Add recall command

This command allows recalling the selected postponed email to edit in
the composer. The command only allows recalling from the postpone
directory.

7 files changed, 154 insertions, 5 deletions

diff --git a/commands/account/compose.go b/commands/account/compose.go
index 42d51d51..b33acf5a 100644
--- a/commands/account/compose.go
+++ b/commands/account/compose.go
@@ -31,7 +31,7 @@ func (Compose) Execute(aerc *widgets.Aerc, args []string) error {
 	}
 	acct := aerc.SelectedAccount()
 
-	composer, err := widgets.NewComposer(aerc, acct
+	composer, err := widgets.NewComposer(aerc, acct,
 		aerc.Config(), acct.AccountConfig(), acct.Worker(),
 		template, nil, models.OriginalMail{})
 	if err != nil {
diff --git a/commands/compose/postpone.go b/commands/compose/postpone.go
index 44aa4118..60c9df1a 100644
--- a/commands/compose/postpone.go
+++ b/commands/compose/postpone.go
@@ -5,10 +5,10 @@ import (
 	"io/ioutil"
 	"time"
 
-	"github.com/emersion/go-imap"
 	"github.com/miolini/datacounter"
 	"github.com/pkg/errors"
 
+	"git.sr.ht/~sircmpwn/aerc/models"
 	"git.sr.ht/~sircmpwn/aerc/widgets"
 	"git.sr.ht/~sircmpwn/aerc/worker/types"
 )
@@ -79,7 +79,7 @@ func (Postpone) Execute(aerc *widgets.Aerc, args []string) error {
 		r, w := io.Pipe()
 		worker.PostAction(&types.AppendMessage{
 			Destination: config.Postpone,
-			Flags:       []string{imap.SeenFlag},
+			Flags:       []models.Flag{models.SeenFlag},
 			Date:        time.Now(),
 			Reader:      r,
 			Length:      int(nbytes),
diff --git a/commands/msg/forward.go b/commands/msg/forward.go
index 833eb9fd..35a65d8e 100644
--- a/commands/msg/forward.go
+++ b/commands/msg/forward.go
@@ -78,7 +78,7 @@ func (forward) Execute(aerc *widgets.Aerc, args []string) error {
 			original.Date = msg.Envelope.Date.Format("Mon Jan 2, 2006 at 3:04 PM")
 		}
 
