improvement: 이력 엑셀 내보내기 API 추가 (#191)

- POST /v1/in/stats/history/export 엔드포인트 추가
- history/list와 동일 필터(keyword/status/date) 기준 엑셀 내보내기
- PushSendLogRepository에서 GroupBy 쿼리를 private helper로 리팩토링
- ClosedXML로 엑셀 생성 (메시지코드/제목/서비스명/발송일시/대상수/성공/실패/오픈율/상태)

Closes #191

SPMS.API/Controllers/StatsController.cs

@@ -109,6 +109,16 @@ public class StatsController : ControllerBase
         return Ok(ApiResponse<HistoryDetailResponseDto>.Success(result, "조회 성공"));
     }
 
+    [HttpPost("history/export")]
+    [SwaggerOperation(Summary = "이력 엑셀 내보내기", Description = "이력 목록과 동일한 필터 기준으로 발송 이력을 엑셀(.xlsx)로 내보냅니다. X-Service-Code 헤더 미지정 시 전체 서비스 이력을 내보냅니다.")]
+    public async Task<IActionResult> ExportHistoryAsync([FromBody] HistoryExportRequestDto request)
+    {
+        var serviceId = GetOptionalServiceId();
+        var fileBytes = await _statsService.ExportHistoryAsync(serviceId, request);
+        var fileName = $"history_export_{DateTime.UtcNow:yyyyMMdd}.xlsx";
+        return File(fileBytes, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", fileName);
+    }
+
     [HttpPost("send-log")]
     [SwaggerOperation(Summary = "발송 상세 로그 조회", Description = "특정 메시지의 개별 디바이스별 발송 상세 로그를 조회합니다. X-Service-Code 헤더 미지정 시 전체 서비스 통계를 조회합니다.")]
     public async Task<IActionResult> GetSendLogDetailAsync([FromBody] SendLogDetailRequestDto request)

SPMS.Application/DTOs/Stats/HistoryExportRequestDto.cs

@@ -0,0 +1,18 @@
+using System.Text.Json.Serialization;
+
+namespace SPMS.Application.DTOs.Stats;
+
+public class HistoryExportRequestDto
+{
+    [JsonPropertyName("keyword")]
+    public string? Keyword { get; set; }
+
+    [JsonPropertyName("status")]
+    public string? Status { get; set; }
+
+    [JsonPropertyName("start_date")]
+    public string? StartDate { get; set; }
+
+    [JsonPropertyName("end_date")]
+    public string? EndDate { get; set; }
+}

SPMS.Application/Interfaces/IStatsService.cs

@@ -15,4 +15,5 @@ public interface IStatsService
     Task<DashboardResponseDto> GetDashboardAsync(long? serviceId, DashboardRequestDto request);
     Task<HistoryListResponseDto> GetHistoryListAsync(long? serviceId, HistoryListRequestDto request);
     Task<HistoryDetailResponseDto> GetHistoryDetailAsync(long? serviceId, HistoryDetailRequestDto request);
+    Task<byte[]> ExportHistoryAsync(long? serviceId, HistoryExportRequestDto request);
 }

SPMS.Application/Services/StatsService.cs

@@ -546,6 +546,50 @@ public class StatsService : IStatsService
         };
     }
 
