templates: unify data interface

Require that all aerc template data objects implement the same
TemplateData interface.

Implement that interface in two different places:

1) state.TemplateData (renamed/moved from templates.TemplateData).
   This structure (along with all its methods) needs to be decoupled
   from the templates package to break the import cycle with the config
   package. This allows much simpler construction of this object and
   ensure that values are calculated only when requested.

2) config.dummyData (extracted from templates).
   This is only used in the config package to validate user templates.
   Putting it here allows also to break an import cycle.

Use state.TemplateData everywhere (including for account tabs title
rendering).

Signed-off-by: Robin Jarry <robin@jarry.cc>
Reviewed-by: Moritz Poldrack <moritz@poldrack.dev>

1 files changed, 353 insertions, 0 deletions

diff --git a/lib/state/templates.go b/lib/state/templates.go
new file mode 100644
index 00000000..fdf662c5
--- /dev/null
+++ b/lib/state/templates.go
@@ -0,0 +1,353 @@
+package state
+
+import (
+	"strings"
+	"time"
+
+	"git.sr.ht/~rjarry/aerc/config"
+	"git.sr.ht/~rjarry/aerc/models"
+	sortthread "github.com/emersion/go-imap-sortthread"
+	"github.com/emersion/go-message/mail"
+)
+
+type TemplateData struct {
+	// only available when composing/replying/forwarding
+	headers *mail.Header
+	// only available when replying with a quote
+	parent *models.OriginalMail
+	// only available for the message list
+	info   *models.MessageInfo
+	marked bool
+	msgNum int
+
+	// message list threading
+	ThreadSameSubject bool
+	ThreadPrefix      string
+
+	// selected account
+	account     *config.AccountConfig
+	myAddresses map[string]bool
+	folder      string // selected folder name
+	folders     []string
+	getRUEcount func(string) (int, int, int)
+}
+
+// only used for compose/reply/forward
+func (d *TemplateData) SetHeaders(h *mail.Header, o *models.OriginalMail) {
+	d.headers = h
+	d.parent = o
+}
+
+// only used for message list templates
+func (d *TemplateData) SetInfo(info *models.MessageInfo, num int, marked bool) {
+	d.info = info
+	d.msgNum = num
+	d.marked = marked
+}
+
+func (d *TemplateData) SetAccount(acct *config.AccountConfig) {
+	d.account = acct
+	d.myAddresses = map[string]bool{acct.From.Address: true}
+	for _, addr := range acct.Aliases {
+		d.myAddresses[addr.Address] = true
+	}
+}
+
+func (d *TemplateData) SetFolder(folder string) {
+	d.folder = folder
+}
+
+func (d *TemplateData) SetRUE(folders []string, cb func(string) (int, int, int)) {
+	d.folders = folders
+	d.getRUEcount = cb
+}
+
+func (d *TemplateData) Account() string {
+	if d.account != nil {
+		return d.account.Name
+	}
+	return ""
+}
+
+func (d *TemplateData) Folder() string {
+	return d.folder
+}
+
+func (d *TemplateData) ui() *config.UIConfig {
+	return config.Ui.ForAccount(d.Account()).ForFolder(d.folder)
+}
+
+func (d *TemplateData) To() []*mail.Address {
+	var to []*mail.Address
+	switch {
+	case d.info != nil && d.info.Envelope != nil:
+		to = d.info.Envelope.To
+	case d.headers != nil:
+		to, _ = d.headers.AddressList("to")
+	}
+	return to
+}
+
+func (d *TemplateData) Cc() []*mail.Address {
+	var cc []*mail.Address
+	switch {
+	case d.info != nil && d.info.Envelope != nil:
+		cc = d.info.Envelope.Cc
+	case d.headers != nil:
+		cc, _ = d.headers.AddressList("cc")
+	}
+	return cc
+}
+
+func (d *TemplateData) Bcc() []*mail.Address {
+	var bcc []*mail.Address
+	switch {
+	case d.info != nil && d.info.Envelope != nil:
+		bcc = d.info.Envelope.Bcc
+	case d.headers != nil:
+		bcc, _ = d.headers.AddressList("bcc")
+	}
+	return bcc
+}
+
+func (d *TemplateData) From() []*mail.Address {
+	var from []*mail.Address
+	switch {
+	case d.info != nil && d.info.Envelope != nil:
+		from = d.info.Envelope.From
+	case d.headers != nil:
+		from, _ = d.headers.AddressList("from")
+	}
+	return from
+}
+
+func (d *TemplateData) Peer() []*mail.Address {
+	var from, to []*mail.Address
+	switch {
+	case d.info != nil && d.info.Envelope != nil:
+		from = d.info.Envelope.From
+		to = d.info.Envelope.To
+	case d.headers != nil:
+		from, _ = d.headers.AddressList("from")
+		to, _ = d.headers.AddressList("to")
+	}
+	for _, addr := range from {
+		if d.myAddresses[addr.Address] {
+			return to
+		}
+	}
+	return from
+}
+
+func (d *TemplateData) ReplyTo() []*mail.Address {
+	var replyTo []*mail.Address
+	switch {
