Factor IMAP-specific structs out of UI models

Before, we were using several IMAP-specific concepts to represent
information being displayed in the UI. Factor these structures out of
the IMAP package to make it easier for other backends to provide the
required information.

10 files changed, 211 insertions, 108 deletions

diff --git a/commands/msg/reply.go b/commands/msg/reply.go
index 7a64d21e..68c20899 100644
--- a/commands/msg/reply.go
+++ b/commands/msg/reply.go
@@ -9,12 +9,11 @@ import (
 	"strings"
 
 	"git.sr.ht/~sircmpwn/getopt"
-	"github.com/emersion/go-imap"
 	"github.com/emersion/go-message"
 	_ "github.com/emersion/go-message/charset"
 	"github.com/emersion/go-message/mail"
 
-	"git.sr.ht/~sircmpwn/aerc/lib"
+	"git.sr.ht/~sircmpwn/aerc/models"
 	"git.sr.ht/~sircmpwn/aerc/widgets"
 )
 
@@ -67,7 +66,7 @@ func (_ reply) Execute(aerc *widgets.Aerc, args []string) error {
 	var (
 		to     []string
 		cc     []string
-		toList []*imap.Address
+		toList []*models.Address
 	)
 	if args[0] == "reply" {
 		if len(msg.Envelope.ReplyTo) != 0 {
@@ -76,24 +75,23 @@ func (_ reply) Execute(aerc *widgets.Aerc, args []string) error {
 			toList = msg.Envelope.From
 		}
 		for _, addr := range toList {
-			if addr.PersonalName != "" {
+			if addr.Name != "" {
 				to = append(to, fmt.Sprintf("%s <%s@%s>",
-					addr.PersonalName, addr.MailboxName, addr.HostName))
+					addr.Name, addr.Mailbox, addr.Host))
 			} else {
-				to = append(to, fmt.Sprintf("<%s@%s>",
-					addr.MailboxName, addr.HostName))
+				to = append(to, fmt.Sprintf("<%s@%s>", addr.Mailbox, addr.Host))
 			}
 		}
 		if replyAll {
 			for _, addr := range msg.Envelope.Cc {
-				cc = append(cc, lib.FormatAddress(addr))
+				cc = append(cc, addr.Format())
 			}
 			for _, addr := range msg.Envelope.To {
-				address := fmt.Sprintf("%s@%s", addr.MailboxName, addr.HostName)
+				address := fmt.Sprintf("%s@%s", addr.Mailbox, addr.Host)
 				if address == us.Address {
 					continue
 				}
-				to = append(to, lib.FormatAddress(addr))
+				to = append(to, addr.Format())
 			}
 		}
 	}
@@ -163,7 +161,7 @@ func (_ reply) Execute(aerc *widgets.Aerc, args []string) error {
 			go composer.SetContents(pipeout)
 			// TODO: Let user customize the date format used here
 			io.WriteString(pipein, fmt.Sprintf("Forwarded message from %s on %s:\n\n",
-				msg.Envelope.From[0].PersonalName,
+				msg.Envelope.From[0].Name,
 				msg.Envelope.Date.Format("Mon Jan 2, 2006 at 3:04 PM")))
 			for scanner.Scan() {
 				io.WriteString(pipein, fmt.Sprintf("%s\n", scanner.Text()))
@@ -176,7 +174,7 @@ func (_ reply) Execute(aerc *widgets.Aerc, args []string) error {
 		if quote {
 			var (
 				path []int
-				part *imap.BodyStructure
+				part *models.BodyStructure
 			)
 			if len(msg.BodyStructure.Parts) != 0 {
 				part, path = findPlaintext(msg.BodyStructure, path)
@@ -212,7 +210,7 @@ func (_ reply) Execute(aerc *widgets.Aerc, args []string) error {
 				// TODO: Let user customize the date format used here
 				io.WriteString(pipein, fmt.Sprintf("On %s %s wrote:\n",
 					msg.Envelope.Date.Format("Mon Jan 2, 2006 at 3:04 PM"),
-					msg.Envelope.From[0].PersonalName))
+					msg.Envelope.From[0].Name))
 				for scanner.Scan() {
 					io.WriteString(pipein, fmt.Sprintf("> %s\n", scanner.Text()))
 				}
@@ -228,8 +226,8 @@ func (_ reply) Execute(aerc *widgets.Aerc, args []string) error {
 	return nil
 }
 
