#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2010 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
 *
 * This file is part of HeuristicLab.
 *
 * HeuristicLab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HeuristicLab 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;

namespace HeuristicLab.Services.Hive.DataAccess {
  using HeuristicLab.Services.Hive.Common.DataTransfer;
  using HeuristicLab.Services.Hive.DataAccess.Properties;
  using DT = HeuristicLab.Services.Hive.Common.DataTransfer;

  public class HiveDao : IHiveDao {
    public static HiveDataContext CreateContext() {
      return new HiveDataContext(Settings.Default.HeuristicLab_Hive_LinqConnectionString);
    }

    public HiveDao() {
    }

    #region Job Methods
    public DT.Job GetJob(Guid id) {
      using (var db = CreateContext()) {
        return Convert.ToDto(db.Jobs.SingleOrDefault(x => x.JobId == id));
      }
    }

    public IEnumerable<DT.Job> GetJobs(Expression<Func<Job, bool>> predicate) {
      using (var db = CreateContext()) {
        return db.Jobs.Where(predicate).Select(x => Convert.ToDto(x)).ToArray();
      }
    }

    public Guid AddJob(DT.Job dto) {
      using (var db = CreateContext()) {
        var entity = Convert.ToEntity(dto);
        db.Jobs.InsertOnSubmit(entity);
        db.SubmitChanges();
        foreach (Guid pluginId in dto.PluginsNeededIds) {
          db.RequiredPlugins.InsertOnSubmit(new RequiredPlugin() { JobId = entity.JobId, PluginId = pluginId });
        }
        db.SubmitChanges();
        return entity.JobId;
      }
    }

    public void UpdateJob(DT.Job dto) {
      using (var db = CreateContext()) {
        var entity = db.Jobs.FirstOrDefault(x => x.JobId == dto.Id);
        if (entity == null) db.Jobs.InsertOnSubmit(Convert.ToEntity(dto));
        else Convert.ToEntity(dto, entity);
        // todo: update required plugins
        db.SubmitChanges();
      }
    }

    public void DeleteJob(Guid id) {
      using (var db = CreateContext()) {
        var entity = db.Jobs.FirstOrDefault(x => x.JobId == id);
        if (entity != null) db.Jobs.DeleteOnSubmit(entity);
        db.SubmitChanges(); // JobData and child jobs are deleted by db-trigger
      }
    }

    public IEnumerable<DT.Job> GetWaitingParentJobs(Guid slaveId) {
      using (var db = CreateContext()) {
        // todo: slaveId is unused!
        var query = from ar in db.AssignedResources
                    where ar.Job.JobState == JobState.WaitingForChildJobs &&
                      (from child in db.Jobs
                       where child.ParentJobId == ar.Job.JobId
                       select child.JobState == JobState.Finished).All(x => x) &&
                      (from child in db.Jobs // avoid returning WaitForChildJobs jobs where no child-jobs exist (yet)
                       where child.ParentJobId == ar.Job.JobId
                       select child).Count() > 0
                    orderby ar.Job.Priority descending
                    select Convert.ToDto(ar.Job);
        return query.ToArray();
      }
    }

    public IEnumerable<DT.Job> GetWaitingJobs(DT.Slave slave) {
      using (var db = CreateContext()) {
        var query = from j in db.Jobs
                    where j.JobState == JobState.Waiting && j.CoresNeeded <= slave.FreeCores && j.MemoryNeeded <= slave.FreeMemory
                    orderby j.Priority descending
                    select Convert.ToDto(j);
        var waitingJobs = query.ToArray();
        var waitingParentJobs = GetWaitingParentJobs(slave.Id);
        return waitingJobs.Union(waitingParentJobs).OrderByDescending(x => x.Priority);
      }
    }
    #endregion

