<?php

defined('BASEPATH') or exit('No direct script access allowed');

class Paystack extends App_Controller
{
    public function __construct()
    {
        parent::__construct();
        $this->load->model('invoices_model');
        $this->load->model('clients_model');
        $this->load->library('paystack_gateway');
        $this->load->model('paystack/paystack_model');
    }

    /**
     * Show payment form
     */
    public function make_payment()
    {
        $payment_data = $this->session->userdata('paystack_payment_data');

        if (!$payment_data) {
            set_alert('danger', _l('invalid_payment'));
            redirect(site_url('invoices'));
        }

        $invoice = $this->invoices_model->get($payment_data['invoice_id']);
        if (!$invoice) {
            set_alert('danger', _l('invoice_not_found'));
            redirect(site_url('invoices'));
        }

        // Get client data
        $client = $this->clients_model->get($invoice->clientid);

        $data = [];
        $data['invoice'] = $invoice;
        $data['payment_data'] = $payment_data;
        $data['client'] = $client;

        $this->load->view('paystack/payment', $data);
    }

    /**
     * Verify payment callback
     */
    public function verify_payment($reference = null)
    {
        if (!$reference) {
            redirect(site_url('clients/invoices'));
        }

        // Log verification attempt
        $this->paystack_model->add_payment_log([
            'message' => 'Verifying payment: ' . $reference,
            'log_type' => 'info'
        ]);

        $transaction = $this->paystack_gateway->verify_transaction($reference);

        if ($transaction['success']) {
            // Get the transaction from our database
            $local_transaction = $this->paystack_model->get_transaction_by_reference($reference);

            if ($local_transaction) {
                // Update local transaction status
                $this->db->where('id', $local_transaction['id']);
                $this->db->update(db_prefix() . 'paystack_transactions', [
                    'status' => 'success',
                    'transaction_date' => date('Y-m-d H:i:s')
                ]);

                // Record the payment in Perfex CRM
                $payment_data = [
                    'amount' => $local_transaction['amount'],
                    'invoiceid' => $local_transaction['invoice_id'],
                    'paymentmode' => 'paystack',
                    'transactionid' => $reference
                ];

                $this->load->model('payments_model');
                $payment_id = $this->payments_model->add($payment_data);

                if ($payment_id) {
                    set_alert('success', _l('payment_recorded_successfully'));
                } else {
                    set_alert('danger', _l('payment_record_failed'));
                }
            }
        } else {
            set_alert('danger', _l('payment_failed'));
        }

        // Redirect to invoice
        redirect(site_url('clients/invoices'));
    }

    /**
     * Handle Paystack webhook
     */
//    public function webhook()
//    {
//        if ((strtoupper($_SERVER['REQUEST_METHOD']) != 'POST') || !array_key_exists('HTTP_X_PAYSTACK_SIGNATURE', $_SERVER)) {
//            exit();
//        }
//
//        $input = file_get_contents("php://input");
//
//        // Verify webhook signature
//        $secret_key = $this->paystack_gateway->decryptSetting('paystack_secret_key');
//        if ($_SERVER['HTTP_X_PAYSTACK_SIGNATURE'] !== hash_hmac('sha512', $input, $secret_key)) {
//            exit();
//        }
//
//        http_response_code(200);
//
//        $event = json_decode($input);
//
//        // Handle the event
//        switch ($event->event) {
//            case 'charge.success':
//                $this->handle_successful_charge($event->data);
//                break;
//            case 'transfer.success':
//                $this->handle_successful_transfer($event->data);
//                break;
//            case 'charge.failed':
//                $this->handle_failed_charge($event->data);
//                break;
//        }
//
//        exit();
//    }
    public function webhook()
    {
        $this->load->helper('paystack_security');

        // Get payload and signature
        $payload = file_get_contents('php://input');
        $signature = isset($_SERVER['HTTP_X_PAYSTACK_SIGNATURE']) ? $_SERVER['HTTP_X_PAYSTACK_SIGNATURE'] : '';

        // Log webhook request
        $this->paystack_model->add_webhook_log([
            'event' => 'webhook_received',
            'payload' => $payload,
            'signature' => $signature,
            'status' => 'received'
        ]);

        // Verify signature
        if (!verify_paystack_webhook_signature($payload, $signature)) {
            $this->paystack_model->add_webhook_log([
                'event' => 'webhook_verification_failed',
                'payload' => $payload,
                'status' => 'failed',
                'message' => 'Invalid signature'
            ]);
            header('HTTP/1.1 401 Unauthorized');
            exit();
        }

        // Parse payload
        $event = json_decode($payload);

