#pragma warning disable CS1591

using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using MediaBrowser.Common.Extensions;
using MediaBrowser.Controller.Configuration;
using MediaBrowser.Controller.Devices;
using MediaBrowser.Controller.Entities;
using MediaBrowser.Controller.Library;
using MediaBrowser.Controller.Security;
using MediaBrowser.Model.Devices;
using MediaBrowser.Model.Events;
using MediaBrowser.Model.Querying;
using MediaBrowser.Model.Serialization;
using MediaBrowser.Model.Session;
using MediaBrowser.Model.Users;

namespace Emby.Server.Implementations.Devices
{
    public class DeviceManager : IDeviceManager
    {
        private readonly IJsonSerializer _json;
        private readonly IUserManager _userManager;
        private readonly IServerConfigurationManager _config;
        private readonly IAuthenticationRepository _authRepo;
        private readonly Dictionary<string, ClientCapabilities> _capabilitiesCache;

        public event EventHandler<GenericEventArgs<Tuple<string, DeviceOptions>>> DeviceOptionsUpdated;

        private readonly object _capabilitiesSyncLock = new object();

        public DeviceManager(
            IAuthenticationRepository authRepo,
            IJsonSerializer json,
            IUserManager userManager,
            IServerConfigurationManager config)
        {
            _json = json;
            _userManager = userManager;
            _config = config;
            _authRepo = authRepo;
            _capabilitiesCache = new Dictionary<string, ClientCapabilities>(StringComparer.OrdinalIgnoreCase);
        }

        public void SaveCapabilities(string deviceId, ClientCapabilities capabilities)
        {
            var path = Path.Combine(GetDevicePath(deviceId), "capabilities.json");
            Directory.CreateDirectory(Path.GetDirectoryName(path));

            lock (_capabilitiesSyncLock)
            {
                _capabilitiesCache[deviceId] = capabilities;

                _json.SerializeToFile(capabilities, path);
            }
        }

        public void UpdateDeviceOptions(string deviceId, DeviceOptions options)
        {
            _authRepo.UpdateDeviceOptions(deviceId, options);

            DeviceOptionsUpdated?.Invoke(this, new GenericEventArgs<Tuple<string, DeviceOptions>>(new Tuple<string, DeviceOptions>(deviceId, options)));
        }

        public DeviceOptions GetDeviceOptions(string deviceId)
        {
            return _authRepo.GetDeviceOptions(deviceId);
        }

        public ClientCapabilities GetCapabilities(string id)
        {
            lock (_capabilitiesSyncLock)
            {
                if (_capabilitiesCache.TryGetValue(id, out var result))
                {
                    return result;
                }

                var path = Path.Combine(GetDevicePath(id), "capabilities.json");
                try
                {
                    return _json.DeserializeFromFile<ClientCapabilities>(path) ?? new ClientCapabilities();
                }
                catch
                {
                }
            }

            return new ClientCapabilities();
        }

        public DeviceInfo GetDevice(string id)
        {
            return GetDevice(id, true);
        }

        private DeviceInfo GetDevice(string id, bool includeCapabilities)
        {
            var session = _authRepo.Get(new AuthenticationInfoQuery
            {
                DeviceId = id
            }).Items.FirstOrDefault();

            var device = session == null ? null : ToDeviceInfo(session);

            return device;
        }

        public QueryResult<DeviceInfo> GetDevices(DeviceQuery query)
        {
            IEnumerable<AuthenticationInfo> sessions = _authRepo.Get(new AuthenticationInfoQuery
            {
                //UserId = query.UserId
                HasUser = true
            }).Items;

            // TODO: DeviceQuery doesn't seem to be used from client. Not even Swagger.
            if (query.SupportsSync.HasValue)
            {
                var val = query.SupportsSync.Value;

                sessions = sessions.Where(i => GetCapabilities(i.DeviceId).SupportsSync == val);
            }

            if (!query.UserId.Equals(Guid.Empty))
            {
                var user = _userManager.GetUserById(query.UserId);

                sessions = sessions.Where(i => CanAccessDevice(user, i.DeviceId));
            }

            var array = sessions.Select(ToDeviceInfo).ToArray();

            return new QueryResult<DeviceInfo>(array);
        }

        private DeviceInfo ToDeviceInfo(AuthenticationInfo authInfo)
        {
            var caps = GetCapabilities(authInfo.DeviceId);

            return new DeviceInfo
            {
                AppName = authInfo.AppName,
                AppVersion = authInfo.AppVersion,
                Id = authInfo.DeviceId,
                LastUserId = authInfo.UserId,
                LastUserName = authInfo.UserName,
                Name = authInfo.DeviceName,
                DateLastActivity = authInfo.DateLastActivity,
                IconUrl = caps?.IconUrl
            };
        }

        private string GetDevicesPath()
        {
            return Path.Combine(_config.ApplicationPaths.DataPath, "devices");
        }

        private string GetDevicePath(string id)
        {
            return Path.Combine(GetDevicesPath(), id.GetMD5().ToString("N", CultureInfo.InvariantCulture));
        }

        public bool CanAccessDevice(User user, string deviceId)
        {
            if (user == null)
            {
                throw new ArgumentException("user not found");
            }
            if (string.IsNullOrEmpty(deviceId))
            {
                throw new ArgumentNullException(nameof(deviceId));
            }

            if (!CanAccessDevice(user.Policy, deviceId))
            {
                var capabilities = GetCapabilities(deviceId);

                if (capabilities != null && capabilities.SupportsPersistentIdentifier)
                {
                    return false;
                }
            }

            return true;
        }

        private static bool CanAccessDevice(UserPolicy policy, string id)
        {
            if (policy.EnableAllDevices)
            {
                return true;
            }

            if (policy.IsAdministrator)
            {
                return true;
            }

            return policy.EnabledDevices.Contains(id, StringComparer.OrdinalIgnoreCase);
        }
    }
}