    #region JobData Methods

    public DT.JobData GetJobData(Guid id) {
      using (var db = CreateContext()) {
        return Convert.ToDto(db.JobDatas.SingleOrDefault(x => x.JobId == id));
      }
    }

    public IEnumerable<DT.JobData> GetJobDatas(Expression<Func<JobData, bool>> predicate) {
      using (var db = CreateContext()) {
        return db.JobDatas.Where(predicate).Select(x => Convert.ToDto(x)).ToArray();
      }
    }

    public Guid AddJobData(DT.JobData dto) {
      using (var db = CreateContext()) {
        var entity = Convert.ToEntity(dto);
        db.JobDatas.InsertOnSubmit(entity);
        db.SubmitChanges();
        return entity.JobId;
      }
    }

    public void UpdateJobData(DT.JobData dto) {
      using (var db = CreateContext()) {
        var entity = db.JobDatas.FirstOrDefault(x => x.JobId == dto.JobId);
        if (entity == null) db.JobDatas.InsertOnSubmit(Convert.ToEntity(dto));
        else Convert.ToEntity(dto, entity);
        db.SubmitChanges();
      }
    }

    public void DeleteJobData(Guid id) {
      using (var db = CreateContext()) {
        var entity = db.JobDatas.FirstOrDefault(x => x.JobId == id); // check if all the byte[] is loaded into memory here. otherwise work around to delete without loading it
        if (entity != null) db.JobDatas.DeleteOnSubmit(entity);
        db.SubmitChanges();
      }
    }
    #endregion

    #region HiveExperiment Methods
    public DT.HiveExperiment GetHiveExperiment(Guid id) {
      using (var db = CreateContext()) {
        return Convert.ToDto(db.HiveExperiments.SingleOrDefault(x => x.HiveExperimentId == id));
      }
    }

    public IEnumerable<DT.HiveExperiment> GetHiveExperiments(Expression<Func<HiveExperiment, bool>> predicate) {
      using (var db = CreateContext()) {
        return db.HiveExperiments.Where(predicate).Select(x => Convert.ToDto(x)).ToArray();
      }
    }

    public Guid AddHiveExperiment(DT.HiveExperiment dto) {
      using (var db = CreateContext()) {
        var entity = Convert.ToEntity(dto);
        db.HiveExperiments.InsertOnSubmit(entity);
        db.SubmitChanges();
        return entity.HiveExperimentId;
      }
    }

    public void UpdateHiveExperiment(DT.HiveExperiment dto) {
      using (var db = CreateContext()) {
        var entity = db.HiveExperiments.FirstOrDefault(x => x.HiveExperimentId == dto.Id);
        if (entity == null) db.HiveExperiments.InsertOnSubmit(Convert.ToEntity(dto));
        else Convert.ToEntity(dto, entity);
        db.SubmitChanges();
      }
    }

    public void DeleteHiveExperiment(Guid id) {
      using (var db = CreateContext()) {
        var entity = db.HiveExperiments.FirstOrDefault(x => x.HiveExperimentId == id);
        if (entity != null) db.HiveExperiments.DeleteOnSubmit(entity);
        db.SubmitChanges();
      }
    }
    #endregion

    #region Plugin Methods
    public DT.Plugin GetPlugin(Guid id) {
      using (var db = CreateContext()) {
        return Convert.ToDto(db.Plugins.SingleOrDefault(x => x.PluginId == id));
      }
    }

    public IEnumerable<DT.Plugin> GetPlugins(Expression<Func<Plugin, bool>> predicate) {
      using (var db = CreateContext()) {
        return db.Plugins.Where(predicate).Select(x => Convert.ToDto(x)).ToArray();
      }
    }

    public Guid AddPlugin(DT.Plugin dto) {
      using (var db = CreateContext()) {
        var entity = Convert.ToEntity(dto);
        db.Plugins.InsertOnSubmit(entity);
        db.SubmitChanges();
        return entity.PluginId;
      }
    }

    public void UpdatePlugin(DT.Plugin dto) {
      using (var db = CreateContext()) {
        var entity = db.Plugins.FirstOrDefault(x => x.PluginId == dto.Id);
        if (entity == null) db.Plugins.InsertOnSubmit(Convert.ToEntity(dto));
        else Convert.ToEntity(dto, entity);
        db.SubmitChanges();
      }
    }

    public void DeletePlugin(Guid id) {
      using (var db = CreateContext()) {
        var entity = db.Plugins.FirstOrDefault(x => x.PluginId == id);
        if (entity != null) db.Plugins.DeleteOnSubmit(entity);
        db.SubmitChanges();
      }
    }
    #endregion