-		composer, err := widgets.NewComposer(aerc, aerc.Config(), acct.AccountConfig(),
+		composer, err := widgets.NewComposer(aerc, acct, aerc.Config(), acct.AccountConfig(),
 			acct.Worker(), template, defaults, original)
 		if err != nil {
 			aerc.PushError("Error: " + err.Error())
diff --git a/commands/msg/recall.go b/commands/msg/recall.go
new file mode 100644
index 00000000..c2f887a1
--- /dev/null
+++ b/commands/msg/recall.go
@@ -0,0 +1,141 @@
+package msg
+
+import (
+	"io"
+
+	"github.com/emersion/go-message"
+	_ "github.com/emersion/go-message/charset"
+	"github.com/emersion/go-message/mail"
+	"github.com/pkg/errors"
+
+	"git.sr.ht/~sircmpwn/aerc/models"
+	"git.sr.ht/~sircmpwn/aerc/widgets"
+	"git.sr.ht/~sircmpwn/aerc/worker/types"
+)
+
+type Recall struct{}
+
+func init() {
+	register(Recall{})
+}
+
+func (Recall) Aliases() []string {
+	return []string{"recall"}
+}
+
+func (Recall) Complete(aerc *widgets.Aerc, args []string) []string {
+	return nil
+}
+
+func (Recall) Execute(aerc *widgets.Aerc, args []string) error {
+	if len(args) != 1 {
+		return errors.New("Usage: recall")
+	}
+
+	widget := aerc.SelectedTab().(widgets.ProvidesMessage)
+	acct := widget.SelectedAccount()
+	if acct == nil {
+		return errors.New("No account selected")
+	}
+	if acct.SelectedDirectory() != acct.AccountConfig().Postpone {
+		return errors.New("Can only recall from the postpone directory: " +
+			acct.AccountConfig().Postpone)
+	}
+	store := widget.Store()
+	if store == nil {
+		return errors.New("Cannot perform action. Messages still loading")
+	}
+
+	msgInfo, err := widget.SelectedMessage()
+	if err != nil {
+		return errors.Wrap(err, "Recall failed")
+	}
+	acct.Logger().Println("Recalling message " + msgInfo.Envelope.MessageId)
+
+	// copy the headers to the defaults map for addition to the composition
+	defaults := make(map[string]string)
+	headerFields := msgInfo.RFC822Headers.Fields()
+	for headerFields.Next() {
+		defaults[headerFields.Key()] = headerFields.Value()
+	}
+
+	composer, err := widgets.NewComposer(aerc, acct, aerc.Config(),
+		acct.AccountConfig(), acct.Worker(), "", defaults, models.OriginalMail{})
+	if err != nil {
+		return errors.Wrap(err, "Cannot open a new composer")
+	}
+
+	// focus the terminal since the header fields are likely already done
+	composer.FocusTerminal()
+
+	addTab := func() {
+		subject := msgInfo.Envelope.Subject
+		if subject == "" {
+			subject = "Recalled email"
+		}
+		tab := aerc.NewTab(composer, subject)
+		composer.OnHeaderChange("Subject", func(subject string) {
+			if subject == "" {
+				tab.Name = "New email"
+			} else {
+				tab.Name = subject
+			}
+			tab.Content.Invalidate()
+		})
+		composer.OnClose(func(composer *widgets.Composer) {
+			worker := composer.Worker()
+			uids := []uint32{msgInfo.Uid}
+
+			worker.PostAction(&types.DeleteMessages{
+				Uids: uids,
+			}, func(msg types.WorkerMessage) {
+				switch msg := msg.(type) {
+				case *types.Error:
+					aerc.PushError(" " + msg.Error.Error())
+					composer.Close()
+				}
+			})
+
+			return
+		})
+	}
+
+	// find the main body part and add it to the editor
+	// TODO: copy all parts of the message over?
+	var (
+		path []int
+		part *models.BodyStructure
+	)
+	if len(msgInfo.BodyStructure.Parts) != 0 {
+		part, path = findPlaintext(msgInfo.BodyStructure, path)
+	}
+	if part == nil {
+		part = msgInfo.BodyStructure
+		path = []int{1}
+	}
+
+	store.FetchBodyPart(msgInfo.Uid, part, path, func(reader io.Reader) {
+		header := message.Header{}
+		header.SetText(
+			"Content-Transfer-Encoding", part.Encoding)
+		header.SetContentType(part.MIMEType, part.Params)
+		header.SetText("Content-Description", part.Description)
+		entity, err := message.New(header, reader)
+		if err != nil {
+			// TODO: Do something with the error
+			addTab()
+			return
+		}
+		mreader := mail.NewReader(entity)
+		part, err := mreader.NextPart()
+		if err != nil {
+			// TODO: Do something with the error
+			addTab()
+			return
+		}
+		composer.SetContents(part.Body)
+		addTab()
+	})
+
+	return nil
+}
diff --git a/doc/aerc.1.scd b/doc/aerc.1.scd
index 230361db..ec3f1718 100644
--- a/doc/aerc.1.scd
+++ b/doc/aerc.1.scd
@@ -103,6 +103,10 @@ message list, the message in the message viewer, etc).
 *delete*
 	Deletes the selected message.
 
+*recall*
+	Opens the selected message for re-editing. Messages can only be
+	recalled from the postpone directory.
+
 *forward* [-A] [address...]
 	Opens the composer to forward the selected message to another recipient.
 
diff --git a/widgets/account.go b/widgets/account.go
index a854fb6e..31384a5f 100644
--- a/widgets/account.go
+++ b/widgets/account.go
@@ -200,6 +200,10 @@ func (acct *AccountView) SelectedAccount() *AccountView {
 	return acct
 }
 
+func (acct *AccountView) SelectedDirectory() string {
+	return acct.dirlist.Selected()
+}
+
 func (acct *AccountView) SelectedMessage() (*models.MessageInfo, error) {
 	if len(acct.msglist.Store().Uids()) == 0 {
 		return nil, errors.New("no message selected")
diff --git a/widgets/compose.go b/widgets/compose.go
index 66877cc1..42819411 100644
--- a/widgets/compose.go
+++ b/widgets/compose.go
@@ -59,7 +59,7 @@ type Composer struct {
 }
 
 func NewComposer(aerc *Aerc, acct *AccountView, conf *config.AercConfig,
-	acct *config.AccountConfig, worker *types.Worker, template string,
+	acctConfig *config.AccountConfig, worker *types.Worker, template string,
 	defaults map[string]string, original models.OriginalMail) (*Composer, error) {
 
 	if defaults == nil {