using System;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading;

namespace AibisDream.Utility
{
    public class CsvUtil
    {
        // 默认编码
        private static readonly Encoding DefaultEncode = Encoding.UTF8;

        // 默认分隔符
        private const char FieldSeparator = ',';

        public static List<string[]> Read(string filePath)
        {
            List<string[]> dataList = new List<string[]>();
            StreamReader reader;
            try
            {
                using (reader = new StreamReader(filePath, DefaultEncode))
                {
                    while (!reader.EndOfStream)
                    {
                        string line = reader.ReadLine();
                        if (line == null) break;
                        string[] data = line.Split(FieldSeparator);
                        dataList.Add(data);
                    }
                }
            }
            catch (Exception ex)
            {
                foreach (Process process in Process.GetProcesses())
                {
                    if (process.ProcessName.ToUpper().Equals("EXCEL"))
                        process.Kill();
                }

                GC.Collect();
                Thread.Sleep(50);
                Console.WriteLine(ex.StackTrace);
                using (reader = new StreamReader(filePath, DefaultEncode))
                {
                    while (!reader.EndOfStream)
                    {
                        string line = reader.ReadLine();
                        if (line == null) break;
                        string[] data = line.Split(FieldSeparator);
                        dataList.Add(data);
                    }
                }
            }

            reader.Close();
            return dataList;
        }

        public static void WriteCsv(string filePath, List<string[]> dataList)
        {
            StreamWriter writer = new StreamWriter(filePath, false, DefaultEncode);
            foreach (string[] data in dataList)
            {
                writer.WriteLine(string.Join(FieldSeparator, data));
            }

            writer.Close();
        }

        public static List<T> ReadAsBean<T>(string filePath) where T : class
        {
            // 反射部分
            var targetType = typeof(T);
            var props = targetType.GetProperties();

            // 读取CSV
            using var reader = new StreamReader(filePath, DefaultEncode);

            // 第一行是注释
            reader.ReadLine();
            // 第二行作为title
            var titles = reader.ReadLine()?.Split(FieldSeparator);
            if (titles == null)
            {
                Debug.WriteLine("csv无标题");
                throw new Exception("csv无标题");
            }

            var res = new List<T>();
            // 第二行开始读配置内容
            while (!reader.EndOfStream)
            {
                string newLine = reader.ReadLine();
                if (string.IsNullOrEmpty(newLine)) break;
                
                string[] rowData = newLine.Split(FieldSeparator);
                if (rowData == null || rowData.Length == 0) continue;

                // 转为Bean
                var obj = Activator.CreateInstance(targetType);
                foreach (var prop in props)
                {
                    string name = prop.Name;
                    if (!titles.Contains(prop.Name)) 
                        continue;

                    int idx = Array.IndexOf(titles, prop.Name);
                    prop.SetValue(obj, GetDefaultValue(prop, rowData[idx]));
                }
                
                res.Add(obj as T);
            }

            return res;
        }

        public static bool ReadAsDataTable(ref DataTable myCsvDt, string filepath)
        {
            var strPath = filepath; //csv文件的路径

            try
            {
                bool blnFlag = true;

                StreamReader reader = new StreamReader(strPath, DefaultEncode);
                myCsvDt = new DataTable();
                while (reader.ReadLine() is { } strLine)
                {
                    var aryLine = strLine.Split(FieldSeparator);
                    //第一行是列的名字，给datatable加上列名,
                    if (blnFlag)
                    {
                        blnFlag = false;
                        var intColCount = aryLine.Length;

                        #region 序号作为列头

                        //int col = 0;
                        //for (int i = 0; i < intColCount; i++)
                        //{
                        //    col = i + 1;
                        //    mydc = new DataColumn(col.ToString());
                        //    mycsvdt.Columns.Add(mydc);
                        //}

                        #endregion

                        #region 第一行作为列头

                        for (int i = 0; i < intColCount; i++)
                        {
                            myCsvDt.Columns.Add(new DataColumn(aryLine[i]));
                        }

                        continue;

                        #endregion
                    }

                    //填充数据并加入到datatable中
                    myCsvDt.Rows.Add(aryLine);
                }

                reader.Close();
                return true;
            }
            catch (Exception)
            {
                return false;
            }
        }

        public static void ExportAsCsv(DataTable dt, string savaPath, string strName)
        {
            string strPath = savaPath + "\\" + strName; //保存到指定目录下

            if (File.Exists(strPath))
            {
                File.Delete(strPath);
            }

