// Copyright (C) 2008 The Android Open Source Project
//
// 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 com.google.gerrit.server.rpc.account;

import com.google.gerrit.client.admin.GroupAdminService;
import com.google.gerrit.client.admin.GroupDetail;
import com.google.gerrit.client.reviewdb.Account;
import com.google.gerrit.client.reviewdb.AccountGroup;
import com.google.gerrit.client.reviewdb.AccountGroupMember;
import com.google.gerrit.client.reviewdb.AccountGroupMemberAudit;
import com.google.gerrit.client.reviewdb.ReviewDb;
import com.google.gerrit.client.reviewdb.AccountGroup.NameKey;
import com.google.gerrit.client.rpc.NameAlreadyUsedException;
import com.google.gerrit.client.rpc.NoSuchAccountException;
import com.google.gerrit.client.rpc.NoSuchEntityException;
import com.google.gerrit.server.BaseServiceImplementation;
import com.google.gerrit.server.IdentifiedUser;
import com.google.gerrit.server.account.AccountCache;
import com.google.gerrit.server.account.AccountResolver;
import com.google.gerrit.server.account.GroupCache;
import com.google.gerrit.server.account.GroupControl;
import com.google.gerrit.server.account.NoSuchGroupException;
import com.google.gwt.user.client.rpc.AsyncCallback;
import com.google.gwtjsonrpc.client.VoidResult;
import com.google.gwtorm.client.OrmException;
import com.google.gwtorm.client.Transaction;
import com.google.inject.Inject;
import com.google.inject.Provider;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

class GroupAdminServiceImpl extends BaseServiceImplementation implements
    GroupAdminService {
  private final Provider<IdentifiedUser> identifiedUser;
  private final AccountCache accountCache;
  private final AccountResolver accountResolver;
  private final GroupCache groupCache;
  private final GroupControl.Factory groupControlFactory;
  private final GroupDetailFactory.Factory groupDetailFactory;

  @Inject
  GroupAdminServiceImpl(final Provider<ReviewDb> schema,
      final Provider<IdentifiedUser> currentUser,
      final AccountCache accountCache, final AccountResolver accountResolver,
      final GroupCache groupCache,
      final GroupControl.Factory groupControlFactory,
      final GroupDetailFactory.Factory groupDetailFactory) {
    super(schema, currentUser);
    this.identifiedUser = currentUser;
    this.accountCache = accountCache;
    this.accountResolver = accountResolver;
    this.groupCache = groupCache;
    this.groupControlFactory = groupControlFactory;
    this.groupDetailFactory = groupDetailFactory;
  }

  public void ownedGroups(final AsyncCallback<List<AccountGroup>> callback) {
    run(callback, new Action<List<AccountGroup>>() {
      public List<AccountGroup> run(ReviewDb db) throws OrmException {
        final IdentifiedUser user = identifiedUser.get();
        final List<AccountGroup> result;
        if (user.isAdministrator()) {
          result = db.accountGroups().all().toList();
        } else {
          final HashSet<AccountGroup.Id> seen = new HashSet<AccountGroup.Id>();
          result = new ArrayList<AccountGroup>();
          for (final AccountGroup.Id myGroup : user.getEffectiveGroups()) {
            for (AccountGroup group : db.accountGroups().ownedByGroup(myGroup)) {
              final AccountGroup.Id id = group.getId();
              if (!seen.add(id)) {
                continue;
              }
              try {
                GroupControl c = groupControlFactory.controlFor(id);
                if (c.isOwner()) {
                  result.add(c.getAccountGroup());
                }
              } catch (NoSuchGroupException e) {
                continue;
              }
            }
          }
        }
        Collections.sort(result, new Comparator<AccountGroup>() {
          public int compare(final AccountGroup a, final AccountGroup b) {
            return a.getName().compareTo(b.getName());
          }
        });
        return result;
      }
    });
  }

  public void createGroup(final String newName,
      final AsyncCallback<AccountGroup.Id> callback) {
    run(callback, new Action<AccountGroup.Id>() {
      public AccountGroup.Id run(final ReviewDb db) throws OrmException,
          Failure {
        final AccountGroup.NameKey nameKey = new AccountGroup.NameKey(newName);
        if (db.accountGroups().get(nameKey) != null) {
          throw new Failure(new NameAlreadyUsedException());
        }

        final AccountGroup group =
            new AccountGroup(nameKey, new AccountGroup.Id(db
                .nextAccountGroupId()));
        group.setNameKey(nameKey);
        group.setDescription("");

        final Account.Id me = getAccountId();
        final AccountGroupMember m =
            new AccountGroupMember(
                new AccountGroupMember.Key(me, group.getId()));

        final Transaction txn = db.beginTransaction();
        db.accountGroups().insert(Collections.singleton(group), txn);
        db.accountGroupMembers().insert(Collections.singleton(m), txn);
        db.accountGroupMembersAudit().insert(
            Collections.singleton(new AccountGroupMemberAudit(m, me)), txn);
        txn.commit();
        accountCache.evict(m.getAccountId());

        return group.getId();
      }
    });
  }

  public void groupDetail(final AccountGroup.Id groupId,
      final AsyncCallback<GroupDetail> callback) {
    groupDetailFactory.create(groupId).to(callback);
  }

  public void changeGroupDescription(final AccountGroup.Id groupId,
      final String description, final AsyncCallback<VoidResult> callback) {
    run(callback, new Action<VoidResult>() {
      public VoidResult run(final ReviewDb db) throws OrmException, Failure {
        final AccountGroup group = db.accountGroups().get(groupId);
        assertAmGroupOwner(db, group);
        group.setDescription(description);
        db.accountGroups().update(Collections.singleton(group));
        groupCache.evict(group);
        return VoidResult.INSTANCE;
      }
    });
  }

