using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using BTCPayServer.Abstractions.Contracts;
using BTCPayServer.Client.Models;
using BTCPayServer.Configuration;
using BTCPayServer.Data;
using BTCPayServer.Logging;
using BTCPayServer.Payments;
using BTCPayServer.Services;
using BTCPayServer.Services.Stores;
using DBriize;
using DBriize.Utils;
using Microsoft.AspNetCore.Identity;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using NBitcoin.DataEncoders;
using NBXplorer;
using Newtonsoft.Json.Linq;

namespace BTCPayServer.Hosting
{
    public class MigrationStartupTask : IStartupTask
    {
        private readonly ApplicationDbContextFactory _DBContextFactory;
        private readonly StoreRepository _StoreRepository;
        private readonly BTCPayNetworkProvider _NetworkProvider;
        private readonly SettingsRepository _Settings;
        private readonly UserManager<ApplicationUser> _userManager;
        public MigrationStartupTask(
            BTCPayNetworkProvider networkProvider,
            StoreRepository storeRepository,
            ApplicationDbContextFactory dbContextFactory,
            UserManager<ApplicationUser> userManager,
            SettingsRepository settingsRepository)
        {
            _DBContextFactory = dbContextFactory;
            _StoreRepository = storeRepository;
            _NetworkProvider = networkProvider;
            _Settings = settingsRepository;
            _userManager = userManager;
        }
        public async Task ExecuteAsync(CancellationToken cancellationToken = default)
        {
            try
            {
                await Migrate(cancellationToken);
                var settings = (await _Settings.GetSettingAsync<MigrationSettings>()) ?? new MigrationSettings();
                if (!settings.PaymentMethodCriteria)
                {
                    await MigratePaymentMethodCriteria();
                    settings.PaymentMethodCriteria = true;
                    await _Settings.UpdateSetting(settings);
                }
                if (!settings.DeprecatedLightningConnectionStringCheck)
                {
                    await DeprecatedLightningConnectionStringCheck();
                    settings.DeprecatedLightningConnectionStringCheck = true;
                    await _Settings.UpdateSetting(settings);
                }
                if (!settings.UnreachableStoreCheck)
                {
                    await UnreachableStoreCheck();
                    settings.UnreachableStoreCheck = true;
                    await _Settings.UpdateSetting(settings);
                }
                if (!settings.ConvertMultiplierToSpread)
                {
                    await ConvertMultiplierToSpread();
                    settings.ConvertMultiplierToSpread = true;
                    await _Settings.UpdateSetting(settings);
                }
                if (!settings.ConvertNetworkFeeProperty)
                {
                    await ConvertNetworkFeeProperty();
                    settings.ConvertNetworkFeeProperty = true;
                    await _Settings.UpdateSetting(settings);
                }
                if (!settings.ConvertCrowdfundOldSettings)
                {
                    await ConvertCrowdfundOldSettings();
                    settings.ConvertCrowdfundOldSettings = true;
                    await _Settings.UpdateSetting(settings);
                }
                if (!settings.ConvertWalletKeyPathRoots)
                {
                    await ConvertConvertWalletKeyPathRoots();
                    settings.ConvertWalletKeyPathRoots = true;
                    await _Settings.UpdateSetting(settings);
                }
                if (!settings.CheckedFirstRun)
                {
                    var themeSettings = await _Settings.GetSettingAsync<ThemeSettings>() ?? new ThemeSettings();
                    var admin = await _userManager.GetUsersInRoleAsync(Roles.ServerAdmin);
                    themeSettings.FirstRun = admin.Count == 0;
                    await _Settings.UpdateSetting(themeSettings);
                    settings.CheckedFirstRun = true;
                    await _Settings.UpdateSetting(settings);
                }

                if (!settings.TransitionToStoreBlobAdditionalData)
                {
                    await TransitionToStoreBlobAdditionalData();
                    settings.TransitionToStoreBlobAdditionalData = true;
                    await _Settings.UpdateSetting(settings);
                }
            }
            catch (Exception ex)
            {
                Logs.PayServer.LogError(ex, "Error on the MigrationStartupTask");
                throw;
            }
        }

