<?php
declare(strict_types=1);

namespace PaypalV2;

/**
 * Kapselt die Orders-v2-Endpunkte: create / get / capture.
 */
final class Orders
{
    private PayPalClient $client;

    public function __construct(?PayPalClient $client = null)
    {
        $this->client = $client ?? new PayPalClient();
    }

    /**
     * Erstellt eine PayPal-Order (intent=CAPTURE) und liefert Order-ID + Approve-URL.
     *
     * @return array{id:string,approve_url:string}
     */
    public function create(
        float $amount,
        string $orderNumber,
        string $shopOrderId,
        string $returnUrl,
        string $cancelUrl
    ): array {
        $value    = \number_format($amount, 2, '.', '');
        $currency = (string) Config::get('currency', 'EUR');

        $payload = [
            'intent' => 'CAPTURE',
            'purchase_units' => [[
                'amount' => [
                    'currency_code' => $currency,
                    'value'         => $value,
                ],
                'custom_id'  => $shopOrderId,
                'invoice_id' => $orderNumber . '-' . $shopOrderId,
            ]],
            'application_context' => [
                'brand_name'          => (string) Config::get('brand_name', 'Shop'),
                'locale'              => 'de-DE',
                'landing_page'        => 'NO_PREFERENCE',
                'shipping_preference' => 'NO_SHIPPING',
                'user_action'         => 'PAY_NOW',
                'return_url'          => $returnUrl,
                'cancel_url'          => $cancelUrl,
            ],
        ];

        // Idempotenz: gleicher Request-Id => PayPal legt keine Doppel-Order an.
        $requestId = 'create-' . $shopOrderId . '-' . \substr(\hash('sha256', $orderNumber . '|' . $value), 0, 16);

        [$status, $body] = $this->client->request('POST', '/v2/checkout/orders', $payload, [
            'PayPal-Request-Id: ' . $requestId,
        ]);

        if ($status !== 201 || empty($body['id'])) {
            throw new \RuntimeException('PayPal v2: Order-Anlage fehlgeschlagen (HTTP ' . $status . '): ' . \json_encode($body));
        }

        $approve = '';
        foreach (($body['links'] ?? []) as $link) {
            $rel = $link['rel'] ?? '';
            if ($rel === 'approve' || $rel === 'payer-action') {
                $approve = (string) ($link['href'] ?? '');
                break;
            }
        }
        if ($approve === '') {
            throw new \RuntimeException('PayPal v2: Kein Approve-Link in der Antwort.');
        }

        return ['id' => (string) $body['id'], 'approve_url' => $approve];
    }

    /** @return array<mixed> */
    public function get(string $paypalOrderId): array
    {
        [$status, $body] = $this->client->request('GET', '/v2/checkout/orders/' . \rawurlencode($paypalOrderId));
        if ($status !== 200) {
            throw new \RuntimeException('PayPal v2: Order-Abruf fehlgeschlagen (HTTP ' . $status . ').');
        }
        return $body;
    }

    /**
     * Captured eine vom Kunden freigegebene Order. Idempotent:
     * Ist bereits gecaptured (Doppel-Return / Webhook-Race), wird der bestehende
     * Zustand aus der Order gelesen statt einen Fehler zu werfen.
     *
     * @return array{order_status:string,capture_id:string,capture_status:string,amount:string,currency:string,payer_email:string,payer_id:string,raw:array}
     */
    public function capture(string $paypalOrderId): array
    {
        [$status, $body] = $this->client->request(
            'POST',
            '/v2/checkout/orders/' . \rawurlencode($paypalOrderId) . '/capture',
            null,
            [
                'PayPal-Request-Id: capture-' . $paypalOrderId,
                'Prefer: return=representation',
            ]
        );

        if ($status === 201 || $status === 200) {
            return $this->normalize($body);
        }

        if ($status === 422 && $this->hasIssue($body, 'ORDER_ALREADY_CAPTURED')) {
            return $this->normalize($this->get($paypalOrderId));
        }

        throw new \RuntimeException('PayPal v2: Capture fehlgeschlagen (HTTP ' . $status . '): ' . \json_encode($body));
    }

    /**
     * Vereinheitlicht Capture- bzw. Order-Antwort auf die Felder, die der Shop braucht.
     *
     * @param  array<mixed> $body
     * @return array{order_status:string,capture_id:string,capture_status:string,amount:string,currency:string,payer_email:string,payer_id:string,raw:array}
     */
    public function normalize(array $body): array
    {
        $cap = $body['purchase_units'][0]['payments']['captures'][0] ?? [];

        return [
            'order_status'   => (string) ($body['status'] ?? ''),
            'capture_id'     => (string) ($cap['id'] ?? ''),
            'capture_status' => (string) ($cap['status'] ?? ''),
            'amount'         => (string) ($cap['amount']['value'] ?? ''),
            'currency'       => (string) ($cap['amount']['currency_code'] ?? ''),
            'payer_email'    => (string) ($body['payer']['email_address'] ?? ''),
            'payer_id'       => (string) ($body['payer']['payer_id'] ?? ''),
            'raw'            => $body,
        ];
    }

    /** @param array<mixed> $body */
    private function hasIssue(array $body, string $issue): bool
    {
        foreach (($body['details'] ?? []) as $d) {
            if (($d['issue'] ?? '') === $issue) {
                return true;
            }
        }
        return false;
    }
}