            //先打印标头
            StringBuilder strColu = new StringBuilder();
            StringBuilder strValue = new StringBuilder();
            StreamWriter sw = new StreamWriter(new FileStream(strPath, FileMode.CreateNew), DefaultEncode);
            try
            {
                for (var i = 0; i <= dt.Columns.Count - 1; i++)
                {
                    strColu.Append(dt.Columns[i].ColumnName);
                    strColu.Append(FieldSeparator);
                }

                strColu.Remove(strColu.Length - 1, 1); //移出掉最后一个,字符
                sw.WriteLine(strColu);
                foreach (DataRow dr in dt.Rows)
                {
                    strValue.Remove(0, strValue.Length); //移出
                    for (var i = 0; i <= dt.Columns.Count - 1; i++)
                    {
                        strValue.Append(dr[i]);
                        strValue.Append(FieldSeparator);
                    }

                    strValue.Remove(strValue.Length - 1, 1); //移出掉最后一个,字符
                    sw.WriteLine(strValue);
                }

                sw.Close();
            }
            catch (Exception ex)
            {
                Debug.WriteLine(ex.Message);
                sw.Close();
            }
        }

        #region 类型转换

        private static object GetDefaultValue(PropertyInfo prop, string value)
        {
            return prop.PropertyType.Name switch
            {
                "String" => ToNormalString(value),
                "Int32" => ToInt32(value),
                "Decimal" => ToDecimal(value),
                "Single" => ToFloat(value),
                "Boolean" => ToBoolean(value),
                "DateTime" => ToDateTime(value),
                "Double" => ToDouble(value),
                _ => ToEnum(value, prop)
            };
        }

        private static object ToEnum(string value, PropertyInfo prop)
        {
            return prop.PropertyType.BaseType == typeof(Enum) ? Enum.Parse(prop.PropertyType, value) : null;
        }

        ///<summary>
        /// 转换为Int32
        /// </summary>
        private static int ToInt32(string obj)
        {
            if (string.IsNullOrEmpty(obj)) return 0;
            try
            {
                if (obj.Contains("."))
                    return (int)Convert.ToSingle(obj);
                if (int.TryParse(obj, out var tmp))
                    return tmp;
            }
            catch
            {
                return 0;
            }

            return 0;
        }


        ///	<summary>	
        /// 转换为字符串
        /// </summary>
        private static string ToNormalString(string obj)
        {
            if (obj == null)
                return string.Empty;
            try
            {
                return Convert.ToString(obj);
            }
            catch
            {
                return string.Empty;
            }
        }

        ///<summary>
        /// 转换为日期
        /// </summary>
        private static DateTime ToDateTime(string obj)
        {
            if (string.IsNullOrEmpty(obj))
            {
                return Convert.ToDateTime("1970-01-01 00:00:00");
            }

            try
            {
                return Convert.ToDateTime(obj);
            }
            catch
            {
                return Convert.ToDateTime("1970-01-01 00:00:00");
            }
        }

        /// <summary>
        /// 转换为布尔型
        /// </summary>
        private static bool ToBoolean(string obj)
        {
            if (obj == null) return false;

            return obj.ToLower() == "true" || obj == "1";
        }

        ///	<summary>
        /// 转换为十进制数值
        /// </summary>
        private static Decimal ToDecimal(string obj)
        {
            if (obj == null)
            {
                return 0M;
            }

            var resultString = Regex.Replace(obj, "[^0-9.]", "");
            var result = resultString.Length == 0 ? 0M : decimal.Parse(resultString);
            if (obj.StartsWith("-"))
            {
                result *= -1M;
            }

            return result;
        }

        ///<summary>
        /// 转换为双精度.
        /// </summary>
        private static double ToDouble(string obj)
        {
            if (double.TryParse(obj, out var num))
                return num;
            else
                return 0;
        }

        /// <summary>
        /// 转换为单精度.
        /// </summary>
        private static float ToFloat(string value)
        {
            var normalStr = ToNormalString(value);
            if (string.IsNullOrEmpty(normalStr))
            {
                return 0;
            }

            if (float.TryParse(normalStr, out var result))
                return result;
            else
                return 0;
        }

        #endregion
    }
}