// Copyright (C) 2014 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.config;

import com.google.gerrit.extensions.registration.DynamicMap;
import com.google.gerrit.extensions.restapi.AuthException;
import com.google.gerrit.extensions.restapi.ChildCollection;
import com.google.gerrit.extensions.restapi.IdString;
import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
import com.google.gerrit.extensions.restapi.RestView;
import com.google.gerrit.server.CurrentUser;
import com.google.gerrit.server.IdentifiedUser;
import com.google.gerrit.server.git.WorkQueue;
import com.google.gerrit.server.git.WorkQueue.ProjectTask;
import com.google.gerrit.server.git.WorkQueue.Task;
import com.google.gerrit.server.project.ProjectCache;
import com.google.gerrit.server.project.ProjectState;
import com.google.inject.Inject;
import com.google.inject.Provider;
import com.google.inject.Singleton;

@Singleton
public class TasksCollection implements
    ChildCollection<ConfigResource, TaskResource> {
  private final DynamicMap<RestView<TaskResource>> views;
  private final ListTasks list;
  private final WorkQueue workQueue;
  private final Provider<IdentifiedUser> self;
  private final ProjectCache projectCache;

  @Inject
  TasksCollection(DynamicMap<RestView<TaskResource>> views, ListTasks list,
      WorkQueue workQueue, Provider<IdentifiedUser> self,
      ProjectCache projectCache) {
    this.views = views;
    this.list = list;
    this.workQueue = workQueue;
    this.self = self;
    this.projectCache = projectCache;
  }

  @Override
  public RestView<ConfigResource> list() {
    return list;
  }

  @Override
  public TaskResource parse(ConfigResource parent, IdString id)
      throws ResourceNotFoundException, AuthException {
    CurrentUser user = self.get();
    if (!user.isIdentifiedUser()) {
      throw new AuthException("Authentication required");
    }

    try {
      int taskId = (int) Long.parseLong(id.get(), 16);
      Task<?> task = workQueue.getTask(taskId);
      if (task != null) {
        if (self.get().getCapabilities().canViewQueue()) {
          return new TaskResource(task);
        } else if (task instanceof ProjectTask) {
          ProjectTask<?> projectTask = ((ProjectTask<?>) task);
          ProjectState e = projectCache.get(projectTask.getProjectNameKey());
          if (e != null && e.controlFor(user).isVisible()) {
            return new TaskResource(task);
          }
        }
      }
      throw new ResourceNotFoundException(id);
    } catch (NumberFormatException e) {
      throw new ResourceNotFoundException(id);
    }
  }

  @Override
  public DynamicMap<RestView<TaskResource>> views() {
    return views;
  }
}