    #region PluginData Methods

    public DT.PluginData GetPluginData(Guid id) {
      using (var db = CreateContext()) {
        return Convert.ToDto(db.PluginDatas.SingleOrDefault(x => x.PluginDataId == id));
      }
    }

    public IEnumerable<DT.PluginData> GetPluginDatas(Expression<Func<PluginData, bool>> predicate) {
      using (var db = CreateContext()) {
        return db.PluginDatas.Where(predicate).Select(x => Convert.ToDto(x)).ToArray();
      }
    }

    public Guid AddPluginData(DT.PluginData dto) {
      using (var db = CreateContext()) {
        var entity = Convert.ToEntity(dto);
        db.PluginDatas.InsertOnSubmit(entity);
        db.SubmitChanges();
        return entity.PluginDataId;
      }
    }

    public void UpdatePluginData(DT.PluginData dto) {
      using (var db = CreateContext()) {
        var entity = db.PluginDatas.FirstOrDefault(x => x.PluginId == dto.PluginId);
        if (entity == null) db.PluginDatas.InsertOnSubmit(Convert.ToEntity(dto));
        else Convert.ToEntity(dto, entity);
        db.SubmitChanges();
      }
    }

    public void DeletePluginData(Guid id) {
      using (var db = CreateContext()) {
        var entity = db.PluginDatas.FirstOrDefault(x => x.PluginDataId == id); // todo: check if all the byte[] is loaded into memory here. otherwise work around to delete without loading it
        if (entity != null) db.PluginDatas.DeleteOnSubmit(entity);
        db.SubmitChanges();
      }
    }
    #endregion

    #region Slave Methods
    public DT.Slave GetSlave(Guid id) {
      using (var db = CreateContext()) {
        return Convert.ToDto(db.Resources.OfType<Slave>().SingleOrDefault(x => x.ResourceId == id));
      }
    }

    public IEnumerable<DT.Slave> GetSlaves(Expression<Func<Slave, bool>> predicate) {
      using (var db = CreateContext()) {
        return db.Resources.OfType<Slave>().Where(predicate).Select(x => Convert.ToDto(x)).ToArray();
      }
    }

    public Guid AddSlave(DT.Slave dto) {
      using (var db = CreateContext()) {
        var entity = Convert.ToEntity(dto);
        db.Resources.InsertOnSubmit(entity);
        db.SubmitChanges();
        return entity.ResourceId;
      }
    }

    public void UpdateSlave(DT.Slave dto) {
      using (var db = CreateContext()) {
        var entity = db.Resources.OfType<Slave>().FirstOrDefault(x => x.ResourceId == dto.Id);
        if (entity == null) db.Resources.InsertOnSubmit(Convert.ToEntity(dto));
        else Convert.ToEntity(dto, entity);
        db.SubmitChanges();
      }
    }

    public void DeleteSlave(Guid id) {
      using (var db = CreateContext()) {
        var entity = db.Resources.OfType<Slave>().FirstOrDefault(x => x.ResourceId == id);
        if (entity != null) db.Resources.DeleteOnSubmit(entity);
        db.SubmitChanges();
      }
    }
    #endregion

