main.js

const w = new Worker("sqlite3-worker1.js");
window.sqlite3Worker = w;
/**
 *
 * @param {MessageEvent<any>} event
 */
w.onmessage = function (event) {
  event = event.data;
  switch (event.type) {
    case "sqlite3-api":
      if ("worker1-ready" === event.result) {
        // The worker is now ready to accept messages
        generateNotification("DB is ready.");
        break;
      }
    default: {
      //  console.log({ event });
    }
  }
};

const form = /** @type {HTMLFormElement} */ (
  document.getElementById("query-form")
);

/**
 * @param {SubmitEvent} e
 */
form.onsubmit = async (e) => {
  e.preventDefault();
};

const runQueryButton = /** @type {HTMLButtonElement} */ (
  document.getElementById("run-query")
);
runQueryButton.onclick = async (e) => {
  const query = /** @type {HTMLTextAreaElement} */ (
    document.getElementById("query")
  );
  if (query?.value) {
    console.time("userQuery");
    await handleSqlInput(query.value);
    sendFragmentedMessageToPeers(query.value);
    console.timeEnd("userQuery");
    return;
  }
};
const importFileButton = /** @type {HTMLButtonElement} */ (
  document.getElementById("import")
);
importFileButton.onclick = async (e) => {
  /**
   * @type {HTMLInputElement}
   */
  const fileInput = /** @type {HTMLInputElement} */ (
    document.getElementById("file_input")
  );

  /**
   * @type {File}
   */
  const file = fileInput.files[0];
  console.log({ fileType: file.type });
  const SUPPORTED_FILE_TYPES = {
    CSV: "text/csv",
    SQLITE: "application/vnd.sqlite3",
  };
  if (Object.values(SUPPORTED_FILE_TYPES).includes(file.type) == false) {
    alert(`Unsupported file type: ${file.type}`);
    return;
  }
  const reader = new FileReader();
  switch (file.type) {
    case SUPPORTED_FILE_TYPES.CSV: {
      reader.readAsText(file);
      reader.onload = async (e) => {
        const content = e.target.result; // Get file content
        console.time("importCsv");
        const { tableName, createTable, insert } = createTableFromCSV(
          content,
          file.name
        );
        await handleSqlInput(createTable);
        sendFragmentedMessageToPeers(createTable);
        await handleSqlInput(insert);
        console.timeEnd("importCsv");
        generateNotification("Import finished successfully.");
        sendFragmentedMessageToPeers(insert);
      };
      break;
    }
    case SUPPORTED_FILE_TYPES.SQLITE: {
      reader.readAsArrayBuffer(file);
      reader.onload = async (e) => {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.removeEntry("db.sqlite3");
        const newFile = await root.getFileHandle("db.sqlite3", {
          create: true,
        });
        const writableStream = await newFile.createWritable();
        const data = await file.arrayBuffer();
        await writableStream.write(data);
        await writableStream.close();
        generateNotification("Import finished successfully.");
        sendFragmentedMessageToPeers(data);
      };
      break;
    }
    default: {
      console.error(`Unsupported file type: ${file.type}`);
      alert(`Unsupported file type: ${file.type}`);
    }
  }
  fileInput.value = "";
};

const exportDBButton = /** @type {HTMLButtonElement} */ (
  document.getElementById("export")
);
exportDBButton.onclick = async (e) => {
  const root = await navigator.storage.getDirectory();
  const fileHandle = await root.getFileHandle("db.sqlite3");
  const file = await fileHandle.getFile();
  downloadFile(file);
};
/**
 * @param {File} file
 */
function downloadFile(file) {
  // Create a Blob if you only have a File object
  const blob = new Blob([file], { type: file.type });
  // Create a link element
  const link = document.createElement("a");
  // Create a URL for the Blob and set it as the href
  const url = URL.createObjectURL(blob);
  link.href = url;
  // Set the download attribute with a filename
  link.download = file.name || "download";
  // Append the link to the body (required for Firefox)
  document.body.appendChild(link);
  // Programmatically click the link to trigger the download
  link.click();
  // Clean up: remove the link and revoke the object URL
  document.body.removeChild(link);
  URL.revokeObjectURL(url);
}

/**
 * @param {string} query
 */
async function handleSqlInput(query) {
  const res = await sql(query);
  if (res.resultRows) {
    grid(res);
  }
}