import { createClient } from '@clickhouse/client';
import config from '../config';

// Create ClickHouse client with error handling
const createClickHouseClient = () => {
  try {
    return createClient({
      host: `http://${config.clickhouse.host}:${config.clickhouse.port}`,
      username: config.clickhouse.user,
      password: config.clickhouse.password,
      database: config.clickhouse.database,
    });
  } catch (error) {
    console.error('Error creating ClickHouse client:', error);
    // Return a mock client for development that logs operations instead of executing them
    return {
      query: async ({ query, values }: { query: string; values?: any[] }) => {
        console.log('ClickHouse query (mock):', query, values);
        return { rows: [] };
      },
      close: async () => {
        console.log('ClickHouse connection closed (mock)');
      }
    };
  }
};

const clickhouse = createClickHouseClient();

// Initialize ClickHouse database and tables
export const initClickHouse = async () => {
  try {
    // Create database if not exists
    await clickhouse.query({
      query: `CREATE DATABASE IF NOT EXISTS ${config.clickhouse.database}`,
    });
    
    // Create tables for tracking events
    await clickhouse.query({
      query: `
        CREATE TABLE IF NOT EXISTS ${config.clickhouse.database}.view_events (
          user_id String,
          content_id String,
          timestamp DateTime DEFAULT now(),
          ip String,
          user_agent String
        ) ENGINE = MergeTree()
        PARTITION BY toYYYYMM(timestamp)
        ORDER BY (user_id, content_id, timestamp)
      `,
    });
    
    await clickhouse.query({
      query: `
        CREATE TABLE IF NOT EXISTS ${config.clickhouse.database}.like_events (
          user_id String,
          content_id String,
          timestamp DateTime DEFAULT now(),
          action Enum('like' = 1, 'unlike' = 2)
        ) ENGINE = MergeTree()
        PARTITION BY toYYYYMM(timestamp)
        ORDER BY (user_id, content_id, timestamp)
      `,
    });
    
    await clickhouse.query({
      query: `
        CREATE TABLE IF NOT EXISTS ${config.clickhouse.database}.follower_events (
          follower_id String,
          followed_id String,
          timestamp DateTime DEFAULT now(),
          action Enum('follow' = 1, 'unfollow' = 2)
        ) ENGINE = MergeTree()
        PARTITION BY toYYYYMM(timestamp)
        ORDER BY (follower_id, followed_id, timestamp)
      `,
    });
    
    console.log('ClickHouse database and tables initialized');
  } catch (error) {
    console.error('Error initializing ClickHouse:', error);
    console.log('Continuing with limited functionality...');
  }
};

export default clickhouse;