/*
 *
 * (c) Copyright Ascensio System Limited 2010-2018
 *
 * This program is freeware. You can redistribute it and/or modify it under the terms of the GNU 
 * General Public License (GPL) version 3 as published by the Free Software Foundation (https://www.gnu.org/copyleft/gpl.html). 
 * In accordance with Section 7(a) of the GNU GPL its Section 15 shall be amended to the effect that 
 * Ascensio System SIA expressly excludes the warranty of non-infringement of any third-party rights.
 *
 * THIS PROGRAM IS DISTRIBUTED WITHOUT ANY WARRANTY; WITHOUT EVEN THE IMPLIED WARRANTY OF MERCHANTABILITY OR
 * FITNESS FOR A PARTICULAR PURPOSE. For more details, see GNU GPL at https://www.gnu.org/copyleft/gpl.html
 *
 * You can contact Ascensio System SIA by email at sales@onlyoffice.com
 *
 * The interactive user interfaces in modified source and object code versions of ONLYOFFICE must display 
 * Appropriate Legal Notices, as required under Section 5 of the GNU GPL version 3.
 *
 * Pursuant to Section 7 § 3(b) of the GNU GPL you must retain the original ONLYOFFICE logo which contains 
 * relevant author attributions when distributing the software. If the display of the logo in its graphic 
 * form is not reasonably feasible for technical reasons, you must include the words "Powered by ONLYOFFICE" 
 * in every copy of the program you distribute. 
 * Pursuant to Section 7 § 3(e) we decline to grant you any rights under trademark law for use of our trademarks.
 *
*/


using System;
using System.Collections.Generic;
using System.Configuration;
using System.Linq;
using ASC.Common.Data.Sql;
using ASC.Common.Data.Sql.Expressions;
using ASC.Core.Tenants;

namespace ASC.Core.Data
{
    public class DbSubscriptionService : DbBaseService, ISubscriptionService
    {
        public DbSubscriptionService(ConnectionStringSettings connectionString)
            : base(connectionString, "tenant")
        {

        }


        public IEnumerable<SubscriptionRecord> GetSubscriptions(int tenant, string sourceId, string actionId)
        {
            if (sourceId == null) throw new ArgumentNullException("sourceId");
            if (actionId == null) throw new ArgumentNullException("actionId");

            var q = GetQuery(tenant, sourceId, actionId);
            return GetSubscriptions(q, tenant);
        }

        public IEnumerable<SubscriptionRecord> GetSubscriptions(int tenant, string sourceId, string actionId, string recipientId, string objectId)
        {
            var q = GetQuery(tenant, sourceId, actionId);
            if (!string.IsNullOrEmpty(recipientId))
            {
                q.Where("recipient", recipientId);
            }
            else
            {
                q.Where("object", objectId ?? string.Empty);
            }

            return GetSubscriptions(q, tenant);
        }

        public SubscriptionRecord GetSubscription(int tenant, string sourceId, string actionId, string recipientId, string objectId)
        {
            if (recipientId == null) throw new ArgumentNullException("recipientId");

            var q = GetQuery(tenant, sourceId, actionId)
                .Where("recipient", recipientId)
                .Where("object", objectId ?? string.Empty);

            return GetSubscriptions(q, tenant).FirstOrDefault();
        }

        public void SaveSubscription(SubscriptionRecord s)
        {
            if (s == null) throw new ArgumentNullException("s");

            var i = Insert("core_subscription", s.Tenant)
                .InColumnValue("source", s.SourceId)
                .InColumnValue("action", s.ActionId)
                .InColumnValue("recipient", s.RecipientId)
                .InColumnValue("object", s.ObjectId ?? string.Empty)
                .InColumnValue("unsubscribed", !s.Subscribed);