-func findPlaintext(bs *imap.BodyStructure,
-	path []int) (*imap.BodyStructure, []int) {
+func findPlaintext(bs *models.BodyStructure,
+	path []int) (*models.BodyStructure, []int) {
 
 	for i, part := range bs.Parts {
 		cur := append(path, i+1)
diff --git a/lib/address.go b/lib/address.go
deleted file mode 100644
index b557195b..00000000
--- a/lib/address.go
+++ /dev/null
@@ -1,40 +0,0 @@
-package lib
-
-import (
-	"bytes"
-	"fmt"
-	"regexp"
-	"strings"
-
-	"github.com/emersion/go-imap"
-)
-
-var (
-	atom *regexp.Regexp = regexp.MustCompile("^[a-z0-9!#$%7'*+-/=?^_`{}|~ ]+$")
-)
-
-func FormatAddresses(addrs []*imap.Address) string {
-	val := bytes.Buffer{}
-	for i, addr := range addrs {
-		val.WriteString(FormatAddress(addr))
-		if i != len(addrs)-1 {
-			val.WriteString(", ")
-		}
-	}
-	return val.String()
-}
-
-func FormatAddress(addr *imap.Address) string {
-	if addr.PersonalName != "" {
-		if atom.MatchString(addr.PersonalName) {
-			return fmt.Sprintf("%s <%s@%s>",
-				addr.PersonalName, addr.MailboxName, addr.HostName)
-		} else {
-			return fmt.Sprintf("\"%s\" <%s@%s>",
-				strings.ReplaceAll(addr.PersonalName, "\"", "'"),
-				addr.MailboxName, addr.HostName)
-		}
-	} else {
-		return fmt.Sprintf("<%s@%s>", addr.MailboxName, addr.HostName)
-	}
-}
diff --git a/lib/indexformat.go b/lib/indexformat.go
index 43d2ef83..fa39909f 100644
--- a/lib/indexformat.go
+++ b/lib/indexformat.go
@@ -6,8 +6,6 @@ import (
 	"strings"
 	"unicode"
 
