XplorePlane/XP.ReportEngine/Services/ReportFormatExtensions.cs

using System;
using XP.ReportEngine.Models;

namespace XP.ReportEngine.Services
{
    /// <summary>
    /// 报告输出格式辅助方法 | Report output format helper methods
    /// 提供格式 → 文件扩展名的映射，供报告服务（ReportService）在解析输出文件路径时使用。
    /// Provides format → file extension mapping, used by ReportService when resolving output file paths.
    /// </summary>
    internal static class ReportFormatExtensions
    {
        /// <summary>
        /// 根据报告输出格式返回对应的文件扩展名（含点号）| Return the file extension (with dot) for the given report output format
        /// 映射规则 | Mapping rules：
        ///   Pdf   → ".pdf"
        ///   Txt   → ".txt"
        ///   Csv   → ".csv"
        ///   Excel → ".xlsx"
        /// </summary>
        /// <param name="format">报告输出格式 | Report output format</param>
        /// <returns>对应的文件扩展名（含点号，如 ".txt"）| Corresponding file extension (with dot, e.g. ".txt")</returns>
        /// <exception cref="NotSupportedException">
        /// 当传入的格式不属于任何已定义的映射时抛出，异常消息包含该传入值。
        /// Thrown when the given format does not map to any defined extension; the exception message contains the passed value.
        /// </exception>
        public static string GetExtension(ReportOutputFormat format)
        {
            switch (format)
            {
                case ReportOutputFormat.Pdf:
                    return ".pdf";
                case ReportOutputFormat.Txt:
                    return ".txt";
                case ReportOutputFormat.Csv:
                    return ".csv";
                case ReportOutputFormat.Excel:
                    return ".xlsx";
                default:
                    // 未定义的格式（含越界整数强转枚举值）| Undefined format (including out-of-range integers cast to enum)
                    throw new NotSupportedException(
                        $"不支持的报告输出格式，无法映射文件扩展名: {format} | Unsupported report output format, cannot map file extension: {format}");
            }
        }
    }
}