using CsvHelper;
using CsvHelper.Configuration;
using FATrace.Com;
using FATrace.OEMApp.Model;
using NLog;
using System.Globalization;
using System.Text;

namespace FATrace.OEMApp.Services
{
    public class CsvService
    {
        private static readonly Logger _logger = LogManager.GetCurrentClassLogger();
        public CsvService()
        {
            RawUseCsvPath = ConfigHelper.GetValue("RawUseCsvPath");
        }

        /// <summary>
        /// 原料使用信息CSV文件路径
        /// </summary>
        public string RawUseCsvPath { get; set; }

        /// <summary>
        /// 将一条原料使用记录导出为单独CSV文件（包含表头）
        /// 文件保存目录来自 RawUseCsvPath；文件名包含时间戳与内袋二维码（若有）
        /// </summary>
        /// <param name="data">原料使用记录</param>
        /// <returns>生成的CSV完整路径</returns>
        /// <exception cref="ArgumentNullException">当 data 为空时抛出</exception>
        /// <exception cref="InvalidOperationException">当 RawUseCsvPath 未配置时抛出</exception>
        /// <exception cref="IOException">当写入文件失败时抛出</exception>
        public string ExportSingle(RawUseCsvDto data)
        {
            if (data == null) throw new ArgumentNullException(nameof(data));

            if (string.IsNullOrWhiteSpace(RawUseCsvPath))
            {
                const string msg = "RawUseCsvPath 未配置，无法导出CSV。";
                _logger.Error(msg);
                throw new InvalidOperationException(msg);
            }

            try
            {
                // 确保目录存在
                Directory.CreateDirectory(RawUseCsvPath);

                // 构建安全文件名：时间戳_内袋二维码.csv（若二维码为空则用RawUse代替）
                var safeCode = SanitizeFileName(string.IsNullOrWhiteSpace(data.InBagCode) ? "RawUse" : data.InBagCode!.Trim());
                var fileName = $"{safeCode}.csv";
                var fullPath = Path.Combine(RawUseCsvPath, fileName);

                var config = new CsvConfiguration(CultureInfo.InvariantCulture)
                {
                    HasHeaderRecord = true,
                };

                using (var writer = new StreamWriter(fullPath, false, new UTF8Encoding(encoderShouldEmitUTF8Identifier: true)))
                using (var csv = new CsvWriter(writer, config))
                {
                    csv.Context.RegisterClassMap<RawUseCsvDtoMap>();

                    csv.WriteHeader<RawUseCsvDto>();
                    csv.NextRecord();
                    csv.WriteRecord(data);
                    csv.NextRecord();
                }

                _logger.Info($"CSV 导出成功: {fullPath}");
                return fullPath;
            }
            catch (Exception ex)
            {
                _logger.Error(ex, "导出原料使用CSV失败。");
                throw new IOException("导出原料使用CSV失败。", ex);
            }
        }

        private static string SanitizeFileName(string name)
        {
            var invalid = Path.GetInvalidFileNameChars();
            var sb = new StringBuilder(name.Length);
            foreach (var ch in name)
            {
                sb.Append(invalid.Contains(ch) ? '_' : ch);
            }
            var result = sb.ToString();
            return string.IsNullOrWhiteSpace(result) ? "RawUse" : result;
        }
    }
}