using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using BTCPayServer.Data;
using BTCPayServer.Models;
using BTCPayServer.Models.InvoicingModels;
using BTCPayServer.Rating;
using BTCPayServer.Services;
using BTCPayServer.Services.Invoices;
using BTCPayServer.Services.Rates;
using NBitcoin;
using NBitpayClient;
using Newtonsoft.Json;

namespace BTCPayServer.Payments.Bitcoin
{
    public class BitcoinLikePaymentHandler : PaymentMethodHandlerBase<DerivationSchemeSettings, BTCPayNetwork>
    {
        ExplorerClientProvider _ExplorerProvider;
        private readonly BTCPayNetworkProvider _networkProvider;
        private IFeeProviderFactory _FeeRateProviderFactory;
        private Services.Wallets.BTCPayWalletProvider _WalletProvider;

        public BitcoinLikePaymentHandler(ExplorerClientProvider provider,
            BTCPayNetworkProvider networkProvider,
            IFeeProviderFactory feeRateProviderFactory,
            Services.Wallets.BTCPayWalletProvider walletProvider)
        {
            _ExplorerProvider = provider;
            _networkProvider = networkProvider;
            _FeeRateProviderFactory = feeRateProviderFactory;
            _WalletProvider = walletProvider;
        }

        class Prepare
        {
            public Task<FeeRate> GetFeeRate;
            public Task<BitcoinAddress> ReserveAddress;
        }

        public override void PreparePaymentModel(PaymentModel model, InvoiceResponse invoiceResponse)
        {
            var paymentMethodId = new PaymentMethodId(model.CryptoCode, PaymentTypes.BTCLike);

            var cryptoInfo = invoiceResponse.CryptoInfo.First(o => o.GetpaymentMethodId() == paymentMethodId);
            var network = _networkProvider.GetNetwork<BTCPayNetwork>(model.CryptoCode);
            model.IsLightning = false;
            model.PaymentMethodName = GetPaymentMethodName(network);
            model.CryptoImage = GetCryptoImage(network);
            model.InvoiceBitcoinUrl = cryptoInfo.PaymentUrls.BIP21;
            model.InvoiceBitcoinUrlQR = cryptoInfo.PaymentUrls.BIP21;
        }

        public override string GetCryptoImage(PaymentMethodId paymentMethodId)
        {
            var network = _networkProvider.GetNetwork<BTCPayNetwork>(paymentMethodId.CryptoCode);
            return GetCryptoImage(network);
        }

        private string GetCryptoImage(BTCPayNetworkBase network)
        {
            return network.CryptoImagePath;
        }

        public override string GetPaymentMethodName(PaymentMethodId paymentMethodId)
        {
            var network = _networkProvider.GetNetwork<BTCPayNetwork>(paymentMethodId.CryptoCode);
            return GetPaymentMethodName(network);
        }

        public override async Task<string> IsPaymentMethodAllowedBasedOnInvoiceAmount(StoreBlob storeBlob,
            Dictionary<CurrencyPair, Task<RateResult>> rate, Money amount, PaymentMethodId paymentMethodId)
        {
            if (storeBlob.OnChainMinValue == null)
            {
                return null;
            }

            var limitValueRate =
                await rate[new CurrencyPair(paymentMethodId.CryptoCode, storeBlob.OnChainMinValue.Currency)];

            if (limitValueRate.BidAsk != null)
            {
                var limitValueCrypto = Money.Coins(storeBlob.OnChainMinValue.Value / limitValueRate.BidAsk.Bid);

                if (amount > limitValueCrypto)
                {
                    return null;
                }
            }

            return "The amount of the invoice is too low to be paid on chain";
        }

        public override IEnumerable<PaymentMethodId> GetSupportedPaymentMethods()
        {
            return _networkProvider.GetAll()
                .Select(network => new PaymentMethodId(network.CryptoCode, PaymentTypes.BTCLike));
        }

        public override CryptoPaymentData GetCryptoPaymentData(PaymentEntity paymentEntity)
        {
#pragma warning disable CS0618

