tsk-44: Record when message was sent (#48)

Closes #44

Reviewed-on: phoenix/textsender-api#48
Co-authored-by: phoenix <kundeng00@pm.me>
Co-committed-by: phoenix <kundeng00@pm.me>

internal/store/message_event_response_store.go

@@ -0,0 +1,30 @@
+package store
+
+import (
+	"context"
+
+	"git.kundeng.us/phoenix/textsender-models/tx0/message"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+type MessageEventResponseStore interface {
+	Create(ctx context.Context, mer *message.MessageEventResponse) error
+}
+
+type PGMessageEventResponseStore struct {
+	db *pgxpool.Pool
+}
+
+func NewMessageEventResponseStore(db *pgxpool.Pool) *PGMessageEventResponseStore {
+	return &PGMessageEventResponseStore{db: db}
+}
+
+func (m *PGMessageEventResponseStore) Create(ctx context.Context, mer *message.MessageEventResponse) error {
+	query := `
+		INSERT INTO message_event_responses (scheduled_message_event_id, response, user_id, sent)
+		VALUES ($1, $2, $3, $4)
+		RETURNING id
+	`
+
+	return m.db.QueryRow(ctx, query, mer.ScheduledMessageEventId, mer.Response, mer.UserId, mer.Sent).Scan(&mer.Id)
+}