Batch report worker poc

server/channels/app/report.go

@@ -0,0 +1,89 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package app
+
+import (
+	"bytes"
+	"encoding/csv"
+	"fmt"
+	"net/http"
+
+	"github.com/mattermost/mattermost/server/public/model"
+)
+
+func (a *App) SaveReportChunk(format string, prefix string, count int, reportData []model.ReportableObject) *model.AppError {
+	switch format {
+	case "csv":
+		return a.saveCSVChunk(prefix, count, reportData)
+	}
+	return model.NewAppError("SaveReportChunk", "", nil, "unsupported report format", http.StatusInternalServerError)
+}
+
+func (a *App) saveCSVChunk(prefix string, count int, reportData []model.ReportableObject) *model.AppError {
+	var buf bytes.Buffer
+	w := csv.NewWriter(&buf)
+
+	for _, report := range reportData {
+		err := w.Write(report.ToReport())
+		if err != nil {
+			return model.NewAppError("saveCSVChunk", "", nil, "failed to write report data to CSV", http.StatusInternalServerError)
+		}
+	}
+
+	w.Flush()
+	_, appErr := a.WriteFile(&buf, makeFilename(prefix, count, "csv"))
+	if appErr != nil {
+		return appErr
+	}
+
+	return nil
+}
+
+func (a *App) CompileReportChunks(format string, prefix string, numberOfChunks int, headers []string) (string, *model.AppError) {
+	switch format {
+	case "csv":
+		return a.compileCSVChunks(prefix, numberOfChunks, headers)
+	}
+	return "", model.NewAppError("CompileReportChunks", "", nil, "unsupported report format", http.StatusInternalServerError)
+}
+
+func (a *App) compileCSVChunks(prefix string, numberOfChunks int, headers []string) (string, *model.AppError) {
+	filename := fmt.Sprintf("batch_report_%s.csv", prefix)
+
+	var headerBuf bytes.Buffer
+	w := csv.NewWriter(&headerBuf)
+	err := w.Write(headers)
+	if err != nil {
+		return "", model.NewAppError("compileCSVChunks", "", nil, "failed to write headers", http.StatusInternalServerError)
+	}
+	w.Flush()
+	_, appErr := a.WriteFile(&headerBuf, filename)
+	if appErr != nil {
+		return "", appErr
+	}
+
+	for i := 0; i < numberOfChunks; i++ {
+		chunkFilename := makeFilename(prefix, i, "csv")
+		chunk, err := a.ReadFile(chunkFilename)
+		if err != nil {
+			return "", err
+		}
+		if _, err = a.AppendFile(bytes.NewReader(chunk), filename); err != nil {
+			return "", err
+		}
+		if err = a.RemoveFile(chunkFilename); err != nil {
+			return "", err
+		}
+	}
+
+	return filename, nil
+}
+
+func (a *App) SendReportToUser(userID string, filename string) *model.AppError {
+	return nil
+}
+
+func makeFilename(prefix string, count int, extension string) string {
+	return fmt.Sprintf("batch_report_%s__%d.%s", prefix, count, extension)
+}

server/channels/app/server.go

@@ -44,6 +44,7 @@ import (
 	"github.com/mattermost/mattermost/server/v8/channels/jobs/expirynotify"
 	"github.com/mattermost/mattermost/server/v8/channels/jobs/export_delete"
 	"github.com/mattermost/mattermost/server/v8/channels/jobs/export_process"
+	"github.com/mattermost/mattermost/server/v8/channels/jobs/export_users_to_csv"
 	"github.com/mattermost/mattermost/server/v8/channels/jobs/extract_content"
 	"github.com/mattermost/mattermost/server/v8/channels/jobs/hosted_purchase_screening"
 	"github.com/mattermost/mattermost/server/v8/channels/jobs/import_delete"
@@ -1674,6 +1675,12 @@ func (s *Server) initJobs() {
 		refresh_post_stats.MakeScheduler(s.Jobs, *s.platform.Config().SqlSettings.DriverName),
 	)
 
+	s.Jobs.RegisterJobType(
+		model.JobTypeExportUsersToCSV,
+		export_users_to_csv.MakeWorker(s.Jobs, s.Store(), New(ServerConnector(s.Channels()))),
+		nil,
+	)
+
 	s.platform.Jobs = s.Jobs
 }