Implement db.event.del (delete)

lib/www/server/lib/db/event/delete.js

@@ -0,0 +1,127 @@
+const { setSurvey, transaction } = require('../connection');
+
+async function deleteTimedEventLabel (label, eventId, client) {
+	const text = `
+		DELETE
+		FROM events_timed_labels
+		WHERE label = $1 AND id = $2;
+	`;
+
+// 	console.log("deleteTimedEventLabel", label, eventId);
+	return await client.query(text, [label, eventId]);
+}
+
+async function deleteSeqLabel (label, eventId, client) {
+	const text = `
+		DELETE
+		FROM events_seq_labels
+		WHERE label = $1 AND id = $2;
+	`;
+
+// 	console.log("deleteSeqLabel", label, eventId);
+	return await client.query(text, [label, eventId]);
+}
+
+async function deleteTimedEvent (eventId, client) {
+	const text = `
+		DELETE
+		FROM events_timed
+		WHERE id = $1;
+	`;
+
+// 	console.log("deleteTimedEvent", eventId);
+	return await client.query(text, [eventId]);
+}
+
+async function deleteSeqEvent (eventId, client) {
+	const text = `
+		DELETE
+		FROM events_seq
+		WHERE id = $1;
+	`;
+
+// 	console.log("deleteSeqEvent", eventId);
+	return await client.query(text, [eventId]);
+}
+
+/**
+ * Delete events from the database.
+ *
+ * Events may have the following forms:
+ *
+ * Delete event associated with a time:
+ *
+ * {
+ *   type: "timed",
+ *   id: …,
+ * }
+ *
+ * Delete the listed labels associated with a
+ * time event, but not the event itself.
+ *
+ * {
+ *   type: "timed",
+ *   id: …,
+ *   labels: [ "…", "…", … ]
+ * }
+ *
+ * Delete event associated with a shotpoint:
+ *
+ * {
+ *   type: "sequence",
+ *   id: …,
+ * }
+ *
+ * Delete only the labels, not the event itself:
+ *
+ * {
+ *   type: "sequence",
+ *   id: …,
+ *   labels: [ "…", "…", … ]
+ * }
+ *
+ */
+async function del (projectId, payload, opts = {}) {
+// 	console.log("delete event", projectId, payload);
+
+	const client = await setSurvey(projectId);
+	await transaction.begin(client);
+	try {
+		if (!Array.isArray(payload)) {
+			payload = [payload];
+		}
+// 		console.log("Payload", payload);
+
+		for (const event of payload) {
+// 			console.log("Event", event);
+			if (event.type && event.id) {
+				const eventId = event.id;
+				if (event.labels) {
+					const handler = event.type == "timed"
+						? deleteTimedEventLabel
+						: deleteSeqLabel;
+
+					for (const label of event.labels) {
+						await handler(label, eventId, client);
+					}
+				} else {
+					if (event.type == "timed") {
+						await deleteTimedEvent(eventId, client);
+					} else {
+						await deleteSeqEvent(eventId, client);
+					}
+				}
+			} else {
+				throw { status: 400, message: "Unrecognised event kind" };
+			}
+		}
+
+		transaction.commit(client);
+	} catch (err) {
+		transaction.rollback(client)
+	} finally {
+		client.release();
+	}
+}
+
+module.exports = del;

lib/www/server/lib/db/event/index.js

@@ -4,5 +4,5 @@ module.exports = {
 	get: require('./get'),
 	post: require('./post'),
 	put: require('./put'),
-	delete: require('./delete')
+	del: require('./delete')
 }