<?php

namespace App\Services\Payments\Providers;

use App\Contracts\Payments\PaymentProviderContract;
use App\Models\Plan;
use App\Models\Subscription;
use App\Models\User;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\Log;

class CryptoProvider implements PaymentProviderContract
{
    protected array $config;

    protected array $supportedCryptos = [
        'BTC' => [
            'name' => 'Bitcoin',
            'network' => 'mainnet',
            'confirmations_required' => 3,
            'block_time_minutes' => 10,
        ],
        'ETH' => [
            'name' => 'Ethereum',
            'network' => 'mainnet',
            'confirmations_required' => 12,
            'block_time_minutes' => 12,
        ],
        'USDT' => [
            'name' => 'Tether',
            'network' => 'ethereum',
            'confirmations_required' => 12,
            'block_time_minutes' => 12,
        ],
        'USDC' => [
            'name' => 'USD Coin',
            'network' => 'ethereum',
            'confirmations_required' => 12,
            'block_time_minutes' => 12,
        ],
        'LTC' => [
            'name' => 'Litecoin',
            'network' => 'mainnet',
            'confirmations_required' => 6,
            'block_time_minutes' => 2.5,
        ],
    ];

    public function __construct(array $config = [])
    {
        $defaultConfig = [
            'webhook_secret' => null,
            'success_url' => null,
            'cancel_url' => null,
            'confirmation_timeout_minutes' => 30,
            'exchange_rate_provider' => 'coingecko', // or 'binance'
        ];

        // Try to get config values if Laravel is available
        try {
            if (function_exists('config')) {
                $defaultConfig['webhook_secret'] = config('payments.crypto.webhook_secret');
            }
            if (function_exists('route')) {
                $defaultConfig['success_url'] = route('payment.success');
                $defaultConfig['cancel_url'] = route('payment.cancel');
            }
        } catch (\Exception $e) {
            // Laravel not available, keep defaults
        }

        $this->config = array_merge($defaultConfig, $config);
    }

    public function getName(): string
    {
        return 'crypto';
    }

    public function isActive(): bool
    {
        return ! empty($this->config['webhook_secret']);
    }

    public function createSubscription(User $user, Plan $plan, array $options = []): array
    {
        try {
            $crypto = $options['crypto'] ?? 'BTC';
            $usdAmount = $plan->price;

            // Get current exchange rate
            $cryptoAmount = $this->convertUsdToCrypto($usdAmount, $crypto);

            // Generate payment address
            $paymentAddress = $this->generatePaymentAddress($crypto);

            // Create payment record
            $paymentId = $this->createPaymentRecord([
                'user_id' => $user->id,
                'plan_id' => $plan->id,
                'crypto' => $crypto,
                'usd_amount' => $usdAmount,
                'crypto_amount' => $cryptoAmount,
                'address' => $paymentAddress,
                'status' => 'pending',
                'expires_at' => now()->addMinutes($this->config['confirmation_timeout_minutes']),
            ]);

            return [
                'provider_subscription_id' => $paymentId,
                'status' => 'pending_payment',
                'payment_address' => $paymentAddress,
                'crypto' => $crypto,
                'crypto_amount' => $cryptoAmount,
                'usd_amount' => $usdAmount,
                'expires_at' => now()->addMinutes($this->config['confirmation_timeout_minutes'])->toISOString(),
                'type' => 'crypto_payment',
            ];

        } catch (\Exception $e) {
            Log::error('Crypto subscription creation failed', [
                'user_id' => $user->id,
                'plan_id' => $plan->id,
                'error' => $e->getMessage(),
            ]);
            throw $e;
        }
    }

    public function cancelSubscription(Subscription $subscription, string $reason = ''): bool
    {
        try {
            // For crypto, we just mark as cancelled since there's no external subscription
            $paymentId = $subscription->provider_subscription_id;

            $this->updatePaymentRecord($paymentId, [
                'status' => 'cancelled',
                'cancelled_at' => now(),
                'cancellation_reason' => $reason,
            ]);

            return true;

        } catch (\Exception $e) {
            Log::error('Crypto subscription cancellation failed', [
                'subscription_id' => $subscription->id,
                'error' => $e->getMessage(),
            ]);
            throw $e;
        }
    }

    public function updateSubscription(Subscription $subscription, Plan $newPlan): array
    {
        try {
            // Cancel old payment and create new one for upgraded plan
            $this->cancelSubscription($subscription, 'Plan upgrade');

