package com.goldenchart.service;

import com.goldenchart.dto.TrendLineConfig;
import com.goldenchart.dto.TrendLineKind;
import org.ta4j.core.BarSeries;
import org.ta4j.core.Indicator;
import org.ta4j.core.indicators.AbstractIndicator;
import org.ta4j.core.num.Num;

import static org.ta4j.core.num.NaN.NaN;

/** bar index 에서 N봉 추세선 Y값 — left 지표·종가와 CROSS 비교용 */
public class TrendLineValueIndicator extends AbstractIndicator<Num> {

    private final Indicator<Num> source;
    private final BarSeries series;
    private final int lookback;
    private final TrendLineConfig config;
    private final TrendLineKind kind;
    private final boolean priceScale;

    public TrendLineValueIndicator(
            Indicator<Num> source,
            BarSeries series,
            int lookback,
            TrendLineConfig config,
            TrendLineKind kind,
            boolean priceScale) {
        super(series);
        this.source = source;
        this.series = series;
        this.lookback = Math.max(2, lookback);
        this.config = config != null ? config : TrendLineConfig.defaults();
        this.kind = kind != null ? kind : TrendLineKind.DOWN;
        this.priceScale = priceScale;
    }

    @Override
    public Num getValue(int index) {
        double v = TrendLineMath.valueAt(series, source, index, lookback, config, kind, priceScale);
        if (!Double.isFinite(v)) {
            return NaN;
        }
        return series.numFactory().numOf(v);
    }

    @Override
    public int getCountOfUnstableBars() {
        return lookback + 1;
    }
}