// Copyright 2021 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only

import type { Database } from 'better-sqlite3';

import { batchMultiVarQuery } from '../util';
import type { ArrayQuery } from '../util';
import type { LoggerType } from '../../types/Logging';

export default function updateToSchemaVersion42(
  currentVersion: number,
  db: Database,
  logger: LoggerType
): void {
  if (currentVersion >= 42) {
    return;
  }

  db.transaction(() => {
    // First, recreate messages table delete trigger with reaction support

    db.exec(`
      DROP TRIGGER messages_on_delete;

      CREATE TRIGGER messages_on_delete AFTER DELETE ON messages BEGIN
        DELETE FROM messages_fts WHERE rowid = old.rowid;
        DELETE FROM sendLogPayloads WHERE id IN (
          SELECT payloadId FROM sendLogMessageIds
          WHERE messageId = old.id
        );
        DELETE FROM reactions WHERE rowid IN (
          SELECT rowid FROM reactions
          WHERE messageId = old.id
        );
      END;
    `);

    // Then, delete previously-orphaned reactions

    // Note: we use `pluck` here to fetch only the first column of
    //   returned row.
    const messageIdList: Array<string> = db
      .prepare('SELECT id FROM messages ORDER BY id ASC;')
      .pluck()
      .all();
    const allReactions: Array<{
      rowid: number;
      messageId: string;
    }> = db.prepare('SELECT rowid, messageId FROM reactions;').all();

    const messageIds = new Set(messageIdList);
    const reactionsToDelete: Array<number> = [];

    allReactions.forEach(reaction => {
      if (!messageIds.has(reaction.messageId)) {
        reactionsToDelete.push(reaction.rowid);
      }
    });

    function deleteReactions(rowids: Array<number>) {
      db.prepare<ArrayQuery>(
        `
        DELETE FROM reactions
        WHERE rowid IN ( ${rowids.map(() => '?').join(', ')} );
        `
      ).run(rowids);
    }

    if (reactionsToDelete.length > 0) {
      logger.info(`Deleting ${reactionsToDelete.length} orphaned reactions`);
      batchMultiVarQuery(db, reactionsToDelete, deleteReactions);
    }

    db.pragma('user_version = 42');
  })();
  logger.info('updateToSchemaVersion42: success!');
}