using IBKRTrader.Core.Logging;
using IBKRTrader.Modules.Accounting.Logic;
using IBKRTrader.Modules.Accounting.Persistence;
using IBKRTrader.Modules.Accounting.Services;

namespace IBKRTrader.UI.Views.Modules;

/// <summary>
/// Fenster des Accounting-Moduls: Übersicht/BWA, Ledger, Steuer (Platzhalter), Abrechnung/Export,
/// Abruf/Status. Alle DB-Zugriffe laufen NUR auf Nutzer-Interaktion (nicht im Konstruktor) – so
/// konstruiert der Smoke-UI-Check das Fenster auch ohne DB fehlerfrei.
/// </summary>
public sealed class AccountingMainForm : Form
{
    private readonly ILedgerRepository       _ledger;
    private readonly IIngestRunRepository    _runs;
    private readonly AccountingReportService _report;
    private readonly AccountingIngestService _ingest;
    private readonly LoggingService          _logger;

    private readonly DateTimePicker _from     = new() { Format = DateTimePickerFormat.Short, Width = 110 };
    private readonly DateTimePicker _to       = new() { Format = DateTimePickerFormat.Short, Width = 110 };
    private readonly ComboBox       _account  = new() { DropDownStyle = ComboBoxStyle.DropDown, Width = 140 };
    private readonly ComboBox       _currency = new() { DropDownStyle = ComboBoxStyle.DropDownList, Width = 80 };

    private readonly Label         _kpis    = new() { AutoSize = true, Location = new Point(12, 8) };
    private readonly DataGridView  _monthly = new() { Dock = DockStyle.Fill, ReadOnly = true, AllowUserToAddRows = false, RowHeadersVisible = false, AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.Fill };
    private readonly DataGridView  _ledgerGrid = new() { Dock = DockStyle.Fill, ReadOnly = true, AllowUserToAddRows = false, RowHeadersVisible = false, AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.Fill };
    private readonly DataGridView  _runsGrid   = new() { Dock = DockStyle.Fill, ReadOnly = true, AllowUserToAddRows = false, RowHeadersVisible = false, AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.Fill };
    private readonly Label         _status  = new() { AutoSize = true, ForeColor = SystemColors.GrayText, Location = new Point(12, 8) };

    public AccountingMainForm(
        ILedgerRepository ledger, IIngestRunRepository runs, AccountingReportService report,
        AccountingIngestService ingest, LoggingService logger)
    {
        _ledger = ledger;
        _runs   = runs;
        _report = report;
        _ingest = ingest;
        _logger = logger;

        Text          = "Accounting";
        Width         = 1000;
        Height        = 680;
        StartPosition = FormStartPosition.CenterScreen;
        MinimumSize   = new Size(760, 480);

        _from.Value = DateTime.Today.AddMonths(-1);
        _to.Value   = DateTime.Today;
        _currency.Items.AddRange(new object[] { "USD", "EUR" });
        _currency.SelectedIndex = 0;

        BuildLayout();
    }

    private void BuildLayout()
    {
        var tabs = new TabControl { Dock = DockStyle.Fill };

        // ── gemeinsame Filterleiste ──
        var filter = new FlowLayoutPanel { Dock = DockStyle.Top, Height = 40, Padding = new Padding(8, 6, 8, 0) };
        filter.Controls.Add(new Label { Text = "Von", AutoSize = true, Margin = new Padding(0, 8, 4, 0) });
        filter.Controls.Add(_from);
        filter.Controls.Add(new Label { Text = "Bis", AutoSize = true, Margin = new Padding(8, 8, 4, 0) });
        filter.Controls.Add(_to);
        filter.Controls.Add(new Label { Text = "Konto", AutoSize = true, Margin = new Padding(8, 8, 4, 0) });
        filter.Controls.Add(_account);
        filter.Controls.Add(new Label { Text = "Währung", AutoSize = true, Margin = new Padding(8, 8, 4, 0) });
        filter.Controls.Add(_currency);
        var btnRefresh = new Button { Text = "Aktualisieren", Width = 120, Margin = new Padding(12, 3, 0, 0) };
        btnRefresh.Click += (_, _) => RefreshAll();
        filter.Controls.Add(btnRefresh);

        // ── Tab: Übersicht/BWA ──
        var tabOverview = new TabPage("Übersicht / BWA");
        _monthly.Top = 90;
        var overviewPanel = new Panel { Dock = DockStyle.Fill };
        overviewPanel.Controls.Add(_monthly);
        var kpiPanel = new Panel { Dock = DockStyle.Top, Height = 84 };
        kpiPanel.Controls.Add(_kpis);
        overviewPanel.Controls.Add(kpiPanel);
        tabOverview.Controls.Add(overviewPanel);

        // ── Tab: Ledger ──
        var tabLedger = new TabPage("Ledger");
        tabLedger.Controls.Add(_ledgerGrid);

