using JetBrains.Annotations;
using LitJson;
using Newtonsoft.Json.Serialization;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Net.Mime;
using System.Reflection;
using UnityEngine;
using yutokun;
using static UnityEngine.Rendering.DebugUI;

public class CSVReader
{
    private static Dictionary<string/*key*/, int/*index*/> m_KeyMapping = new Dictionary<string, int>();
    private static List<List<string>> m_Rows = new List<List<string>>();

    /// <summary>
    /// 解析csv表格，并返回列表
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="content"></param>
    /// <returns></returns>
    public static List<T> Read<T>(string content) where T : new() 
    {
        List<T> result = new List<T>();
        Read<T>(result, content);
        return result;
    }

    /// <summary>
    /// 解析csv表格，并返回数量
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="content"></param>
    /// <returns></returns>
    public static int Read<T>(List<T> target, string content) where T : new()
    {
        m_KeyMapping.Clear();
        m_Rows.Clear();

        m_Rows = CSVParser.LoadFromString(content);
        // 第一行是key
        List<string> keys = m_Rows[0];
        for (int i = 0; i < keys.Count; ++i)
        {
            m_KeyMapping.Add(keys[i], i);
        }
        int count = 0;
        Type type = typeof(T);
        for (int i = 1; i < m_Rows.Count; ++i)
        {
            if (m_Rows[i] == null || m_Rows[i].Count == 0) // 空行
                continue;

            bool isBlank = true;
            m_Rows[i].ForEach(s => { if (!string.IsNullOrEmpty(s)) isBlank = false; });
            if (isBlank)
                continue;

            if (m_Rows[i][0].Length > 0 && m_Rows[i][0][0] == '#') // 注释
                continue;

            List<string> row = m_Rows[i];
            T obj = new T();
            foreach (var key in m_KeyMapping)
            {
                int index = key.Value;
                var fieldInfo = type.GetField(key.Key);
                if (fieldInfo != null)
                {
                    Type fieldType = fieldInfo.FieldType;
                    if (fieldType.IsEnum) // 如果是枚举，先转成int
                    {
                        int value = int.Parse(row[index]);
                        fieldInfo.SetValue(obj, value);
                    }
                    else
                    {
                        fieldInfo.SetValue(obj, Convert.ChangeType(row[index], fieldInfo.FieldType));
                    }
                }
            }
            target.Add(obj);
            count++;
        }
        return count;
    }

    /// <summary>
    /// 解析csv表格，并按key存储到字典里，返回数量
    /// </summary>
    /// <typeparam name="TKey"></typeparam>
    /// <typeparam name="TValue"></typeparam>
    /// <param name="target"></param>
    /// <param name="content"></param>
    /// <param name="keyName"></param>
    /// <returns></returns>
    public static int ReadDictionary<TKey, TValue>(Dictionary<TKey, TValue> target, string content, string keyName) where TValue : new()
    {
        List<TValue> data = CSVReader.Read<TValue>(content);
        if (data == null || data.Count == 0)
            return 0;
        Type type_key = typeof(TKey);
        Type type_value = typeof(TValue);
        FieldInfo field = type_value.GetField(keyName);
        Type type_field = field.FieldType;
        int count = 0;
        for (int i = 0; i < data.Count; ++i)
        {
            TValue d = data[i];

            TKey key = default(TKey);
            if (type_key.IsEnum)
            {
                if(type_field == typeof(string))
                {
                    key = (TKey)Enum.Parse(type_key, field.GetValue(d).ToString());
                }
                else if(type_field == typeof(int))
                {
                    key = (TKey)field.GetValue(d);
                }
            }
            else
            {
                key = (TKey)field.GetValue(d);
            }
            if (key == null)
            {
                LogHelper.LogError("CSVReader.ReadDictionary(): key is null");
                continue;
            }

            target.Add(key, d);
            count++;
        }
        return count;
    }

}