    #region SlaveGroup Methods
    public DT.SlaveGroup GetSlaveGroup(Guid id) {
      using (var db = CreateContext()) {
        return Convert.ToDto(db.Resources.OfType<SlaveGroup>().SingleOrDefault(x => x.ResourceId == id));
      }
    }

    public IEnumerable<DT.SlaveGroup> GetSlaveGroups(Expression<Func<SlaveGroup, bool>> predicate) {
      using (var db = CreateContext()) {
        return db.Resources.OfType<SlaveGroup>().Where(predicate).Select(x => Convert.ToDto(x)).ToArray();
      }
    }

    public Guid AddSlaveGroup(DT.SlaveGroup dto) {
      using (var db = CreateContext()) {
        if (dto.Id == Guid.Empty)
          dto.Id = Guid.NewGuid();
        var entity = Convert.ToEntity(dto);
        db.Resources.InsertOnSubmit(entity);
        db.SubmitChanges();
        return entity.ResourceId;
      }
    }

    public void UpdateSlaveGroup(DT.SlaveGroup dto) {
      using (var db = CreateContext()) {
        var entity = db.Resources.OfType<SlaveGroup>().FirstOrDefault(x => x.ResourceId == dto.Id);
        if (entity == null) db.Resources.InsertOnSubmit(Convert.ToEntity(dto));
        else Convert.ToEntity(dto, entity);
        db.SubmitChanges();
      }
    }

    public void DeleteSlaveGroup(Guid id) {
      using (var db = CreateContext()) {
        var entity = db.Resources.OfType<SlaveGroup>().FirstOrDefault(x => x.ResourceId == id);
        if (entity != null) db.Resources.DeleteOnSubmit(entity);
        db.SubmitChanges();
      }
    }
    #endregion

    #region Resource Methods
    public DT.Resource GetResource(Guid id) {
      using (var db = CreateContext()) {
        return Convert.ToDto(db.Resources.SingleOrDefault(x => x.ResourceId == id));
      }
    }

    public IEnumerable<DT.Resource> GetResources(Expression<Func<Resource, bool>> predicate) {
      using (var db = CreateContext()) {
        return db.Resources.Where(predicate).Select(x => Convert.ToDto(x)).ToArray();
      }
    }

    public Guid AddResource(DT.Resource dto) {
      using (var db = CreateContext()) {
        var entity = Convert.ToEntity(dto);
        db.Resources.InsertOnSubmit(entity);
        db.SubmitChanges();
        return entity.ResourceId;
      }
    }

    public void UpdateResource(DT.Resource dto) {
      using (var db = CreateContext()) {
        var entity = db.Resources.FirstOrDefault(x => x.ResourceId == dto.Id);
        if (entity == null) db.Resources.InsertOnSubmit(Convert.ToEntity(dto));
        else Convert.ToEntity(dto, entity);
        db.SubmitChanges();
      }
    }

    public void DeleteResource(Guid id) {
      using (var db = CreateContext()) {
        var entity = db.Resources.FirstOrDefault(x => x.ResourceId == id);
        if (entity != null) db.Resources.DeleteOnSubmit(entity);
        db.SubmitChanges();
      }
    }

    public void AssignJobToResource(Guid jobId, Guid resourceId) {
      using (var db = CreateContext()) {
        var job = db.Jobs.Where(x => x.JobId == jobId).Single();
        job.AssignedResources.Add(new AssignedResource() { JobId = jobId, ResourceId = resourceId });
        db.SubmitChanges();
      }
    }

    public IEnumerable<DT.Resource> GetAssignedResources(Guid jobId) {
      using (var db = CreateContext()) {
        var job = db.Jobs.Where(x => x.JobId == jobId).Single();
        return job.AssignedResources.Select(x => Convert.ToDto(x.Resource)).ToArray();
      }
    }
    #endregion

    #region Authorization Methods
    public bool IsUserAuthorizedForJobs(Guid userId, params Guid[] jobIds) {
      using (var db = CreateContext()) {
        var userIds = from job in db.Jobs // this needs to be fast!
                      where jobIds.Contains(job.JobId)
                      select job.UserId;
        return userIds.All(x => x == userId);
      }
    }
    #endregion
  }
}