using System;
using System.Collections.Generic;
using MQTTnet.Exceptions;
using MQTTnet.Packets;
using MQTTnet.Protocol;

namespace MQTTnet.Formatter.V5
{
    public class MqttV500PropertiesReader
    {
        private readonly IMqttPacketBodyReader _body;
        private readonly int _length;
        private readonly int _targetOffset;

        public MqttV500PropertiesReader(IMqttPacketBodyReader body)
        {
            _body = body ?? throw new ArgumentNullException(nameof(body));

            if (!body.EndOfStream)
            {
                _length = (int)body.ReadVariableLengthInteger();
            }

            _targetOffset = body.Offset + _length;
        }

        public MqttPropertyId CurrentPropertyId { get; private set; }

        public bool MoveNext()
        {
            if (_length == 0)
            {
                return false;
            }

            if (_body.Offset >= _targetOffset)
            {
                return false;
            }

            CurrentPropertyId = (MqttPropertyId)_body.ReadByte();
            return true;
        }

        public void AddUserPropertyTo(List<MqttUserProperty> userProperties)
        {
            if (userProperties == null) throw new ArgumentNullException(nameof(userProperties));

            var name = _body.ReadStringWithLengthPrefix();
            var value = _body.ReadStringWithLengthPrefix();

            userProperties.Add(new MqttUserProperty(name, value));
        }

        public string ReadReasonString()
        {
            return _body.ReadStringWithLengthPrefix();
        }

        public string ReadAuthenticationMethod()
        {
            return _body.ReadStringWithLengthPrefix();
        }

        public byte[] ReadAuthenticationData()
        {
            return _body.ReadWithLengthPrefix();
        }

        public bool ReadRetainAvailable()
        {
            return _body.ReadBoolean();
        }

        public uint ReadSessionExpiryInterval()
        {
            return _body.ReadFourByteInteger();
        }

        public ushort ReadReceiveMaximum()
        {
            return _body.ReadTwoByteInteger();
        }

        public string ReadAssignedClientIdentifier()
        {
            return _body.ReadStringWithLengthPrefix();
        }

        public string ReadServerReference()
        {
            return _body.ReadStringWithLengthPrefix();
        }

        public ushort ReadTopicAliasMaximum()
        {
            return _body.ReadTwoByteInteger();
        }

        public uint ReadMaximumPacketSize()
        {
            return _body.ReadFourByteInteger();
        }

        public ushort ReadServerKeepAlive()
        {
            return _body.ReadTwoByteInteger();
        }

        public string ReadResponseInformation()
        {
            return _body.ReadStringWithLengthPrefix();
        }

        public bool ReadSharedSubscriptionAvailable()
        {
            return _body.ReadBoolean();
        }

        public bool ReadSubscriptionIdentifiersAvailable()
        {
            return _body.ReadBoolean();
        }

        public bool ReadWildcardSubscriptionAvailable()
        {
            return _body.ReadBoolean();
        }

        public uint ReadSubscriptionIdentifier()
        {
            return _body.ReadVariableLengthInteger();
        }

        public MqttPayloadFormatIndicator? ReadPayloadFormatIndicator()
        {
            return (MqttPayloadFormatIndicator)_body.ReadByte();
        }

        public uint ReadMessageExpiryInterval()
        {
            return _body.ReadFourByteInteger();
        }

        public ushort ReadTopicAlias()
        {
            return _body.ReadTwoByteInteger();
        }

        public string ReadResponseTopic()
        {
            return _body.ReadStringWithLengthPrefix();
        }

        public byte[] ReadCorrelationData()
        {
            return _body.ReadWithLengthPrefix();
        }

        public string ReadContentType()
        {
            return _body.ReadStringWithLengthPrefix();
        }

        public uint ReadWillDelayInterval()
        {
            return _body.ReadFourByteInteger();
        }

        public bool RequestResponseInformation()
        {
            return _body.ReadBoolean();
        }

        public bool RequestProblemInformation()
        {
            return _body.ReadBoolean();
        }

        public void ThrowInvalidPropertyIdException(Type type)
        {
            throw new MqttProtocolViolationException($"Property ID '{CurrentPropertyId}' is not supported for package type '{type.Name}'.");
        }
    }
}