        private async Task TransitionToStoreBlobAdditionalData()
        {
            await using var ctx = _DBContextFactory.CreateContext();
            foreach (var store in await ctx.Stores.AsQueryable().ToArrayAsync())
            {
                var blob = store.GetStoreBlob();
                blob.AdditionalData.Remove("walletKeyPathRoots");
                blob.AdditionalData.Remove("onChainMinValue");
                blob.AdditionalData.Remove("lightningMaxValue");
                blob.AdditionalData.Remove("networkFeeDisabled");
                blob.AdditionalData.Remove("rateRules");
                store.SetStoreBlob(blob);
            }

            await ctx.SaveChangesAsync();
        }

        private async Task Migrate(CancellationToken cancellationToken)
        {
            using (CancellationTokenSource timeout = new CancellationTokenSource(10_000))
            using (CancellationTokenSource cts = CancellationTokenSource.CreateLinkedTokenSource(timeout.Token, cancellationToken))
            {
retry:
                try
                {
                    await _DBContextFactory.CreateContext().Database.MigrateAsync();
                }
                // Starting up
                catch when (!cts.Token.IsCancellationRequested)
                {
                    try
                    {
                        await Task.Delay(1000, cts.Token);
                    }
                    catch { }
                    goto retry;
                }
            }
        }

        private async Task ConvertConvertWalletKeyPathRoots()
        {
            bool save = false;
            using (var ctx = _DBContextFactory.CreateContext())
            {
                foreach (var store in await ctx.Stores.AsQueryable().ToArrayAsync())
                {
#pragma warning disable CS0618 // Type or member is obsolete
                    var blob = store.GetStoreBlob();

                    if (blob.AdditionalData.TryGetValue("walletKeyPathRoots", out var walletKeyPathRootsJToken))
                    {
                        var walletKeyPathRoots = walletKeyPathRootsJToken.ToObject<Dictionary<string, string>>();

                        if (!(walletKeyPathRoots?.Any() is true))
                            continue;
                        foreach (var scheme in store.GetSupportedPaymentMethods(_NetworkProvider)
                            .OfType<DerivationSchemeSettings>())
                        {
                            if (walletKeyPathRoots.TryGetValue(scheme.PaymentId.ToString().ToLowerInvariant(),
                                out var root))
                            {
                                scheme.AccountKeyPath = new NBitcoin.KeyPath(root);
                                store.SetSupportedPaymentMethod(scheme);
                                save = true;
                            }
                        }

                        blob.AdditionalData.Remove("walletKeyPathRoots");
                        store.SetStoreBlob(blob);
                    }
#pragma warning restore CS0618 // Type or member is obsolete
                }
                if (save)
                    await ctx.SaveChangesAsync();
            }
        }

        private async Task ConvertCrowdfundOldSettings()
        {
            using (var ctx = _DBContextFactory.CreateContext())
            {
                foreach (var app in await ctx.Apps.Where(a => a.AppType == "Crowdfund").ToArrayAsync())
                {
                    var settings = app.GetSettings<Services.Apps.CrowdfundSettings>();
#pragma warning disable CS0618 // Type or member is obsolete
                    if (settings.UseAllStoreInvoices)
#pragma warning restore CS0618 // Type or member is obsolete
                    {
                        app.TagAllInvoices = true;
                    }
                }
                await ctx.SaveChangesAsync();
            }
        }

        private async Task MigratePaymentMethodCriteria()
        {
            using (var ctx = _DBContextFactory.CreateContext())
            {
                foreach (var store in await ctx.Stores.AsQueryable().ToArrayAsync())
                {
                    var blob = store.GetStoreBlob();