        // ── Tab: Steuer (Platzhalter) ──
        var tabTax = new TabPage("Steuer");
        tabTax.Controls.Add(new Label
        {
            Dock = DockStyle.Fill, Padding = new Padding(16),
            Text = "Steuerliche Einordnung ist noch offen (Jurisdiktion nicht festgelegt).\n\n" +
                   "Der neutrale Ledger und die Periodenabrechnung sind davon unabhängig gültig.\n" +
                   "Eine konkrete Steuerschicht (z. B. DE-Kapitalertragsteuer oder US Form 8949 / Schedule D)\n" +
                   "wird hier später als klar dokumentierte, prüfbare Rechenschicht ergänzt.\n\n" +
                   "Hinweis: Dies ist keine Steuerberatung."
        });

        // ── Tab: Abrechnung / Export ──
        var tabExport = new TabPage("Abrechnung / Export");
        var exportPanel = new FlowLayoutPanel { Dock = DockStyle.Fill, Padding = new Padding(16), FlowDirection = FlowDirection.TopDown };
        exportPanel.Controls.Add(new Label { AutoSize = true, Text = "Exportiert die aktuelle Auswahl (Zeitraum / Konto / Währung):" });
        var btnCsvLedger = new Button { Text = "Ledger als CSV…", Width = 180, Margin = new Padding(0, 8, 0, 0) };
        btnCsvLedger.Click += (_, _) => ExportCsvLedger();
        var btnCsvStmt = new Button { Text = "Abrechnung als CSV…", Width = 180, Margin = new Padding(0, 8, 0, 0) };
        btnCsvStmt.Click += (_, _) => ExportCsvStatement();
        var btnPdf = new Button { Text = "Abrechnung als PDF…", Width = 180, Margin = new Padding(0, 8, 0, 0) };
        btnPdf.Click += (_, _) => ExportPdf();
        exportPanel.Controls.Add(btnCsvLedger);
        exportPanel.Controls.Add(btnCsvStmt);
        exportPanel.Controls.Add(btnPdf);
        tabExport.Controls.Add(exportPanel);

        // ── Tab: Abruf / Status ──
        var tabIngest = new TabPage("Abruf / Status");
        var ingestButtons = new FlowLayoutPanel { Dock = DockStyle.Top, Height = 40, Padding = new Padding(8, 6, 8, 0) };
        var btnIncr = new Button { Text = "Inkrementell abrufen", Width = 160 };
        btnIncr.Click += async (_, _) => await RunIngest(backfill: false);
        var btnBackfill = new Button { Text = "Backfill (voll)", Width = 140, Margin = new Padding(8, 0, 0, 0) };
        btnBackfill.Click += async (_, _) => await RunIngest(backfill: true);
        ingestButtons.Controls.Add(btnIncr);
        ingestButtons.Controls.Add(btnBackfill);
        var statusPanel = new Panel { Dock = DockStyle.Top, Height = 40 };
        statusPanel.Controls.Add(_status);
        _status.Text = "Offline-Standard: keine Live-Quelle registriert → der Ingest bucht nichts (korrekt).";
        tabIngest.Controls.Add(_runsGrid);
        tabIngest.Controls.Add(statusPanel);
        tabIngest.Controls.Add(ingestButtons);

        tabs.TabPages.AddRange(new[] { tabOverview, tabLedger, tabTax, tabExport, tabIngest });

        Controls.Add(tabs);
        Controls.Add(filter);
    }

    // ── Daten laden (nur auf Interaktion) ──

    private string? SelectedAccount()
    {
        var text = _account.Text?.Trim();
        return string.IsNullOrWhiteSpace(text) || text == "(alle)" ? null : text;
    }

    private void RefreshAll()
    {
        try
        {
            LoadAccounts();
            LoadOverview();
            LoadLedger();
            LoadRuns();
        }
        catch (Exception ex)
        {
            _logger.Error("Accounting", $"UI-Refresh fehlgeschlagen: {ex.Message}", ex);
            MessageBox.Show(this, ex.Message, "Fehler", MessageBoxButtons.OK, MessageBoxIcon.Warning);
        }
    }

    private void LoadAccounts()
    {
        var current = _account.Text;
        _account.Items.Clear();
        _account.Items.Add("(alle)");
        foreach (var a in _ledger.DistinctAccounts()) _account.Items.Add(a);
        _account.Text = string.IsNullOrEmpty(current) ? "(alle)" : current;
    }

    private void LoadOverview()
    {
        DateTime from = _from.Value.Date, to = _to.Value.Date.AddDays(1).AddTicks(-1);
        var stmt = _report.BuildStatement(SelectedAccount(), from, to);
        var view = _report.GetCurrencyView(_currency.Text, to);
        decimal C(decimal v) => Math.Round(v * view.Factor, 2);

