const mysql = require('mysql2/promise');
const path = require('path');
const dotenv = require('dotenv');
const fs = require('fs');

dotenv.config({ path: path.join(__dirname, '../.env') });

const dbConfig = {
    host: process.env.DB_HOST,
    user: process.env.DB_USER,
    password: process.env.DB_PASSWORD,
    database: process.env.DB_NAME,
    multipleStatements: true
};

// Helper function to output progress in JSON format
function outputProgress(data) {
    if (!data.status) {
        data = {
            status: 'running',
            ...data
        };
    }
    console.log(JSON.stringify(data));
}

async function resetDatabase() {
    outputProgress({
        operation: 'Starting database reset',
        message: 'Connecting to database...'
    });

    const connection = await mysql.createConnection(dbConfig);
    
    try {
        // Get list of all tables efficiently
        outputProgress({
            operation: 'Getting table list',
            message: 'Retrieving all table names...'
        });

        // More efficient query to get table names
        const [tables] = await connection.query(`
            SELECT GROUP_CONCAT(table_name) as tables 
            FROM information_schema.tables 
            WHERE table_schema = DATABASE()`
        );

        if (!tables[0].tables) {
            outputProgress({
                operation: 'No tables found',
                message: 'Database is already empty'
            });
        } else {
            // Disable foreign key checks and drop all tables in one query
            outputProgress({
                operation: 'Dropping tables',
                message: 'Dropping all tables...'
            });

            await connection.query('SET FOREIGN_KEY_CHECKS = 0');
            
            // Create DROP TABLE statements for all tables at once
            const dropQuery = `DROP TABLE IF EXISTS ${tables[0].tables.split(',').map(table => '`' + table + '`').join(', ')}`;
            await connection.query(dropQuery);
            
            await connection.query('SET FOREIGN_KEY_CHECKS = 1');
        }

        // Read and execute main schema
        outputProgress({
            operation: 'Running database setup',
            message: 'Creating core tables...'
        });

        const schemaSQL = fs.readFileSync(path.join(__dirname, '../db/schema.sql'), 'utf8');
        await connection.query(schemaSQL);

        // Read and execute metrics schema
        outputProgress({
            operation: 'Running metrics setup',
            message: 'Creating metrics tables...'
        });

        const metricsSchemaSQL = fs.readFileSync(path.join(__dirname, '../db/metrics-schema.sql'), 'utf8');
        await connection.query(metricsSchemaSQL);

        outputProgress({
            status: 'complete',
            operation: 'Database reset complete',
            message: 'Database has been reset and all tables recreated'
        });
    } catch (error) {
        outputProgress({
            status: 'error',
            error: error.message
        });
        process.exit(1);
    } finally {
        await connection.end();
    }
}

// Run the reset
resetDatabase();