From e572087e58aaa36b6fdbf0086491907c9169efb0 Mon Sep 17 00:00:00 2001
From: Koni Marti <koni.marti@gmail.com>
Date: Mon, 11 Jul 2022 20:11:21 +0200
Subject: [PATCH] account: import mbox file to a folder

Append all messages from an mbox file to the selected folder with the
import-mbox command.

User confirmation is required when the folder already contains messages.

A failed append will be retried a few times. If a backend timeout
occurs, the entire import is stopped to prevent a hang.

Signed-off-by: Koni Marti <koni.marti@gmail.com>
Acked-by: Robin Jarry <robin@jarry.cc>
---
 commands/account/import-mbox.go | 153 ++++++++++++++++++++++++++++++++
 doc/aerc.1.scd                  |   3 +
 worker/maildir/worker.go        |   4 +-
 3 files changed, 159 insertions(+), 1 deletion(-)
 create mode 100644 commands/account/import-mbox.go

diff --git a/commands/account/import-mbox.go b/commands/account/import-mbox.go
new file mode 100644
index 0000000..1430deb
--- /dev/null
+++ b/commands/account/import-mbox.go
@@ -0,0 +1,153 @@
+package account
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"sync/atomic"
+	"time"
+
+	"git.sr.ht/~rjarry/aerc/commands"
+	"git.sr.ht/~rjarry/aerc/models"
+	"git.sr.ht/~rjarry/aerc/widgets"
+	mboxer "git.sr.ht/~rjarry/aerc/worker/mbox"
+	"git.sr.ht/~rjarry/aerc/worker/types"
+)
+
+type ImportMbox struct{}
+
+func init() {
+	register(ImportMbox{})
+}
+
+func (ImportMbox) Aliases() []string {
+	return []string{"import-mbox"}
+}
+
+func (ImportMbox) Complete(aerc *widgets.Aerc, args []string) []string {
+	return commands.CompletePath(filepath.Join(args...))
+}
+
+func (ImportMbox) Execute(aerc *widgets.Aerc, args []string) error {
+	if len(args) != 2 {
+		return importFolderUsage(args[0])
+	}
+	filename := args[1]
+
+	acct := aerc.SelectedAccount()
+	if acct == nil {
+		return errors.New("No account selected")
+	}
+	store := acct.Store()
+	if store == nil {
+		return errors.New("No message store selected")
+	}
+
+	folder := acct.SelectedDirectory()
+	if folder == "" {
+		return errors.New("No directory selected")
+	}
+
+	importFolder := func() {
+		statusInfo := fmt.Sprintln("Importing", filename, "to folder", folder)
+		aerc.PushStatus(statusInfo, 10*time.Second)
+		acct.Logger().Println(args[0], statusInfo)
+		f, err := os.Open(filename)
+		if err != nil {
+			aerc.PushError(err.Error())
+			return
+		}
+		defer f.Close()
+
+		messages, err := mboxer.Read(f)
+		if err != nil {
+			aerc.PushError(err.Error())
+			return
+		}
+		worker := acct.Worker()
+
+		var appended uint32
+		for i, m := range messages {
+			done := make(chan bool)
+			var retries int = 4
+			for retries > 0 {
+				var buf bytes.Buffer
+				r, err := m.NewReader()
+				if err != nil {
+					acct.Logger().Println(fmt.Sprintf("%s: could not get reader for uid %d", args[0], m.UID()))
+					break
+				}
+				nbytes, _ := io.Copy(&buf, r)
+				worker.PostAction(&types.AppendMessage{
+					Destination: folder,
+					Flags:       []models.Flag{models.SeenFlag},
+					Date:        time.Now(),
+					Reader:      &buf,
+					Length:      int(nbytes),
+				}, func(msg types.WorkerMessage) {
+					switch msg := msg.(type) {
+					case *types.Unsupported:
+						errMsg := fmt.Sprintf("%s: AppendMessage is unsupported", args[0])
+						acct.Logger().Println(errMsg)
+						aerc.PushError(errMsg)
+						return
+					case *types.Error:
+						acct.Logger().Println(args[0], msg.Error.Error())
+						done <- false
+					case *types.Done:
+						atomic.AddUint32(&appended, 1)
+						done <- true
+					}
+				})
+
+				select {
+				case ok := <-done:
+					if ok {
+						retries = 0
+					} else {
+						// error encountered; try to append again after a quick nap
+						retries -= 1
+						sleeping := time.Duration((5 - retries) * 1e9)
+						acct.Logger().Println(args[0], "sleeping for", sleeping, "before append message", i, "again")
+						time.Sleep(sleeping)
+					}
+				case <-time.After(30 * time.Second):
+					acct.Logger().Println(args[0], "timed-out; appended", appended, "of", len(messages))
+					return
+				}
+			}
+		}
+		infoStr := fmt.Sprintf("%s: imported %d of %d sucessfully.", args[0], appended, len(messages))
+		acct.Logger().Println(infoStr)
+		aerc.SetStatus(infoStr)
+	}
+
+	if len(store.Uids()) > 0 {
+		confirm := widgets.NewSelectorDialog(
+			"Selected directory is not empty",
+			fmt.Sprintf("Import mbox file to %s anyways?", folder),
+			[]string{"No", "Yes"}, 0, aerc.SelectedAccountUiConfig(),
+			func(option string, err error) {
+				aerc.CloseDialog()
+				aerc.Invalidate()
+				switch option {
+				case "Yes":
+					go importFolder()
+				}
+				return
+			},
+		)
+		aerc.AddDialog(confirm)
+	} else {
+		go importFolder()
+	}
+
+	return nil
+}
+
+func importFolderUsage(cmd string) error {
+	return fmt.Errorf("Usage: %s <filename>", cmd)
+}
diff --git a/doc/aerc.1.scd b/doc/aerc.1.scd
index 97a9eab..17e9042 100644
--- a/doc/aerc.1.scd
+++ b/doc/aerc.1.scd
@@ -314,6 +314,9 @@ message list, the message in the message viewer, etc).
 *export-mbox* <file>
 	Exports all messages in the current folder to an mbox file.
 
+*import-mbox* <file>
+	Imports all messages from an mbox file to the current folder.
+
 *next-result*, *prev-result*
 	Selects the next or previous search result.
 
diff --git a/worker/maildir/worker.go b/worker/maildir/worker.go
index b217bd2..222b672 100644
--- a/worker/maildir/worker.go
+++ b/worker/maildir/worker.go
@@ -666,7 +666,9 @@ func (w *Worker) handleAppendMessage(msg *types.AppendMessage) error {
 		w.worker.Logger.Printf("could not write message to destination: %v", err)
 		return err
 	}
-
+	w.worker.PostMessage(&types.Done{
+		Message: types.RespondTo(msg),
+	}, nil)
 	w.worker.PostMessage(&types.DirectoryInfo{
 		Info: w.getDirectoryInfo(msg.Destination),
 	}, nil)