using MediaBrowser.Common.Configuration;
using MediaBrowser.Controller.Entities;
using MediaBrowser.Controller.Persistence;
using MediaBrowser.Model.Logging;
using System;
using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Threading;
using System.Threading.Tasks;

namespace MediaBrowser.Server.Implementations.Persistence
{
    public class SqliteUserDataRepository : BaseSqliteRepository, IUserDataRepository
    {
        private IDbConnection _connection;
        private readonly IApplicationPaths _appPaths;

        public SqliteUserDataRepository(ILogManager logManager, IApplicationPaths appPaths) : base(logManager)
        {
            _appPaths = appPaths;
        }

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

        /// <summary>
        /// Opens the connection to the database
        /// </summary>
        /// <returns>Task.</returns>
        public async Task Initialize()
        {
            var dbFile = Path.Combine(_appPaths.DataPath, "userdata_v2.db");

            _connection = await SqliteExtensions.ConnectToDb(dbFile, Logger).ConfigureAwait(false);

            string[] queries = {

                                "create table if not exists userdata (key nvarchar, userId GUID, rating float null, played bit, playCount int, isFavorite bit, playbackPositionTicks bigint, lastPlayedDate datetime null)",

                                "create unique index if not exists userdataindex on userdata (key, userId)",

                                //pragmas
                                "pragma temp_store = memory",

                                "pragma shrink_memory"
                               };

            _connection.RunQueries(queries, Logger);
        }

        /// <summary>
        /// Saves the user data.
        /// </summary>
        /// <param name="userId">The user id.</param>
        /// <param name="key">The key.</param>
        /// <param name="userData">The user data.</param>
        /// <param name="cancellationToken">The cancellation token.</param>
        /// <returns>Task.</returns>
        /// <exception cref="System.ArgumentNullException">userData
        /// or
        /// cancellationToken
        /// or
        /// userId
        /// or
        /// userDataId</exception>
        public Task SaveUserData(Guid userId, string key, UserItemData userData, CancellationToken cancellationToken)
        {
            if (userData == null)
            {
                throw new ArgumentNullException("userData");
            }
            if (userId == Guid.Empty)
            {
                throw new ArgumentNullException("userId");
            }
            if (string.IsNullOrEmpty(key))
            {
                throw new ArgumentNullException("key");
            }

            return PersistUserData(userId, key, userData, cancellationToken);
        }

        public Task SaveAllUserData(Guid userId, IEnumerable<UserItemData> userData, CancellationToken cancellationToken)
        {
            if (userData == null)
            {
                throw new ArgumentNullException("userData");
            }
            if (userId == Guid.Empty)
            {
                throw new ArgumentNullException("userId");
            }

            return PersistAllUserData(userId, userData, cancellationToken);
        }

        /// <summary>
        /// Persists the user data.
        /// </summary>
        /// <param name="userId">The user id.</param>
        /// <param name="key">The key.</param>
        /// <param name="userData">The user data.</param>
        /// <param name="cancellationToken">The cancellation token.</param>
        /// <returns>Task.</returns>
        public async Task PersistUserData(Guid userId, string key, UserItemData userData, CancellationToken cancellationToken)
        {
            cancellationToken.ThrowIfCancellationRequested();

            await WriteLock.WaitAsync(cancellationToken).ConfigureAwait(false);

            IDbTransaction transaction = null;

            try
            {
                transaction = _connection.BeginTransaction();

                using (var cmd = _connection.CreateCommand())
                {
                    cmd.CommandText = "replace into userdata (key, userId, rating,played,playCount,isFavorite,playbackPositionTicks,lastPlayedDate) values (@key, @userId, @rating,@played,@playCount,@isFavorite,@playbackPositionTicks,@lastPlayedDate)";

                    cmd.Parameters.Add(cmd, "@key", DbType.String).Value = key;
                    cmd.Parameters.Add(cmd, "@userId", DbType.Guid).Value = userId;
                    cmd.Parameters.Add(cmd, "@rating", DbType.Double).Value = userData.Rating;
                    cmd.Parameters.Add(cmd, "@played", DbType.Boolean).Value = userData.Played;
                    cmd.Parameters.Add(cmd, "@playCount", DbType.Int32).Value = userData.PlayCount;
                    cmd.Parameters.Add(cmd, "@isFavorite", DbType.Boolean).Value = userData.IsFavorite;
                    cmd.Parameters.Add(cmd, "@playbackPositionTicks", DbType.Int64).Value = userData.PlaybackPositionTicks;
                    cmd.Parameters.Add(cmd, "@lastPlayedDate", DbType.DateTime).Value = userData.LastPlayedDate;

                    cmd.Transaction = transaction;

                    cmd.ExecuteNonQuery();
                }

                transaction.Commit();
            }
            catch (OperationCanceledException)
            {
                if (transaction != null)
                {
                    transaction.Rollback();
                }

                throw;
            }
            catch (Exception e)
            {
                Logger.ErrorException("Failed to save user data:", e);

                if (transaction != null)
                {
                    transaction.Rollback();
                }

                throw;
            }
            finally
            {
                if (transaction != null)
                {
                    transaction.Dispose();
                }

                WriteLock.Release();
            }
        }

        /// <summary>
        /// Persist all user data for the specified user
        /// </summary>
        /// <param name="userId"></param>
        /// <param name="userData"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        private async Task PersistAllUserData(Guid userId, IEnumerable<UserItemData> userData, CancellationToken cancellationToken)
        {
            cancellationToken.ThrowIfCancellationRequested();

            await WriteLock.WaitAsync(cancellationToken).ConfigureAwait(false);

