<?php

namespace App\Services\Billing;

use App\Models\PlatformSetting;
use Illuminate\Http\Client\Response;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Schema;
use RuntimeException;

class PaystackService
{
    public function publicKey(): string
    {
        return (string) $this->settingValue('paystack_public_key', config('services.paystack.public_key', ''));
    }

    public function initializeTransaction(array $payload): array
    {
        return $this->initializeTransactionWithCredentials($payload);
    }

    public function initializeTransactionWithCredentials(array $payload, ?string $secretKey = null, ?string $baseUrl = null): array
    {
        $response = $this->request(secretKey: $secretKey, baseUrl: $baseUrl)
            ->post('/transaction/initialize', $payload);

        return $this->extractData($response, 'Failed to initialize Paystack transaction.');
    }

    public function verifyTransaction(string $reference): array
    {
        return $this->verifyTransactionWithCredentials($reference);
    }

    public function verifyTransactionWithCredentials(string $reference, ?string $secretKey = null, ?string $baseUrl = null): array
    {
        $response = $this->request(secretKey: $secretKey, baseUrl: $baseUrl)
            ->get('/transaction/verify/' . urlencode($reference));

        return $this->extractData($response, 'Failed to verify Paystack transaction.');
    }

    public function verifyWebhookSignature(string $rawBody, ?string $signature): bool
    {
        $secret = (string) $this->settingValue('paystack_webhook_secret', config('services.paystack.webhook_secret'));
        if ($secret === '') {
            $secret = (string) $this->settingValue('paystack_secret_key', config('services.paystack.secret_key'));
        }
        if ($secret === '' || !$signature) {
            return false;
        }

        $computed = hash_hmac('sha512', $rawBody, $secret);
        return hash_equals($computed, $signature);
    }

    protected function request(?string $secretKey = null, ?string $baseUrl = null)
    {
        $resolvedBaseUrl = rtrim((string) ($baseUrl ?: $this->settingValue('paystack_base_url', config('services.paystack.base_url', 'https://api.paystack.co'))), '/');
        $secret = $this->normalizeSecretKey(
            (string) ($secretKey ?: $this->settingValue('paystack_secret_key', config('services.paystack.secret_key')))
        );

        return Http::baseUrl($resolvedBaseUrl)
            ->withToken($secret)
            ->acceptJson()
            ->asJson();
    }

    protected function settingsConnection(): string
    {
        return (string) config('billing.platform_settings_connection', 'platform');
    }

    protected function settingValue(string $key, mixed $fallback = null): mixed
    {
        try {
            $connection = $this->settingsConnection();

            if (! Schema::connection($connection)->hasTable('platform_settings')) {
                return $fallback;
            }

            $setting = PlatformSetting::query()
                ->where('key', $key)
                ->where('is_active', true)
                ->first();

            return $setting ? ($setting->value['value'] ?? $fallback) : $fallback;
        } catch (\Throwable) {
            return $fallback;
        }
    }

    protected function extractData(Response $response, string $message): array
    {
        if ($response->failed()) {
            throw new RuntimeException($message);
        }

        $json = $response->json();
        if (!is_array($json) || !($json['status'] ?? false)) {
            throw new RuntimeException((string) ($json['message'] ?? $message));
        }

        $data = $json['data'] ?? null;
        return is_array($data) ? $data : [];
    }

    /**
     * List supported banks / mobile money providers.
     * @param  string  $country  e.g. 'ghana', 'nigeria'
     * @param  string  $type     'nuban', 'mobile_money', or '' for all
     */
    public function listBanks(string $country = 'ghana', string $type = '', ?string $currency = null): array
    {
        $query = ['perPage' => 200];
        if ($currency !== null && $currency !== '') {
            $query['currency'] = strtoupper($currency);
        } else {
            $query['country'] = $country;
        }
        if ($type !== '') {
            $query['type'] = $type;
        }
        $response = $this->request()->get('/bank', $query);
        $json = $response->json();
        return is_array($json['data'] ?? null) ? $json['data'] : [];
    }

    /**
     * Create a transfer recipient (bank account or mobile money).
     * @param  array{type: string, name: string, account_number: string, bank_code: string, currency?: string}  $payload
     */
    public function createTransferRecipient(array $payload): array
    {
        $response = $this->request()->post('/transferrecipient', $payload);
        return $this->extractData($response, 'Failed to create transfer recipient.');
    }

    /**
     * Initiate a transfer to a recipient.
     * @param  array{source: string, amount: int, recipient: string, reason?: string, reference?: string}  $payload
     */
    public function initiateTransfer(array $payload): array
    {
        $response = $this->request()->post('/transfer', $payload);
        return $this->extractData($response, 'Failed to initiate transfer.');
    }

    /**
     * Verify a transfer by reference.
     */
    public function verifyTransfer(string $reference): array
    {
        $response = $this->request()->get('/transfer/verify/' . urlencode($reference));
        return $this->extractData($response, 'Failed to verify transfer.');
    }

    protected function normalizeSecretKey(string $secret): string
    {
        $normalized = trim($secret);

        if (str_starts_with(strtolower($normalized), 'bearer ')) {
            $normalized = trim(substr($normalized, 7));
        }

        return $normalized;
    }
}