nostr-mailing-list/utils.ts

import type * as net from "node:net";
import type { Event } from "@nostr/tools";
import { exists } from "jsr:@std/fs/exists";
import type { ImapCommandParameters } from "./imapParsing.ts";
import type { ImapSession } from "./imapServer.ts";

export async function isMessageRead(
  session: ImapSession,
  eventId: string,
): Promise<boolean> {
  if (!session.npub) {
    return false;
  }
  const readMessages = JSON.parse(
    await getFileOrDefault("readMessages.json", "{}"),
  );
  const readMessagesForUser = readMessages[session.npub];
  if (!readMessagesForUser) {
    return false;
  }
  return readMessagesForUser.includes(eventId);
}

export async function markMessageAsRead(
  session: ImapSession,
  eventId: string,
  positive = true,
) {
  if (!session.npub) {
    return;
  }
  const readMessages = JSON.parse(
    await getFileOrDefault("readMessages.json", "{}"),
  );
  readMessages[session.npub] = readMessages[session.npub] || [];
  if (positive) {
    readMessages[session.npub].push(eventId);
  } else {
    readMessages[session.npub] = readMessages[session.npub].filter(
      (id: string) => id !== eventId,
    );
  }
  await Deno.writeTextFile(
    "data/readMessages.json",
    JSON.stringify(readMessages, null, 2),
  );
}

export async function isMessageFlagged(
  session: ImapSession,
  eventId: string,
): Promise<boolean> {
  if (!session.npub) {
    return false;
  }
  const flaggedMessages = JSON.parse(
    await getFileOrDefault("flaggedMessages.json", "{}"),
  );
  const flaggedMessagesForUser = flaggedMessages[session.npub];
  if (!flaggedMessagesForUser) {
    return false;
  }
  return flaggedMessagesForUser.includes(eventId);
}

export async function markMessageAsFlagged(
  session: ImapSession,
  eventId: string,
  positive = true,
) {
  if (!session.npub) {
    return;
  }
  const flaggedMessages = JSON.parse(
    await getFileOrDefault("flaggedMessages.json", "{}"),
  );
  flaggedMessages[session.npub] = flaggedMessages[session.npub] || [];
  if (positive) {
    flaggedMessages[session.npub].push(eventId);
  } else {
    flaggedMessages[session.npub] = flaggedMessages[session.npub].filter(
      (id: string) => id !== eventId,
    );
  }
  await Deno.writeTextFile(
    "data/flaggedMessages.json",
    JSON.stringify(flaggedMessages, null, 2),
  );
}

export async function getFlags(
  session: ImapSession,
  eventId: string,
): Promise<string[]> {
  const isRead = await isMessageRead(session, eventId);
  const isFlagged = await isMessageFlagged(session, eventId);
  return [isRead ? "\\Seen" : "", isFlagged ? "\\Flagged" : ""].filter(Boolean);
}

export function parseUid(uid: ImapCommandParameters): [number, number] {
  if (typeof uid !== "string") {
    throw new Error("Invalid UID");
  }
  const [start, end] = uid.split(":");
  if (end === undefined) {
    return [Number.parseInt(start), Number.parseInt(start)];
  }
  if (start === "*") {
    return [Number.NEGATIVE_INFINITY, Number.POSITIVE_INFINITY];
  }
  if (end === "*") {
    return [Number.parseInt(start), Number.POSITIVE_INFINITY];
  }
  return [Number.parseInt(start), Number.parseInt(end)];
}

export function getByteLength(text: string): number {
  return new Blob([text]).size;
}

export function parseBasicNostrMarkdown(text: string): string {
  let generatedHtml = text.replaceAll("<", "&lt;");
  generatedHtml = generatedHtml.replaceAll(">", "&gt;");

  generatedHtml = generatedHtml.replace(/\*\*(.*?)\*\*/g, "<b>$1</b>");

  generatedHtml = generatedHtml.replace(/\*(.*?)\*/g, "<i>$1</i>");

  generatedHtml = generatedHtml.replace(/`(.*?)`/g, "<code>$1</code>");

  generatedHtml = generatedHtml.replace(/^###\s+(.*?)$/gm, "<h3>$1</h3>");
  generatedHtml = generatedHtml.replace(/^##\s+(.*?)$/gm, "<h2>$1</h2>");
  generatedHtml = generatedHtml.replace(/^#\s+(.*?)$/gm, "<h1>$1</h1>");

  generatedHtml = generatedHtml.replace(
    /!\[(.*?)\]\((https?:\/\/[^\s)]+\.(jpg|jpeg|png|gif|webp))\)/g,
    '<img src="$2" alt="$1">',
  );
  generatedHtml = generatedHtml.replace(
    /(https?:\/\/[^\s)]+)/g,
    '<img src="$1" alt="$1">',
  );

  generatedHtml = generatedHtml.replace(
    /nostr:(npub1[a-z0-9]+)/g,
    '<a href="nostr:$1">$1</a>',
  );
  generatedHtml = generatedHtml.replace(
    /nostr:(note1[a-z0-9]+)/g,
    '<a href="nostr:$1">$1</a>',
  );
  generatedHtml = generatedHtml.replace(
    /nostr:(event1[a-z0-9]+)/g,
    '<a href="nostr:$1">$1</a>',
  );

  generatedHtml = generatedHtml.replace(/\n\n/g, "<br><br>");

  return generatedHtml;
}

const eventIdToUidMap: string[] = JSON.parse(
  await getFileOrDefault("event-id-to-uid-map.json", "[]"),
);

export function findEventIdForUid(uid: number): string {
  return eventIdToUidMap[uid];
}

export function findUidForEvent(event: Event): number {
  const eventId = event.id;
  const uid = eventIdToUidMap.findIndex((id) => id === eventId);
  if (uid !== -1) {
    return uid;
  }
  eventIdToUidMap.push(eventId);
  Deno.writeFileSync(
    "event-id-to-uid-map.json",
    new TextEncoder().encode(JSON.stringify(eventIdToUidMap)),
  );
  return eventIdToUidMap.length;
}

export function sendSocketMessage(socket: net.Socket, message: string) {
  if (socket.destroyed || socket.closed) {
    console.error("Socket is destroyed or closed");
    return;
  }
  socket.write(message);
  logMessage("out", message);
}

export function logMessage(direction: string, message: string) {
  Deno.writeTextFileSync(
    "data/message-logs.txt",
    `${
      JSON.stringify({
        direction,
        message,
      })
    }\n`,
    {
      append: true,
    },
  );
}

export async function getFileOrDefault(path: string, defaultValue: string) {
  if (!await exists("data")) {
    await Deno.mkdir("data");
  }

  if (!await exists(`data/${path}`)) {
    await Deno.writeTextFile(`data/${path}`, defaultValue);
  }

  return await Deno.readTextFile(`data/${path}`);
}