export.ts

import { Database } from "sqlite3";
import { resolve } from "path";
import { writeFileSync } from "fs";

function connectToSqlite() {
  const pth = resolve("database", "zvms.db");
  return new Database(pth);
}

const tables = [
  "volunteer",
  "user",
  "class",
  "class_vol",
  "user_vol",
  "picture",
  "issue",
  "notice",
  "user_notice",
  "class_notice",
];

function exportTables(
  db: Database
): Promise<{ key: string; value: unknown[] }[]> {
  const promises = tables.map((table: string) => {
    return new Promise((resolve, reject) => {
      db.all(`SELECT * FROM ${table}`, (err: Error, rows: unknown[]) => {
        if (err) {
          reject(err);
        }
        resolve({
          key: table,
          value: rows,
        } as { key: string; value: unknown[] });
      });
    });
  }) as Promise<{ key: string; value: unknown[] }>[];
  return Promise.all(promises);
}

export async function exportToJSON() {
  const db = connectToSqlite();
  const folder = resolve("data", "export");
  const tables = await exportTables(db);
  tables.forEach((table: { key: string; value: unknown[] }) => {
    console.log("Exporting table", table.key);
    writeFileSync(
      resolve(folder, table.key + ".json"),
      JSON.stringify(table.value, null, 2)
    );
  });
}