using System;
using System.Linq;
using System.Windows.Forms;
using Microsoft.Extensions.DependencyInjection;
using PolyTrader.Modules.ResolutionFarming.Models;
using PolyTrader.Modules.ResolutionFarming.Persistence;
using PolyTraderSharp;

namespace PolyTrader.Modules.ResolutionFarming.Ui
{
    /// <summary>
    /// Hauptfenster des ResolutionFarming-Moduls: Tabs Kandidaten, Positionen, Historie/Statistik,
    /// Settings. Layout im Designer (ResolutionFarmingMainForm.Designer.cs), Verhalten/Daten hier.
    /// DB-Zugriffe defensiv (Guarded), damit die UI auch ohne angewendete rf_-Migration bedienbar bleibt.
    /// </summary>
    public partial class ResolutionFarmingMainForm : Form
    {
        private IRfCandidateRepository? _candidates;
        private IRfPositionRepository? _positions;
        private IRfClosedTradeRepository? _closed;
        private IRfSettingsRepository? _settingsRepo;
        private TradingState? _state;

        private RfSettings? _currentSettings;

        public ResolutionFarmingMainForm()
        {
            InitializeComponent();

            btnCandRefresh.Click += (_, _) => RefreshCandidates();
            cbCandAccount.SelectedIndexChanged += (_, _) => RefreshCandidates();
            btnPosRefresh.Click += (_, _) => RefreshPositions();
            btnHistRefresh.Click += (_, _) => RefreshHistory();
            btnSettingsSave.Click += (_, _) => SaveSettings();
            cbSettingsAccount.SelectedIndexChanged += (_, _) => LoadSettings();
        }

        /// <summary>Injiziert Repos/State (nach DI-Auflösung) und lädt die Ansichten.</summary>
        public void Initialize(IServiceProvider services)
        {
            _candidates = services.GetRequiredService<IRfCandidateRepository>();
            _positions = services.GetRequiredService<IRfPositionRepository>();
            _closed = services.GetRequiredService<IRfClosedTradeRepository>();
            _settingsRepo = services.GetRequiredService<IRfSettingsRepository>();
            _state = services.GetRequiredService<TradingState>();

            PopulateAccounts();
            RefreshCandidates();
            RefreshPositions();
            RefreshHistory();
        }

        // ---------------- Daten ----------------

        private void PopulateAccounts()
        {
            if (_state == null) return;
            var items = _state.Accounts.Values
                .OrderBy(a => a.AccountId)
                .Select(a => new AccountItem(a.AccountId, string.IsNullOrEmpty(a.Name) ? $"#{a.AccountId}" : $"{a.Name} (#{a.AccountId}){(a.IsDemo ? " · Demo" : "")}"))
                .ToList();

            foreach (var combo in new[] { cbCandAccount, cbSettingsAccount })
            {
                combo.DisplayMember = nameof(AccountItem.Label);
                combo.ValueMember = nameof(AccountItem.Id);
                combo.DataSource = items.ToList();
            }

            if (items.Count > 0) LoadSettings();
            else SetStatus("Keine Accounts vorhanden.");
        }

        private int? SelectedAccountId(ComboBox combo) =>
            combo.SelectedItem is AccountItem it ? it.Id : (int?)null;

        private void RefreshCandidates()
        {
            if (_candidates == null || SelectedAccountId(cbCandAccount) is not int accId) return;
            Guarded("Kandidaten", () => dgvCandidates.DataSource = _candidates.GetRecent(accId, 200));
        }

        private void RefreshPositions()
        {
            if (_positions == null) return;
            Guarded("Positionen", () => dgvPositions.DataSource = _positions.GetAllOpen());
        }

        private void RefreshHistory()
        {
            if (_closed == null) return;
            Guarded("Historie", () =>
            {
                var trades = _closed.Find(_ => true);
                dgvHistory.DataSource = trades;
                lblHistSummary.Text = BuildSummary(trades);
            });
        }

        private static string BuildSummary(System.Collections.Generic.List<RfClosedTrade> trades)
        {
            if (trades.Count == 0) return "Noch keine abgeschlossenen Trades.";
            int wins = trades.Count(t => t.RealizedPnl > 0m);
            decimal pnl = trades.Sum(t => t.RealizedPnl);
            decimal fees = trades.Sum(t => t.TotalFees);
            double winrate = 100.0 * wins / trades.Count;
            // Winrate je Preisband (Kalibrierung: realisierte Winrate sollte > Band-Mitte liegen).
            var bands = trades
                .GroupBy(t => $"{Math.Floor(t.EntryPrice * 20m) / 20m:F2}") // 5-¢-Bänder
                .OrderBy(g => g.Key)
                .Select(g => $"{g.Key}: {100.0 * g.Count(x => x.RealizedPnl > 0m) / g.Count():F0}% ({g.Count()})");
            return $"Trades: {trades.Count} | Winrate: {winrate:F1}% | Netto-PnL: {pnl:F2} USDC | Fees: {fees:F2}\n" +
                   $"Winrate je Preisband: {string.Join("  |  ", bands)}";
        }

        private void LoadSettings()
        {
            if (_settingsRepo == null || SelectedAccountId(cbSettingsAccount) is not int accId) return;
            Guarded("Settings", () =>
            {
                _currentSettings = _settingsRepo.Get(accId) ?? new RfSettings { AccountId = accId };
                pgSettings.SelectedObject = _currentSettings;
                SetStatus($"Einstellungen für Konto #{accId}.");
            });
        }

        private void SaveSettings()
        {
            if (_settingsRepo == null || _currentSettings == null) return;
            Guarded("Speichern", () =>
            {
                _settingsRepo.Upsert(_currentSettings);
                SetStatus($"Gespeichert für Konto #{_currentSettings.AccountId} um {DateTime.Now:HH:mm:ss}.");
            });
        }

        private void Guarded(string what, Action action)
        {
            try { action(); }
            catch (Exception ex) { SetStatus($"{what}: DB nicht bereit ({ex.Message}). Migration angewendet?"); }
        }

        private void SetStatus(string text) => lblRfStatus.Text = text;

        private sealed record AccountItem(int Id, string Label);
    }
}