/*
 * SonarQube
 * Copyright (C) 2009-2018 SonarSource SA
 * mailto:info AT sonarsource DOT com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package org.sonar.server.permission;

import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import javax.annotation.CheckForNull;
import javax.annotation.Nullable;
import org.apache.commons.lang.StringUtils;
import org.sonar.api.resources.Qualifiers;
import org.sonar.api.server.ServerSide;
import org.sonar.db.DbClient;
import org.sonar.db.DbSession;
import org.sonar.db.component.ComponentDto;
import org.sonar.db.organization.DefaultTemplates;
import org.sonar.db.permission.GroupPermissionDto;
import org.sonar.db.permission.OrganizationPermission;
import org.sonar.db.permission.UserPermissionDto;
import org.sonar.db.permission.template.PermissionTemplateCharacteristicDto;
import org.sonar.db.permission.template.PermissionTemplateDto;
import org.sonar.db.permission.template.PermissionTemplateGroupDto;
import org.sonar.db.permission.template.PermissionTemplateUserDto;
import org.sonar.server.es.ProjectIndexer;
import org.sonar.server.es.ProjectIndexers;
import org.sonar.server.permission.ws.template.DefaultTemplatesResolver;
import org.sonar.server.permission.ws.template.DefaultTemplatesResolverImpl;
import org.sonar.server.user.UserSession;

import static com.google.common.base.Preconditions.checkArgument;
import static java.lang.String.format;
import static java.util.Collections.singletonList;
import static org.sonar.api.security.DefaultGroups.isAnyone;
import static org.sonar.api.web.UserRole.PUBLIC_PERMISSIONS;

@ServerSide
public class PermissionTemplateService {

  private final DbClient dbClient;
  private final ProjectIndexers projectIndexers;
  private final UserSession userSession;
  private final DefaultTemplatesResolver defaultTemplatesResolver;

  public PermissionTemplateService(DbClient dbClient, ProjectIndexers projectIndexers, UserSession userSession,
    DefaultTemplatesResolver defaultTemplatesResolver) {
    this.dbClient = dbClient;
    this.projectIndexers = projectIndexers;
    this.userSession = userSession;
    this.defaultTemplatesResolver = defaultTemplatesResolver;
  }

  public boolean wouldUserHaveScanPermissionWithDefaultTemplate(DbSession dbSession,
    String organizationUuid, @Nullable Integer userId,
    String projectKey, String qualifier) {
    if (userSession.hasPermission(OrganizationPermission.SCAN, organizationUuid)) {
      return true;
    }

    ComponentDto dto = new ComponentDto().setOrganizationUuid(organizationUuid).setDbKey(projectKey).setQualifier(qualifier);
    PermissionTemplateDto template = findTemplate(dbSession, organizationUuid, dto);
    if (template == null) {
      return false;
    }

    List<String> potentialPermissions = dbClient.permissionTemplateDao().selectPotentialPermissionsByUserIdAndTemplateId(dbSession, userId, template.getId());
    return potentialPermissions.contains(OrganizationPermission.SCAN.getKey());
  }

  /**
   * Apply a permission template to a set of projects. Authorization to administrate these projects
   * is not verified. The projects must exist, so the "project creator" permissions defined in the
   * template are ignored.
   */
  public void applyAndCommit(DbSession dbSession, PermissionTemplateDto template, Collection<ComponentDto> projects) {
    if (projects.isEmpty()) {
      return;
    }

    for (ComponentDto project : projects) {
      copyPermissions(dbSession, template, project, null);
    }
    projectIndexers.commitAndIndex(dbSession, projects, ProjectIndexer.Cause.PERMISSION_CHANGE);
  }

  /**
   * Apply the default permission template to project. The project can already exist (so it has permissions) or
   * can be provisioned (so has no permissions yet).
   * @param projectCreatorUserId id of the user who creates the project, only if project is provisioned. He will
   */
  public void applyDefault(DbSession dbSession, String organizationUuid, ComponentDto component, @Nullable Integer projectCreatorUserId) {
    PermissionTemplateDto template = findTemplate(dbSession, organizationUuid, component);
    checkArgument(template != null, "Cannot retrieve default permission template");
    copyPermissions(dbSession, template, component, projectCreatorUserId);
  }

  public boolean hasDefaultTemplateWithPermissionOnProjectCreator(DbSession dbSession, String organizationUuid, ComponentDto component) {
    PermissionTemplateDto template = findTemplate(dbSession, organizationUuid, component);
    return hasProjectCreatorPermission(dbSession, template);
  }

  private boolean hasProjectCreatorPermission(DbSession dbSession, @Nullable PermissionTemplateDto template) {
    return template != null && dbClient.permissionTemplateCharacteristicDao().selectByTemplateIds(dbSession, singletonList(template.getId())).stream()
      .anyMatch(PermissionTemplateCharacteristicDto::getWithProjectCreator);
  }

  private void copyPermissions(DbSession dbSession, PermissionTemplateDto template, ComponentDto project, @Nullable Integer projectCreatorUserId) {
    dbClient.groupPermissionDao().deleteByRootComponentId(dbSession, project.getId());
    dbClient.userPermissionDao().deleteProjectPermissions(dbSession, project.getId());

    List<PermissionTemplateUserDto> usersPermissions = dbClient.permissionTemplateDao().selectUserPermissionsByTemplateId(dbSession, template.getId());
    String organizationUuid = template.getOrganizationUuid();
    usersPermissions
      .stream()
      .filter(up -> permissionValidForProject(project, up.getPermission()))
      .forEach(up -> {
        UserPermissionDto dto = new UserPermissionDto(organizationUuid, up.getPermission(), up.getUserId(), project.getId());
        dbClient.userPermissionDao().insert(dbSession, dto);
      });

