/*
 * Copyright 2000-2018 JetBrains s.r.o.
 *
 * 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 jetbrains.buildServer.server.rest.model.agent;

import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
import jetbrains.buildServer.AgentRestrictorType;
import jetbrains.buildServer.ServiceLocator;
import jetbrains.buildServer.controllers.agent.OSKind;
import jetbrains.buildServer.server.rest.data.*;
import jetbrains.buildServer.server.rest.errors.AuthorizationFailedException;
import jetbrains.buildServer.server.rest.errors.BadRequestException;
import jetbrains.buildServer.server.rest.errors.NotFoundException;
import jetbrains.buildServer.server.rest.model.*;
import jetbrains.buildServer.server.rest.model.build.Build;
import jetbrains.buildServer.server.rest.model.buildType.BuildTypes;
import jetbrains.buildServer.server.rest.util.BeanContext;
import jetbrains.buildServer.server.rest.util.ValueWithDefault;
import jetbrains.buildServer.serverSide.*;
import jetbrains.buildServer.serverSide.agentTypes.AgentTypeFinder;
import jetbrains.buildServer.serverSide.agentTypes.SAgentType;
import jetbrains.buildServer.serverSide.auth.AccessChecker;
import jetbrains.buildServer.serverSide.auth.AuthUtil;
import jetbrains.buildServer.serverSide.auth.Permission;
import jetbrains.buildServer.serverSide.impl.agent.DeadAgent;
import jetbrains.buildServer.serverSide.impl.agent.DummyAgentType;
import jetbrains.buildServer.serverSide.impl.agent.PollingRemoteAgentConnection;
import jetbrains.buildServer.users.SUser;
import jetbrains.buildServer.util.StringUtil;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

/**
 * @author Yegor.Yarko
 *         Date: 01.08.2009
 */
@XmlRootElement(name = "agent")
@SuppressWarnings("PublicField")
public class Agent {

  public static final int UNKNOWN_AGENT_ID = -1;
  @XmlAttribute public Integer id;
  @XmlAttribute public String name;
  @XmlAttribute public Integer typeId;
  @XmlAttribute public Boolean connected;
  @XmlAttribute public Boolean enabled;
  @XmlAttribute public Boolean authorized;
  @XmlAttribute public Boolean uptodate;
  @XmlAttribute public String ip;
  @XmlAttribute public String protocol;
  @XmlAttribute public String version; //experimental
  @XmlAttribute public String lastActivityTime; //experimental
  @XmlAttribute public String disconnectionComment;  //experimental
  @XmlAttribute public String href;
  @XmlAttribute public String webUrl;

  @XmlElement public Build build;
  @XmlElement public Links links;
  @XmlElement public AgentEnabledInfo enabledInfo;
  @XmlElement public AgentAuthorizedInfo authorizedInfo;
  @XmlElement public Properties properties;
  /**
   * Experimental support only
   */
  @XmlElement public Environment environment;
  @XmlElement public AgentPool pool;
  @XmlElement public CompatibilityPolicy compatibilityPolicy;
  @XmlElement public BuildTypes compatibleBuildTypes;
  @XmlElement public Compatibilities incompatibleBuildTypes;

  public static final String COMPATIBILITY_POLICY = "compatibilityPolicy";
  public static final String COMPATIBLE_BUILD_TYPES = "compatibleBuildTypes";
  public static final String INCOMPATIBLE_BUILD_TYPES = "incompatibleBuildTypes";
  /**
   * This is used only when posting a link to an agent.
   */
  @XmlAttribute public String locator;

  public Agent() {
  }

  /**
   *  Used only for build triggering
   */
  public Agent(@NotNull final jetbrains.buildServer.serverSide.agentPools.AgentPool agentPool, final @NotNull Fields fields, @NotNull final BeanContext beanContext) {
    pool = ValueWithDefault.decideDefault(fields.isIncluded("pool", true), new ValueWithDefault.Value<AgentPool>() {
      @Nullable
      public AgentPool get() {
        return new AgentPool(agentPool, fields.getNestedField("pool", Fields.SHORT, Fields.SHORT), beanContext);
      }
    });
  }

