feat(GODT-2666): feat(GODT-2667): introduce sessionID in bridge.

internal/logging/session_id.go

@@ -0,0 +1,64 @@
+// Copyright (c) 2023 Proton AG
+//
+// This file is part of Proton Mail Bridge.
+//
+// Proton Mail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Proton Mail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+
+package logging
+
+import (
+	"fmt"
+	"strconv"
+	"time"
+)
+
+type SessionID string
+
+const (
+	timeFormat = "20060102_150405" // time format in Go does not support milliseconds without dot, so we'll process it manually.
+)
+
+// NewSessionID creates a sessionID based on the current time.
+func NewSessionID() SessionID {
+	now := time.Now()
+	return SessionID(now.Format(timeFormat) + fmt.Sprintf("%03d", now.Nanosecond()/1000000))
+}
+
+// NewSessionIDFromString Return a new sessionID from string. If the str is empty a new time based sessionID is returned, otherwise the string
+// is used as the sessionID.
+func NewSessionIDFromString(str string) SessionID {
+	if (len(str)) > 0 {
+		return SessionID(str)
+	}
+
+	return NewSessionID()
+}
+
+// toTime converts a sessionID to a date/Time, considering the time zone is local.
+func (s SessionID) toTime() time.Time {
+	if len(s) < 3 {
+		return time.Time{}
+	}
+
+	t, err := time.ParseInLocation(timeFormat, string(s)[:len(s)-3], time.Local)
+	if err != nil {
+		return time.Time{}
+	}
+
+	var ms int
+	if ms, err = strconv.Atoi(string(s)[len(s)-3:]); err != nil {
+		return time.Time{}
+	}
+
+	return t.Add(time.Duration(ms) * time.Millisecond)
+}