using System;
using System.Collections.Generic;

namespace Masuit.Tools
{
    public static class IDictionaryExtensions
    {
        /// <summary>
        /// 添加或更新键值对
        /// </summary>
        /// <typeparam name="TKey"></typeparam>
        /// <typeparam name="TValue"></typeparam>
        /// <param name="this"></param>
        /// <param name="key">键</param>
        /// <param name="value">值</param>
        /// <returns></returns>
        public static TValue AddOrUpdate<TKey, TValue>(
            this IDictionary<TKey, TValue> @this,
            TKey key,
            TValue value)
        {
            if (!@this.ContainsKey(key))
            {
                @this.Add(new KeyValuePair<TKey, TValue>(key, value));
            }
            else
            {
                @this[key] = value;
            }

            return @this[key];
        }

        /// <summary>
        /// 添加或更新键值对
        /// </summary>
        /// <typeparam name="TKey"></typeparam>
        /// <typeparam name="TValue"></typeparam>
        /// <param name="this"></param>
        /// <param name="key">键</param>
        /// <param name="addValue">添加时的值</param>
        /// <param name="updateValueFactory">更新时的操作</param>
        /// <returns></returns>
        public static TValue AddOrUpdate<TKey, TValue>(
            this IDictionary<TKey, TValue> @this,
            TKey key,
            TValue addValue,
            Func<TKey, TValue, TValue> updateValueFactory)
        {
            if (!@this.ContainsKey(key))
            {
                @this.Add(new KeyValuePair<TKey, TValue>(key, addValue));
            }
            else
            {
                @this[key] = updateValueFactory(key, @this[key]);
            }

            return @this[key];
        }

        /// <summary>
        /// 添加或更新键值对
        /// </summary>
        /// <typeparam name="TKey"></typeparam>
        /// <typeparam name="TValue"></typeparam>
        /// <param name="this"></param>
        /// <param name="key">键</param>
        /// <param name="addValueFactory">添加时的操作</param>
        /// <param name="updateValueFactory">更新时的操作</param>
        /// <returns></returns>
        public static TValue AddOrUpdate<TKey, TValue>(
            this IDictionary<TKey, TValue> @this,
            TKey key,
            Func<TKey, TValue> addValueFactory,
            Func<TKey, TValue, TValue> updateValueFactory)
        {
            if (!@this.ContainsKey(key))
            {
                @this.Add(new KeyValuePair<TKey, TValue>(key, addValueFactory(key)));
            }
            else
            {
                @this[key] = updateValueFactory(key, @this[key]);
            }

            return @this[key];
        }
    }
}