-	"github.com/emersion/go-imap"
-
 	"git.sr.ht/~sircmpwn/aerc/config"
 	"git.sr.ht/~sircmpwn/aerc/models"
 )
@@ -70,10 +68,9 @@ func ParseIndexFormat(conf *config.AercConfig, number int,
 			}
 			addr := msg.Envelope.From[0]
 			retval = append(retval, 's')
-			args = append(args, fmt.Sprintf("%s@%s", addr.MailboxName,
-				addr.HostName))
+			args = append(args, fmt.Sprintf("%s@%s", addr.Mailbox, addr.Host))
 		case 'A':
-			var addr *imap.Address
+			var addr *models.Address
 			if len(msg.Envelope.ReplyTo) == 0 {
 				if len(msg.Envelope.From) == 0 {
 					return "", nil,
@@ -85,8 +82,7 @@ func ParseIndexFormat(conf *config.AercConfig, number int,
 				addr = msg.Envelope.ReplyTo[0]
 			}
 			retval = append(retval, 's')
-			args = append(args, fmt.Sprintf("%s@%s", addr.MailboxName,
-				addr.HostName))
+			args = append(args, fmt.Sprintf("%s@%s", addr.Mailbox, addr.Host))
 		case 'C':
 			retval = append(retval, 'd')
 			args = append(args, number)
@@ -100,7 +96,7 @@ func ParseIndexFormat(conf *config.AercConfig, number int,
 			if len(msg.Envelope.From) == 0 {
 				return "", nil, errors.New("found no address for sender")
 			}
-			addr := FormatAddress(msg.Envelope.From[0])
+			addr := msg.Envelope.From[0].Format()
 			retval = append(retval, 's')
 			args = append(args, addr)
 		case 'F':
@@ -111,11 +107,10 @@ func ParseIndexFormat(conf *config.AercConfig, number int,
 			// TODO: handle case when sender is current user. Then
 			// use recipient's name
 			var val string
-			if addr.PersonalName != "" {
-				val = addr.PersonalName
+			if addr.Name != "" {
+				val = addr.Name
 			} else {
-				val = fmt.Sprintf("%s@%s",
-					addr.MailboxName, addr.HostName)
+				val = fmt.Sprintf("%s@%s", addr.Mailbox, addr.Host)
 			}
 			retval = append(retval, 's')
 			args = append(args, val)
@@ -129,20 +124,19 @@ func ParseIndexFormat(conf *config.AercConfig, number int,
 			}
 			addr := msg.Envelope.From[0]
 			var val string
-			if addr.PersonalName != "" {
-				val = addr.PersonalName
+			if addr.Name != "" {
+				val = addr.Name
 			} else {
-				val = fmt.Sprintf("%s@%s",
-					addr.MailboxName, addr.HostName)
+				val = fmt.Sprintf("%s@%s", addr.Mailbox, addr.Host)
 			}
 			retval = append(retval, 's')
 			args = append(args, val)
 		case 'r':
-			addrs := FormatAddresses(msg.Envelope.To)
+			addrs := models.FormatAddresses(msg.Envelope.To)
 			retval = append(retval, 's')
 			args = append(args, addrs)
 		case 'R':
-			addrs := FormatAddresses(msg.Envelope.Cc)
+			addrs := models.FormatAddresses(msg.Envelope.Cc)
 			retval = append(retval, 's')
 			args = append(args, addrs)
 		case 's':
@@ -154,16 +148,16 @@ func ParseIndexFormat(conf *config.AercConfig, number int,
 			}
 			addr := msg.Envelope.From[0]
 			retval = append(retval, 's')
-			args = append(args, addr.MailboxName)
+			args = append(args, addr.Mailbox)
 		case 'v':
 			if len(msg.Envelope.From) == 0 {
 				return "", nil, errors.New("found no address for sender")
 			}
 			addr := msg.Envelope.From[0]
 			// check if message is from current user
-			if addr.PersonalName != "" {
+			if addr.Name != "" {
 				retval = append(retval, 's')
-				args = append(args, strings.Split(addr.PersonalName, " ")[0])
+				args = append(args, strings.Split(addr.Name, " ")[0])
 			}
 		case 'Z':
 			// calculate all flags
@@ -171,18 +165,18 @@ func ParseIndexFormat(conf *config.AercConfig, number int,
 			var delFlag = ""
 			var flaggedFlag = ""
 			for _, flag := range msg.Flags {
-				if flag == imap.SeenFlag {
+				if flag == models.SeenFlag {
 					readFlag = "O" // message is old
-				} else if flag == imap.RecentFlag {
+				} else if flag == models.RecentFlag {
 					readFlag = "N" // message is new
-				} else if flag == imap.AnsweredFlag {
+				} else if flag == models.AnsweredFlag {
 					readFlag = "r" // message has been replied to
 				}
-				if flag == imap.DeletedFlag {
+				if flag == models.DeletedFlag {
 					delFlag = "D"
 					// TODO: check if attachments
 				}
-				if flag == imap.FlaggedFlag {
+				if flag == models.FlaggedFlag {
 					flaggedFlag = "!"
 				}
 				// TODO: check gpg stuff
diff --git a/models/models.go b/models/models.go
index cff05b1e..28d256c4 100644
--- a/models/models.go
+++ b/models/models.go
@@ -1,13 +1,37 @@
 package models
 
 import (
+	"bytes"
+	"fmt"
 	"io"
+	"regexp"
+	"strings"
 	"time"
 
-	"github.com/emersion/go-imap"
 	"github.com/emersion/go-message/mail"
 )
 
+// Flag is an abstraction around the different flags which can be present in
+// different email backends and represents a flag that we use in the UI.
+type Flag int
+
+const (
+	// SeenFlag marks a message as having been seen previously
+	SeenFlag Flag = iota
+
+	// RecentFlag marks a message as being recent
+	RecentFlag
+
+	// AnsweredFlag marks a message as having been replied to
+	AnsweredFlag
+
+	// DeletedFlag marks a message as having been deleted
+	DeletedFlag
+
+	// FlaggedFlag marks a message with a user flag
+	FlaggedFlag
+)
+
 type Directory struct {
 	Name       string
 	Attributes []string
@@ -30,9 +54,9 @@ type DirectoryInfo struct {
 
