using System;
using System.Collections.Generic;

namespace FinlyticCore.Dtos.TechnicalAnalysis;

/// <summary>
/// Execution context supplied to pattern detectors and strategy evaluators containing multi-timeframe candles and indicators.
/// </summary>
public class TechnicalContext
{
    public string Isin { get; init; } = string.Empty;
    public string Symbol { get; init; } = string.Empty;
    public string Timeframe { get; init; } = "15m";
    public DateTime TimestampUtc { get; init; } = DateTime.UtcNow;
    public decimal CurrentPrice { get; init; }
    public decimal CurrentSpread { get; init; }
    public bool IsSpreadVolatile { get; init; }
    public decimal CurrentAtr { get; init; }
    public MarketRegime Regime { get; init; } = MarketRegime.LowVolatilityRangebound;

    /// <summary>
    /// Multi-timeframe historical candles (e.g. "1m", "5m", "15m", "1h", "1d").
    /// </summary>
    public Dictionary<string, IReadOnlyList<CandleDto>> MultiTimeframeCandles { get; init; } = new(StringComparer.OrdinalIgnoreCase);

    /// <summary>
    /// Pre-calculated mathematical indicator values for the primary timeframe.
    /// </summary>
    public Dictionary<string, decimal> Indicators { get; init; } = new(StringComparer.OrdinalIgnoreCase);

    /// <summary>
    /// Per-run overrides for a strategy's tunable indicator parameters (e.g. <c>"MeanReversion.RsiOversold"</c>),
    /// keyed by <c>"{StrategyKey}.{ParameterName}"</c> so a single context could in principle carry overrides
    /// for more than one strategy without name collisions. Always empty for live scanning
    /// (<c>TechnicalScoringEngine</c> never populates this - Rules.md §4: no silent behavior change to live
    /// trade generation as a side effect of a backtesting feature); populated only by
    /// <c>FinlyticSimulation.Engine.HistoricalReplayRunner</c> from <c>BacktestRequestDto.StrategyParameters</c>,
    /// so per-asset/per-strategy tuning is opt-in and scoped to backtesting. See <see cref="GetParameter"/>.
    /// </summary>
    public Dictionary<string, decimal> ParameterOverrides { get; init; } = new(StringComparer.OrdinalIgnoreCase);

    /// <summary>
    /// Resolves a tunable strategy parameter: the override in <see cref="ParameterOverrides"/> under
    /// <c>"{strategyKey}.{parameterName}"</c> if present, otherwise <paramref name="defaultValue"/> (the
    /// strategy's own hardcoded default, unchanged from before parametrization existed).
    /// </summary>
    public decimal GetParameter(string strategyKey, string parameterName, decimal defaultValue)
    {
        return ParameterOverrides.TryGetValue($"{strategyKey}.{parameterName}", out var v) ? v : defaultValue;
    }

    /// <summary>
    /// Gets the candles for a specific timeframe (defaults to empty list if not found).
    /// </summary>
    public IReadOnlyList<CandleDto> GetCandles(string timeframe)
    {
        if (MultiTimeframeCandles.TryGetValue(timeframe, out var list))
        {
            return list;
        }
        return [];
    }

    /// <summary>
    /// Gets the primary timeframe candle sequence.
    /// </summary>
    public IReadOnlyList<CandleDto> PrimaryCandles => GetCandles(Timeframe);

    /// <summary>
    /// Gets a specific indicator value or null if not computed.
    /// </summary>
    public decimal? GetIndicator(string key)
    {
        if (Indicators.TryGetValue(key, out var val))
        {
            return val;
        }
        return null;
    }
}