mastodon-to-bluesky/main.js

require("dotenv").config();
const fs = require("fs");
const path = require("path");
const { RichText, BskyAgent } = require("@atproto/api");
const axios = require("axios");

// Mastodon credentials
const mastodonInstance = process.env.MASTODON_INSTANCE;
const mastodonUser = process.env.MASTODON_USER;

// Bluesky agent
const agent = new BskyAgent({ service: process.env.BLUESKY_ENDPOINT });

// File to store the last processed Mastodon post ID
const lastProcessedPostIdFile = path.join(__dirname, "lastProcessedPostId.txt");

// Variable to store the last processed Mastodon post ID
let lastProcessedPostId = loadLastProcessedPostId();

// Function to load the last processed post ID from the file
function loadLastProcessedPostId() {
  try {
    return fs.readFileSync(lastProcessedPostIdFile, "utf8").trim();
  } catch (error) {
    console.error("Error loading last processed post ID:", error);
    return null;
  }
}

// Function to save the last processed post ID to the file
function saveLastProcessedPostId() {
  try {
    fs.writeFileSync(lastProcessedPostIdFile, `${lastProcessedPostId}`);
  } catch (error) {
    console.error("Error saving last processed post ID:", error);
  }
}
async function getImages(item) {
  const responses = item.object.attachment
    .filter(attachment => attachment.mediaType.includes("image"));
  const infos = responses.map(attachment => {
    return {
      url: attachment.url,
      width: attachment.width,
      height: attachment.height
    }
  });
  const respromise = await Promise.all(responses.map(attachment =>
    axios.get(
      attachment.url,
      {
        responseType: "arraybuffer"
      }
    )
  ));

  return respromise.map((buf, index) => {
    return {
      blob: new Blob(
        [buf.data],
        {
          type: buf.headers["content-type"]
        }
      ),
      url: infos[index].url,
      width: infos[index].width,
      height: infos[index].height
    }
  })
}


async function postToBluesky(text, images) {
  await agent.login({
    identifier: process.env.BLUESKY_HANDLE,
    password: process.env.BLUESKY_PASSWORD,
  });

  // let imgdatas = await Promise.all(images.map(async img => {
  //   const buf = await img.blob.arrayBuffer();
  //   console.log(`detected img: ${buf}, ${buf}`);
  //   const dataArray = new Uint8Array(buf);
  //   const data = await agent.uploadBlob(
  //     dataArray,
  //     {
  //       // 画像の形式を指定 ('image/jpeg' 等の MIME タイプ)
  //       encoding: img.type,
  //     }
  //   );
  //   return {
  //     alt: "",
  //     image: data.data.blob,
  //     aspectRatio: {
  //       width: img.width,
  //       height: img.height
  //     }
  //   };
  // }));
  let completetext = text;
  if (images.length > 0) {
    completetext = text + " " + images.map(img => img.url).join(" ")
  }
  const richText = new RichText({ text: completetext });
  await richText.detectFacets(agent);

  return agent.post({
    text: richText.text,
    facets: richText.facets,
  });
}

function removeHtmlTags(input) {
  return input.replace(/<[^>]*>/g, "");
}
function convertQuote(input) {
  return input.replace(/&quot;/g, '"');
}
function isReplyToMyself(item) {
  const uri = item.object.inReplyTo;
  if (uri === null) {
    return false;
  }
  return uri.includes("${mastodonInstance}/users/${mastodonUser}");
}
// Function to periodically fetch new Mastodon posts
async function fetchNewPosts() {
  const response = await axios.get(`${mastodonInstance}/users/${mastodonUser}/outbox?page=true`);

  const reversed = response.data.orderedItems.filter(item => item.object.type === 'Note')
    .filter(item => item.object.inReplyTo === null || isReplyToMyself(item))
    .reverse();

  let newTimestampId = 0;
  for (item in reversed) {
    const currentTimestampId = Date.parse(item.published);

    if (currentTimestampId > newTimestampId) {
      newTimestampId = currentTimestampId;
    }

    if (currentTimestampId > lastProcessedPostId && lastProcessedPostId != 0) {
      const text = removeHtmlTags(convertQuote(item.object.content));
      const images = await getImages(item);
      let {uri} = await postToBluesky(text, images);
      console.log(`posted ${item.object.id} to ${uri} . ${newTimestampId}`);
    }
  }

  if (newTimestampId > 0) {
    lastProcessedPostId = newTimestampId;
    saveLastProcessedPostId();
  }
}

fetchNewPosts();
// Fetch new posts every 5 minutes (adjust as needed)
setInterval(fetchNewPosts, 1 * 60 * 1000);