snapshot of https://github.com/pion/webrtc.git (main, 2026-09-15; blobs > 131072B omitted)

sdptype.go

@@ -0,0 +1,105 @@
+// SPDX-FileCopyrightText: 2026 The Pion community <https://pion.ly>
+// SPDX-License-Identifier: MIT
+
+package webrtc
+
+import (
+	"encoding/json"
+	"strings"
+)
+
+// SDPType describes the type of an SessionDescription.
+type SDPType int
+
+const (
+	// SDPTypeUnknown is the enum's zero-value.
+	SDPTypeUnknown SDPType = iota
+
+	// SDPTypeOffer indicates that a description MUST be treated as an SDP offer.
+	SDPTypeOffer
+
+	// SDPTypePranswer indicates that a description MUST be treated as an
+	// SDP answer, but not a final answer. A description used as an SDP
+	// pranswer may be applied as a response to an SDP offer, or an update to
+	// a previously sent SDP pranswer.
+	SDPTypePranswer
+
+	// SDPTypeAnswer indicates that a description MUST be treated as an SDP
+	// final answer, and the offer-answer exchange MUST be considered complete.
+	// A description used as an SDP answer may be applied as a response to an
+	// SDP offer or as an update to a previously sent SDP pranswer.
+	SDPTypeAnswer
+
+	// SDPTypeRollback indicates that a description MUST be treated as
+	// canceling the current SDP negotiation and moving the SDP offer and
+	// answer back to what it was in the previous stable state. Note the
+	// local or remote SDP descriptions in the previous stable state could be
+	// null if there has not yet been a successful offer-answer negotiation.
+	SDPTypeRollback
+)
+
+// This is done this way because of a linter.
+const (
+	sdpTypeOfferStr    = "offer"
+	sdpTypePranswerStr = "pranswer"
+	sdpTypeAnswerStr   = "answer"
+	sdpTypeRollbackStr = "rollback"
+)
+
+// NewSDPType creates an SDPType from a string.
+func NewSDPType(raw string) SDPType {
+	switch raw {
+	case sdpTypeOfferStr:
+		return SDPTypeOffer
+	case sdpTypePranswerStr:
+		return SDPTypePranswer
+	case sdpTypeAnswerStr:
+		return SDPTypeAnswer
+	case sdpTypeRollbackStr:
+		return SDPTypeRollback
+	default:
+		return SDPTypeUnknown
+	}
+}
+
+func (t SDPType) String() string {
+	switch t {
+	case SDPTypeOffer:
+		return sdpTypeOfferStr
+	case SDPTypePranswer:
+		return sdpTypePranswerStr
+	case SDPTypeAnswer:
+		return sdpTypeAnswerStr
+	case SDPTypeRollback:
+		return sdpTypeRollbackStr
+	default:
+		return ErrUnknownType.Error()
+	}
+}
+
+// MarshalJSON enables JSON marshaling of a SDPType.
+func (t SDPType) MarshalJSON() ([]byte, error) {
+	return json.Marshal(t.String())
+}
+
+// UnmarshalJSON enables JSON unmarshaling of a SDPType.
+func (t *SDPType) UnmarshalJSON(b []byte) error {
+	var s string
+	if err := json.Unmarshal(b, &s); err != nil {
+		return err
+	}
+	switch strings.ToLower(s) {
+	default:
+		return ErrUnknownType
+	case "offer":
+		*t = SDPTypeOffer
+	case "pranswer":
+		*t = SDPTypePranswer
+	case "answer":
+		*t = SDPTypeAnswer
+	case "rollback":
+		*t = SDPTypeRollback
+	}
+
+	return nil
+}