compose: only allow setting content at creation

Add a parameter for the initial value of the body to be inserted
*before* the signature when composing a message.

Make AppendContents and SetContents private methods to ensure there is
no other way to change the composer contents from the outside after
creation.

Signed-off-by: Robin Jarry <robin@jarry.cc>
Tested-by: Bence Ferdinandy <bence@ferdinandy.com>
Tested-by: Koni Marti <koni.marti@gmail.com>

9 files changed, 45 insertions, 74 deletions

diff --git a/commands/account/compose.go b/commands/account/compose.go
index a8b16791..3c603f34 100644
--- a/commands/account/compose.go
+++ b/commands/account/compose.go
@@ -11,7 +11,6 @@ import (
 	"github.com/emersion/go-message/mail"
 
 	"git.sr.ht/~rjarry/aerc/config"
-	"git.sr.ht/~rjarry/aerc/log"
 	"git.sr.ht/~rjarry/aerc/widgets"
 	"git.sr.ht/~sircmpwn/getopt"
 )
@@ -53,16 +52,11 @@ func (Compose) Execute(aerc *widgets.Aerc, args []string) error {
 
 	composer, err := widgets.NewComposer(aerc, acct,
 		acct.AccountConfig(), acct.Worker(),
-		template, &headers, nil)
+		template, &headers, nil, msg.Body)
 	if err != nil {
 		return err
 	}
 	composer.Tab = aerc.NewTab(composer, "New email")
-	go func() {
-		defer log.PanicHandler()
-
-		composer.AppendContents(msg.Body)
-	}()
 	return nil
 }
 
diff --git a/commands/account/recover.go b/commands/account/recover.go
index 350daf17..3e4e9136 100644
--- a/commands/account/recover.go
+++ b/commands/account/recover.go
@@ -8,7 +8,6 @@ import (
 	"path/filepath"
 
 	"git.sr.ht/~rjarry/aerc/commands"
-	"git.sr.ht/~rjarry/aerc/log"
 	"git.sr.ht/~rjarry/aerc/widgets"
 	"git.sr.ht/~sircmpwn/getopt"
 )
@@ -85,17 +84,11 @@ func (r Recover) Execute(aerc *widgets.Aerc, args []string) error {
 
 	composer, err := widgets.NewComposer(aerc, acct,
 		acct.AccountConfig(), acct.Worker(),
-		"", nil, nil)
+		"", nil, nil, bytes.NewReader(data))
 	if err != nil {
 		return err
 	}
-
 	composer.Tab = aerc.NewTab(composer, "Recovered")
-	go func() {
-		defer log.PanicHandler()
-
-		composer.AppendContents(bytes.NewReader(data))
-	}()
 
 	// remove file if force flag is set
 	if force {
diff --git a/commands/msg/forward.go b/commands/msg/forward.go
index 92575abd..ed0043fe 100644
--- a/commands/msg/forward.go
+++ b/commands/msg/forward.go
@@ -100,7 +100,7 @@ func (forward) Execute(aerc *widgets.Aerc, args []string) error {
 
 	addTab := func() (*widgets.Composer, error) {
 		composer, err := widgets.NewComposer(aerc, acct,
-			acct.AccountConfig(), acct.Worker(), template, h, &original)
+			acct.AccountConfig(), acct.Worker(), template, h, &original, nil)
 		if err != nil {
 			aerc.PushError("Error: " + err.Error())
 			return nil, err
diff --git a/commands/msg/invite.go b/commands/msg/invite.go
index 774c4a69..6273d520 100644
--- a/commands/msg/invite.go
+++ b/commands/msg/invite.go
@@ -138,13 +138,11 @@ func (invite) Execute(aerc *widgets.Aerc, args []string) error {
 
 	addTab := func(cr *calendar.Reply) error {
 		composer, err := widgets.NewComposer(aerc, acct,
-			acct.AccountConfig(), acct.Worker(), "", h, &original)
+			acct.AccountConfig(), acct.Worker(), "", h, &original, cr.PlainText)
 		if err != nil {
 			aerc.PushError("Error: " + err.Error())
 			return err
 		}
-
-		composer.SetContents(cr.PlainText)
 		err = composer.AppendPart(cr.MimeType, cr.Params, cr.CalendarText)
 		if err != nil {
 			return fmt.Errorf("failed to write invitation: %w", err)
diff --git a/commands/msg/recall.go b/commands/msg/recall.go
index 4eda8339..71f8b8a5 100644
--- a/commands/msg/recall.go
+++ b/commands/msg/recall.go
@@ -7,14 +7,11 @@ import (
 	"sync"
 	"time"
 
