using System;
using System.Collections.Generic;

namespace AibisDream.FixSystem
{
    /// <summary>
    /// 以两个Key为索引的Dic
    /// </summary>
    /// <typeparam name="T">Value类型</typeparam>
    public class StateDictionary<T>
    {
        private readonly Dictionary<StateTransKey, T> _stateDic = new();

        public T Get(FixState source, FixState target)
        {
            var key = new StateTransKey(source, target);
            return _stateDic[key];
        }

        public void Add(FixState source, FixState target, T value)
        {
            var key = new StateTransKey(source, target);
            _stateDic[key] = value;
        }

        public void Clear()
        {
            _stateDic.Clear();
        }

        public bool ContainsKey(FixState source, FixState target)
        {
            var key = new StateTransKey(source, target);
            return _stateDic.ContainsKey(key);
        }

        public bool TryGetValue(FixState source, FixState target, out T value)
        {
            var key = new StateTransKey(source, target);
            return _stateDic.TryGetValue(key, out value);
        }
        
        /// <summary>
        /// 用于实现两个Key的Dictionary
        /// </summary>
        private class StateTransKey
        {
            private readonly FixState _sourceState;
            private readonly FixState _targetState;

            public StateTransKey(FixState sourceState, FixState targetState)
            {
                _sourceState = sourceState;
                _targetState = targetState;
            }

            public override bool Equals(object obj)
            {
                // 类型不同肯定不相等
                if (obj is not StateTransKey other) return false;
                // 判断两个key相等
                return _sourceState == other._sourceState && _targetState == other._targetState;
            }

            public override int GetHashCode()
            {
                return HashCode.Combine(_sourceState, _targetState);
            }
        }
    }
}