using System;
using System.Collections.Generic;
using System.Linq;
using FinlyticCore.Dtos.TechnicalAnalysis;

namespace FinlyticTechnicals.Patterns.SmartMoney;

/// <summary>
/// Detects institutional Bearish Order Blocks (last bullish candle before a strong downward displacement).
/// </summary>
public class BearishOrderBlockDetector : IPatternDetector
{
    /// <inheritdoc />
    public PatternType HandledType => PatternType.OrderBlock;

    /// <inheritdoc />
    public PatternCategory Category => PatternCategory.SmartMoney;

    /// <inheritdoc />
    public PatternResultDto? Evaluate(TechnicalContext context)
    {
        var candles = context.PrimaryCandles;
        if (candles.Count < 5) return null;

        var obCandle = candles[^3];
        var impulse1 = candles[^2];
        var impulse2 = candles.Last();

        // Bearish Order Block: Green candle followed by 2 strong red candles that drop price > 1.5 ATR
        if (obCandle.Close > obCandle.Open && impulse1.Close < impulse1.Open && impulse2.Close < impulse2.Open)
        {
            decimal displacement = obCandle.High - impulse2.Close;
            if (displacement >= context.CurrentAtr * 1.5m)
            {
                return new PatternResultDto(
                    Id: Guid.NewGuid(),
                    Type: PatternType.OrderBlock,
                    Category: PatternCategory.SmartMoney,
                    Bias: PatternBias.Bearish,
                    Name: "Bearish Institutional Order Block",
                    Timeframe: context.Timeframe,
                    DetectedAt: impulse2.Timestamp,
                    KeyPriceLevel: (obCandle.Open + obCandle.Close) / 2m,
                    UpperBoundary: obCandle.High,
                    LowerBoundary: obCandle.Low,
                    InvalidationLevel: obCandle.High * 1.005m,
                    QualityScore: 86m,
                    Description: $"Bearish order block zone [{obCandle.Low:F2} - {obCandle.High:F2}] with strong downward displacement."
                );
            }
        }

        return null;
    }
}