  public void changeGroupOwner(final AccountGroup.Id groupId,
      final String newOwnerName, final AsyncCallback<VoidResult> callback) {
    run(callback, new Action<VoidResult>() {
      public VoidResult run(final ReviewDb db) throws OrmException, Failure {
        final AccountGroup group = db.accountGroups().get(groupId);
        assertAmGroupOwner(db, group);

        final AccountGroup owner =
            db.accountGroups().get(new AccountGroup.NameKey(newOwnerName));
        if (owner == null) {
          throw new Failure(new NoSuchEntityException());
        }

        group.setOwnerGroupId(owner.getId());
        db.accountGroups().update(Collections.singleton(group));
        groupCache.evict(group);
        return VoidResult.INSTANCE;
      }
    });
  }

  public void renameGroup(final AccountGroup.Id groupId, final String newName,
      final AsyncCallback<VoidResult> callback) {
    run(callback, new Action<VoidResult>() {
      public VoidResult run(final ReviewDb db) throws OrmException, Failure {
        final AccountGroup group = db.accountGroups().get(groupId);
        assertAmGroupOwner(db, group);

        final AccountGroup.NameKey oldKey = group.getNameKey();
        final AccountGroup.NameKey newKey = new AccountGroup.NameKey(newName);
        if (!newKey.equals(oldKey)) {
          if (db.accountGroups().get(newKey) != null) {
            throw new Failure(new NameAlreadyUsedException());
          }
          group.setNameKey(newKey);
          db.accountGroups().update(Collections.singleton(group));
          groupCache.evict(group);
          groupCache.evictAfterRename(oldKey);
        }
        return VoidResult.INSTANCE;
      }
    });
  }

  public void addGroupMember(final AccountGroup.Id groupId,
      final String nameOrEmail, final AsyncCallback<GroupDetail> callback) {
    run(callback, new Action<GroupDetail>() {
      public GroupDetail run(ReviewDb db) throws OrmException, Failure,
          NoSuchGroupException {
        final GroupControl control = groupControlFactory.validateFor(groupId);
        if (control.getAccountGroup().isAutomaticMembership()) {
          throw new Failure(new NameAlreadyUsedException());
        }

        final Account a = findAccount(nameOrEmail);
        if (!control.canAdd(a.getId())) {
          throw new Failure(new NoSuchEntityException());
        }

        final AccountGroupMember.Key key =
            new AccountGroupMember.Key(a.getId(), groupId);
        AccountGroupMember m = db.accountGroupMembers().get(key);
        if (m == null) {
          m = new AccountGroupMember(key);
          final Transaction txn = db.beginTransaction();
          db.accountGroupMembers().insert(Collections.singleton(m), txn);
          db.accountGroupMembersAudit().insert(
              Collections.singleton(new AccountGroupMemberAudit(m,
                  getAccountId())), txn);
          txn.commit();
          accountCache.evict(m.getAccountId());
        }

        return groupDetailFactory.create(groupId).call();
      }
    });
  }

  public void deleteGroupMembers(final AccountGroup.Id groupId,
      final Set<AccountGroupMember.Key> keys,
      final AsyncCallback<VoidResult> callback) {
    run(callback, new Action<VoidResult>() {
      public VoidResult run(final ReviewDb db) throws OrmException,
          NoSuchGroupException, Failure {
        final GroupControl control = groupControlFactory.validateFor(groupId);
        if (control.getAccountGroup().isAutomaticMembership()) {
          throw new Failure(new NameAlreadyUsedException());
        }

        for (final AccountGroupMember.Key k : keys) {
          if (!groupId.equals(k.getAccountGroupId())) {
            throw new Failure(new NoSuchEntityException());
          }
        }

        final Account.Id me = getAccountId();
        for (final AccountGroupMember.Key k : keys) {
          final AccountGroupMember m = db.accountGroupMembers().get(k);
          if (m != null) {
            if (!control.canRemove(m.getAccountId())) {
              throw new Failure(new NoSuchEntityException());
            }

            AccountGroupMemberAudit audit = null;
            for (AccountGroupMemberAudit a : db.accountGroupMembersAudit()
                .byGroupAccount(m.getAccountGroupId(), m.getAccountId())) {
              if (a.isActive()) {
                audit = a;
                break;
              }
            }

            final Transaction txn = db.beginTransaction();
            db.accountGroupMembers().delete(Collections.singleton(m), txn);
            if (audit != null) {
              audit.removed(me);
              db.accountGroupMembersAudit().update(
                  Collections.singleton(audit), txn);
            } else {
              audit = new AccountGroupMemberAudit(m, me);
              audit.removedLegacy();
              db.accountGroupMembersAudit().insert(
                  Collections.singleton(audit), txn);
            }
            txn.commit();
            accountCache.evict(m.getAccountId());
          }
        }
        return VoidResult.INSTANCE;
      }
    });
  }

  private void assertAmGroupOwner(final ReviewDb db, final AccountGroup group)
      throws Failure {
    try {
      if (!groupControlFactory.controlFor(group.getId()).isOwner()) {
        throw new Failure(new NoSuchGroupException(group.getId()));
      }
    } catch (NoSuchGroupException e) {
      throw new Failure(new NoSuchGroupException(group.getId()));
    }
  }

  private Account findAccount(final String nameOrEmail) throws OrmException,
      Failure {
    final Account r = accountResolver.find(nameOrEmail);
    if (r == null) {
      throw new Failure(new NoSuchAccountException(nameOrEmail));
    }
    return r;
  }
}