get discord message by date range

discord.js

const serverId = '1012618482094968903';
const channelId = '1193845566204035092';
const authorization = 'token string';
const startTime = 1704672000000;
const endTime = 1705190400000;

function pick(obj, keys) {
  const result = {};
  keys.forEach((key) => {
    result[key] = obj[key];
  });
  return result;
}

function uniqueArrayObject(arr, key = 'id') {
  return arr.reduce((acc, current) => {
    const x = acc.find((item) => item[key] === current[key]);
    if (!x) {
      return acc.concat([current]);
    } else {
      return acc;
    }
  }, []);
}

async function getMessages(before) {
  const myHeaders = new Headers();
  myHeaders.append('authorization', authorization);

  const requestOptions = {
    method: 'GET',
    headers: myHeaders,
    redirect: 'follow',
  };
  if (before) {
    before = `before=${before}`;
  } else {
    before = '';
  }

  const messages = await fetch(
    `https://discord.com/api/v9/channels/${channelId}/messages?limit=100&${before}`,
    requestOptions,
  )
    .then((response) => response.json())
    .catch(() => [])
    .then((_messages) => {
      return _messages
        .filter((message) => {
          const messageTimestamp = new Date(message.timestamp).getTime();
          return messageTimestamp >= startTime && messageTimestamp < endTime;
        })
        .map((message) => {
          return {
            author: pick(message.author, ['global_name', 'id', 'username']),
            ...pick(message, ['timestamp', 'id', 'reactions']),
          };
        });
    });
  if (messages.length) {
    messages.push(...(await getMessages(messages[messages.length - 1].id)));
  }
  return messages;
}

async function getReactionsByReaction(messageId, reaction, after) {
  const myHeaders = new Headers();
  myHeaders.append('authorization', authorization);

  const requestOptions = {
    method: 'GET',
    headers: myHeaders,
    redirect: 'follow',
  };
  if (after) {
    after = `after=${after}`;
  } else {
    after = '';
  }

  const reactions = await fetch(
    `https://discord.com/api/v9/channels/${channelId}/messages/${messageId}/reactions/${reaction}?limit=100&${after}`,
    requestOptions,
  )
    .then((response) => response.json())
    .catch(() => [])
    .then((_reactions) => {
      return _reactions.map((reaction) => pick(reaction, ['global_name', 'id', 'username']));
    });
  if (reactions.length) {
    reactions.push(
      ...(await getReactionsByReaction(messageId, reaction, reactions[reactions.length - 1].id)),
    );
  }
  return reactions;
}

async function getReactions(message) {
  const reactions = (
    await Promise.all(
      (message.reactions || []).map((reaction) => {
        const emoji = reaction.emoji;
        return getReactionsByReaction(
          message.id,
          encodeURIComponent(emoji.id ? emoji.name + ':' + emoji.id : emoji.name),
          '',
        );
      }),
    )
  ).flat();
  message.reactions = uniqueArrayObject(reactions);
  message.reactionCount = message.reactions.length;
}

(async () => {
  const messages = await getMessages();
  for (const message of messages) {
    message.link = `https://discord.com/channels/${serverId}/${channelId}/${message.id}`;
    await getReactions(message);
  }
  // sort by reactionCount
  messages.sort((a, b) => b.reactionCount - a.reactionCount);
  console.log(JSON.stringify(messages));
})().catch(console.error);