try {
                            depth = DepthParam.forUriValue(depthStr);
                        } catch (IllegalArgumentException e) {
                            throw new RestconfDocumentedException(e, new RestconfError(ErrorType.PROTOCOL,
                                ErrorTag.INVALID_VALUE, "Invalid depth parameter: " + depthStr, null,
                                "The depth parameter must be an integer between 1 and 65535 or \"unbounded\""));
                        }
                        break;
                    case FieldsParam.uriName:
                        fields = optionalParam(FieldsParam::forUriValue, paramName, paramValues);
                        break;
                    case WithDefaultsParam.uriName:
                        final var defaultsVal = optionalParam(WithDefaultsParam::forUriValue, paramName, paramValues);
                        if (defaultsVal != null) {
                            switch (defaultsVal) {
                                case REPORT_ALL:
                                    withDefaults = null;
                                    tagged = false;
                                    break;
                                case REPORT_ALL_TAGGED:
                                    withDefaults = null;
                                    tagged = true;
                                    break;
                                default:
                                    withDefaults = defaultsVal;
                                    tagged = false;
                            }
                        }
                        break;
                    case PrettyPrintParam.uriName:
                        prettyPrint = optionalParam(PrettyPrintParam::forUriValue, paramName, paramValues);
                        break;
                    default:
                        throw unhandledParam("read", paramName);
                }
            } catch (IllegalArgumentException e) {
                throw new RestconfDocumentedException("Invalid " + paramName + " value: " + e.getMessage(),
                    ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE, e);
            }
        }

        return ReadDataParams.of(content, depth, fields, withDefaults, tagged, prettyPrint);
    }

    public static @NonNull WriteDataParams newWriteDataParams(final UriInfo uriInfo) {
        InsertParam insert = null;
        PointParam point = null;

        for (final Entry<String, List<String>> entry : uriInfo.getQueryParameters().entrySet()) {
            final String paramName = entry.getKey();
            final List<String> paramValues = entry.getValue();

            try {
                switch (paramName) {
                    case InsertParam.uriName:
                        insert = optionalParam(InsertParam::forUriValue, paramName, paramValues);
                        break;
                    case PointParam.uriName:
                        point = optionalParam(PointParam::forUriValue, paramName, paramValues);
                        break;
                    default:
                        throw unhandledParam("write", paramName);
                }
            } catch (IllegalArgumentException e) {
                throw new RestconfDocumentedException("Invalid " + paramName + " value: " + e.getMessage(),
                    ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE, e);
            }
        }

        try {
            return WriteDataParams.of(insert, point);
        } catch (IllegalArgumentException e) {
            throw new RestconfDocumentedException("Invalid query parameters: " + e.getMessage(), e);
        }
    }

    private static RestconfDocumentedException unhandledParam(final String operation, final String name) {
        return KNOWN_PARAMS.contains(name)
            ? new RestconfDocumentedException("Invalid parameter in " + operation + ": " + name,
                ErrorType.PROTOCOL, ErrorTag.MALFORMED_MESSAGE)
            : new RestconfDocumentedException("Unknown parameter in " + operation + ": " + name,
                ErrorType.PROTOCOL, ErrorTag.UNKNOWN_ATTRIBUTE);
    }

    @VisibleForTesting
    static @Nullable String optionalParam(final String name, final List<String> values) {
        switch (values.size()) {
            case 0:
                return null;
            case 1:
                return requireNonNull(values.get(0));
            default:
                throw new RestconfDocumentedException("Parameter " + name + " can appear at most once in request URI",
                    ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE);
        }
    }

    private static <T> @Nullable T optionalParam(final Function<String, @NonNull T> factory, final String name,
            final List<String> values) {
        final String str = optionalParam(name, values);
        return str == null ? null : factory.apply(str);
    }
}