            BitcoinLikePaymentData paymentData;
            if (string.IsNullOrEmpty(paymentEntity.CryptoPaymentDataType))
            {
                // For invoices created when CryptoPaymentDataType was not existing, we just consider that it is a RBFed payment for safety
                paymentData = new BitcoinLikePaymentData();
                paymentData.Outpoint = paymentEntity.Outpoint;
                paymentData.Output = paymentEntity.Output;
                paymentData.RBF = true;
                paymentData.ConfirmationCount = 0;
                paymentData.Legacy = true;
                return paymentData;
            }

            paymentData =
                JsonConvert.DeserializeObject<BitcoinLikePaymentData>(paymentEntity.CryptoPaymentData);
            // legacy
            paymentData.Output = paymentEntity.Output;
            paymentData.Outpoint = paymentEntity.Outpoint;
#pragma warning restore CS0618
            return paymentData;
        }

        private string GetPaymentMethodName(BTCPayNetworkBase network)
        {
            return network.DisplayName;
        }


        public override object PreparePayment(DerivationSchemeSettings supportedPaymentMethod, StoreData store,
            BTCPayNetworkBase network)
        {
            return new Prepare()
            {
                GetFeeRate = _FeeRateProviderFactory.CreateFeeProvider(network).GetFeeRateAsync(),
                ReserveAddress = _WalletProvider.GetWallet(network)
                    .ReserveAddressAsync(supportedPaymentMethod.AccountDerivation)
            };
        }

        public override string PrettyDescription => "On-Chain";
        public override PaymentTypes PaymentType => PaymentTypes.BTCLike;

        public override async Task<IPaymentMethodDetails> CreatePaymentMethodDetails(
            DerivationSchemeSettings supportedPaymentMethod, PaymentMethod paymentMethod, StoreData store,
            BTCPayNetwork network, object preparePaymentObject)
        {
            if (!_ExplorerProvider.IsAvailable(network))
                throw new PaymentMethodUnavailableException($"Full node not available");
            var prepare = (Prepare)preparePaymentObject;
            Payments.Bitcoin.BitcoinLikeOnChainPaymentMethod onchainMethod =
                new Payments.Bitcoin.BitcoinLikeOnChainPaymentMethod();
            onchainMethod.NetworkFeeMode = store.GetStoreBlob().NetworkFeeMode;
            onchainMethod.FeeRate = await prepare.GetFeeRate;
            switch (onchainMethod.NetworkFeeMode)
            {
                case NetworkFeeMode.Always:
                    onchainMethod.NextNetworkFee = onchainMethod.FeeRate.GetFee(100); // assume price for 100 bytes
                    break;
                case NetworkFeeMode.Never:
                case NetworkFeeMode.MultiplePaymentsOnly:
                    onchainMethod.NextNetworkFee = Money.Zero;
                    break;
            }
            onchainMethod.DepositAddress = (await prepare.ReserveAddress).ToString();
            return onchainMethod;
        }

        public override void PrepareInvoiceDto(InvoiceResponse invoiceResponse, InvoiceEntity invoiceEntity,
            InvoiceCryptoInfo invoiceCryptoInfo,
            PaymentMethodAccounting accounting, PaymentMethod info)
        {
            var scheme = info.Network.UriScheme;

            var minerInfo = new MinerFeeInfo();
            minerInfo.TotalFee = accounting.NetworkFee.Satoshi;
            minerInfo.SatoshiPerBytes = ((BitcoinLikeOnChainPaymentMethod)info.GetPaymentMethodDetails()).FeeRate
                .GetFee(1).Satoshi;
            invoiceResponse.MinerFees.TryAdd(invoiceCryptoInfo.CryptoCode, minerInfo);
            invoiceCryptoInfo.PaymentUrls = new NBitpayClient.InvoicePaymentUrls()
            {
                BIP21 = $"{scheme}:{invoiceCryptoInfo.Address}?amount={invoiceCryptoInfo.Due}",
            };

#pragma warning disable 618
            if (info.CryptoCode == "BTC")
            {
                invoiceResponse.BTCPrice = invoiceCryptoInfo.Price;
                invoiceResponse.Rate = invoiceCryptoInfo.Rate;
                invoiceResponse.ExRates = invoiceCryptoInfo.ExRates;
                invoiceResponse.BitcoinAddress = invoiceCryptoInfo.Address;
                invoiceResponse.BTCPaid = invoiceCryptoInfo.Paid;
                invoiceResponse.BTCDue = invoiceCryptoInfo.Due;
                invoiceResponse.PaymentUrls = invoiceCryptoInfo.PaymentUrls;
            }
#pragma warning restore 618
        }
    }
}