// Copyright 2016 The Domain Registry Authors. All Rights Reserved.
//
// 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 google.registry.tools;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Strings.nullToEmpty;
import static com.google.common.collect.Sets.difference;
import static google.registry.model.EppResourceUtils.checkResourcesExist;
import static google.registry.model.EppResourceUtils.loadByUniqueId;
import static google.registry.model.ofy.ObjectifyService.ofy;
import static org.joda.time.DateTimeZone.UTC;

import com.beust.jcommander.Parameter;
import com.beust.jcommander.Parameters;
import com.google.common.base.Joiner;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.ImmutableSortedSet;
import com.google.template.soy.data.SoyMapData;
import google.registry.model.domain.DomainResource;
import google.registry.model.domain.secdns.DelegationSignerData;
import google.registry.model.eppcommon.StatusValue;
import google.registry.model.host.HostResource;
import google.registry.tools.Command.GtechCommand;
import google.registry.tools.soy.UniformRapidSuspensionSoyInfo;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.xml.bind.annotation.adapters.HexBinaryAdapter;
import org.joda.time.DateTime;
import org.json.simple.JSONArray;
import org.json.simple.JSONValue;
import org.json.simple.parser.ParseException;

/** A command to suspend a domain for the Uniform Rapid Suspension process. */
@Parameters(separators = " =",
    commandDescription = "Suspend a domain for Uniform Rapid Suspension.")
final class UniformRapidSuspensionCommand extends MutatingEppToolCommand implements GtechCommand {

  private static final ImmutableSet<String> URS_LOCKS = ImmutableSet.of(
      StatusValue.SERVER_DELETE_PROHIBITED.getXmlName(),
      StatusValue.SERVER_TRANSFER_PROHIBITED.getXmlName(),
      StatusValue.SERVER_UPDATE_PROHIBITED.getXmlName());

  /** Client id that made this change. Only recorded in the history entry. **/
  private static final String CLIENT_ID = "CharlestonRoad";

  private static final ImmutableSet<String> DSDATA_FIELDS =
      ImmutableSet.of("keyTag", "alg", "digestType", "digest");

  @Parameter(
      names = {"-n", "--domain_name"},
      description = "Domain to suspend.",
      required = true)
  private String domainName;

  @Parameter(
      names = {"-h", "--hosts"},
      description = "Comma-delimited set of fully qualified host names to replace the current hosts"
          + " on the domain.")
  private List<String> newHosts = new ArrayList<>();

  @Parameter(
      names = {"-s", "--dsdata"},
      description = "Comma-delimited set of dsdata to replace the current dsdata on the domain, "
          + "where each dsdata is represented as a JSON object with fields 'keyTag', 'alg', "
          + "'digestType' and 'digest'.")
  private String newDsData;

  @Parameter(
      names = {"-p", "--locks_to_preserve"},
      description = "Comma-delimited set of locks to preserve (only valid with --undo). "
          + "Valid locks: serverDeleteProhibited, serverTransferProhibited, serverUpdateProhibited")
  private List<String> locksToPreserve = new ArrayList<>();

  @Parameter(
      names = {"--undo"},
      description = "Flag indicating that is is an undo command, which removes locks.")
  private boolean undo;

  /** Set of existing locks that need to be preserved during undo, sorted for nicer output. */
  ImmutableSortedSet<String> existingLocks;

  /** Set of existing nameservers that need to be restored during undo, sorted for nicer output. */
  ImmutableSortedSet<String> existingNameservers;

  /** Set of existing dsdata jsons that need to be restored during undo, sorted for nicer output. */
  ImmutableSortedSet<String> existingDsData;

