// ==UserScript==
// @name        CharacterAI Dumper
// @namespace   Violentmonkey Scripts
// @match       https://beta.character.ai/*
// @grant       none
// @version     1.0
// @author      0x000011b
// @description Allows downloading saved chat messages from CharacterAI.
// @downloadURL https://git.fuwafuwa.moe/waifu-collective/toolbox/raw/branch/master/extras/characterai-dumper/characterai-dumper-user.js
// @updateURL   https://git.fuwafuwa.moe/waifu-collective/toolbox/raw/branch/master/extras/characterai-dumper/characterai-dumper-user.js
// ==/UserScript==

const log = (firstArg, ...remainingArgs) =>
  console.log(`[CharacterAI Dumper v1.0] ${firstArg}`, ...remainingArgs);
log.error = (firstArg, ...remainingArgs) =>
  console.error(`[CharacterAI Dumper v1.0] ${firstArg}`, ...remainingArgs);

const CHARACTER_INFO_URL = "https://beta.character.ai/chat/character/info/";
const CHARACTER_HISTORIES_URL =
  "https://beta.character.ai/chat/character/histories/";

const characterToSavedDataMap = {};

//
// Code to add download link to the page.
//
const addDownloadLinkFor = (dataString, filename) => {
  // Don't create duplicate links.
  if (document.getElementById("injected-chat-dl-link")) {
    return;
  }

  // We want to add a link next to the "your past conversations with XXX" text.
  const suspectedElements = document.getElementsByClassName("home-sec-header");
  for (const element of suspectedElements) {
    if (!element.textContent.includes("Your Past Conversations with")) {
      continue;
    }

    const dataBlob = new Blob([dataString], { type: "text/plain" });
    const downloadLink = document.createElement("a");
    downloadLink.id = "injected-chat-dl-link";
    downloadLink.textContent = "Download";
    downloadLink.href = URL.createObjectURL(dataBlob);
    downloadLink.download = filename;
    downloadLink.style = "padding-left: 8px";
    element.appendChild(downloadLink);
  }
};

//
// Logic to remove personal data from the dumps.
//
const escapeStringForRegExp = (stringToGoIntoTheRegex) => {
  return stringToGoIntoTheRegex.replace(/[-\/\\^$*+?.()|[\]{}]/g, "\\$&");
};

const anonymizeHistories = (histories) => {
  let nameToReplace;

  for (const history of histories.histories) {
    for (const msg of history.msgs) {
      if (msg.src.is_human) {
        // First, save the user's name so we can replace it in the messages.
        nameToReplace ||= msg.display_name;

        // Need to anonymize `src`.
        msg.src.user.username = "[USERNAME_REDACTED]";
        msg.src.user.first_name = "[FIRST_NAME_REDACTED]";
        msg.src.user.account.name = "[ACCOUNT_NAME_REDACTED]";
        msg.src.user.name = "[NAME_REDACTED]";
        msg.src.name = "[NAME_REDACTED]";
        msg.display_name = "[DISPLAY_NAME_REDACTED]";
      } else {
        nameToReplace ||= msg.tgt.name;

        // Need to anonymize `tgt`.
        msg.tgt.user.username = "[USERNAME_REDACTED]";
        msg.tgt.user.first_name = "[FIRST_NAME_REDACTED]";
        msg.tgt.user.account.name = "[ACCOUNT_NAME_REDACTED]";
        msg.tgt.user.name = "[NAME_REDACTED]";
        msg.tgt.name = "[NAME_REDACTED]";

        // And since this is a bot message, there's a chance that the bot
        // uttered the user's name, so let's replace that inside the message
        // text.
        const replacementRegex = new RegExp(
          "\\b" + escapeStringForRegExp(nameToReplace) + "\\b",
          "g"
        );
        msg.text.replace(replacementRegex, "[DISPLAY_NAME_REDACTED]");
      }
    }
  }

  // This was modified in-place, but we return it here for simplicity at the
  // call site even though it's technically useless (and slightly misleading).
  return histories;
};

//
// Request intercept and data handling logic.
//
const configureXHookIntercepts = () => {
  xhook.after((_req, res) => {
    try {
      const endpoint = res.finalUrl;
      if (
        endpoint !== CHARACTER_INFO_URL &&
        endpoint !== CHARACTER_HISTORIES_URL
      ) {
        // We don't care about other endpoints.
        return;
      }

      const data = JSON.parse(res.data);
      let characterIdentifier;

      if (res.finalUrl === CHARACTER_INFO_URL) {
        characterIdentifier = data.character.name;
        log(`Got character info for ${characterIdentifier}, caching...`);

        if (!characterToSavedDataMap[characterIdentifier]) {
          characterToSavedDataMap[characterIdentifier] = {};
        }
        characterToSavedDataMap[characterIdentifier].info = data;
      } else if (res.finalUrl === CHARACTER_HISTORIES_URL) {
        characterIdentifier = data.histories[0].msgs[0].src.name;
        log(`Got chat histories for ${characterIdentifier}, caching...`);

        if (!characterToSavedDataMap[characterIdentifier]) {
          characterToSavedDataMap[characterIdentifier] = {};
        }
        characterToSavedDataMap[characterIdentifier].histories =
          anonymizeHistories(data);
      }

      const currentCharacter = characterToSavedDataMap[characterIdentifier];
      if (currentCharacter.info && currentCharacter.histories) {
        // We have all the downloadable data for this character, and we're on the
        // correct page. Create the download link.
        log(
          `Got all the data for ${characterIdentifier}, creating download link.`
        );

        log(
          "If it doesn't show up, here's the data:",
          JSON.stringify(currentCharacter)
        );

        // For some reason, the link doesn't get added if we call this right now,
        // so we wait a little while instead. Probably React re-render fuckery.
        setTimeout(
          () =>
            addDownloadLinkFor(
              JSON.stringify(currentCharacter),
              `${characterIdentifier}.json`
            ),
          2000
        );
      }
    } catch (err) {
      log.error("ERROR:", err);
    }
  });
};

// This is where XHook (lib for intercepting XHR/AJAX calls) gets injected into
// the document, and once it gets properly parsed it'll call out to the setup
// function.
//
// Copy-pasted and slightly adapted from: https://stackoverflow.com/a/8578840
log("Injecting XHook to intercept XHR/AJAX calls.");
(function (document, elementTagName, elementTagId) {
  var js,
    fjs = document.getElementsByTagName(elementTagName)[0];
  if (document.getElementById(elementTagId)) {
    return;
  }
  js = document.createElement(elementTagName);
  js.id = elementTagId;
  js.onload = function () {
    log("Done! Configuring intercepts.");
    configureXHookIntercepts();
  };
  // Link to hosted version taken from the official repo:
  // https://github.com/jpillora/xhook
  js.src = "https://jpillora.com/xhook/dist/xhook.min.js";
  fjs.parentNode.insertBefore(js, fjs);
})(document, "script", "xhook");