Remove hard coded bodystruct path everywhere

Aerc usually used the path []int{1} if it didn't know what the proper path is.
However this only works for multipart messages and breaks if it isn't one.

This patch removes all the hard coding and extracts the necessary helpers to lib.

commands/msg/forward.go

@@ -10,6 +10,7 @@ import (
 	"path"
 	"strings"
 
+	"git.sr.ht/~sircmpwn/aerc/lib"
 	"git.sr.ht/~sircmpwn/aerc/models"
 	"git.sr.ht/~sircmpwn/aerc/widgets"
 	"git.sr.ht/~sircmpwn/aerc/worker/types"
@@ -137,12 +138,10 @@ func (forward) Execute(aerc *widgets.Aerc, args []string) error {
 		}
 
 		// TODO: add attachments!
-		part := findPlaintext(msg.BodyStructure, nil)
+		part := lib.FindPlaintext(msg.BodyStructure, nil)
 		if part == nil {
-			part = findFirstNonMultipart(msg.BodyStructure, nil)
-			if part == nil {
-				part = []int{1}
-			}
+			part = lib.FindFirstNonMultipart(msg.BodyStructure, nil)
+			// if it's still nil here, we don't have a multipart msg, that's fine
 		}
 		store.FetchBodyPart(msg.Uid, part, func(reader io.Reader) {
 			buf := new(bytes.Buffer)

commands/msg/recall.go

@@ -8,6 +8,7 @@ import (
 	"github.com/emersion/go-message/mail"
 	"github.com/pkg/errors"
 
+	"git.sr.ht/~sircmpwn/aerc/lib"
 	"git.sr.ht/~sircmpwn/aerc/models"
 	"git.sr.ht/~sircmpwn/aerc/widgets"
 	"git.sr.ht/~sircmpwn/aerc/worker/types"
@@ -107,12 +108,11 @@ func (Recall) Execute(aerc *widgets.Aerc, args []string) error {
 		part *models.BodyStructure
 	)
 	if len(msgInfo.BodyStructure.Parts) != 0 {
-		path = findPlaintext(msgInfo.BodyStructure, path)
+		path = lib.FindPlaintext(msgInfo.BodyStructure, path)
 	}
 	part, err = msgInfo.BodyStructure.PartAtIndex(path)
 	if part == nil || err != nil {
 		part = msgInfo.BodyStructure
-		path = []int{1}
 	}
 
 	store.FetchBodyPart(msgInfo.Uid, path, func(reader io.Reader) {

commands/msg/reply.go

@@ -10,6 +10,7 @@ import (
 
 	"git.sr.ht/~sircmpwn/getopt"
 
+	"git.sr.ht/~sircmpwn/aerc/lib"
 	"git.sr.ht/~sircmpwn/aerc/models"
 	"git.sr.ht/~sircmpwn/aerc/widgets"
 )
@@ -169,14 +170,12 @@ func (reply) Execute(aerc *widgets.Aerc, args []string) error {
 			template = aerc.Config().Templates.QuotedReply
 		}
 
-		part := findPlaintext(msg.BodyStructure, nil)
+		part := lib.FindPlaintext(msg.BodyStructure, nil)
 		if part == nil {
-			//mkey... let's get the first thing that isn't a container
-			part = findFirstNonMultipart(msg.BodyStructure, nil)
-			if part == nil {
-				// give up, use whatever is first
-				part = []int{1}
-			}
+			// mkey... let's get the first thing that isn't a container
+			// if that's still nil it's either not a multipart msg (ok) or
+			// broken (containers only)
+			part = lib.FindFirstNonMultipart(msg.BodyStructure, nil)
 		}
 		store.FetchBodyPart(msg.Uid, part, func(reader io.Reader) {
 			buf := new(bytes.Buffer)

commands/msg/utils.go

@@ -2,7 +2,6 @@ package msg
 
 import (
 	"errors"
-	"strings"
 
 	"git.sr.ht/~sircmpwn/aerc/commands"
 	"git.sr.ht/~sircmpwn/aerc/lib"
@@ -49,34 +48,3 @@ func (h *helper) messages() ([]*models.MessageInfo, error) {
 	}
 	return commands.MsgInfoFromUids(store, uid)
 }
-
-func findPlaintext(bs *models.BodyStructure, path []int) []int {
-	for i, part := range bs.Parts {
-		cur := append(path, i+1)
-		if strings.ToLower(part.MIMEType) == "text" &&
-			strings.ToLower(part.MIMESubType) == "plain" {
-			return cur
-		}
-		if strings.ToLower(part.MIMEType) == "multipart" {
-			if path := findPlaintext(part, cur); path != nil {
-				return path
-			}
-		}
-	}
-	return nil
-}
-
-func findFirstNonMultipart(bs *models.BodyStructure, path []int) []int {
-	for i, part := range bs.Parts {
-		cur := append(path, i+1)
-		mimetype := strings.ToLower(part.MIMEType)
-		if mimetype != "multipart" {
-			return path
-		} else if mimetype == "multipart" {
-			if path := findPlaintext(part, cur); path != nil {
-				return path
-			}
-		}
-	}
-	return nil
-}