// Verify NodeJS version
const nodeMajorVersion = parseInt(process.versions.node.split('.')[0], 10);
if (nodeMajorVersion < 10) {
  console.error('Unsupported NodeJS version! Please install NodeJS 10 or newer.');
  process.exit(1);
}

// Verify node modules have been installed
const fs = require('fs');
const path = require('path');

try {
  fs.accessSync(path.join(__dirname, '..', 'node_modules'));
} catch (e) {
  console.error('Please run "npm ci" before starting the bot');
  process.exit(1);
}

// Error handling
process.on('uncaughtException', err => {
  // Unknown message types (nitro boosting messages at the time) should be safe to ignore
  if (err && err.message && err.message.startsWith('Unhandled MESSAGE_CREATE type')) {
    return;
  }

  // For everything else, crash with the error
  console.error(err);
  process.exit(1);
});

let testedPackage = '';
try {
  const packageJson = require('../package.json');
  const modules = Object.keys(packageJson.dependencies);
  modules.forEach(mod => {
    testedPackage = mod;
    fs.accessSync(path.join(__dirname, '..', 'node_modules', mod))
  });
} catch (e) {
  console.error(`Please run "npm ci" again! Package "${testedPackage}" is missing.`);
  process.exit(1);
}

const config = require('./config');
const utils = require('./utils');
const main = require('./main');
const knex = require('./knex');
const legacyMigrator = require('./legacy/legacyMigrator');

// Force crash on unhandled rejections (use something like forever/pm2 to restart)
process.on('unhandledRejection', err => {
  if (err instanceof utils.BotError || (err && err.code)) {
    // We ignore stack traces for BotErrors (the message has enough info) and network errors from Eris (their stack traces are unreadably long)
    console.error(`Error: ${err.message}`);
  } else {
    console.error(err);
  }

  process.exit(1);
});

(async function() {
  // Make sure the database is up to date
  const migrationDelta = await knex.migrate.status();
  if (migrationDelta !== 0) {
    console.log('Updating database. This can take a while. Don\'t close the bot!');
    await knex.migrate.latest();
    console.log('Done!');
  }

  // Migrate legacy data if we need to
  if (await legacyMigrator.shouldMigrate()) {
    console.log('=== MIGRATING LEGACY DATA ===');
    console.log('Do not close the bot!');
    console.log('');

    await legacyMigrator.migrate();

    const relativeDbDir = (path.isAbsolute(config.dbDir) ? config.dbDir : path.resolve(process.cwd(), config.dbDir));
    const relativeLogDir = (path.isAbsolute(config.logDir) ? config.logDir : path.resolve(process.cwd(), config.logDir));

    console.log('');
    console.log('=== LEGACY DATA MIGRATION FINISHED ===');
    console.log('');
    console.log('IMPORTANT: After the bot starts, please verify that all logs, threads, blocked users, and snippets are still working correctly.');
    console.log('Once you\'ve done that, the following files/directories are no longer needed. I would recommend keeping a backup of them, however.');
    console.log('');
    console.log('FILE: ' + path.resolve(relativeDbDir, 'threads.json'));
    console.log('FILE: ' + path.resolve(relativeDbDir, 'blocked.json'));
    console.log('FILE: ' + path.resolve(relativeDbDir, 'snippets.json'));
    console.log('DIRECTORY: ' + relativeLogDir);
    console.log('');
    console.log('Starting the bot...');
  }

  // Start the bot
  main.start();
})();