import 'reflect-metadata';
import fs from 'fs';
import path from 'path';
import { parse } from 'csv-parse/sync';
import { getDataSource } from '../lib/database';
import { Customer } from '../lib/database/entities/Customer';

interface CustomerCSVRow {
    City: string;
    Name: string;
    'Website URL': string;
    Email: string;
}

async function importCustomers(csvFilePath: string): Promise<void> {
    try {
        // Initialize database connection
        const dataSource = await getDataSource();
        const customerRepository = dataSource.getRepository(Customer);

        // Read and parse CSV file
        const fileContent = fs.readFileSync(csvFilePath, 'utf-8');
        const records = parse(fileContent, {
            columns: true,
            skip_empty_lines: true,
            trim: true,
        }) as CustomerCSVRow[];

        console.log(`Found ${records.length} records in CSV file`);

        // Track processed emails to skip duplicates
        const processedEmails = new Set<string>();
        // Track existing names to ensure uniqueness
        const existingNames = new Set<string>(
            (await customerRepository.find()).map(customer => customer.name)
        );

        let importedCount = 0;
        let skippedDuplicateEmail = 0;
        let skippedDuplicateName = 0;

        for (const record of records) {
            const email = record.Email === 'null' ? '' : record.Email;
            const name = record.Name;

            // Skip if email is already processed (not empty and already seen)
            if (email && processedEmails.has(email)) {
                console.log(`Skipping record with duplicate email: ${email}`);
                skippedDuplicateEmail++;
                continue;
            }

            // Skip if name already exists in database
            if (existingNames.has(name)) {
                console.log(`Skipping record with duplicate name: ${name}`);
                skippedDuplicateName++;
                continue;
            }

            // Add to processed sets
            if (email) {
                processedEmails.add(email);
            }
            existingNames.add(name);

            // Create new customer
            const customer = new Customer();
            customer.name = name;
            customer.url = record['Website URL'] === 'null' ? '' : record['Website URL'];
            customer.email = email;

            // Save to database
            await customerRepository.save(customer);
            importedCount++;

            console.log(`Imported customer: ${name}`);
        }

        console.log('Import summary:');
        console.log(`- Total records in CSV: ${records.length}`);
        console.log(`- Successfully imported: ${importedCount}`);
        console.log(`- Skipped (duplicate email): ${skippedDuplicateEmail}`);
        console.log(`- Skipped (duplicate name): ${skippedDuplicateName}`);

    } catch (error) {
        console.error('Error importing customers:', error);
        throw error;
    }
}

// Check if file path is provided as command line argument
const csvFilePath = process.argv[2];
if (!csvFilePath) {
    console.error('Please provide the path to the CSV file as a command line argument');
    console.error('Example: npm run import-customers -- ./data/customers.csv');
    process.exit(1);
}

// Run the import function
importCustomers(csvFilePath)
    .then(() => {
        console.log('Import completed successfully');
        process.exit(0);
    })
    .catch((error) => {
        console.error('Import failed:', error);
        process.exit(1);
    });