        _kpis.Text =
            $"Netto-Handelsergebnis: {C(stmt.NetTradingResult):N2} {view.Code}    " +
            $"Handelsvolumen: {C(stmt.TradeVolume):N2}    Dividenden: {C(stmt.Dividends):N2}    Fees: {C(stmt.Fees):N2}\n" +
            $"Einzahlungen: {C(stmt.Deposits):N2}    Auszahlungen: {C(stmt.Withdrawals):N2}    " +
            $"Endsaldo: {C(stmt.ClosingBalance):N2}    Trades: {stmt.TradeCount}    Buchungen: {stmt.EntryCount}\n" +
            $"{view.Note}";

        var monthly = _report.BuildMonthly(SelectedAccount(), from, to)
            .Select(m => new
            {
                Monat = m.From.ToString("yyyy-MM"),
                Anfang = C(m.OpeningBalance),
                Einzahlungen = C(m.Deposits),
                Auszahlungen = C(m.Withdrawals),
                Volumen = C(m.TradeVolume),
                Fees = C(m.Fees),
                Ergebnis = C(m.NetTradingResult),
                Endsaldo = C(m.ClosingBalance)
            }).ToList();
        _monthly.DataSource = monthly;
    }

    private void LoadLedger()
    {
        DateTime from = _from.Value.Date, to = _to.Value.Date.AddDays(1).AddTicks(-1);
        var rows = _ledger.Query(SelectedAccount(), from, to, 2000)
            .Select(e => new
            {
                Zeit = e.Timestamp, e.AccountId, Typ = e.EventType.ToString(), e.Side, e.Symbol,
                e.Currency, e.Quantity, Preis = e.PriceNative, Brutto = e.GrossBase, Fee = e.FeeBase,
                Netto = e.NetBase, e.TransactionId
            }).ToList();
        _ledgerGrid.DataSource = rows;
    }

    private void LoadRuns()
    {
        var rows = _runs.GetRecent(SelectedAccount(), 100)
            .Select(r => new
            {
                r.AccountId, Start = r.StartedAt, Ende = r.FinishedAt, r.Backfill,
                Neu = r.NewEntries, Duplikate = r.DuplicateEntries, r.Success,
                Anker = r.BalanceAnchorBase, LedgerNetto = r.LedgerNetBase, Delta = r.BalanceDeltaBase, r.Message
            }).ToList();
        _runsGrid.DataSource = rows;
    }

    // ── Export ──

    private void ExportCsvLedger()
    {
        DateTime from = _from.Value.Date, to = _to.Value.Date.AddDays(1).AddTicks(-1);
        var entries = _ledger.Query(SelectedAccount(), from, to, 100000);
        SaveText("ledger.csv", "CSV|*.csv", CsvExporter.Ledger(entries));
    }

    private void ExportCsvStatement()
    {
        DateTime from = _from.Value.Date, to = _to.Value.Date.AddDays(1).AddTicks(-1);
        var stmt = _report.BuildStatement(SelectedAccount(), from, to);
        SaveText("abrechnung.csv", "CSV|*.csv", CsvExporter.Statement(stmt));
    }

    private void ExportPdf()
    {
        try
        {
            DateTime from = _from.Value.Date, to = _to.Value.Date.AddDays(1).AddTicks(-1);
            var account = SelectedAccount();
            var stmt = _report.BuildStatement(account, from, to);
            var monthly = _report.BuildMonthly(account, from, to);
            var entries = _ledger.Query(account, from, to, 100000).OrderBy(e => e.Timestamp).ToList();
            var view = _report.GetCurrencyView(_currency.Text, to);

            byte[] pdf = PdfExporter.Render(stmt, monthly, entries, view.Code, view.Factor, view.Note);

            using var dlg = new SaveFileDialog { FileName = "abrechnung.pdf", Filter = "PDF|*.pdf" };
            if (dlg.ShowDialog(this) == DialogResult.OK)
            {
                File.WriteAllBytes(dlg.FileName, pdf);
                _logger.Info("Accounting", $"PDF-Abrechnung geschrieben: {dlg.FileName}");
            }
        }
        catch (Exception ex)
        {
            _logger.Error("Accounting", $"PDF-Export fehlgeschlagen: {ex.Message}", ex);
            MessageBox.Show(this, ex.Message, "Fehler", MessageBoxButtons.OK, MessageBoxIcon.Warning);
        }
    }

    private void SaveText(string suggested, string filter, string content)
    {
        try
        {
            using var dlg = new SaveFileDialog { FileName = suggested, Filter = filter };
            if (dlg.ShowDialog(this) == DialogResult.OK)
            {
                File.WriteAllText(dlg.FileName, content);
                _logger.Info("Accounting", $"Export geschrieben: {dlg.FileName}");
            }
        }
        catch (Exception ex)
        {
            _logger.Error("Accounting", $"Export fehlgeschlagen: {ex.Message}", ex);
            MessageBox.Show(this, ex.Message, "Fehler", MessageBoxButtons.OK, MessageBoxIcon.Warning);
        }
    }

    // ── Ingest ──

    private async Task RunIngest(bool backfill)
    {
        try
        {
            _status.Text = backfill ? "Backfill läuft…" : "Inkrementeller Abruf läuft…";
            await _ingest.IngestAllAsync(backfill, CancellationToken.None);
            _status.Text = $"Abruf abgeschlossen ({DateTime.Now:HH:mm:ss}).";
            LoadRuns();
        }
        catch (Exception ex)
        {
            _status.Text = $"Fehler: {ex.Message}";
            _logger.Error("Accounting", $"Manueller Ingest fehlgeschlagen: {ex.Message}", ex);
        }
    }
}