-	"github.com/emersion/go-message"
 	_ "github.com/emersion/go-message/charset"
-	"github.com/emersion/go-message/mail"
 	"github.com/pkg/errors"
 
 	"git.sr.ht/~rjarry/aerc/lib"
 	"git.sr.ht/~rjarry/aerc/log"
-	"git.sr.ht/~rjarry/aerc/models"
 	"git.sr.ht/~rjarry/aerc/widgets"
 	"git.sr.ht/~rjarry/aerc/worker/types"
 	"git.sr.ht/~sircmpwn/getopt"
@@ -71,17 +68,7 @@ func (Recall) Execute(aerc *widgets.Aerc, args []string) error {
 	}
 	log.Debugf("Recalling message <%s>", msgInfo.Envelope.MessageId)
 
-	composer, err := widgets.NewComposer(aerc, acct,
-		acct.AccountConfig(), acct.Worker(), "", msgInfo.RFC822Headers,
-		nil)
-	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() {
+	addTab := func(composer *widgets.Composer) {
 		subject := msgInfo.Envelope.Subject
 		if subject == "" {
 			subject = "Recalled email"
@@ -136,39 +123,19 @@ func (Recall) Execute(aerc *widgets.Aerc, args []string) error {
 				aerc.PushError(err.Error())
 				return
 			}
-
-			var (
-				path []int
-				part *models.BodyStructure
-			)
+			var path []int
 			if len(msg.BodyStructure().Parts) != 0 {
 				path = lib.FindPlaintext(msg.BodyStructure(), path)
 			}
-			part, err = msg.BodyStructure().PartAtIndex(path)
-			if part == nil || err != nil {
-				part = msg.BodyStructure()
-			}
 
 			msg.FetchBodyPart(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)
+				composer, err := widgets.NewComposer(aerc, acct,
+					acct.AccountConfig(), acct.Worker(),
+					"", msgInfo.RFC822Headers, nil, reader)
 				if err != nil {
 					aerc.PushError(err.Error())
-					addTab()
 					return
 				}
-				mreader := mail.NewReader(entity)
-				part, err := mreader.NextPart()
-				if err != nil {
-					aerc.PushError(err.Error())
-					addTab()
-					return
-				}
-				composer.SetContents(part.Body)
 				if md := msg.MessageDetails(); md != nil {
 					if md.IsEncrypted {
 						composer.SetEncrypt(md.IsEncrypted)
@@ -180,7 +147,6 @@ func (Recall) Execute(aerc *widgets.Aerc, args []string) error {
 						}
 					}
 				}
-				addTab()
 
 				// add attachements if present
 				var mu sync.Mutex
@@ -210,6 +176,10 @@ func (Recall) Execute(aerc *widgets.Aerc, args []string) error {
 						}
 					})
 				}
+
+				// focus the terminal since the header fields are likely already done
+				composer.FocusTerminal()
+				addTab(composer)
 			})
 		})
 
diff --git a/commands/msg/reply.go b/commands/msg/reply.go
index 2b9f5d4f..8cdb50d4 100644
--- a/commands/msg/reply.go
+++ b/commands/msg/reply.go
@@ -176,7 +176,7 @@ func (reply) Execute(aerc *widgets.Aerc, args []string) error {
 	addTab := func() error {
 		composer, err := widgets.NewComposer(aerc, acct,
 			acct.AccountConfig(), acct.Worker(), template, h,
-			&original)
+			&original, nil)
 		if err != nil {
 			aerc.PushError("Error: " + err.Error())
 			return err
diff --git a/commands/msg/unsubscribe.go b/commands/msg/unsubscribe.go
index 5fce7ece..cefa69cb 100644
--- a/commands/msg/unsubscribe.go
+++ b/commands/msg/unsubscribe.go
@@ -154,11 +154,11 @@ func unsubscribeMailto(aerc *widgets.Aerc, u *url.URL) error {
 		"",
 		h,
 		nil,
+		strings.NewReader(u.Query().Get("body")),
 	)
 	if err != nil {
 		return err
 	}
-	composer.SetContents(strings.NewReader(u.Query().Get("body")))
 	composer.Tab = aerc.NewTab(composer, "unsubscribe")
 	composer.FocusTerminal()
 	return nil
diff --git a/widgets/aerc.go b/widgets/aerc.go
index 85ce686b..8f744b4c 100644
--- a/widgets/aerc.go
+++ b/widgets/aerc.go
@@ -734,11 +734,11 @@ func (aerc *Aerc) Mailto(addr *url.URL) error {
 	defer ui.Invalidate()
 
