BTCPayServerPlugins/Plugins/BTCPayServer.Plugins.Blink/BlinkLightningConnectionStringHandler.cs

#nullable enable
using System;
using System.Linq;
using System.Net.Http;
using BTCPayServer.HostedServices;
using BTCPayServer.Lightning;
using Network = NBitcoin.Network;

namespace BTCPayServer.Plugins.Blink;

public class BlinkLightningConnectionStringHandler : ILightningConnectionStringHandler
{
    private readonly IHttpClientFactory _httpClientFactory;
    private readonly NBXplorerDashboard _nbXplorerDashboard;

    public BlinkLightningConnectionStringHandler(IHttpClientFactory httpClientFactory,
        NBXplorerDashboard nbXplorerDashboard)
    {
        _httpClientFactory = httpClientFactory;
        _nbXplorerDashboard = nbXplorerDashboard;
    }


    public ILightningClient? Create(string connectionString, Network network, out string? error)
    {
        var kv = LightningConnectionStringHelper.ExtractValues(connectionString, out var type);
        if (type != "blink")
        {
            error = null;
            return null;
        }

        if (!kv.TryGetValue("server", out var server))
        {
            error = $"The key 'server' is mandatory for blink connection strings";
            return null;
        }

        if (!Uri.TryCreate(server, UriKind.Absolute, out var uri)
            || uri.Scheme != "http" && uri.Scheme != "https")
        {
            error = "The key 'server' should be an URI starting by http:// or https://";
            return null;
        }

        bool allowInsecure = false;
        if (kv.TryGetValue("allowinsecure", out var allowinsecureStr))
        {
            var allowedValues = new[] {"true", "false"};
            if (!allowedValues.Any(v => v.Equals(allowinsecureStr, StringComparison.OrdinalIgnoreCase)))
            {
                error = "The key 'allowinsecure' should be true or false";
                return null;
            }

            allowInsecure = allowinsecureStr.Equals("true", StringComparison.OrdinalIgnoreCase);
        }

        if (!LightningConnectionStringHelper.VerifySecureEndpoint(uri, allowInsecure))
        {
            error = "The key 'allowinsecure' is false, but server's Uri is not using https";
            return null;
        }

        if (!kv.TryGetValue("api-key", out var apiKey))
        {
            error = "The key 'api-key' is not found";
            return null;
        }

        error = null;

        var client = _httpClientFactory.CreateClient();

        client.DefaultRequestHeaders.Add("X-Api-Key", apiKey);

        client.BaseAddress = uri;

        kv.TryGetValue("wallet-id", out var walletId);
        var bclient = new BlinkLightningClient(apiKey, uri, walletId, network, _nbXplorerDashboard, client);
        (Network Network, string DefaultWalletId) res;
        try
        {
            res = bclient.GetNetworkAndDefaultWallet().GetAwaiter().GetResult();
            if (res.Network != network)
            {
                error = $"The wallet is not on the right network ({res.Network.Name} instead of {network.Name})";
                return null;
            }

            if (walletId is null && string.IsNullOrEmpty(res.DefaultWalletId))
            {
                error = $"The wallet-id is not set and no default wallet is set";
                return null;
            }
        }
        catch (Exception e)
        {
            error = $"Invalid server or api key";
            return null;
        }

        if (walletId is null)
        {
            bclient.WalletId = res.DefaultWalletId;
        }
        else
        {
            try
            {
                bclient.GetBalance().GetAwaiter().GetResult();
                if (!bclient.WalletCurrency.Equals("btc", StringComparison.InvariantCultureIgnoreCase))
                {
                    error = "Cannot use a non BTC denominated wallet";
                    return null;
                    
                }
            }
            catch (Exception e)
            {
                error = "Invalid wallet id";
                return null;
            }
        }

        return bclient;
    }
}