// Copyright (C) 2016 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.extensions.events;

import com.google.common.collect.Maps;
import com.google.gerrit.extensions.api.changes.NotifyHandling;
import com.google.gerrit.extensions.common.AccountInfo;
import com.google.gerrit.extensions.common.ApprovalInfo;
import com.google.gerrit.extensions.common.ChangeInfo;
import com.google.gerrit.extensions.common.RevisionInfo;
import com.google.gerrit.extensions.events.VoteDeletedListener;
import com.google.gerrit.extensions.registration.DynamicSet;
import com.google.gerrit.reviewdb.client.Account;
import com.google.gerrit.reviewdb.client.Change;
import com.google.gerrit.reviewdb.client.PatchSet;
import com.google.gerrit.server.GpgException;
import com.google.gerrit.server.patch.PatchListNotAvailableException;
import com.google.gwtorm.server.OrmException;
import com.google.inject.Inject;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.sql.Timestamp;
import java.util.Map;

public class VoteDeleted {
  private static final Logger log =
      LoggerFactory.getLogger(VoteDeleted.class);

  private final DynamicSet<VoteDeletedListener> listeners;
  private final EventUtil util;

  @Inject
  VoteDeleted(DynamicSet<VoteDeletedListener> listeners,
      EventUtil util) {
    this.listeners = listeners;
    this.util = util;
  }

  public void fire(Change change, PatchSet ps,
      Map<String, Short> approvals,
      Map<String, Short> oldApprovals,
      NotifyHandling notify, String message,
      Account remover, Timestamp when) {
    if (!listeners.iterator().hasNext()) {
      return;
    }
    try {
      Event event = new Event(
          util.changeInfo(change),
          util.revisionInfo(change.getProject(), ps),
          util.approvals(remover, approvals, when),
          util.approvals(remover, oldApprovals, when),
          notify, message,
          util.accountInfo(remover), when);
      for (VoteDeletedListener l : listeners) {
        try {
          l.onVoteDeleted(event);
        } catch (Exception e) {
          util.logEventListenerError(this, l, e);
        }
      }
    } catch (PatchListNotAvailableException | GpgException | IOException
        | OrmException e) {
      log.error("Couldn't fire event", e);
    }
  }

  private static class Event extends AbstractRevisionEvent
      implements VoteDeletedListener.Event {

    private final Map<String, ApprovalInfo> approvals;
    private final Map<String, ApprovalInfo> oldApprovals;
    private final String message;

    Event(ChangeInfo change, RevisionInfo revision,
        Map<String, ApprovalInfo> approvals,
        Map<String, ApprovalInfo> oldApprovals,
        NotifyHandling notify, String message,
        AccountInfo remover, Timestamp when) {
      super(change, revision, remover, when, notify);
      this.approvals = approvals;
      this.oldApprovals = oldApprovals;
      this.message = message;
    }

    @Override
    public Map<String, ApprovalInfo> getApprovals() {
      return approvals;
    }

    @Override
    public Map<String, ApprovalInfo> getOldApprovals() {
      return oldApprovals;
    }

    @Override
    public Map<String, ApprovalInfo> getRemoved() {
      return Maps.difference(oldApprovals, approvals).entriesOnlyOnLeft();
    }

    @Override
    public String getMessage() {
      return message;
    }
  }
}