 	composer, err := NewComposer(aerc, acct,
-		acct.AccountConfig(), acct.Worker(), template, h, nil)
+		acct.AccountConfig(), acct.Worker(), template, h, nil,
+		strings.NewReader(body))
 	if err != nil {
 		return err
 	}
-	composer.SetContents(strings.NewReader(body))
 	composer.FocusEditor("subject")
 	title := "New email"
 	if subject != "" {
diff --git a/widgets/compose.go b/widgets/compose.go
index 43657a29..c4a93d83 100644
--- a/widgets/compose.go
+++ b/widgets/compose.go
@@ -71,7 +71,7 @@ type Composer struct {
 func NewComposer(
 	aerc *Aerc, acct *AccountView, acctConfig *config.AccountConfig,
 	worker *types.Worker, template string,
-	h *mail.Header, orig *models.OriginalMail,
+	h *mail.Header, orig *models.OriginalMail, body io.Reader,
 ) (*Composer, error) {
 	if h == nil {
 		h = new(mail.Header)
@@ -100,7 +100,7 @@ func NewComposer(
 	data.SetAccount(acct.acct)
 	data.SetFolder(acct.Directories().SelectedDirectory())
 	data.SetHeaders(h, orig)
-	if err := c.AddTemplate(template, data.Data()); err != nil {
+	if err := c.addTemplate(template, data.Data(), body); err != nil {
 		return nil, err
 	}
 	c.AddSignature()
@@ -428,7 +428,7 @@ func (c *Composer) updateCrypto() error {
 
 // Note: this does not reload the editor. You must call this before the first
 // Draw() call.
-func (c *Composer) SetContents(reader io.Reader) *Composer {
+func (c *Composer) setContents(reader io.Reader) *Composer {
 	_, err := c.email.Seek(0, io.SeekStart)
 	if err != nil {
 		log.Warnf("failed to seek beginning of mail: %v", err)
@@ -448,7 +448,7 @@ func (c *Composer) SetContents(reader io.Reader) *Composer {
 	return c
 }
 
-func (c *Composer) AppendContents(reader io.Reader) {
+func (c *Composer) appendContents(reader io.Reader) {
 	_, err := c.email.Seek(0, io.SeekEnd)
 	if err != nil {
 		log.Warnf("failed to seek beginning of mail: %v", err)
@@ -496,20 +496,36 @@ func (c *Composer) RemovePart(mimetype string) error {
 	return fmt.Errorf("%s part not found", mimetype)
 }
 
-func (c *Composer) AddTemplate(template string, data models.TemplateData) error {
-	if template == "" {
+func (c *Composer) addTemplate(
+	template string, data models.TemplateData, body io.Reader,
+) error {
+	var readers []io.Reader
+
+	if template != "" {
+		templateText, err := templates.ParseTemplateFromFile(
+			template, config.Templates.TemplateDirs, data)
+		if err != nil {
+			return err
+		}
+		readers = append(readers, templateText)
+	}
+	if body != nil {
+		readers = append(readers, body)
+	}
+	if len(readers) == 0 {
 		return nil
 	}
 
-	templateText, err := templates.ParseTemplateFromFile(
-		template, config.Templates.TemplateDirs, data)
+	buf, err := io.ReadAll(io.MultiReader(readers...))
 	if err != nil {
 		return err
 	}
 
-	mr, err := mail.CreateReader(templateText)
+	mr, err := mail.CreateReader(bytes.NewReader(buf))
 	if err != nil {
-		return fmt.Errorf("Template loading failed: %w", err)
+		// no headers in the template nor body
+		c.setContents(bytes.NewReader(buf))
+		return nil
 	}
 
 	// copy the headers contained in the template to the compose headers
@@ -523,7 +539,7 @@ func (c *Composer) AddTemplate(template string, data models.TemplateData) error
 		return fmt.Errorf("Could not get body of template: %w", err)
 	}
 
-	c.AppendContents(part.Body)
+	c.setContents(part.Body)
 	return nil
 }
 
@@ -542,7 +558,7 @@ func (c *Composer) AddSignature() {
 		return
 	}
 	signature = ensureSignatureDelimiter(signature)
-	c.AppendContents(bytes.NewReader(signature))
+	c.appendContents(bytes.NewReader(signature))
 }
 
 func (c *Composer) readSignatureFromCmd() ([]byte, error) {