            IDbTransaction transaction = null;

            try
            {
                transaction = _connection.BeginTransaction();

                foreach (var userItemData in userData)
                {
                    using (var cmd = _connection.CreateCommand())
                    {
                        cmd.CommandText = "replace into userdata (key, userId, rating,played,playCount,isFavorite,playbackPositionTicks,lastPlayedDate) values (@key, @userId, @rating,@played,@playCount,@isFavorite,@playbackPositionTicks,@lastPlayedDate)";

                        cmd.Parameters.Add(cmd, "@key", DbType.String).Value = userItemData.Key;
                        cmd.Parameters.Add(cmd, "@userId", DbType.Guid).Value = userId;
                        cmd.Parameters.Add(cmd, "@rating", DbType.Double).Value = userItemData.Rating;
                        cmd.Parameters.Add(cmd, "@played", DbType.Boolean).Value = userItemData.Played;
                        cmd.Parameters.Add(cmd, "@playCount", DbType.Int32).Value = userItemData.PlayCount;
                        cmd.Parameters.Add(cmd, "@isFavorite", DbType.Boolean).Value = userItemData.IsFavorite;
                        cmd.Parameters.Add(cmd, "@playbackPositionTicks", DbType.Int64).Value = userItemData.PlaybackPositionTicks;
                        cmd.Parameters.Add(cmd, "@lastPlayedDate", DbType.DateTime).Value = userItemData.LastPlayedDate;

                        cmd.Transaction = transaction;

                        cmd.ExecuteNonQuery();
                    }

                    cancellationToken.ThrowIfCancellationRequested();
                }

                transaction.Commit();
            }
            catch (OperationCanceledException)
            {
                if (transaction != null)
                {
                    transaction.Rollback();
                }

                throw;
            }
            catch (Exception e)
            {
                Logger.ErrorException("Failed to save user data:", e);

                if (transaction != null)
                {
                    transaction.Rollback();
                }

                throw;
            }
            finally
            {
                if (transaction != null)
                {
                    transaction.Dispose();
                }

                WriteLock.Release();
            }
        }

        /// <summary>
        /// Gets the user data.
        /// </summary>
        /// <param name="userId">The user id.</param>
        /// <param name="key">The key.</param>
        /// <returns>Task{UserItemData}.</returns>
        /// <exception cref="System.ArgumentNullException">
        /// userId
        /// or
        /// key
        /// </exception>
        public UserItemData GetUserData(Guid userId, string key)
        {
            if (userId == Guid.Empty)
            {
                throw new ArgumentNullException("userId");
            }
            if (string.IsNullOrEmpty(key))
            {
                throw new ArgumentNullException("key");
            }

            using (var cmd = _connection.CreateCommand())
            {
                cmd.CommandText = "select key,userid,rating,played,playCount,isFavorite,playbackPositionTicks,lastPlayedDate from userdata where key = @key and userId=@userId";

                cmd.Parameters.Add(cmd, "@key", DbType.String).Value = key;
                cmd.Parameters.Add(cmd, "@userId", DbType.Guid).Value = userId;

                using (var reader = cmd.ExecuteReader(CommandBehavior.SequentialAccess | CommandBehavior.SingleResult | CommandBehavior.SingleRow))
                {
                    if (reader.Read())
                    {
                        return ReadRow(reader);
                    }
                }

                return new UserItemData
                {
                    UserId = userId,
                    Key = key
                };
            }
        }

        /// <summary>
        /// Return all user-data associated with the given user
        /// </summary>
        /// <param name="userId"></param>
        /// <returns></returns>
        public IEnumerable<UserItemData> GetAllUserData(Guid userId)
        {
            if (userId == Guid.Empty)
            {
                throw new ArgumentNullException("userId");
            }

            using (var cmd = _connection.CreateCommand())
            {
                cmd.CommandText = "select key,userid,rating,played,playCount,isFavorite,playbackPositionTicks,lastPlayedDate from userdata where userId=@userId";

                cmd.Parameters.Add(cmd, "@userId", DbType.Guid).Value = userId;

                using (var reader = cmd.ExecuteReader(CommandBehavior.SequentialAccess | CommandBehavior.SingleResult))
                {
                    while (reader.Read())
                    {
                        yield return ReadRow(reader);
                    }
                }
            }
        }

        /// <summary>
        /// Read a row from the specified reader into the provided userData object
        /// </summary>
        /// <param name="reader"></param>
        private UserItemData ReadRow(IDataReader reader)
        {
            var userData = new UserItemData();

            userData.Key = reader.GetString(0);
            userData.UserId = reader.GetGuid(1);

            if (!reader.IsDBNull(2))
            {
                userData.Rating = reader.GetDouble(2);
            }

            userData.Played = reader.GetBoolean(3);
            userData.PlayCount = reader.GetInt32(4);
            userData.IsFavorite = reader.GetBoolean(5);
            userData.PlaybackPositionTicks = reader.GetInt64(6);

            if (!reader.IsDBNull(7))
            {
                userData.LastPlayedDate = reader.GetDateTime(7).ToUniversalTime();
            }

            return userData;
        }

        protected override void CloseConnection()
        {
            if (_connection != null)
            {
                if (_connection.IsOpen())
                {
                    _connection.Close();
                }

                _connection.Dispose();
                _connection = null;
            }
        }
    }
}