cp: allow to copy messages across accounts

Add a new -a flag to :cp. When specified, an account name is required
before the folder name. If the destination folder doesn't exist,
it will be created whether or not the -p flag is specified.

Changelog-added: Copy messages across accounts with `:cp -a <account>
 <folder>`.
Signed-off-by: Johannes Thyssen Tishman <johannes@thyssentishman.com>
Acked-by: Robin Jarry <robin@jarry.cc>

2 files changed, 112 insertions, 23 deletions

diff --git a/commands/msg/copy.go b/commands/msg/copy.go
index 3620238a..ed963707 100644
--- a/commands/msg/copy.go
+++ b/commands/msg/copy.go
@@ -1,16 +1,21 @@
 package msg
 
 import (
+	"bytes"
 	"fmt"
 	"time"
 
 	"git.sr.ht/~rjarry/aerc/app"
 	"git.sr.ht/~rjarry/aerc/commands"
+	"git.sr.ht/~rjarry/aerc/lib"
+	"git.sr.ht/~rjarry/aerc/log"
+	"git.sr.ht/~rjarry/aerc/models"
 	"git.sr.ht/~rjarry/aerc/worker/types"
 )
 
 type Copy struct {
 	CreateFolders bool   `opt:"-p"`
+	Account       string `opt:"-a" complete:"CompleteAccount"`
 	Folder        string `opt:"folder" complete:"CompleteFolder"`
 }
 
@@ -26,8 +31,21 @@ func (Copy) Aliases() []string {
 	return []string{"cp", "copy"}
 }
 
-func (*Copy) CompleteFolder(arg string) []string {
-	return commands.GetFolders(arg)
+func (*Copy) CompleteAccount(arg string) []string {
+	return commands.FilterList(app.AccountNames(), arg, commands.QuoteSpace)
+}
+
+func (c *Copy) CompleteFolder(arg string) []string {
+	var acct *app.AccountView
+	if len(c.Account) > 0 {
+		acct, _ = app.Account(c.Account)
+	} else {
+		acct = app.SelectedAccount()
+	}
+	if acct == nil {
+		return nil
+	}
+	return commands.FilterList(acct.Directories().List(), arg, nil)
 }
 
 func (c Copy) Execute(args []string) error {
@@ -40,23 +58,91 @@ func (c Copy) Execute(args []string) error {
 	if err != nil {
 		return err
 	}
-	store.Copy(uids, c.Folder,
-		c.CreateFolders, func(
-			msg types.WorkerMessage,
-		) {
-			switch msg := msg.(type) {
-			case *types.Done:
-				var s string
-				if len(uids) > 1 {
-					s = "%d messages copied to %s"
-				} else {
-					s = "%d message copied to %s"
-				}
-				app.PushStatus(fmt.Sprintf(s, len(uids), c.Folder), 10*time.Second)
-				store.Marker().ClearVisualMark()
-			case *types.Error:
-				app.PushError(msg.Error.Error())
-			}
+
+	if len(c.Account) == 0 {
+		store.Copy(uids, c.Folder, c.CreateFolders, func(msg types.WorkerMessage) {
+			c.CallBack(msg, uids, store)
 		})
+		return nil
+	}
+
+	destAcct, err := app.Account(c.Account)
+	if err != nil {
+		return err
+	}
+
+	destStore := destAcct.Store()
+	if destStore == nil {
+		app.PushError(fmt.Sprintf("No message store in %s", c.Account))
+		return nil
+	}
+
+	var messages []*types.FullMessage
+	fetchDone := make(chan bool, 1)
+	store.FetchFull(uids, func(fm *types.FullMessage) {
+		messages = append(messages, fm)
+		if len(messages) == len(uids) {
+			fetchDone <- true
+		}
+	})
+
+	// Since this operation can take some time with some backends
+	// (e.g. IMAP), provide some feedback to inform the user that
+	// something is happening
+	app.PushStatus("Copying messages...", 10*time.Second)
+	go func() {
+		defer log.PanicHandler()
+
+		select {
+		case <-fetchDone:
+			break
+		case <-time.After(30 * time.Second):
+			// TODO: find a better way to determine if store.FetchFull()
+			// has finished with some errors.
+			app.PushError("Failed to fetch all messages")
+			if len(messages) == 0 {
+				return
+			}
+		}
+		for _, fm := range messages {
+			buf := new(bytes.Buffer)
+			_, err = buf.ReadFrom(fm.Content.Reader)
+			if err != nil {
+				log.Warnf("failed to read message: %v", err)
+				continue
+			}
+			destStore.Append(
+				c.Folder,
+				models.SeenFlag,
+				time.Now(),
+				buf,
+				buf.Len(),
+				func(msg types.WorkerMessage) {
+					c.CallBack(msg, uids, store)
+				},
+			)
+		}
+	}()
 	return nil
 }
+
+func (c Copy) CallBack(msg types.WorkerMessage, uids []uint32, store *lib.MessageStore) {
+	dest := c.Folder
+	if len(c.Account) != 0 {
+		dest = fmt.Sprintf("%s in %s", c.Folder, c.Account)
+	}
+
+	switch msg := msg.(type) {
+	case *types.Done:
+		var s string
+		if len(uids) > 1 {
+			s = "%d messages copied to %s"
+		} else {
+			s = "%d message copied to %s"
+		}
+		app.PushStatus(fmt.Sprintf(s, len(uids), dest), 10*time.Second)
+		store.Marker().ClearVisualMark()
+	case *types.Error:
+		app.PushError(msg.Error.Error())
+	}
+}
diff --git a/doc/aerc.1.scd b/doc/aerc.1.scd
index 5be01751..c7fc8542 100644
--- a/doc/aerc.1.scd
+++ b/doc/aerc.1.scd
@@ -272,11 +272,14 @@ message list, the message in the message viewer, etc).
 
 	*-E*: Forces *[compose].edit-headers* = _false_ for this message only.
 
-*:copy* [*-p*] _<target>_++
-*:cp* [*-p*] _<target>_
-	Copies the selected message(s) to the target folder.
+*:copy* [*-p*] [*-a* _<account>_] _<folder>_++
+*:cp* [*-p*] [*-a* _<account>_] _<folder>_
+	Copies the selected message(s) to _<folder>_.
 
-	*-p*: Create the _<target>_ folder if it does not exist.
+	*-p*: Create _<folder>_ if it does not exist.
+
+	*-a*: Copy to _<folder>_ of _<account>_. If _<folder>_ does
+	not exist, it will be created whether or not *-p* is used.
 
 *:decline* [*-e*|*-E*]
 	Declines an iCalendar meeting invitation.