using System.Collections.Generic;

namespace SLSFramework.General
{
    /// <summary>
    /// 指令内容 (Command Context)
    /// 包含了指令执行时可能需要的所有游戏状态信息。
    /// 指令组开始执行时创建的CommandContext，会被传递给每一个子指令。
    /// 在ICommand内置的CommandContext中，则包含了该指令执行时特有的信息。
    /// </summary>
    public class CommandContext
    {
        public readonly Dictionary<string, object> context;

        public CommandContext()
        {
            context = new Dictionary<string, object>();
        }
        
        public CommandContext(string key, object value)
        {
            context = new Dictionary<string, object>
            {
                { key, value }
            };
        }
        
        public CommandContext(List<KeyValuePair<string, object>> initialInfo)
        {
            context = new Dictionary<string, object>();
            foreach (var pair in initialInfo)
            {
                context[pair.Key] = pair.Value;
            }
        }
        
        public CommandContext Clone()
        {
            var newContext = new CommandContext();
            foreach (var pair in context)
            {
                newContext.context[pair.Key] = pair.Value;
            }
            return newContext;
        }
        
        public T GetInfo<T>(string key)
        {
            if (context.TryGetValue(key, out object value) && value is T typedValue)
            {
                return typedValue;
            }
            return default;
        }
    }
}