invoiceninja/app/Import/Transformer/Wave/InvoiceTransformer.php

<?php
/**
 * Invoice Ninja (https://invoiceninja.com).
 *
 * @link https://github.com/clientninja/clientninja source repository
 *
 * @copyright Copyright (c) 2021. Invoice Ninja LLC (https://clientninja.com)
 *
 * @license https://www.elastic.co/licensing/elastic-license
 */

namespace App\Import\Transformer\Wave;

use App\Import\ImportException;
use App\Import\Transformer\BaseTransformer;
use App\Models\Invoice;

/**
 * Class InvoiceTransformer.
 */
class InvoiceTransformer extends BaseTransformer {
	/**
	 * @param $line_items_data
	 *
	 * @return bool|array
	 */
	public function transform( $line_items_data ) {
		$invoice_data = reset( $line_items_data );

		if ( $this->hasInvoice( $invoice_data['Invoice Number'] ) ) {
			throw new ImportException( 'Invoice number already exists' );
		}

		if(array_key_exists('Invoice Date', $invoice_data))
			$date_key = 'Invoice Date';
		else
			$date_key = 'Transaction Date';

		if(array_key_exists('Customer Name', $invoice_data))
			$customer_key = 'Customer Name';
		else
			$customer_key = 'Customer';

		$transformed = [
			'company_id'  => $this->company->id,
			'client_id'   => $this->getClient( $customer_name = $this->getString( $invoice_data, $customer_key ), null ),
			'number'      => $invoice_number = $this->getString( $invoice_data, 'Invoice Number' ),
			'date'        => date( 'Y-m-d', strtotime( $invoice_data[$date_key] ) ) ?: now()->format('Y-m-d'), //27-01-2022
			'currency_id' => $this->getCurrencyByCode( $invoice_data, 'Currency' ),
			'status_id'   => Invoice::STATUS_SENT,
			'due_date'	  => array_key_exists('Due Date', $invoice_data) ? date( 'Y-m-d', strtotime( $invoice_data['Due Date'] ) ) : null,
		];

		$line_items = [];
		$payments   = [];
		foreach ( $line_items_data as $record ) {
			if (array_key_exists('Account Type', $record) && $record['Account Type'] === 'Income' ) {
				$description = $this->getString( $record, 'Transaction Line Description' );

				// Remove duplicate data from description
				if ( substr( $description, 0, strlen( $customer_name ) + 3 ) === $customer_name . ' - ' ) {
					$description = substr( $description, strlen( $customer_name ) + 3 );
				}

				if ( substr( $description, 0, strlen( $invoice_number ) + 3 ) === $invoice_number . ' - ' ) {
					$description = substr( $description, strlen( $invoice_number ) + 3 );
				}

				$line_items[] = [
					'notes'     => $description,
					'cost'      => $this->getFloat( $record, 'Amount Before Sales Tax' ),
					'tax_name1' => $this->getString( $record, 'Sales Tax Name' ),
					'tax_rate1' => $this->getFloat( $record, 'Sales Tax Amount' ),

					'quantity' => 1,
				];
			} elseif (array_key_exists('Account Type', $record) && $record['Account Type'] === 'System Receivable Invoice' ) {
				// This is a payment
				$payments[] = [
					'date'   => date( 'Y-m-d', strtotime( $invoice_data[$date_key] ) ),
					'amount' => $this->getFloat( $record, 'Amount (One column)' ),
				];
			}
			else {
				//could be a generate invoices.csv file
				$line_items[] = [
					'notes'     => 'Imported Invoice',
					'cost'      => $this->getFloat( $record, 'Invoice Total' ),
					'tax_name1' => 'Tax',
					'tax_rate1' => round($this->getFloat( $record, 'Invoice Tax Total' ) / $this->getFloat( $record, 'Invoice Total' ) * 100,2),
					'quantity' => 1,
				];

				if($record['Invoice Paid'] > 0){
					$payments[] = [
						'date'   => date( 'Y-m-d', strtotime( $record['Last Payment Date'] ) ),
						'amount' => $this->getFloat( $record, 'Invoice Paid' ),
					];
				} 

			}
		}

		$transformed['line_items'] = $line_items;
		$transformed['payments']   = $payments;

		return $transformed;
	}
}