using System.Globalization;
using System.Text.Json;

namespace Encelado.Core.Baskets;

/// <summary>
/// An entry the decider approved whose execution is not finished: leg A is on its way
/// (state <c>PendingA</c>) or filled while leg B is on its way (<c>PendingB</c>). Holds
/// everything needed to finish the basket later — or to undo leg A — without the
/// original decision object, which does not survive a restart.
/// </summary>
public sealed class PendingEntry
{
    public required string BasketId { get; init; }

    public required bool BuyCross { get; init; }

    public required double EntryZ { get; init; }

    public required double UnitsA { get; init; }

    public required double UnitsB { get; init; }

    public required double TpPips { get; init; }

    public required double MaxLossUsd { get; init; }

    public double EntryCostPips { get; init; } = double.NaN;

    public required double EquityAtEntry { get; init; }

    public string Motivazione { get; init; } = string.Empty;

    public required DateTime DecidedUtc { get; init; }

    public string ClientRefA { get; set; } = string.Empty;

    public string ClientRefB { get; set; } = string.Empty;

    /// <summary>The quotes seen at decision time, for the slippage of each leg.</summary>
    public double QuoteA { get; init; }

    public double QuoteB { get; init; }

    /// <summary>Leg A as filled, once it is.</summary>
    public BasketLeg? LegA { get; set; }

    public void Write(Utf8JsonWriter w)
    {
        ArgumentNullException.ThrowIfNull(w);
        w.WriteStartObject("pending");
        w.WriteString("basketId", BasketId);
        w.WriteBoolean("buyCross", BuyCross);
        w.WriteNumber("entryZ", EntryZ);
        w.WriteNumber("unitsA", UnitsA);
        w.WriteNumber("unitsB", UnitsB);
        w.WriteNumber("tpPips", TpPips);
        w.WriteNumber("maxLossUsd", MaxLossUsd);
        w.WriteNumber("entryCostPips", double.IsFinite(EntryCostPips) ? EntryCostPips : 0);
        w.WriteNumber("equityAtEntry", EquityAtEntry);
        w.WriteString("motivazione", Motivazione);
        w.WriteString("decidedUtc", DecidedUtc.ToString("O", CultureInfo.InvariantCulture));
        w.WriteString("clientRefA", ClientRefA);
        w.WriteString("clientRefB", ClientRefB);
        w.WriteNumber("quoteA", QuoteA);
        w.WriteNumber("quoteB", QuoteB);
        if (LegA is { } leg)
        {
            BasketLeg.Write(w, "legA", leg);
        }

        w.WriteEndObject();
    }

    public static PendingEntry Read(JsonElement e)
    {
        PendingEntry p = new()
        {
            BasketId = e.GetProperty("basketId").GetString() ?? string.Empty,
            BuyCross = e.GetProperty("buyCross").GetBoolean(),
            EntryZ = e.GetProperty("entryZ").GetDouble(),
            UnitsA = e.GetProperty("unitsA").GetDouble(),
            UnitsB = e.GetProperty("unitsB").GetDouble(),
            TpPips = e.GetProperty("tpPips").GetDouble(),
            MaxLossUsd = e.GetProperty("maxLossUsd").GetDouble(),
            EntryCostPips = e.GetProperty("entryCostPips").GetDouble(),
            EquityAtEntry = e.GetProperty("equityAtEntry").GetDouble(),
            Motivazione = e.GetProperty("motivazione").GetString() ?? string.Empty,
            DecidedUtc = DateTime.Parse(e.GetProperty("decidedUtc").GetString()!, CultureInfo.InvariantCulture, DateTimeStyles.AdjustToUniversal | DateTimeStyles.AssumeUniversal),
            QuoteA = e.TryGetProperty("quoteA", out JsonElement qa) ? qa.GetDouble() : 0,
            QuoteB = e.TryGetProperty("quoteB", out JsonElement qb) ? qb.GetDouble() : 0,
        };
        p.ClientRefA = e.TryGetProperty("clientRefA", out JsonElement ca) ? ca.GetString() ?? string.Empty : string.Empty;
        p.ClientRefB = e.TryGetProperty("clientRefB", out JsonElement cb) ? cb.GetString() ?? string.Empty : string.Empty;
        if (e.TryGetProperty("legA", out JsonElement la))
        {
            p.LegA = BasketLeg.Read(la);
        }

        return p;
    }
}