using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Microsoft.Extensions.Logging;
using System.Net;
using System.Threading.Tasks;
using NBitcoin;
using System.Text;
using CommandLine;

namespace BTCPayServer.Configuration
{
    public class DefaultConfiguration : StandardConfiguration.DefaultConfiguration
    {
        protected override CommandLineApplication CreateCommandLineApplicationCore()
        {
            CommandLineApplication app = new CommandLineApplication(true)
            {
                FullName = "BTCPay\r\nOpen source, self-hosted payment processor.",
                Name = "BTCPay"
            };
            app.HelpOption("-? | -h | --help");
            app.Option("-n | --network", $"Set the network among ({NetworkInformation.ToStringAll()}) (default: {Network.Main.ToString()})", CommandOptionType.SingleValue);
            app.Option("--testnet | -testnet", $"Use testnet", CommandOptionType.BoolValue);
            app.Option("--regtest | -regtest", $"Use regtest", CommandOptionType.BoolValue);
            app.Option("--postgres", $"Connection string to postgres database (default: sqlite is used)", CommandOptionType.SingleValue);
            foreach (var network in new BTCPayNetworkProvider(Network.Main).GetAll())
            {
                app.Option($"--{network.CryptoCode}explorerurl", $"Url of the NBxplorer for {network.CryptoCode} (default: If no explorer is specified, the default for Bitcoin will be selected)", CommandOptionType.SingleValue);
                app.Option($"--{network.CryptoCode}explorercookiefile", $"Path to the cookie file (default: Default setting of NBXplorer for the network)", CommandOptionType.SingleValue);
            }
            app.Option("--externalurl", $"The expected external url of this service, to use if BTCPay is behind a reverse proxy (default: empty, use the incoming HTTP request to figure out)", CommandOptionType.SingleValue);
            return app;
        }

        public override string EnvironmentVariablePrefix => "BTCPAY_";

        protected override string GetDefaultDataDir(IConfiguration conf)
        {
            return GetNetwork(conf).DefaultDataDirectory;
        }

        protected override string GetDefaultConfigurationFile(IConfiguration conf)
        {
            var network = GetNetwork(conf);
            var dataDir = conf["datadir"];
            if (dataDir == null)
                return network.DefaultConfigurationFile;
            var fileName = Path.GetFileName(network.DefaultConfigurationFile);
            return Path.Combine(dataDir, fileName);
        }

        public static NetworkInformation GetNetwork(IConfiguration conf)
        {
            var network = conf.GetOrDefault<string>("network", null);
            if (network != null)
            {
                var info = NetworkInformation.GetNetworkByName(network);
                if (info == null)
                    throw new ConfigException($"Invalid network name {network}");
                return info;
            }

            var net = conf.GetOrDefault<bool>("regtest", false) ? Network.RegTest :
                        conf.GetOrDefault<bool>("testnet", false) ? Network.TestNet : Network.Main;

            return NetworkInformation.GetNetworkByName(net.Name);
        }

        protected override string GetDefaultConfigurationFileTemplate(IConfiguration conf)
        {
            var network = GetNetwork(conf);
            StringBuilder builder = new StringBuilder();
            builder.AppendLine("### Global settings ###");
            builder.AppendLine("#testnet=0");
            builder.AppendLine("#regtest=0");
            builder.AppendLine();
            builder.AppendLine("### Server settings ###");
            builder.AppendLine("#port=" + network.DefaultPort);
            builder.AppendLine("#bind=127.0.0.1");
            builder.AppendLine();
            builder.AppendLine("### Database ###");
            builder.AppendLine("#postgres=User ID=root;Password=myPassword;Host=localhost;Port=5432;Database=myDataBase;");
            builder.AppendLine();
            builder.AppendLine("### NBXplorer settings ###");
            foreach (var n in new BTCPayNetworkProvider(network.Network).GetAll())
            {
                var nbxplorer = NBXplorer.Configuration.NetworkInformation.GetNetworkByName(n.NBitcoinNetwork.ToString());
                builder.AppendLine($"#{n.CryptoCode}.explorer.url={nbxplorer.GetDefaultExplorerUrl()}");
                builder.AppendLine($"#{n.CryptoCode}.explorer.cookiefile={ nbxplorer.GetDefaultCookieFile()}");
            }
            return builder.ToString();
        }



        protected override IPEndPoint GetDefaultEndpoint(IConfiguration conf)
        {
            return new IPEndPoint(IPAddress.Parse("127.0.0.1"), GetNetwork(conf).DefaultPort);
        }
    }
}