+    public async Task<byte[]> ExportHistoryAsync(long? serviceId, HistoryExportRequestDto request)
+    {
+        DateTime? startDate = ParseOptionalDate(request.StartDate);
+        DateTime? endDate = ParseOptionalDate(request.EndDate);
+
+        var items = await _pushSendLogRepository.GetMessageHistoryAllAsync(
+            serviceId, request.Keyword, request.Status, startDate, endDate);
+
+        using var workbook = new XLWorkbook();
+        var ws = workbook.Worksheets.Add("발송 이력");
+
+        // 헤더
+        ws.Cell(1, 1).Value = "메시지코드";
+        ws.Cell(1, 2).Value = "제목";
+        ws.Cell(1, 3).Value = "서비스명";
+        ws.Cell(1, 4).Value = "발송일시";
+        ws.Cell(1, 5).Value = "대상수";
+        ws.Cell(1, 6).Value = "성공";
+        ws.Cell(1, 7).Value = "실패";
+        ws.Cell(1, 8).Value = "오픈율(%)";
+        ws.Cell(1, 9).Value = "상태";
+        ws.Row(1).Style.Font.Bold = true;
+
+        var row = 2;
+        foreach (var item in items)
+        {
+            ws.Cell(row, 1).Value = item.MessageCode;
+            ws.Cell(row, 2).Value = item.Title;
+            ws.Cell(row, 3).Value = item.ServiceName;
+            ws.Cell(row, 4).Value = item.FirstSentAt.ToString("yyyy-MM-dd HH:mm:ss");
+            ws.Cell(row, 5).Value = item.TotalSendCount;
+            ws.Cell(row, 6).Value = item.SuccessCount;
+            ws.Cell(row, 7).Value = item.FailCount;
+            ws.Cell(row, 8).Value = 0;
+            ws.Cell(row, 9).Value = SendStatus.Determine(item.TotalSendCount, item.SuccessCount);
+            row++;
+        }
+        ws.Columns().AdjustToContents();
+
+        using var stream = new MemoryStream();
+        workbook.SaveAs(stream);
+        return stream.ToArray();
+    }
+
     private static string GetFailReasonDescription(string failReason)
     {
         return failReason switch

SPMS.Domain/Interfaces/IPushSendLogRepository.cs

@@ -27,6 +27,11 @@ public interface IPushSendLogRepository : IRepository<PushSendLog>
         long? serviceId, int page, int size,
         string? keyword = null, string? status = null,
         DateTime? startDate = null, DateTime? endDate = null);
+    Task<IReadOnlyList<MessageHistorySummary>> GetMessageHistoryAllAsync(
+        long? serviceId,
+        string? keyword = null, string? status = null,
+        DateTime? startDate = null, DateTime? endDate = null,
+        int maxCount = 100000);
 }
 
 public class HourlyStatRaw

SPMS.Infrastructure/Persistence/Repositories/PushSendLogRepository.cs

@@ -164,6 +164,37 @@ public class PushSendLogRepository : Repository<PushSendLog>, IPushSendLogReposi
         long? serviceId, int page, int size,
         string? keyword = null, string? status = null,
         DateTime? startDate = null, DateTime? endDate = null)
+    {
+        var grouped = BuildMessageHistoryQuery(serviceId, keyword, status, startDate, endDate);
+
+        var totalCount = await grouped.CountAsync();
+
+        var items = await grouped
+            .OrderByDescending(g => g.FirstSentAt)
+            .Skip((page - 1) * size)
+            .Take(size)
+            .ToListAsync();
+
+        return (items, totalCount);
+    }
+
+    public async Task<IReadOnlyList<MessageHistorySummary>> GetMessageHistoryAllAsync(
+        long? serviceId,
+        string? keyword = null, string? status = null,
+        DateTime? startDate = null, DateTime? endDate = null,
+        int maxCount = 100000)
+    {
+        var grouped = BuildMessageHistoryQuery(serviceId, keyword, status, startDate, endDate);
+
+        return await grouped
+            .OrderByDescending(g => g.FirstSentAt)
+            .Take(maxCount)
+            .ToListAsync();
+    }
+
+    private IQueryable<MessageHistorySummary> BuildMessageHistoryQuery(
+        long? serviceId, string? keyword, string? status,
+        DateTime? startDate, DateTime? endDate)
     {
         var query = _dbSet
             .Include(l => l.Message)
@@ -209,15 +240,7 @@ public class PushSendLogRepository : Repository<PushSendLog>, IPushSendLogReposi
             };
         }
 
-        var totalCount = await grouped.CountAsync();
+        return grouped;
-
-        var items = await grouped
-            .OrderByDescending(g => g.FirstSentAt)
-            .Skip((page - 1) * size)
-            .Take(size)
-            .ToListAsync();
-
-        return (items, totalCount);
     }
 
     public async Task<List<FailureStatRaw>> GetFailureStatsByMessageAsync(long serviceId, long messageId, int limit)