            $user = $subscription->user;

            return $this->createSubscription($user, $newPlan);

        } catch (\Exception $e) {
            Log::error('Crypto subscription update failed', [
                'subscription_id' => $subscription->id,
                'new_plan_id' => $newPlan->id,
                'error' => $e->getMessage(),
            ]);
            throw $e;
        }
    }

    public function pauseSubscription(Subscription $subscription): bool
    {
        // Crypto subscriptions don't support pausing in the traditional sense
        // We could implement a temporary suspension logic here if needed
        return false;
    }

    public function resumeSubscription(Subscription $subscription): bool
    {
        // Crypto subscriptions don't support pausing
        return false;
    }

    public function getSubscriptionDetails(string $providerSubscriptionId): array
    {
        try {
            $payment = $this->getPaymentRecord($providerSubscriptionId);

            return [
                'id' => $payment['id'],
                'status' => $payment['status'],
                'crypto' => $payment['crypto'],
                'usd_amount' => $payment['usd_amount'],
                'crypto_amount' => $payment['crypto_amount'],
                'address' => $payment['address'],
                'confirmations' => $payment['confirmations'],
                'created_at' => $payment['created_at'],
                'expires_at' => $payment['expires_at'],
                'confirmed_at' => $payment['confirmed_at'],
            ];

        } catch (\Exception $e) {
            Log::error('Crypto subscription details retrieval failed', [
                'subscription_id' => $providerSubscriptionId,
                'error' => $e->getMessage(),
            ]);
            throw $e;
        }
    }

    public function createCheckoutSession(User $user, Plan $plan, array $options = []): array
    {
        return $this->createSubscription($user, $plan, $options);
    }

    public function createCustomerPortalSession(User $user): array
    {
        // Crypto doesn't have customer portals
        return [
            'portal_url' => route('dashboard'),
            'message' => 'Crypto payments are managed through the dashboard',
        ];
    }

    public function processWebhook(Request $request): array
    {
        try {
            $payload = $request->getContent();
            $webhookData = json_decode($payload, true);

            if (! $this->validateWebhook($request)) {
                throw new \Exception('Invalid webhook signature');
            }

            $eventType = $webhookData['type'] ?? 'unknown';
            $result = [
                'event_type' => $eventType,
                'processed' => false,
                'data' => [],
            ];

            switch ($eventType) {
                case 'payment_received':
                    $result = $this->handlePaymentReceived($webhookData);
                    break;
                case 'payment_confirmed':
                    $result = $this->handlePaymentConfirmed($webhookData);
                    break;
                case 'payment_expired':
                    $result = $this->handlePaymentExpired($webhookData);
                    break;
                default:
                    Log::info('Unhandled crypto webhook event', ['event_type' => $eventType]);
            }

            return $result;

        } catch (\Exception $e) {
            Log::error('Crypto webhook processing failed', [
                'error' => $e->getMessage(),
                'payload' => $request->getContent(),
            ]);
            throw $e;
        }
    }

    public function validateWebhook(Request $request): bool
    {
        try {
            $signature = $request->header('X-Signature');
            $payload = $request->getContent();

            if (! $signature || ! $this->config['webhook_secret']) {
                return false;
            }

            $expectedSignature = hash_hmac('sha256', $payload, $this->config['webhook_secret']);

            return hash_equals($signature, $expectedSignature);

        } catch (\Exception $e) {
            Log::warning('Crypto webhook validation failed', [
                'error' => $e->getMessage(),
            ]);

            return false;
        }
    }

    public function getConfiguration(): array
    {
        return $this->config;
    }

    public function syncSubscriptionStatus(Subscription $subscription): array
    {
        return $this->getSubscriptionDetails($subscription->provider_subscription_id);
    }

    public function getPaymentMethodDetails(string $paymentMethodId): array
    {
        try {
            $payment = $this->getPaymentRecord($paymentMethodId);

            return [
                'id' => $payment['id'],
                'type' => 'crypto_address',
                'crypto' => $payment['crypto'],
                'address' => $payment['address'],
                'network' => $this->supportedCryptos[$payment['crypto']]['network'] ?? 'unknown',
                'created_at' => $payment['created_at'],
            ];