  /**
   *  Used only for build triggering
   */
  public Agent(@NotNull final SAgentType agentType, final @NotNull Fields fields, @NotNull final BeanContext beanContext) {
    typeId = ValueWithDefault.decideDefault(fields.isIncluded("typeId", true), agentType.getAgentTypeId());
  }

  public Agent(@NotNull final SBuildAgent agent, @NotNull final AgentPoolFinder agentPoolFinder, final @NotNull Fields fields, @NotNull final BeanContext beanContext) {
    final int agentId = agent.getId();
    final boolean unknownAgent = agentId == UNKNOWN_AGENT_ID;
    name = ValueWithDefault.decideIncludeByDefault(fields.isIncluded("name"), agent.getName());
    typeId = ValueWithDefault.decideIncludeByDefault(fields.isIncluded("typeId"), agent.getAgentTypeId());
    if (!unknownAgent) {
      id = ValueWithDefault.decideIncludeByDefault(fields.isIncluded("id"), agentId);
      href = ValueWithDefault.decideDefault(fields.isIncluded("href"), beanContext.getApiUrlBuilder().getHref(agent));
      connected = ValueWithDefault.decideIncludeByDefault(fields.isIncluded("connected", false), agent.isRegistered());
      enabled = ValueWithDefault.decideIncludeByDefault(fields.isIncluded("enabled", false), agent.isEnabled());
      authorized = ValueWithDefault.decideIncludeByDefault(fields.isIncluded("authorized", false), agent.isAuthorized());

      build = ValueWithDefault.decideDefault(fields.isIncluded("build", false), () -> {
        SRunningBuild runningBuild = agent.getRunningBuild();
        if (runningBuild == null ) return null;
        try {
          beanContext.getSingletonService(PermissionChecker.class).checkPermission(Permission.VIEW_PROJECT, runningBuild.getBuildPromotion());
          return new Build(runningBuild, fields.getNestedField("build"), beanContext);
        } catch (AuthorizationFailedException e) {
          return Build.getNoPermissionsBuild(runningBuild, fields.getNestedField("build"), beanContext); //should probably include "empty" build node instead so that it's clear some build is running
        }
      });
    }

    boolean hasMeaningfulData = !unknownAgent ||
                                !(((BuildAgentEx)agent).getAgentType() instanceof DummyAgentType); //agent type is still in the system
    //check permission to match UI
    if (hasMeaningfulData) {
      if(AuthUtil.canViewAgentDetails(beanContext.getSingletonService(PermissionChecker.class).getCurrent(), agent)){
        WebLinks webLinks = beanContext.getSingletonService(WebLinks.class);
        webUrl = ValueWithDefault.decideDefault(fields.isIncluded("webUrl", true), () -> webLinks.getAgentUrl(agent, agent.getAgentTypeId()));
        links = ValueWithDefault.decideDefault(fields.isIncluded("links", false, false), new ValueWithDefault.Value<Links>() {
          @Nullable
          @Override
          public Links get() {
            Links.LinksBuilder builder = new Links.LinksBuilder();
            String absoluteUrl = webLinks.getAgentUrl(agent, agent.getAgentTypeId());
            String relativeUrl = new RelativeWebLinks().getAgentUrl(agent, agent.getAgentTypeId());
            if (absoluteUrl != null && relativeUrl != null) {
              builder.add(Link.WEB_VIEW_TYPE, absoluteUrl, relativeUrl);
            }
            return builder.build(fields.getNestedField("links"));
          }
        });
        environment = ValueWithDefault.decideDefaultIgnoringAccessDenied(fields.isIncluded("environment", false, false),
                                                                         () -> new Environment(agent, fields.getNestedField("environment", Fields.NONE, Fields.LONG), beanContext)
        );

        if (!unknownAgent) {
          uptodate = ValueWithDefault.decideIncludeByDefault(fields.isIncluded("uptodate", false), !agent.isOutdated() && !agent.isPluginsOutdated());
          ip = ValueWithDefault.decideDefaultIgnoringAccessDenied(fields.isIncluded("ip", false), new ValueWithDefault.Value<String>() {
            @Nullable
            public String get() {
              final String hostAddress = agent.getHostAddress();
              return DeadAgent.NA.equals(hostAddress) ? null : hostAddress;
            }
          });
          protocol = ValueWithDefault.decideDefaultIgnoringAccessDenied(fields.isIncluded("protocol", false, false), new ValueWithDefault.Value<String>() {  //hide by default for now
            @Nullable
            public String get() {
              return getAgentProtocol(agent);
            }
          });

          version = ValueWithDefault.decideDefault(fields.isIncluded("version", false, false), () -> agent.getVersion());

          lastActivityTime = ValueWithDefault.decideDefault(fields.isIncluded("lastActivityTime", false, false),
                                                            () -> Util.formatTime(agent.getLastCommunicationTimestamp()));

          disconnectionComment = ValueWithDefault.decideDefault(fields.isIncluded("disconnectionComment", false, false),
                                                                () -> agent.getUnregistrationComment());

          enabledInfo = ValueWithDefault.decideIncludeByDefault(fields.isIncluded("enabledInfo", false), new ValueWithDefault.Value<AgentEnabledInfo>() {
            @Nullable
            public AgentEnabledInfo get() {
              return new AgentEnabledInfo(agent, fields.getNestedField("enabledInfo", Fields.NONE, Fields.LONG), beanContext);
            }
          });

          authorizedInfo = ValueWithDefault.decideIncludeByDefault(fields.isIncluded("authorizedInfo", false), new ValueWithDefault.Value<AgentAuthorizedInfo>() {
            @Nullable
            public AgentAuthorizedInfo get() {
              return new AgentAuthorizedInfo(agent.isAuthorized(), agent.getAuthorizeComment(), fields.getNestedField("authorizedInfo", Fields.NONE, Fields.LONG), beanContext);
            }
          });