+	case d.info != nil && d.info.Envelope != nil:
+		replyTo = d.info.Envelope.ReplyTo
+	case d.headers != nil:
+		replyTo, _ = d.headers.AddressList("reply-to")
+	}
+	return replyTo
+}
+
+func (d *TemplateData) Date() time.Time {
+	var date time.Time
+	switch {
+	case d.info != nil && d.info.Envelope != nil:
+		date = d.info.Envelope.Date
+	case d.info != nil:
+		date = d.info.InternalDate
+	default:
+		date = time.Now()
+	}
+	return date
+}
+
+func (d *TemplateData) DateAutoFormat(date time.Time) string {
+	if date.IsZero() {
+		return ""
+	}
+	ui := d.ui()
+	year := date.Year()
+	day := date.YearDay()
+	now := time.Now()
+	thisYear := now.Year()
+	thisDay := now.YearDay()
+	fmt := ui.TimestampFormat
+	if year == thisYear {
+		switch {
+		case day == thisDay && ui.ThisDayTimeFormat != "":
+			fmt = ui.ThisDayTimeFormat
+		case day > thisDay-7 && ui.ThisWeekTimeFormat != "":
+			fmt = ui.ThisWeekTimeFormat
+		case ui.ThisYearTimeFormat != "":
+			fmt = ui.ThisYearTimeFormat
+		}
+	}
+	return date.Format(fmt)
+}
+
+func (d *TemplateData) Header(name string) string {
+	var h *mail.Header
+	switch {
+	case d.headers != nil:
+		h = d.headers
+	case d.info != nil && d.info.RFC822Headers != nil:
+		h = d.info.RFC822Headers
+	default:
+		return ""
+	}
+	text, err := h.Text(name)
+	if err != nil {
+		text = h.Get(name)
+	}
+	return text
+}
+
+func (d *TemplateData) Subject() string {
+	var subject string
+	switch {
+	case d.info != nil && d.info.Envelope != nil:
+		subject = d.info.Envelope.Subject
+	case d.headers != nil:
+		subject = d.Header("subject")
+	}
+	if d.ThreadSameSubject {
+		subject = ""
+	}
+	return d.ThreadPrefix + subject
+}
+
+func (d *TemplateData) SubjectBase() string {
+	base, _ := sortthread.GetBaseSubject(d.Subject())
+	return base
+}
+
+func (d *TemplateData) Number() int {
+	return d.msgNum
+}
+
+func (d *TemplateData) Labels() []string {
+	if d.info == nil {
+		return nil
+	}
+	return d.info.Labels
+}
+
+func (d *TemplateData) Flags() []string {
+	var flags []string
+	if d.info == nil {
+		return flags
+	}
+
+	switch {
+	case d.info.Flags.Has(models.SeenFlag | models.AnsweredFlag):
+		flags = append(flags, "r") // message has been replied to
+	case d.info.Flags.Has(models.SeenFlag):
+		break
+	case d.info.Flags.Has(models.RecentFlag):
+		flags = append(flags, "N") // message is new
+	default:
+		flags = append(flags, "O") // message is old
+	}
+	if d.info.Flags.Has(models.DeletedFlag) {
+		flags = append(flags, "D")
+	}
+	if d.info.BodyStructure != nil {
+		for _, bS := range d.info.BodyStructure.Parts {
+			if strings.ToLower(bS.Disposition) == "attachment" {
+				flags = append(flags, d.ui().IconAttachment)
+				break
+			}
+		}
+	}
+	if d.info.Flags.Has(models.FlaggedFlag) {
+		flags = append(flags, "!")
+	}
+	if d.marked {
+		flags = append(flags, "*")
+	}
+	return flags
+}
+
+func (d *TemplateData) MessageId() string {
+	if d.info == nil || d.info.Envelope == nil {
+		return ""
+	}
+	return d.info.Envelope.MessageId
+}
+
+func (d *TemplateData) Size() int {
+	if d.info == nil || d.info.Envelope == nil {
+		return 0
+	}
+	return int(d.info.Size)
+}
+
+func (d *TemplateData) OriginalText() string {
+	if d.parent == nil {
+		return ""
+	}
+	return d.parent.Text
+}
+
+func (d *TemplateData) OriginalDate() time.Time {
+	if d.parent == nil {
+		return time.Time{}
+	}
+	return d.parent.Date
+}
+
+func (d *TemplateData) OriginalFrom() []*mail.Address {
+	if d.parent == nil || d.parent.RFC822Headers == nil {
+		return nil
+	}
+	from, _ := d.parent.RFC822Headers.AddressList("from")
+	return from
+}
+
+func (d *TemplateData) OriginalMIMEType() string {
+	if d.parent == nil {
+		return ""
+	}
+	return d.parent.MIMEType
+}
+
+func (d *TemplateData) OriginalHeader(name string) string {
+	if d.parent == nil || d.parent.RFC822Headers == nil {
+		return ""
+	}
+	text, err := d.parent.RFC822Headers.Text(name)
+	if err != nil {
+		text = d.parent.RFC822Headers.Get(name)
+	}
+	return text
+}
+
+func (d *TemplateData) rue() (int, int, int) {
+	var recent, unread, exists int
+	if d.getRUEcount != nil {
+		for _, dir := range d.folders {
+			r, u, e := d.getRUEcount(dir)
+			recent += r
+			unread += u
+			exists += e
+		}
+	}
+	return recent, unread, exists
+}
+
+func (d *TemplateData) Recent() int {
+	r, _, _ := d.rue()
+	return r
+}
+
+func (d *TemplateData) Unread() int {
+	_, u, _ := d.rue()
+	return u
+}
+
+func (d *TemplateData) Exists() int {
+	_, _, e := d.rue()
+	return e
+}