[node] begin the great typescript rewrite

nodejs/database/contracts.ts

@@ -0,0 +1,29 @@
+import { Contract } from '../model/contract.ts';
+import db from './db.ts';
+
+const addContractStatement = db.prepare(`INSERT INTO contracts(data) VALUES (json(?));`);
+const getContractStatement = db.prepare(`SELECT data FROM contracts WHERE data->>'id' = ?;`);
+const getContractsStatement = db.prepare(`SELECT data FROM contracts WHERE data->>'fulfilled' = false;`);
+const updateContractStatement = db.prepare(`UPDATE contracts SET data = json(:data) WHERE data->>'id' = :id;`);
+
+export function getContract(id: string): Contract|null {
+	const data = getContractStatement.get(id) as {data: string}|undefined;
+	if (!data) return null;
+	return JSON.parse(data.data);
+}
+
+export function getContracts(): Array<Contract> {
+	const data = getContractsStatement.all() as Array<{data: string}>;
+	return data.map(contractData => JSON.parse(contractData.data));
+}
+
+export function setContract(data: Contract) {
+	if (getContract(data.id) === null) {
+		addContractStatement.run(JSON.stringify(data));
+	} else {
+		updateContractStatement.run({
+			data: JSON.stringify(data),
+			id: data.id,
+		});
+	}
+}