 // A MessageInfo holds information about the structure of a message
 type MessageInfo struct {
-	BodyStructure *imap.BodyStructure
-	Envelope      *imap.Envelope
-	Flags         []string
+	BodyStructure *BodyStructure
+	Envelope      *Envelope
+	Flags         []Flag
 	InternalDate  time.Time
 	RFC822Headers *mail.Header
 	Size          uint32
@@ -50,3 +74,59 @@ type FullMessage struct {
 	Reader io.Reader
 	Uid    uint32
 }
+
+type BodyStructure struct {
+	MIMEType          string
+	MIMESubType       string
+	Params            map[string]string
+	Description       string
+	Encoding          string
+	Parts             []*BodyStructure
+	Disposition       string
+	DispositionParams map[string]string
+}
+
+type Envelope struct {
+	Date      time.Time
+	Subject   string
+	From      []*Address
+	ReplyTo   []*Address
+	To        []*Address
+	Cc        []*Address
+	Bcc       []*Address
+	MessageId string
+}
+
+type Address struct {
+	Name    string
+	Mailbox string
+	Host    string
+}
+
+var atom *regexp.Regexp = regexp.MustCompile("^[a-z0-9!#$%7'*+-/=?^_`{}|~ ]+$")
+
+func (a Address) Format() string {
+	if a.Name != "" {
+		if atom.MatchString(a.Name) {
+			return fmt.Sprintf("%s <%s@%s>", a.Name, a.Mailbox, a.Host)
+		} else {
+			return fmt.Sprintf("\"%s\" <%s@%s>",
+				strings.ReplaceAll(a.Name, "\"", "'"),
+				a.Mailbox, a.Host)
+		}
+	} else {
+		return fmt.Sprintf("<%s@%s>", a.Mailbox, a.Host)
+	}
+}
+
+// FormatAddresses formats a list of addresses, separating each by a comma
+func FormatAddresses(addrs []*Address) string {
+	val := bytes.Buffer{}
+	for i, addr := range addrs {
+		val.WriteString(addr.Format())
+		if i != len(addrs)-1 {
+			val.WriteString(", ")
+		}
+	}
+	return val.String()
+}
diff --git a/widgets/msglist.go b/widgets/msglist.go
index 70514789..8968653a 100644
--- a/widgets/msglist.go
+++ b/widgets/msglist.go
@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"log"
 
-	"github.com/emersion/go-imap"
 	"github.com/gdamore/tcell"
 	"github.com/mattn/go-runewidth"
 
@@ -86,7 +85,7 @@ func (ml *MessageList) Draw(ctx *ui.Context) {
 		// unread message
 		seen := false
 		for _, flag := range msg.Flags {
-			if flag == imap.SeenFlag {
+			if flag == models.SeenFlag {
 				seen = true
 			}
 		}
diff --git a/widgets/msgviewer.go b/widgets/msgviewer.go
index 6a645f9a..f6bef2d8 100644
--- a/widgets/msgviewer.go
+++ b/widgets/msgviewer.go
@@ -9,7 +9,6 @@ import (
 	"strings"
 
 	"github.com/danwakefield/fnmatch"
-	"github.com/emersion/go-imap"
 	"github.com/emersion/go-message"
 	_ "github.com/emersion/go-message/charset"
 	"github.com/emersion/go-message/mail"
@@ -66,12 +65,12 @@ func NewMessageViewer(acct *AccountView, conf *config.AercConfig,
 	headers.AddChild(
 		&HeaderView{
 			Name:  "From",
-			Value: lib.FormatAddresses(msg.Envelope.From),
+			Value: models.FormatAddresses(msg.Envelope.From),
 		}).At(0, 0)
 	headers.AddChild(
 		&HeaderView{
 			Name:  "To",
-			Value: lib.FormatAddresses(msg.Envelope.To),
+			Value: models.FormatAddresses(msg.Envelope.To),
 		}).At(0, 1)
 	headers.AddChild(
 		&HeaderView{
@@ -112,7 +111,7 @@ handle_error:
 }
 
