import { readFile, writeFile } from 'fs/promises';

import { getArg } from './lib/args.js';
import { getMany } from './lib/dl.js';
import { error, log } from './lib/log.js';

const ctx = 'downloadUser.js';

/**
 * Downloads all media possible for a user stored/to-be-stored in db.json at the specified `--path`.
 * Useful for first run or for augmenting existing media
 * if it may be only partially archived in an uncertain state.
 * Safely checks if the db.json doesn't yet exist and/or the user isn't stored in the db.json at the directory provided.
 */
const downloadUser = async () => {
  log(ctx, 'Grabbing db');
  let directory, threadMax = 1, user, db;
  try {
    directory = getArg('path');
    user = getArg('user');
  } catch (err) {
    error(ctx, err);
    return;
  }
  try {
    let file = await readFile(`${directory}/db.json`, { encoding: 'utf8' });
    db = JSON.parse(file);
  } catch (err) {
    if (err.toString().includes('ENOENT')) {
      try {
        db = [];
        await writeFile(`${directory}/db.json`, JSON.stringify(db, null, 2));
      } catch (err2) {
        error(ctx, err2);
        return;
      }
    } else {
      error(ctx, err);
      return;
    }
  }

  let index = db.findIndex(other => other.user === user);
  if (index < 0) {
    index = db.push({ user }) - 1;
  }

  let processes = db.filter((other) => other.user === user).map(entry => ({
    ...entry,
    lastUpdated: Date.now(),
    logs: [],
  }));

  log(ctx, `Downloading media using /<user>/media for ${processes.length} users`);
  await getMany(processes, threadMax, directory, 'media');

  log(ctx, 'Downloading media using /search');
  await getMany(processes, threadMax, directory, 'search');

  processes.forEach(entry => {
    entry.logs.forEach(log => {
      if (log.includes('NotFoundError')) {
        const strOut = `${entry.user} wasn't found: "${log.replace('\n', '')}". You may want to remove them from the db.json file or update their username.`;
        error(ctx, strOut);
        entry.lastError = strOut;
      } else if (log.includes('AuthorizationError')) {
        const strOut = `There was an authorization error for user ${entry.user}: "${log.replace('\n', '')}"`;
        error(ctx, strOut);
        entry.lastError = strOut;
      }
    });
  });

  log(ctx, 'Saving db');
  try {
    processes.forEach(process => {
      let i = db.findIndex(other => other.user === process.user);
      db[i] = {
        user: process.user,
        lastUpdated: process.lastUpdated,
        lastError: process.lastError,
      }
    });
    await writeFile(`${directory}/db.json`, JSON.stringify(db, null, 2));
  } catch (err) {
    error(ctx, err);
    return;
  }
  log(ctx, 'Done');
}

downloadUser();