                    CurrencyValue onChainMinValue = null;
                    CurrencyValue lightningMaxValue = null;
                    if (blob.AdditionalData.TryGetValue("onChainMinValue", out var onChainMinValueJToken))
                    {
                        CurrencyValue.TryParse(onChainMinValueJToken.Value<string>(), out onChainMinValue);
                        blob.AdditionalData.Remove("onChainMinValue");
                    }
                    if (blob.AdditionalData.TryGetValue("lightningMaxValue", out var lightningMaxValueJToken))
                    {
                        CurrencyValue.TryParse(lightningMaxValueJToken.Value<string>(), out lightningMaxValue);
                        blob.AdditionalData.Remove("lightningMaxValue");
                    }
                    blob.PaymentMethodCriteria =  store.GetEnabledPaymentIds(_NetworkProvider).Select(paymentMethodId=>
                    {
                        var matchedFromBlob =
                            blob.PaymentMethodCriteria?.SingleOrDefault(criteria => criteria.PaymentMethod == paymentMethodId && criteria.Value != null);
                        return matchedFromBlob switch
                        {
                            null when paymentMethodId.PaymentType == LightningPaymentType.Instance &&
                                      lightningMaxValue != null => new PaymentMethodCriteria()
                            {
                                Above = false, PaymentMethod = paymentMethodId, Value = lightningMaxValue
                            },
                            null when paymentMethodId.PaymentType == BitcoinPaymentType.Instance &&
                                      onChainMinValue != null => new PaymentMethodCriteria()
                            {
                                Above = true, PaymentMethod = paymentMethodId, Value = onChainMinValue
                            },
                            _ => new PaymentMethodCriteria()
                            {
                                PaymentMethod = paymentMethodId,
                                Above = matchedFromBlob?.Above ?? true,
                                Value = matchedFromBlob?.Value
                            }
                        };
                    }).ToList();

                    store.SetStoreBlob(blob);
                }

                await ctx.SaveChangesAsync();
            }
        }

        private async Task ConvertNetworkFeeProperty()
        {
            using (var ctx = _DBContextFactory.CreateContext())
            {
                foreach (var store in await ctx.Stores.AsQueryable().ToArrayAsync())
                {
                    var blob = store.GetStoreBlob();
                    if (blob.AdditionalData.TryGetValue("networkFeeDisabled", out var networkFeeModeJToken))
                    {
                        var networkFeeMode = networkFeeModeJToken.ToObject<bool?>();
                        if (networkFeeMode != null)
                        {
                            blob.NetworkFeeMode = networkFeeMode.Value ? NetworkFeeMode.Never : NetworkFeeMode.Always;
                        }

                        blob.AdditionalData.Remove("networkFeeDisabled");
                        store.SetStoreBlob(blob);
                    }
                }
                await ctx.SaveChangesAsync();
            }
        }

        private async Task ConvertMultiplierToSpread()
        {
            using (var ctx = _DBContextFactory.CreateContext())
            {
                foreach (var store in await ctx.Stores.AsQueryable().ToArrayAsync())
                {
                    var blob = store.GetStoreBlob();
                    decimal multiplier = 1.0m;
                    if (blob.AdditionalData.TryGetValue("rateRules", out var rateRulesJToken))
                    {
                        var rateRules = new Serializer(null).ToObject<List<RateRule_Obsolete>>(rateRulesJToken.ToString());
                        if (rateRules != null && rateRules.Count != 0)
                        {
                            foreach (var rule in rateRules)
                            {
                                multiplier = rule.Apply(null, multiplier);
                            }
                        }

                        blob.AdditionalData.Remove("rateRules");
                        blob.Spread = Math.Min(1.0m, Math.Max(0m, -(multiplier - 1.0m)));
                        store.SetStoreBlob(blob);
                    }
                }
                await ctx.SaveChangesAsync();
            }
        }

        public class RateRule_Obsolete
        {
            public RateRule_Obsolete()
            {
                RuleName = "Multiplier";
            }
            public string RuleName { get; set; }

            public double Multiplier { get; set; }

            public decimal Apply(BTCPayNetworkBase network, decimal rate)
            {
                return rate * (decimal)Multiplier;
            }
        }

        private Task UnreachableStoreCheck()
        {
            return _StoreRepository.CleanUnreachableStores();
        }

        private async Task DeprecatedLightningConnectionStringCheck()
        {
            using (var ctx = _DBContextFactory.CreateContext())
            {
                foreach (var store in await ctx.Stores.AsQueryable().ToArrayAsync())
                {
                    foreach (var method in store.GetSupportedPaymentMethods(_NetworkProvider).OfType<Payments.Lightning.LightningSupportedPaymentMethod>())
                    {
                        var lightning = method.GetLightningUrl();
                        if (lightning.IsLegacy)
                        {
                            method.SetLightningUrl(lightning);
                            store.SetSupportedPaymentMethod(method);
                        }
                    }
                }
                await ctx.SaveChangesAsync();
            }
        }
    }
}