using System;
using System.Collections.Generic;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
using MediaBrowser.Common.Configuration;
using MediaBrowser.Common.Extensions;
using MediaBrowser.Controller.Persistence;
using MediaBrowser.Model.Entities;
using MediaBrowser.Model.IO;
using MediaBrowser.Model.Logging;
using MediaBrowser.Model.Serialization;
using SQLitePCL.pretty;

namespace Emby.Server.Implementations.Data
{
    /// <summary>
    /// Class SQLiteDisplayPreferencesRepository
    /// </summary>
    public class SqliteDisplayPreferencesRepository : BaseSqliteRepository, IDisplayPreferencesRepository
    {
        private readonly IMemoryStreamFactory _memoryStreamProvider;

        public SqliteDisplayPreferencesRepository(ILogger logger, IJsonSerializer jsonSerializer, IApplicationPaths appPaths, IMemoryStreamFactory memoryStreamProvider)
            : base(logger)
        {
            _jsonSerializer = jsonSerializer;
            _memoryStreamProvider = memoryStreamProvider;
            DbFilePath = Path.Combine(appPaths.DataPath, "displaypreferences.db");
        }

        /// <summary>
        /// Gets the name of the repository
        /// </summary>
        /// <value>The name.</value>
        public string Name
        {
            get
            {
                return "SQLite";
            }
        }

        /// <summary>
        /// The _json serializer
        /// </summary>
        private readonly IJsonSerializer _jsonSerializer;

        /// <summary>
        /// Opens the connection to the database
        /// </summary>
        /// <returns>Task.</returns>
        public void Initialize()
        {
            using (var connection = CreateConnection())
            {
                string[] queries = {

                                "create table if not exists userdisplaypreferences (id GUID, userId GUID, client text, data BLOB)",
                                "create unique index if not exists userdisplaypreferencesindex on userdisplaypreferences (id, userId, client)"
                               };

                connection.RunQueries(queries);
            }
        }

        /// <summary>
        /// Save the display preferences associated with an item in the repo
        /// </summary>
        /// <param name="displayPreferences">The display preferences.</param>
        /// <param name="userId">The user id.</param>
        /// <param name="client">The client.</param>
        /// <param name="cancellationToken">The cancellation token.</param>
        /// <returns>Task.</returns>
        /// <exception cref="System.ArgumentNullException">item</exception>
        public async Task SaveDisplayPreferences(DisplayPreferences displayPreferences, Guid userId, string client, CancellationToken cancellationToken)
        {
            if (displayPreferences == null)
            {
                throw new ArgumentNullException("displayPreferences");
            }
            if (string.IsNullOrWhiteSpace(displayPreferences.Id))
            {
                throw new ArgumentNullException("displayPreferences.Id");
            }

            cancellationToken.ThrowIfCancellationRequested();

            lock (WriteLock)
            {
                using (var connection = CreateConnection())
                {
                    connection.RunInTransaction(db =>
                    {
                        SaveDisplayPreferences(displayPreferences, userId, client, db);
                    });
                }
            }
        }

        private void SaveDisplayPreferences(DisplayPreferences displayPreferences, Guid userId, string client, IDatabaseConnection connection)
        {
            var commandText = "replace into userdisplaypreferences (id, userid, client, data) values (?, ?, ?, ?)";
            var serialized = _jsonSerializer.SerializeToBytes(displayPreferences, _memoryStreamProvider);

            connection.Execute(commandText,
                displayPreferences.Id.ToGuidParamValue(),
                userId.ToGuidParamValue(),
                client,
                serialized);
        }

        /// <summary>
        /// Save all display preferences associated with a user in the repo
        /// </summary>
        /// <param name="displayPreferences">The display preferences.</param>
        /// <param name="userId">The user id.</param>
        /// <param name="cancellationToken">The cancellation token.</param>
        /// <returns>Task.</returns>
        /// <exception cref="System.ArgumentNullException">item</exception>
        public async Task SaveAllDisplayPreferences(IEnumerable<DisplayPreferences> displayPreferences, Guid userId, CancellationToken cancellationToken)
        {
            if (displayPreferences == null)
            {
                throw new ArgumentNullException("displayPreferences");
            }

            cancellationToken.ThrowIfCancellationRequested();

            lock (WriteLock)
            {
                using (var connection = CreateConnection())
                {
                    connection.RunInTransaction(db =>
                    {
                        foreach (var displayPreference in displayPreferences)
                        {
                            SaveDisplayPreferences(displayPreference, userId, displayPreference.Client, db);
                        }
                    });
                }
            }
        }

        /// <summary>
        /// Gets the display preferences.
        /// </summary>
        /// <param name="displayPreferencesId">The display preferences id.</param>
        /// <param name="userId">The user id.</param>
        /// <param name="client">The client.</param>
        /// <returns>Task{DisplayPreferences}.</returns>
        /// <exception cref="System.ArgumentNullException">item</exception>
        public DisplayPreferences GetDisplayPreferences(string displayPreferencesId, Guid userId, string client)
        {
            if (string.IsNullOrWhiteSpace(displayPreferencesId))
            {
                throw new ArgumentNullException("displayPreferencesId");
            }

            var guidId = displayPreferencesId.GetMD5();

            using (var connection = CreateConnection(true))
            {
                var commandText = "select data from userdisplaypreferences where id = ? and userId=? and client=?";

                var paramList = new List<object>();
                paramList.Add(guidId.ToGuidParamValue());
                paramList.Add(userId.ToGuidParamValue());
                paramList.Add(client);

                foreach (var row in connection.Query(commandText, paramList.ToArray()))
                {
                    return Get(row);
                }

                return new DisplayPreferences
                {
                    Id = guidId.ToString("N")
                };
            }
        }

        /// <summary>
        /// Gets all display preferences for the given user.
        /// </summary>
        /// <param name="userId">The user id.</param>
        /// <returns>Task{DisplayPreferences}.</returns>
        /// <exception cref="System.ArgumentNullException">item</exception>
        public IEnumerable<DisplayPreferences> GetAllDisplayPreferences(Guid userId)
        {
            var list = new List<DisplayPreferences>();

            using (var connection = CreateConnection(true))
            {
                var commandText = "select data from userdisplaypreferences where userId=?";

                var paramList = new List<object>();
                paramList.Add(userId.ToGuidParamValue());

                foreach (var row in connection.Query(commandText, paramList.ToArray()))
                {
                    list.Add(Get(row));
                }
            }

            return list;
        }

        private DisplayPreferences Get(IReadOnlyList<IResultSetValue> row)
        {
            using (var stream = _memoryStreamProvider.CreateNew(row[0].ToBlob()))
            {
                stream.Position = 0;
                return _jsonSerializer.DeserializeFromStream<DisplayPreferences>(stream);
            }
        }

        public Task SaveDisplayPreferences(DisplayPreferences displayPreferences, string userId, string client, CancellationToken cancellationToken)
        {
            return SaveDisplayPreferences(displayPreferences, new Guid(userId), client, cancellationToken);
        }

        public DisplayPreferences GetDisplayPreferences(string displayPreferencesId, string userId, string client)
        {
            return GetDisplayPreferences(displayPreferencesId, new Guid(userId), client);
        }
    }
}