compose: use a proper header instead of a string map

Prior to this commit, the composer was based on a map[string]string.
While this approach was very versatile, it lead to a constant encoding / decoding
of addresses and other headers.

This commit switches to a different model, where the composer is based on a header.
Commands which want to interact with it can simply set some defaults they would
like to have. Users can overwrite them however they like.

In order to get access to the functions generating / getting the msgid go-message
was upgraded.

3 files changed, 32 insertions, 9 deletions

diff --git a/commands/compose/header.go b/commands/compose/header.go
index 5188a8a..dd0adee 100644
--- a/commands/compose/header.go
+++ b/commands/compose/header.go
@@ -57,18 +57,17 @@ func (Header) Execute(aerc *widgets.Aerc, args []string) error {
 	composer, _ := aerc.SelectedTab().(*widgets.Composer)
 
 	if !force {
-		headers, _, err := composer.PrepareHeader()
+		headers, err := composer.PrepareHeader()
 		if err != nil {
 			return err
 		}
 
-		if headers.Has(strings.Title(args[optind])) {
+		if headers.Has(args[optind]) {
 			return fmt.Errorf("Header %s already exists", args[optind])
 		}
 	}
 
-	composer.AddEditor(strings.Title(args[optind]),
-		strings.Join(args[optind+1:], " "), false)
+	composer.AddEditor(args[optind], strings.Join(args[optind+1:], " "), false)
 
 	return nil
 }
diff --git a/commands/compose/postpone.go b/commands/compose/postpone.go
index 60c9df1..365b683 100644
--- a/commands/compose/postpone.go
+++ b/commands/compose/postpone.go
@@ -40,7 +40,7 @@ func (Postpone) Execute(aerc *widgets.Aerc, args []string) error {
 
 	aerc.Logger().Println("Postponing mail")
 
-	header, _, err := composer.PrepareHeader()
+	header, err := composer.PrepareHeader()
 	if err != nil {
 		return errors.Wrap(err, "PrepareHeader")
 	}
diff --git a/commands/compose/send.go b/commands/compose/send.go
index abbcb54..70446da 100644
--- a/commands/compose/send.go
+++ b/commands/compose/send.go
@@ -4,7 +4,6 @@ import (
 	"crypto/tls"
 	"fmt"
 	"io"
-	"net/mail"
 	"net/url"
 	"os/exec"
 	"strings"
@@ -17,9 +16,11 @@ import (
 	"github.com/pkg/errors"
 
 	"git.sr.ht/~sircmpwn/aerc/lib"
+	"git.sr.ht/~sircmpwn/aerc/lib/format"
 	"git.sr.ht/~sircmpwn/aerc/models"
 	"git.sr.ht/~sircmpwn/aerc/widgets"
 	"git.sr.ht/~sircmpwn/aerc/worker/types"
+	"github.com/emersion/go-message/mail"
 	"golang.org/x/oauth2"
 )
 
@@ -71,15 +72,19 @@ func (Send) Execute(aerc *widgets.Aerc, args []string) error {
 		}
 	}
 
-	header, rcpts, err := composer.PrepareHeader()
+	header, err := composer.PrepareHeader()
 	if err != nil {
 		return errors.Wrap(err, "PrepareHeader")
 	}
+	rcpts, err := listRecipients(header)
+	if err != nil {
+		return errors.Wrap(err, "listRecipients")
+	}
 
 	if config.From == "" {
 		return errors.New("No 'From' configured for this account")
 	}
-	from, err := mail.ParseAddress(config.From)
+	from, err := format.ParseAddress(config.From)
 	if err != nil {
 		return errors.Wrap(err, "ParseAddress(config.From)")
 	}
@@ -288,7 +293,12 @@ func (Send) Execute(aerc *widgets.Aerc, args []string) error {
 					composer.Close()
 				}
 			})
-			header, _, _ := composer.PrepareHeader()
+			header, err := composer.PrepareHeader()
+			if err != nil {
+				aerc.PushError(" " + err.Error())
+				w.Close()
+				return
+			}
 			composer.WriteMessage(header, w)
 			w.Close()
 		} else {
@@ -299,3 +309,17 @@ func (Send) Execute(aerc *widgets.Aerc, args []string) error {
 	}()
 	return nil
 }
+
+func listRecipients(h *mail.Header) ([]string, error) {
+	var rcpts []string
+	for _, key := range []string{"to", "cc", "bcc"} {
+		list, err := h.AddressList(key)
+		if err != nil {
+			return nil, err
+		}
+		for _, addr := range list {
+			rcpts = append(rcpts, addr.Address)
+		}
+	}
+	return rcpts, nil
+}