1 files changed, 102 insertions, 0 deletions
diff --git a/internal/pushrules/action.go b/internal/pushrules/action.go
new file mode 100644
index 00000000..c7b8cec8
--- /dev/null
+++ b/internal/pushrules/action.go
@@ -0,0 +1,102 @@
+package pushrules
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+)
+
+// An Action is (part of) an outcome of a rule. There are
+// (unofficially) terminal actions, and modifier actions.
+type Action struct {
+	// Kind is the type of action. Has custom encoding in JSON.
+	Kind ActionKind `json:"-"`
+
+	// Tweak is the property to tweak. Has custom encoding in JSON.
+	Tweak TweakKey `json:"-"`
+
+	// Value is some value interpreted according to Kind and Tweak.
+	Value interface{} `json:"value"`
+}
+
+func (a *Action) MarshalJSON() ([]byte, error) {
+	if a.Tweak == UnknownTweak && a.Value == nil {
+		return json.Marshal(a.Kind)
+	}
+
+	if a.Kind != SetTweakAction {
+		return nil, fmt.Errorf("only set_tweak actions may have a value, but got kind %q", a.Kind)
+	}
+
+	m := map[string]interface{}{
+		string(a.Kind): a.Tweak,
+	}
+	if a.Value != nil {
+		m["value"] = a.Value
+	}
+
+	return json.Marshal(m)
+}
+
+func (a *Action) UnmarshalJSON(bs []byte) error {
+	if bytes.HasPrefix(bs, []byte("\"")) {
+		return json.Unmarshal(bs, &a.Kind)
+	}
+
+	var raw struct {
+		SetTweak TweakKey    `json:"set_tweak"`
+		Value    interface{} `json:"value"`
+	}
+	if err := json.Unmarshal(bs, &raw); err != nil {
+		return err
+	}
+	if raw.SetTweak == UnknownTweak {
+		return fmt.Errorf("got unknown action JSON: %s", string(bs))
+	}
+	a.Kind = SetTweakAction
+	a.Tweak = raw.SetTweak
+	if raw.Value != nil {
+		a.Value = raw.Value
+	}
+
+	return nil
+}
+
+// ActionKind is the primary discriminator for actions.
+type ActionKind string
+
+const (
+	UnknownAction ActionKind = ""
+
+	// NotifyAction indicates the clients should show a notification.
+	NotifyAction ActionKind = "notify"
+
+	// DontNotifyAction indicates the clients should not show a notification.
+	DontNotifyAction ActionKind = "dont_notify"
+
+	// CoalesceAction tells the clients to show a notification, and
+	// tells both servers and clients that multiple events can be
+	// coalesced into a single notification. The behaviour is
+	// implementation-specific.
+	CoalesceAction ActionKind = "coalesce"
+
+	// SetTweakAction uses the Tweak and Value fields to add a
+	// tweak. Multiple SetTweakAction can be provided in a rule,
+	// combined with NotifyAction or CoalesceAction.
+	SetTweakAction ActionKind = "set_tweak"
+)
+
+// A TweakKey describes a property to be modified/tweaked for events
+// that match the rule.
+type TweakKey string
+
+const (
+	UnknownTweak TweakKey = ""
+
+	// SoundTweak describes which sound to play. Using "default" means
+	// "enable sound".
+	SoundTweak TweakKey = "sound"
+
+	// HighlightTweak asks the clients to highlight the conversation.
+	HighlightTweak TweakKey = "highlight"
+)