        // Validate payload
        if (!is_object($event) || !isset($event->event)) {
            $this->paystack_model->add_webhook_log([
                'event' => 'webhook_invalid_payload',
                'payload' => $payload,
                'status' => 'failed',
                'message' => 'Invalid payload format'
            ]);
            header('HTTP/1.1 400 Bad Request');
            exit();
        }

        try {
            // Process different event types
            switch ($event->event) {
                case 'charge.success':
                    $this->handle_successful_charge($event->data);
                    break;

                case 'charge.failed':
                    $this->handle_failed_charge($event->data);
                    break;

                case 'transfer.success':
                    $this->handle_successful_transfer($event->data);
                    break;

                case 'transfer.failed':
                    $this->handle_failed_transfer($event->data);
                    break;

                default:
                    // Log unknown event type
                    $this->paystack_model->add_webhook_log([
                        'event' => $event->event,
                        'payload' => $payload,
                        'status' => 'skipped',
                        'message' => 'Unknown event type'
                    ]);
                    break;
            }

            header('HTTP/1.1 200 OK');
            echo json_encode(['status' => 'success']);
        } catch (Exception $e) {
            // Log error
            $this->paystack_model->add_webhook_log([
                'event' => $event->event,
                'payload' => $payload,
                'status' => 'error',
                'message' => $e->getMessage()
            ]);

            header('HTTP/1.1 500 Internal Server Error');
            echo json_encode(['status' => 'error', 'message' => 'Internal processing error']);
        }
    }

    /**
     * Handle successful charge
     */
    private function handle_successful_charge($data)
    {
        // Validate the charge data
        if (!isset($data->reference) || !isset($data->amount)) {
            throw new Exception('Invalid charge data');
        }

        // Find the transaction
        $transaction = $this->paystack_model->get_transaction_by_reference($data->reference);

        if (!$transaction) {
            throw new Exception('Transaction not found');
        }

        // Verify amount
        $expected_amount = $transaction['amount'] * 100; // Convert to kobo
        if ($data->amount !== $expected_amount) {
            throw new Exception('Amount mismatch');
        }

        // Update transaction status
        $this->paystack_model->update_transaction($transaction['id'], [
            'status' => 'success',
            'transaction_date' => date('Y-m-d H:i:s')
        ]);

        // Add to payment logs
        $this->paystack_model->add_payment_log([
            'transaction_id' => $transaction['id'],
            'invoice_id' => $transaction['invoice_id'],
            'amount' => $transaction['amount'],
            'message' => 'Payment successful',
            'log_type' => 'success'
        ]);

        // Record payment in Perfex CRM
        $payment_data = [
            'amount' => $transaction['amount'],
            'invoiceid' => $transaction['invoice_id'],
            'paymentmode' => 'paystack',
            'transactionid' => $data->reference
        ];

        $this->load->model('payments_model');
        $payment_id = $this->payments_model->add($payment_data);

        if (!$payment_id) {
            throw new Exception('Failed to record payment');
        }

        // Send email notification
        $this->send_payment_notification($transaction['invoice_id'], $payment_id);
    }

    /**
     * Handle failed charge
     */
    private function handle_failed_charge($data)
    {
        if (!isset($data->reference)) {
            throw new Exception('Invalid charge data');
        }

        $transaction = $this->paystack_model->get_transaction_by_reference($data->reference);

        if ($transaction) {
            // Update transaction status
            $this->paystack_model->update_transaction($transaction['id'], [
                'status' => 'failed',
                'transaction_date' => date('Y-m-d H:i:s')
            ]);

            // Add to payment logs
            $this->paystack_model->add_payment_log([
                'transaction_id' => $transaction['id'],
                'invoice_id' => $transaction['invoice_id'],
                'amount' => $transaction['amount'],
                'message' => 'Payment failed: ' . ($data->gateway_response ?? 'Unknown error'),
                'log_type' => 'error'
            ]);
        }
    }

    /**
     * Handle successful transfer
     */
    private function handle_successful_transfer($data)
    {
        log_activity('Paystack Webhook: Successful transfer - Reference: ' . $data->reference);
    }

    /**
     * Send payment success email
     */
    private function send_payment_success_email($invoice_id, $transaction)
    {
        $this->load->model('emails_model');

        $invoice = $this->invoices_model->get($invoice_id);
        $client = $this->clients_model->get($invoice->clientid);

        $email_template = 'invoice-payment-recorded';
        $merge_fields = [];
        $merge_fields = array_merge($merge_fields, get_invoice_merge_fields($invoice_id));
        $merge_fields = array_merge($merge_fields, get_client_merge_fields($client->userid));
        $merge_fields['{payment_total}'] = app_format_money($transaction['data']->amount / 100, $invoice->currency_name);
        $merge_fields['{payment_reference}'] = $transaction['data']->reference;

        $this->emails_model->send_email_template($email_template, $client->email, $merge_fields);
    }
}