index: allow dynamic formatting of message dates

When a message has been sent today (or this year) allow formatting the
date differently.

For example, with:

 [ui]
 index-format=%-25.25n   %-25.25D   %s
 timestamp-format=2006 Jan 02, 15:04 GMT-0700
 this-day-time-format=Today at 15:04
 this-year-time-format=Jan 02

The message list would look like this (spaces collapsed):

 Robin Jarry        Today at 16:30             [PATCH 1/2] bindings: prepare for more modifers
 bugzilla@dpdk.org  Oct 26                     [dpdk-dev] [Bug 839] pdump: any subsequent runs of pdump_autotest fail
 Holger Levsen      2020 Mar 15, 13:44 GMT+01  +1 (Re: FTP Team -- call for volunteers)

Signed-off-by: Robin Jarry <robin@jarry.cc>

6 files changed, 53 insertions, 7 deletions

diff --git a/config/aerc.conf.in b/config/aerc.conf.in
index b9381a8b..0421901a 100644
--- a/config/aerc.conf.in
+++ b/config/aerc.conf.in
@@ -16,6 +16,20 @@ index-format=%D %-17.17n %Z %s
 timestamp-format=2006-01-02 03:04 PM
 
 #
+# Index-only time format for messages that were received/sent today.
+# If this is not specified, timestamp-format is used instead.
+#
+# Default: ""
+today-time-format=
+
+#
+# Index-only time format for messages that were received/sent this year.
+# If this is not specified, timestamp-format is used instead.
+#
+# Default: ""
+this-year-time-format=
+
+#
 # Width of the sidebar, including the border.
 #
 # Default: 20
diff --git a/config/config.go b/config/config.go
index af9c63b2..dfcbd4dd 100644
--- a/config/config.go
+++ b/config/config.go
@@ -29,6 +29,8 @@ type GeneralConfig struct {
 type UIConfig struct {
 	IndexFormat         string        `ini:"index-format"`
 	TimestampFormat     string        `ini:"timestamp-format"`
+	ThisDayTimeFormat   string        `ini:"this-day-time-format"`
+	ThisYearTimeFormat  string        `ini:"this-year-time-format"`
 	ShowHeaders         []string      `delim:","`
 	RenderAccountTabs   string        `ini:"render-account-tabs"`
 	PinnedTabMarker     string        `ini:"pinned-tab-marker"`
@@ -491,8 +493,10 @@ func LoadConfigFromFile(root *string, sharedir string) (*AercConfig, error) {
 		Ini: file,
 
 		Ui: UIConfig{
-			IndexFormat:     "%D %-17.17n %s",
-			TimestampFormat: "2006-01-02 03:04 PM",
+			IndexFormat:        "%D %-17.17n %s",
+			TimestampFormat:    "2006-01-02 03:04 PM",
+			ThisDayTimeFormat:  "",
+			ThisYearTimeFormat: "",
 			ShowHeaders: []string{
 				"From", "To", "Cc", "Bcc", "Subject", "Date",
 			},
diff --git a/config/triggers.go b/config/triggers.go
index 847a10f3..4777371b 100644
--- a/config/triggers.go
+++ b/config/triggers.go
@@ -38,6 +38,8 @@ func (trig *TriggersConfig) ExecNewEmail(account *AccountConfig,
 		func(part string) (string, error) {
 			formatstr, args, err := format.ParseMessageFormat(
 				part, conf.Ui.TimestampFormat,
+				conf.Ui.ThisDayTimeFormat,
+				conf.Ui.ThisYearTimeFormat,
 				format.Ctx{
 					FromAddress: account.From,
 					AccountName: account.Name,
diff --git a/doc/aerc-config.5.scd b/doc/aerc-config.5.scd
index 46c44166..d781164e 100644
--- a/doc/aerc-config.5.scd
+++ b/doc/aerc-config.5.scd
@@ -87,6 +87,18 @@ These options are configured in the *[ui]* section of aerc.conf.
 
 	Default: 2006-01-02 03:04 PM (ISO 8601 + 12 hour time)
 
+*today-time-format*
+	Index-only time format for messages that were received/sent today.
+	If this is not specified, *timestamp-format* is used instead.
+
+	Default: ""
+
+*this-year-time-format*
+	Index-only time format for messages that were received/sent this year.
+	If this is not specified, *timestamp-format* is used instead.
+
+	Default: ""
+
 *sidebar-width*
 	Width of the sidebar, including the border. Set to zero to disable the
 	sidebar.
diff --git a/lib/format/format.go b/lib/format/format.go
index 30e8be7f..16398865 100644
--- a/lib/format/format.go
+++ b/lib/format/format.go
@@ -47,8 +47,8 @@ type Ctx struct {
 	MsgIsMarked bool
 }
 
-func ParseMessageFormat(format string, timeFmt string, ctx Ctx) (string,
-	[]interface{}, error) {
+func ParseMessageFormat(format string, timeFmt string, thisDayTimeFmt string,
+	thisYearTimeFmt string, ctx Ctx) (string, []interface{}, error) {
 	retval := make([]byte, 0, len(format))
 	var args []interface{}
 
@@ -144,7 +144,8 @@ func ParseMessageFormat(format string, timeFmt string, ctx Ctx) (string,
 			}
 			retval = append(retval, 's')
 			args = append(args,
-				dummyIfZeroDate(date.Local(), timeFmt))
+				dummyIfZeroDate(date.Local(),
+					timeFmt, thisDayTimeFmt, thisYearTimeFmt))
 		case 'D':
 			date := envelope.Date
 			if date.IsZero() {
@@ -152,7 +153,8 @@ func ParseMessageFormat(format string, timeFmt string, ctx Ctx) (string,
 			}
 			retval = append(retval, 's')
 			args = append(args,
-				dummyIfZeroDate(date.Local(), timeFmt))
+				dummyIfZeroDate(date.Local(),
+					timeFmt, thisDayTimeFmt, thisYearTimeFmt))
 		case 'f':
 			if envelope == nil {
 				return "", nil,
@@ -374,9 +376,20 @@ handle_end_error:
 		errors.New("reached end of string while parsing message format")
 }
 
-func dummyIfZeroDate(date time.Time, format string) string {
+func dummyIfZeroDate(date time.Time, format string, todayFormat string,
+	thisYearFormat string) string {
 	if date.IsZero() {
 		return strings.Repeat("?", len(format))
 	}
+	year, month, day := date.Date()
+	thisYear, thisMonth, thisDay := time.Now().Date()
+	if year == thisYear {
+		if month == thisMonth && day == thisDay && todayFormat != "" {
+			return date.Format(todayFormat)
+		}
+		if thisYearFormat != "" {
+			return date.Format(thisYearFormat)
+		}
+	}
 	return date.Format(format)
 }
diff --git a/widgets/msglist.go b/widgets/msglist.go
index 8f5a06e0..6055da37 100644
--- a/widgets/msglist.go
+++ b/widgets/msglist.go
@@ -155,6 +155,7 @@ func (ml *MessageList) Draw(ctx *ui.Context) {
 		ctx.Fill(0, row, ctx.Width(), 1, ' ', style)
 		fmtStr, args, err := format.ParseMessageFormat(
 			uiConfig.IndexFormat, uiConfig.TimestampFormat,
+			uiConfig.ThisDayTimeFormat, uiConfig.ThisYearTimeFormat,
 			format.Ctx{
 				FromAddress: ml.aerc.SelectedAccount().acct.From,
 				AccountName: ml.aerc.SelectedAccount().Name(),