          //TODO: review, if it should return all parameters on agent, use #getDefinedParameters()
          properties = ValueWithDefault.decideDefaultIgnoringAccessDenied(fields.isIncluded("properties", false), new ValueWithDefault.Value<Properties>() {
            @Nullable
            public Properties get() {
              return new Properties(agent.getAvailableParameters(), null, fields.getNestedField("properties", Fields.NONE, Fields.LONG), beanContext);
            }
          });

          compatibilityPolicy = ValueWithDefault.decideDefaultIgnoringAccessDenied(fields.isIncluded(COMPATIBILITY_POLICY, false, false),
                                           () -> CompatibilityPolicy.getCompatibilityPolicy(agent, fields.getNestedField(COMPATIBILITY_POLICY), beanContext));

          compatibleBuildTypes =
            ValueWithDefault.decideDefault(fields.isIncluded(COMPATIBLE_BUILD_TYPES, false, false), new ValueWithDefault.Value<BuildTypes>() {
              @Nullable
              public BuildTypes get() {
                BuildTypeFinder buildTypeFinder = beanContext.getSingletonService(BuildTypeFinder.class);
                return new BuildTypes(buildTypeFinder.getItems(BuildTypeFinder.getLocatorCompatible(agent)).myEntries, null, fields.getNestedField(COMPATIBLE_BUILD_TYPES), beanContext);
              }
            });
          incompatibleBuildTypes = ValueWithDefault.decideDefault(fields.isIncluded(INCOMPATIBLE_BUILD_TYPES, false, false), new ValueWithDefault.Value<Compatibilities>() {
            @Nullable
            public Compatibilities get() {
              return new Compatibilities(AgentFinder.getIncompatible(agent, null, beanContext.getServiceLocator()), agent, null, fields.getNestedField(INCOMPATIBLE_BUILD_TYPES), beanContext);
            }
          });
        }
      }

      if(!unknownAgent){
        pool = ValueWithDefault.decideDefault(fields.isIncluded("pool", false), new ValueWithDefault.Value<AgentPool>() {
          @Nullable
          public AgentPool get() {
            return new AgentPool(agentPoolFinder.getAgentPool(agent), fields.getNestedField("pool"), beanContext);
          }
        });
      }
    }
  }

  static String getAgentOsType(@NotNull final SBuildAgent agent) {
    String osName = agent.getOperatingSystemName();
    if ("N/A".equalsIgnoreCase(osName) || "<unknown>".equalsIgnoreCase(osName) || "".equals(osName)) {
      osName = ((BuildAgentEx)agent).getAgentType().getOperatingSystemName();
    }
    OSKind os = OSKind.guessByName(osName);
    if (os == null) return null;
    switch (os) {
      case WINDOWS:
        return "Windows";
      case MAC:
        return "macOS";
      case LINUX:
        return "Linux";
      case SOLARIS:
        return "Solaris";
      case FREEBSD:
        return "FreeBSD";
      case OTHERUNIX:
        return "Unix";
      default:
        return null;
    }
  }

  @NotNull
  private static String getAgentProtocol(final @NotNull SBuildAgent agent) {
    final String protocolType = agent.getCommunicationProtocolType();
    if (PollingRemoteAgentConnection.TYPE.equals(protocolType)) return "unidirectional";
    // would be better to check, but that is in another module: if (XmlRpcRemoteAgentConnection.DESCRIPTION.equals(communicationProtocolDescription)) return "bidirectional";
    return "bidirectional";
  }

  public static String getFieldValue(@NotNull final SBuildAgent agent, @Nullable final String name, @NotNull final ServiceLocator serviceLocator) {
    if (StringUtil.isEmpty(name)) {
      throw new BadRequestException("Field name cannot be empty");
    }
    if ("id".equals(name)) {
      return String.valueOf(agent.getId());
    } else if ("typeId".equals(name)) {
      return String.valueOf(agent.getAgentTypeId());
    } else if ("name".equals(name)) {
      return agent.getName();
    } else if ("connected".equals(name)) {
      return String.valueOf(agent.isRegistered());
    } else if ("enabled".equals(name)) {
      return String.valueOf(agent.isEnabled());
    } else if ("authorized".equals(name)) {
      return String.valueOf(agent.isAuthorized());
    } else if ("authToken".equals(name)) {
      serviceLocator.getSingletonService(AccessChecker.class).checkHasPermissionForPool(agent.getAgentPool(), Permission.AUTHORIZE_AGENT, Permission.AUTHORIZE_AGENT_FOR_PROJECT);
      return String.valueOf(agent.getAuthorizationToken());
    }