  @Override
  protected void initMutatingEppToolCommand() throws ParseException {
    superuser = true;
    DateTime now = DateTime.now(UTC);
    ImmutableSet<String> newHostsSet = ImmutableSet.copyOf(newHosts);
    ImmutableSet.Builder<Map<String, Object>> newDsDataBuilder = new ImmutableSet.Builder<>();
    try {
      // Add brackets around newDsData to convert it to a parsable JSON array.
      String jsonArrayString = String.format("[%s]", nullToEmpty(newDsData));
      for (Object dsData : (JSONArray) JSONValue.parseWithException(jsonArrayString)) {
        @SuppressWarnings("unchecked")
        Map<String, Object> dsDataJson = (Map<String, Object>) dsData;
        checkArgument(
            dsDataJson.keySet().equals(DSDATA_FIELDS),
            "Incorrect fields on --dsdata JSON: " + JSONValue.toJSONString(dsDataJson));
        newDsDataBuilder.add(dsDataJson);
      }
    } catch (ClassCastException | ParseException e) {
      throw new IllegalArgumentException("Invalid --dsdata JSON", e);
    }
    DomainResource domain = loadByUniqueId(DomainResource.class, domainName, now);
    checkArgument(domain != null, "Domain '%s' does not exist", domainName);
    Set<String> missingHosts =
        difference(newHostsSet, checkResourcesExist(HostResource.class, newHosts, now));
    checkArgument(missingHosts.isEmpty(), "Hosts do not exist: %s", missingHosts);
    checkArgument(
        locksToPreserve.isEmpty() || undo,
        "Locks can only be preserved when running with --undo");
    existingNameservers = getExistingNameservers(domain);
    existingLocks = getExistingLocks(domain);
    existingDsData = getExistingDsData(domain);
    setSoyTemplate(
        UniformRapidSuspensionSoyInfo.getInstance(),
        UniformRapidSuspensionSoyInfo.UNIFORMRAPIDSUSPENSION);
    addSoyRecord(CLIENT_ID, new SoyMapData(
        "domainName", domainName,
        "hostsToAdd", difference(newHostsSet, existingNameservers),
        "hostsToRemove", difference(existingNameservers, newHostsSet),
        "locksToApply", undo ? ImmutableSet.of() : URS_LOCKS,
        "locksToRemove",
            undo ? difference(URS_LOCKS, ImmutableSet.copyOf(locksToPreserve)) : ImmutableSet.of(),
        "newDsData", newDsDataBuilder.build(),
        "reason", (undo ? "Undo " : "") + "Uniform Rapid Suspension"));
  }

  private ImmutableSortedSet<String> getExistingNameservers(DomainResource domain) {
    ImmutableSortedSet.Builder<String> nameservers = ImmutableSortedSet.naturalOrder();
    for (HostResource host : ofy().load().keys(domain.getNameservers()).values()) {
      nameservers.add(host.getForeignKey());
    }
    return nameservers.build();
  }

  private ImmutableSortedSet<String> getExistingLocks(DomainResource domain) {
    ImmutableSortedSet.Builder<String> locks = ImmutableSortedSet.naturalOrder();
    for (StatusValue lock : domain.getStatusValues()) {
      if (URS_LOCKS.contains(lock.getXmlName())) {
        locks.add(lock.getXmlName());
      }
    }
    return locks.build();
  }

  private ImmutableSortedSet<String> getExistingDsData(DomainResource domain) {
    ImmutableSortedSet.Builder<String> dsDataJsons = ImmutableSortedSet.naturalOrder();
    HexBinaryAdapter hexBinaryAdapter = new HexBinaryAdapter();
    for (DelegationSignerData dsData : domain.getDsData()) {
      dsDataJsons.add(JSONValue.toJSONString(ImmutableMap.of(
          "keyTag", dsData.getKeyTag(),
          "algorithm", dsData.getAlgorithm(),
          "digestType", dsData.getDigestType(),
          "digest", hexBinaryAdapter.marshal(dsData.getDigest()))));
    }
    return dsDataJsons.build();
  }

  @Override
  protected String postExecute() throws Exception {
    if (undo) {
      return "";
    }
    StringBuilder undoBuilder = new StringBuilder("UNDO COMMAND:\n\ngtech_tool -e ")
        .append(RegistryToolEnvironment.get())
        .append(" uniform_rapid_suspension --undo --domain_name ")
        .append(domainName);
    if (!existingNameservers.isEmpty()) {
      undoBuilder.append(" --hosts ").append(Joiner.on(',').join(existingNameservers));
    }
    if (!existingLocks.isEmpty()) {
      undoBuilder.append(" --locks_to_preserve ").append(Joiner.on(',').join(existingLocks));
    }
    if (!existingDsData.isEmpty()) {
      undoBuilder.append(" --dsdata ").append(Joiner.on(',').join(existingDsData));
    }
    return undoBuilder.toString();
  }
}