 func enumerateParts(conf *config.AercConfig, store *lib.MessageStore,
-	msg *models.MessageInfo, body *imap.BodyStructure,
+	msg *models.MessageInfo, body *models.BodyStructure,
 	showHeaders bool, index []int) ([]*PartViewer, error) {
 
 	var parts []*PartViewer
@@ -324,7 +323,7 @@ type PartViewer struct {
 	msg         *models.MessageInfo
 	pager       *exec.Cmd
 	pagerin     io.WriteCloser
-	part        *imap.BodyStructure
+	part        *models.BodyStructure
 	showHeaders bool
 	sink        io.WriteCloser
 	source      io.Reader
@@ -334,7 +333,7 @@ type PartViewer struct {
 
 func NewPartViewer(conf *config.AercConfig,
 	store *lib.MessageStore, msg *models.MessageInfo,
-	part *imap.BodyStructure, showHeaders bool,
+	part *models.BodyStructure, showHeaders bool,
 	index []int) (*PartViewer, error) {
 
 	var (
@@ -365,11 +364,11 @@ func NewPartViewer(conf *config.AercConfig,
 			case "subject":
 				header = msg.Envelope.Subject
 			case "from":
-				header = lib.FormatAddresses(msg.Envelope.From)
+				header = models.FormatAddresses(msg.Envelope.From)
 			case "to":
-				header = lib.FormatAddresses(msg.Envelope.To)
+				header = models.FormatAddresses(msg.Envelope.To)
 			case "cc":
-				header = lib.FormatAddresses(msg.Envelope.Cc)
+				header = models.FormatAddresses(msg.Envelope.Cc)
 			}
 			if f.Regex.Match([]byte(header)) {
 				filter = exec.Command("sh", "-c", f.Command)
diff --git a/widgets/providesmessage.go b/widgets/providesmessage.go
index d8b1e771..a1cfaa8f 100644
--- a/widgets/providesmessage.go
+++ b/widgets/providesmessage.go
@@ -1,8 +1,6 @@
 package widgets
 
 import (
-	"github.com/emersion/go-imap"
-
 	"git.sr.ht/~sircmpwn/aerc/lib"
 	"git.sr.ht/~sircmpwn/aerc/lib/ui"
 	"git.sr.ht/~sircmpwn/aerc/models"
@@ -10,8 +8,8 @@ import (
 
 type PartInfo struct {
 	Index []int
-	Msg   *types.MessageInfo
-	Part  *imap.BodyStructure
+	Msg   *models.MessageInfo
+	Part  *models.BodyStructure
 	Store *lib.MessageStore
 }
 
diff --git a/worker/imap/fetch.go b/worker/imap/fetch.go
index fe259777..1745eadd 100644
--- a/worker/imap/fetch.go
+++ b/worker/imap/fetch.go
@@ -82,9 +82,9 @@ func (imapw *IMAPWorker) handleFetchMessages(
 				imapw.worker.PostMessage(&types.MessageInfo{
 					Message: types.RespondTo(msg),
 					Info: &models.MessageInfo{
-						BodyStructure: _msg.BodyStructure,
-						Envelope:      _msg.Envelope,
-						Flags:         _msg.Flags,
+						BodyStructure: translateBodyStructure(_msg.BodyStructure),
+						Envelope:      translateEnvelope(_msg.Envelope),
+						Flags:         translateFlags(_msg.Flags),
 						InternalDate:  _msg.InternalDate,
 						RFC822Headers: header,
 						Uid:           _msg.Uid,
@@ -103,7 +103,7 @@ func (imapw *IMAPWorker) handleFetchMessages(
 				imapw.worker.PostMessage(&types.MessageInfo{
 					Message: types.RespondTo(msg),
 					Info: &models.MessageInfo{
-						Flags: _msg.Flags,
+						Flags: translateFlags(_msg.Flags),
 						Uid:   _msg.Uid,
 					},
 				}, nil)
@@ -120,7 +120,7 @@ func (imapw *IMAPWorker) handleFetchMessages(
 				imapw.worker.PostMessage(&types.MessageInfo{
 					Message: types.RespondTo(msg),
 					Info: &models.MessageInfo{
-						Flags: _msg.Flags,
+						Flags: translateFlags(_msg.Flags),
 						Uid:   _msg.Uid,
 					},
 				}, nil)
diff --git a/worker/imap/imap.go b/worker/imap/imap.go
index 28bac931..06bcd009 100644
--- a/worker/imap/imap.go
+++ b/worker/imap/imap.go
@@ -2,6 +2,8 @@ package imap
 