        } catch (\Exception $e) {
            Log::error('Crypto payment method details retrieval failed', [
                'payment_method_id' => $paymentMethodId,
                'error' => $e->getMessage(),
            ]);
            throw $e;
        }
    }

    public function processRefund(string $paymentId, float $amount, string $reason = ''): array
    {
        try {
            // Crypto payments are typically not refundable
            // We could implement a manual refund process if needed
            throw new \Exception('Crypto payments are not refundable');
        } catch (\Exception $e) {
            Log::error('Crypto refund processing failed', [
                'payment_id' => $paymentId,
                'amount' => $amount,
                'error' => $e->getMessage(),
            ]);
            throw $e;
        }
    }

    public function getTransactionHistory(User $user, array $filters = []): array
    {
        try {
            $payments = $this->getUserPayments($user->id, $filters);

            $transactions = [];

            foreach ($payments as $payment) {
                $transactions[] = [
                    'id' => $payment['id'],
                    'crypto' => $payment['crypto'],
                    'amount' => $payment['usd_amount'],
                    'crypto_amount' => $payment['crypto_amount'],
                    'status' => $payment['status'],
                    'address' => $payment['address'],
                    'confirmations' => $payment['confirmations'],
                    'created_at' => $payment['created_at'],
                    'confirmed_at' => $payment['confirmed_at'],
                ];
            }

            return $transactions;

        } catch (\Exception $e) {
            Log::error('Crypto transaction history retrieval failed', [
                'user_id' => $user->id,
                'error' => $e->getMessage(),
            ]);
            throw $e;
        }
    }

    public function calculateFees(float $amount): array
    {
        // Crypto fees: 1% network fee + 0.5% service fee
        $networkFee = $amount * 0.01;
        $serviceFee = $amount * 0.005;
        $totalFee = $networkFee + $serviceFee;

        return [
            'fixed_fee' => 0,
            'percentage_fee' => $totalFee,
            'total_fee' => $totalFee,
            'net_amount' => $amount - $totalFee,
        ];
    }

    public function getSupportedCurrencies(): array
    {
        return ['USD']; // We accept USD but process in crypto
    }

    public function supportsRecurring(): bool
    {
        return true; // Through manual renewal
    }

    public function supportsOneTime(): bool
    {
        return true;
    }

    // Helper methods
    public function convertUsdToCrypto(float $usdAmount, string $crypto): float
    {
        $cacheKey = "crypto_rate_{$crypto}_usd";

        return Cache::remember($cacheKey, now()->addMinutes(5), function () use ($usdAmount, $crypto) {
            $rate = $this->getExchangeRate($crypto, 'USD');

            return $usdAmount / $rate;
        });
    }

    protected function getExchangeRate(string $fromCrypto, string $toCurrency): float
    {
        // This would integrate with CoinGecko, Binance, or other exchange rate APIs
        // For now, return mock rates
        $mockRates = [
            'BTC' => 45000.00,  // 1 BTC = $45,000
            'ETH' => 3000.00,   // 1 ETH = $3,000
            'USDT' => 1.00,     // 1 USDT = $1.00
            'USDC' => 1.00,     // 1 USDC = $1.00
            'LTC' => 150.00,    // 1 LTC = $150
        ];

        return $mockRates[$fromCrypto] ?? 1.0;
    }

    protected function generatePaymentAddress(string $crypto): string
    {
        // In a real implementation, this would integrate with a crypto payment processor
        // For now, generate a mock address
        $prefix = [
            'BTC' => 'bc1q',
            'ETH' => '0x',
            'USDT' => '0x',
            'USDC' => '0x',
            'LTC' => 'ltc1',
        ];

        $randomPart = bin2hex(random_bytes(32));

        return ($prefix[$crypto] ?? '0x').substr($randomPart, 0, 40);
    }

    protected function createPaymentRecord(array $data): string
    {
        // In a real implementation, this would save to a database
        // For now, generate a mock ID and cache it
        $paymentId = 'crypto_'.uniqid(more_entropy: true);