    if ("enabledInfoCommentText".equals(name)) {
      return String.valueOf(agent.getStatusComment().getComment());
    } else if ("authorizedInfoCommentText".equals(name)) {
      return String.valueOf(agent.getAuthorizeComment().getComment());
    } else if ("ip".equals(name)) {
      return agent.getHostAddress();
    } else if ("protocol".equals(name)) {
      return getAgentProtocol(agent);
    }
    throw new BadRequestException("Unknown field '" + name + "'. Supported fields are: id, name, connected, enabled, authorized, ip, authToken");
  }

  public static void setFieldValue(@NotNull final SBuildAgent agent,
                                   @Nullable final String name,
                                   @NotNull final String value,
                                   @NotNull final ServiceLocator serviceLocator) {
    if (StringUtil.isEmpty(name)) {
      throw new BadRequestException("Field name cannot be empty");
    }
    SUser currentUser = serviceLocator.getSingletonService(UserFinder.class).getCurrentUser();
    if ("enabled".equals(name)) {
      agent.setEnabled(Boolean.valueOf(value), currentUser, getActualActionComment(null));
      //todo (TeamCity) why not use current user by default?
      return;
    } else if ("authorized".equals(name)) {
      agent.setAuthorized(Boolean.valueOf(value), currentUser, getActualActionComment(null));
      //todo (TeamCity) why not use current user by default?
      return;
    } else if ("enabledInfoCommentText".equals(name)) {
      agent.setEnabled(agent.isEnabled(), currentUser, value);
      return;
    } else if ("authorizedInfoCommentText".equals(name)) {
      agent.setAuthorized(agent.isAuthorized(), currentUser, value);
      return;
    }
    throw new BadRequestException("Changing field '" + name + "' is not supported. Supported fields are: enabled, authorized");
  }

  @NotNull
  public static String getActualActionComment(final @Nullable String submittedComment) {
    return StringUtil.isEmpty(submittedComment) ? TeamCityProperties.getProperty("rest.defaultActionComment") : submittedComment;
  }

  @NotNull
  public SBuildAgent getAgentFromPosted(@NotNull final AgentFinder agentFinder) {
    String locatorText = "";
    if (id != null) locatorText += (!locatorText.isEmpty() ? "," : "") + AgentFinder.DIMENSION_ID + ":" + id;
    if (locatorText.isEmpty()) {
      locatorText = locator;
    } else {
      if (locator != null) {
        throw new BadRequestException("Both 'locator' and 'id' attributes are specified. Only one should be present.");
      }
    }
    if (StringUtil.isEmpty(locatorText)){
      throw new BadRequestException("No agent specified. Either 'id' or 'locator' attribute should be present.");
    }
    return agentFinder.getItem(locatorText);
  }

  @Nullable
  public SAgentRestrictor getAgentRestrictor(@NotNull final ServiceLocator serviceLocator) {
    final AgentRestrictorFactory agentRestrictorFactory = serviceLocator.getSingletonService(AgentRestrictorFactory.class);
    final AgentFinder agentFinder = serviceLocator.getSingletonService(AgentFinder.class);
    try {
      int agentIdFromPosted = getAgentFromPosted(agentFinder).getId();
      return agentRestrictorFactory.createFor(AgentRestrictorType.SINGLE_AGENT, agentIdFromPosted);
    } catch (BadRequestException | NotFoundException e) {
      //agent not found
      if (locator != null || id != null) throw e; // agent should be found
      if (pool != null) {
        final AgentPoolFinder agentPoolFinder = serviceLocator.getSingletonService(AgentPoolFinder.class);
        return agentRestrictorFactory.createFor(AgentRestrictorType.AGENT_POOL, pool.getAgentPoolFromPosted(agentPoolFinder).getAgentPoolId());
      }
      if (typeId != null) {
        return agentRestrictorFactory.createFor(AgentRestrictorType.CLOUD_IMAGE,
                                                AgentFinder.getAgentType(String.valueOf(typeId), serviceLocator.getSingletonService(AgentTypeFinder.class)).getAgentTypeId());
      }
      throw e;
    }
  }

  public int getAgentTypeIdFromPosted(@NotNull final ServiceLocator serviceLocator) {
    try {
      return getAgentFromPosted(serviceLocator.getSingletonService(AgentFinder.class)).getAgentTypeId();
    } catch (BadRequestException | NotFoundException e) {
      //agent not found
      if (locator != null || id != null) throw e; // agent should be found
      if (typeId != null) return AgentFinder.getAgentType(String.valueOf(typeId), serviceLocator.getSingletonService(AgentTypeFinder.class)).getAgentTypeId();
      throw e;
    }
  }
}