    List<PermissionTemplateGroupDto> groupsPermissions = dbClient.permissionTemplateDao().selectGroupPermissionsByTemplateId(dbSession, template.getId());
    groupsPermissions
      .stream()
      .filter(gp -> groupNameValidForProject(project, gp.getGroupName()))
      .filter(gp -> permissionValidForProject(project, gp.getPermission()))
      .forEach(gp -> {
        GroupPermissionDto dto = new GroupPermissionDto()
          .setOrganizationUuid(organizationUuid)
          .setGroupId(isAnyone(gp.getGroupName()) ? null : gp.getGroupId())
          .setRole(gp.getPermission())
          .setResourceId(project.getId());
        dbClient.groupPermissionDao().insert(dbSession, dto);
      });

    List<PermissionTemplateCharacteristicDto> characteristics = dbClient.permissionTemplateCharacteristicDao().selectByTemplateIds(dbSession, singletonList(template.getId()));
    if (projectCreatorUserId != null) {
      Set<String> permissionsForCurrentUserAlreadyInDb = usersPermissions.stream()
        .filter(userPermission -> projectCreatorUserId.equals(userPermission.getUserId()))
        .map(PermissionTemplateUserDto::getPermission)
        .collect(java.util.stream.Collectors.toSet());
      characteristics.stream()
        .filter(PermissionTemplateCharacteristicDto::getWithProjectCreator)
        .filter(up -> permissionValidForProject(project, up.getPermission()))
        .filter(characteristic -> !permissionsForCurrentUserAlreadyInDb.contains(characteristic.getPermission()))
        .forEach(c -> {
          UserPermissionDto dto = new UserPermissionDto(organizationUuid, c.getPermission(), projectCreatorUserId, project.getId());
          dbClient.userPermissionDao().insert(dbSession, dto);
        });
    }
  }

  private static boolean permissionValidForProject(ComponentDto project, String permission) {
    return project.isPrivate() || !PUBLIC_PERMISSIONS.contains(permission);
  }

  private static boolean groupNameValidForProject(ComponentDto project, String groupName) {
    return !project.isPrivate() || !isAnyone(groupName);
  }

  /**
   * Return the permission template for the given component. If no template key pattern match then consider default
   * template for the component qualifier.
   */
  @CheckForNull
  private PermissionTemplateDto findTemplate(DbSession dbSession, String organizationUuid, ComponentDto component) {
    List<PermissionTemplateDto> allPermissionTemplates = dbClient.permissionTemplateDao().selectAll(dbSession, organizationUuid, null);
    List<PermissionTemplateDto> matchingTemplates = new ArrayList<>();
    for (PermissionTemplateDto permissionTemplateDto : allPermissionTemplates) {
      String keyPattern = permissionTemplateDto.getKeyPattern();
      if (StringUtils.isNotBlank(keyPattern) && component.getDbKey().matches(keyPattern)) {
        matchingTemplates.add(permissionTemplateDto);
      }
    }
    checkAtMostOneMatchForComponentKey(component.getDbKey(), matchingTemplates);
    if (matchingTemplates.size() == 1) {
      return matchingTemplates.get(0);
    }

    DefaultTemplates defaultTemplates = dbClient.organizationDao().getDefaultTemplates(dbSession, organizationUuid)
      .orElseThrow(() -> new IllegalStateException(
        format("No Default templates defined for organization with uuid '%s'", organizationUuid)));

    String qualifier = component.qualifier();
    DefaultTemplatesResolverImpl.ResolvedDefaultTemplates resolvedDefaultTemplates = defaultTemplatesResolver.resolve(defaultTemplates);
    switch (qualifier) {
      case Qualifiers.PROJECT:
        return dbClient.permissionTemplateDao().selectByUuid(dbSession, resolvedDefaultTemplates.getProject());
      case Qualifiers.VIEW:
        String portDefaultTemplateUuid = resolvedDefaultTemplates.getPortfolio().orElseThrow(
          () -> new IllegalStateException("Attempt to create a view when Governance plugin is not installed"));
        return dbClient.permissionTemplateDao().selectByUuid(dbSession, portDefaultTemplateUuid);
      case Qualifiers.APP:
        String appDefaultTemplateUuid = resolvedDefaultTemplates.getApplication().orElseThrow(
          () -> new IllegalStateException("Attempt to create a view when Governance plugin is not installed"));
        return dbClient.permissionTemplateDao().selectByUuid(dbSession, appDefaultTemplateUuid);
      default:
        throw new IllegalArgumentException(format("Qualifier '%s' is not supported", qualifier));
    }
  }

  private static void checkAtMostOneMatchForComponentKey(String componentKey, List<PermissionTemplateDto> matchingTemplates) {
    if (matchingTemplates.size() > 1) {
      StringBuilder templatesNames = new StringBuilder();
      for (Iterator<PermissionTemplateDto> it = matchingTemplates.iterator(); it.hasNext();) {
        templatesNames.append("\"").append(it.next().getName()).append("\"");
        if (it.hasNext()) {
          templatesNames.append(", ");
        }
      }
      throw new IllegalStateException(MessageFormat.format(
        "The \"{0}\" key matches multiple permission templates: {1}."
          + " A system administrator must update these templates so that only one of them matches the key.",
        componentKey,
        templatesNames.toString()));
    }
  }

}