        Cache::put("crypto_payment_{$paymentId}", array_merge($data, [
            'id' => $paymentId,
            'created_at' => now()->toISOString(),
            'confirmations' => 0,
        ]), now()->addHours(24));

        return $paymentId;
    }

    protected function getPaymentRecord(string $paymentId): array
    {
        return Cache::get("crypto_payment_{$paymentId}", []);
    }

    protected function updatePaymentRecord(string $paymentId, array $updates): void
    {
        $payment = Cache::get("crypto_payment_{$paymentId}", []);
        if ($payment) {
            $updatedPayment = array_merge($payment, $updates);
            Cache::put("crypto_payment_{$paymentId}", $updatedPayment, now()->addHours(24));
        }
    }

    protected function getUserPayments(int $userId, array $filters = []): array
    {
        // In a real implementation, this would query the database
        // For now, return empty array
        return [];
    }

    protected function confirmPayment(string $paymentId, int $confirmations, string $transactionHash): void
    {
        $this->updatePaymentRecord($paymentId, [
            'status' => 'confirmed',
            'confirmations' => $confirmations,
            'transaction_hash' => $transactionHash,
            'confirmed_at' => now()->toISOString(),
        ]);
    }

    // Webhook handlers
    protected function handlePaymentReceived(array $webhookData): array
    {
        $paymentId = $webhookData['payment_id'];
        $confirmations = $webhookData['confirmations'] ?? 0;
        $transactionHash = $webhookData['transaction_hash'] ?? '';

        $this->confirmPayment($paymentId, $confirmations, $transactionHash);

        return [
            'event_type' => 'payment_received',
            'processed' => true,
            'data' => [
                'payment_id' => $paymentId,
                'confirmations' => $confirmations,
                'transaction_hash' => $transactionHash,
            ],
        ];
    }

    protected function handlePaymentConfirmed(array $webhookData): array
    {
        $paymentId = $webhookData['payment_id'];

        // Mark as fully confirmed
        $this->updatePaymentRecord($paymentId, [
            'status' => 'completed',
        ]);

        return [
            'event_type' => 'payment_confirmed',
            'processed' => true,
            'data' => [
                'payment_id' => $paymentId,
            ],
        ];
    }

    protected function handlePaymentExpired(array $webhookData): array
    {
        $paymentId = $webhookData['payment_id'];

        $this->updatePaymentRecord($paymentId, [
            'status' => 'expired',
        ]);

        return [
            'event_type' => 'payment_expired',
            'processed' => true,
            'data' => [
                'payment_id' => $paymentId,
            ],
        ];
    }

    // Additional interface methods
    public function getSubscriptionMetadata(Subscription $subscription): array
    {
        $payment = $this->getPaymentRecord($subscription->provider_subscription_id);

        return $payment['metadata'] ?? [];
    }

    public function updateSubscriptionMetadata(Subscription $subscription, array $metadata): bool
    {
        $paymentId = $subscription->provider_subscription_id;
        $payment = $this->getPaymentRecord($paymentId);

        if ($payment) {
            $this->updatePaymentRecord($paymentId, ['metadata' => $metadata]);

            return true;
        }

        return false;
    }

    public function startTrial(Subscription $subscription, int $trialDays): bool
    {
        // Crypto subscriptions don't have trials in the traditional sense
        return false;
    }

    public function applyCoupon(Subscription $subscription, string $couponCode): array
    {
        // Crypto doesn't support coupons natively
        throw new \Exception('Coupons not supported for crypto payments');
    }

    public function removeCoupon(Subscription $subscription): bool
    {
        return false; // No coupons to remove
    }

    public function getUpcomingInvoice(Subscription $subscription): array
    {
        // Crypto subscriptions don't have invoices
        return [
            'amount_due' => 0,
            'currency' => 'USD',
            'next_payment_date' => null,
        ];
    }

    public function retryFailedPayment(Subscription $subscription): array
    {
        // Crypto payments can't be retried automatically
        // User would need to make a new payment
        return $this->syncSubscriptionStatus($subscription);
    }

    public function canModifySubscription(Subscription $subscription): bool
    {
        try {
            $details = $this->getSubscriptionDetails($subscription->provider_subscription_id);

            return in_array($details['status'], ['pending_payment', 'confirmed', 'completed']);
        } catch (\Exception $e) {
            return false;
        }
    }

    public function getCancellationTerms(Subscription $subscription): array
    {
        return [
            'immediate_cancellation' => true,
            'refund_policy' => 'non_refundable',
            'cancellation_effective' => 'immediately',
            'billing_cycle_proration' => false,
        ];
    }

    public function exportSubscriptionData(Subscription $subscription): array
    {
        return [
            'provider' => 'crypto',
            'provider_subscription_id' => $subscription->provider_subscription_id,
            'data' => $subscription->provider_data,
        ];
    }

    public function importSubscriptionData(User $user, array $subscriptionData): array
    {
        throw new \Exception('Import to crypto payments not implemented');
    }
}