 import (
 	"github.com/emersion/go-imap"
+
+	"git.sr.ht/~sircmpwn/aerc/models"
 )
 
 func toSeqSet(uids []uint32) *imap.SeqSet {
@@ -11,3 +13,76 @@ func toSeqSet(uids []uint32) *imap.SeqSet {
 	}
 	return &set
 }
+
+func translateBodyStructure(bs *imap.BodyStructure) *models.BodyStructure {
+	if bs == nil {
+		return nil
+	}
+	var parts []*models.BodyStructure
+	for _, part := range bs.Parts {
+		parts = append(parts, translateBodyStructure(part))
+	}
+	return &models.BodyStructure{
+		MIMEType:          bs.MIMEType,
+		MIMESubType:       bs.MIMESubType,
+		Params:            bs.Params,
+		Description:       bs.Description,
+		Encoding:          bs.Encoding,
+		Parts:             parts,
+		Disposition:       bs.Disposition,
+		DispositionParams: bs.DispositionParams,
+	}
+}
+
+func translateEnvelope(e *imap.Envelope) *models.Envelope {
+	if e == nil {
+		return nil
+	}
+	return &models.Envelope{
+		Date:      e.Date,
+		Subject:   e.Subject,
+		From:      translateAddresses(e.From),
+		ReplyTo:   translateAddresses(e.ReplyTo),
+		To:        translateAddresses(e.To),
+		Cc:        translateAddresses(e.Cc),
+		Bcc:       translateAddresses(e.Bcc),
+		MessageId: e.MessageId,
+	}
+}
+
+func translateAddress(a *imap.Address) *models.Address {
+	if a == nil {
+		return nil
+	}
+	return &models.Address{
+		Name:    a.PersonalName,
+		Mailbox: a.MailboxName,
+		Host:    a.HostName,
+	}
+}
+
+func translateAddresses(addrs []*imap.Address) []*models.Address {
+	var converted []*models.Address
+	for _, addr := range addrs {
+		converted = append(converted, translateAddress(addr))
+	}
+	return converted
+}
+
+var flagMap = map[string]models.Flag{
+	imap.SeenFlag:     models.SeenFlag,
+	imap.RecentFlag:   models.RecentFlag,
+	imap.AnsweredFlag: models.AnsweredFlag,
+	imap.DeletedFlag:  models.DeletedFlag,
+	imap.FlaggedFlag:  models.FlaggedFlag,
+}
+
+func translateFlags(imapFlags []string) []models.Flag {
+	var flags []models.Flag
+	for _, imapFlag := range imapFlags {
+		if flag, ok := flagMap[imapFlag]; ok {
+			flags = append(flags, flag)
+		}
+	}
+	return flags
+}
diff --git a/worker/imap/worker.go b/worker/imap/worker.go
index 9ddaa47e..88f8b376 100644
--- a/worker/imap/worker.go
+++ b/worker/imap/worker.go
@@ -187,9 +187,9 @@ func (w *IMAPWorker) handleImapUpdate(update client.Update) {
 		}
 		w.worker.PostMessage(&types.MessageInfo{
 			Info: &models.MessageInfo{
-				BodyStructure: msg.BodyStructure,
-				Envelope:      msg.Envelope,
-				Flags:         msg.Flags,
+				BodyStructure: translateBodyStructure(msg.BodyStructure),
+				Envelope:      translateEnvelope(msg.Envelope),
+				Flags:         translateFlags(msg.Flags),
 				InternalDate:  msg.InternalDate,
 				Uid:           msg.Uid,
 			},