            ExecNonQuery(i);
        }

        public void RemoveSubscriptions(int tenant, string sourceId, string actionId)
        {
            RemoveSubscriptions(tenant, sourceId, actionId, string.Empty);
        }

        public void RemoveSubscriptions(int tenant, string sourceId, string actionId, string objectId)
        {
            if (sourceId == null) throw new ArgumentNullException("sourceId");
            if (actionId == null) throw new ArgumentNullException("actionId");

            var d = Delete("core_subscription", tenant).Where("source", sourceId).Where("action", actionId);
            if (objectId != string.Empty)
            {
                d.Where("object", objectId ?? string.Empty);
            }
            ExecNonQuery(d);
        }


        public IEnumerable<SubscriptionMethod> GetSubscriptionMethods(int tenant, string sourceId, string actionId, string recipientId)
        {
            if (sourceId == null) throw new ArgumentNullException("sourceId");
            if (actionId == null) throw new ArgumentNullException("actionId");

            var q = new SqlQuery("core_subscriptionmethod")
                .Select("tenant", "recipient", "sender", "action")
                .Where(Exp.Eq("tenant", -1) | Exp.Eq("tenant", tenant))
                .Where("source", sourceId)
                .GroupBy("recipient", "action")
                .OrderBy("tenant", true);

            if (recipientId != null) q.Where("recipient", recipientId);

            var methods = ExecList(q)
                .ConvertAll(r => new SubscriptionMethod
                {
                    Tenant = Convert.ToInt32(r[0]),
                    SourceId = sourceId,
                    ActionId = Convert.ToString(r[3]),
                    RecipientId = (string)r[1],
                    Methods = Convert.ToString(r[2]).Split(new[] { '|' }, StringSplitOptions.RemoveEmptyEntries),
                });

            var result = methods.ToList();
            var common = new Dictionary<string, SubscriptionMethod>();
            foreach (var m in methods)
            {
                var key = m.SourceId + m.ActionId + m.RecipientId;
                if (m.Tenant == Tenant.DEFAULT_TENANT)
                {
                    m.Tenant = tenant;
                    common.Add(key, m);
                }
                else
                {
                    if (common.TryGetValue(key, out var r))
                    {
                        result.Remove(r);
                    }
                }
            }
            return result;
        }

        public void SetSubscriptionMethod(SubscriptionMethod m)
        {
            if (m == null) throw new ArgumentNullException("m");

            ISqlInstruction i;
            if (m.Methods == null || m.Methods.Length == 0)
            {
                i = Delete("core_subscriptionmethod", m.Tenant)
                    .Where("source", m.SourceId)
                    .Where("action", m.ActionId)
                    .Where("recipient", m.RecipientId);
            }
            else
            {
                i = Insert("core_subscriptionmethod", m.Tenant)
                    .InColumnValue("source", m.SourceId)
                    .InColumnValue("action", m.ActionId)
                    .InColumnValue("recipient", m.RecipientId)
                    .InColumnValue("sender", string.Join("|", m.Methods));
            }
            ExecNonQuery(i);
        }


        private SqlQuery GetQuery(int tenant, string sourceId, string actionId)
        {
            if (sourceId == null) throw new ArgumentNullException("sourceId");
            if (actionId == null) throw new ArgumentNullException("actionId");

            return new SqlQuery("core_subscription")
                .Select("tenant", "source", "action", "recipient", "object", "unsubscribed")
                .Where(Exp.Eq("tenant", -1) | Exp.Eq("tenant", tenant))
                .Where("source", sourceId)
                .Where("action", actionId)
                .OrderBy("tenant", true);
        }

        private IEnumerable<SubscriptionRecord> GetSubscriptions(ISqlInstruction q, int tenant)
        {
            var subs = ExecList(q)
                .ConvertAll(r =>
                {
                    var result = new SubscriptionRecord
                    {
                        Tenant = Convert.ToInt32(r[0]),
                        SourceId = (string)r[1],
                        ActionId = (string)r[2],
                        RecipientId = (string)r[3],
                        Subscribed = !Convert.ToBoolean(r[5]),
                    };
                    if (!string.Empty.Equals(r[4]))
                    {
                        result.ObjectId = (string)r[4];
                    }
                    return result;
                });

            var result = subs.ToList();
            var common = new Dictionary<string, SubscriptionRecord>();
            foreach (var s in subs)
            {
                var key = s.SourceId + s.ActionId + s.RecipientId + s.ObjectId;
                if (s.Tenant == Tenant.DEFAULT_TENANT)
                {
                    s.Tenant = tenant;
                    common.Add(key, s);
                }
                else
                {
                    if (common.TryGetValue(key, out var r))
                    {
                        result.Remove(r);
                    }
                }
            }
            return result;
        }
    }
}