package market.guess.ui.desktop.util;

import java.time.Instant;
import java.time.LocalDate;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.util.List;
import javafx.scene.chart.LineChart;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.XYChart;
import javafx.util.StringConverter;
import market.guess.ui.desktop.model.ChartPoint;

/** Utilities for populating LineChart series and formatting time/value axes. */
public final class Charts {
  private Charts() {}

  public static final long BASE_TIME =
      LocalDate.of(2026, 9, 12).atTime(9, 0).atZone(ZoneId.systemDefault()).toEpochSecond();

  public static double toEpochSecond(double x) {
    if (x >= 1_000_000_000) {
      return x;
    }
    return BASE_TIME + (long) (x * 1800);
  }

  public static void setSingleSeries(
      LineChart<Number, Number> chart, String name, List<ChartPoint> pts) {
    configureTimeXAxis(chart, pts);
    chart.getData().setAll(List.of(series(name, pts)));
  }

  public static void setDualSeries(
      LineChart<Number, Number> chart,
      String name1,
      List<ChartPoint> pts1,
      String name2,
      List<ChartPoint> pts2) {
    configureTimeXAxis(chart, (pts1 != null && !pts1.isEmpty()) ? pts1 : pts2);
    chart.getData().setAll(List.of(series(name1, pts1), series(name2, pts2)));
  }

  public static void configureTimeXAxis(LineChart<Number, Number> chart, List<ChartPoint> pts) {
    if (!(chart.getXAxis() instanceof NumberAxis xAxis)) return;

    xAxis.setTickMarkVisible(true);
    xAxis.setTickLabelsVisible(true);
    xAxis.setMinorTickVisible(false);
    xAxis.setForceZeroInRange(false);

    if (pts == null || pts.isEmpty()) {
      xAxis.setAutoRanging(true);
      return;
    }

    double min = pts.stream().mapToDouble(p -> toEpochSecond(p.x())).min().orElse(BASE_TIME);
    double max = pts.stream().mapToDouble(p -> toEpochSecond(p.x())).max().orElse(BASE_TIME + 3600);

    if (min == max) {
      min -= 60;
      max += 60;
    }

    double range = max - min;
    double targetInterval = range / 5.5;

    double[] cleanIntervals = {
      1, 5, 10, 15, 30, 60, 300, 600, 900, 1800, 3600, 7200, 14400, 21600, 43200, 86400
    };
    double tickUnit = cleanIntervals[cleanIntervals.length - 1];
    for (double unit : cleanIntervals) {
      if (unit >= targetInterval) {
        tickUnit = unit;
        break;
      }
    }

    double lower = Math.floor(min / tickUnit) * tickUnit;
    double upper = Math.ceil(max / tickUnit) * tickUnit;
    if (upper <= max) {
      upper += tickUnit;
    }

    xAxis.setAutoRanging(false);
    xAxis.setLowerBound(lower);
    xAxis.setUpperBound(upper);
    xAxis.setTickUnit(tickUnit);

    DateTimeFormatter fmt =
        (range > 86400)
            ? DateTimeFormatter.ofPattern("MM-dd HH:mm").withZone(ZoneId.systemDefault())
            : (range < 300)
                ? DateTimeFormatter.ofPattern("HH:mm:ss").withZone(ZoneId.systemDefault())
                : DateTimeFormatter.ofPattern("HH:mm").withZone(ZoneId.systemDefault());

    xAxis.setTickLabelFormatter(
        new StringConverter<Number>() {
          @Override
          public String toString(Number n) {
            if (n == null) return "";
            try {
              return fmt.format(Instant.ofEpochSecond(n.longValue()));
            } catch (Exception e) {
              return n.toString();
            }
          }

          @Override
          public Number fromString(String s) {
            return 0;
          }
        });
  }

  /**
   * Scales the Y axis dynamically with sensible headroom and round tick marks so values (like
   * balances > $1,500) never get cut off at the top or bottom.
   */
  public static void scaleYAxis(NumberAxis yAxis, List<ChartPoint> pts, Double currentVal) {
    if (yAxis == null) return;
    if ((pts == null || pts.isEmpty()) && currentVal == null) {
      yAxis.setAutoRanging(true);
      return;
    }

    double min =
        (pts != null && !pts.isEmpty())
            ? pts.stream().mapToDouble(ChartPoint::y).min().orElse(0.0)
            : (currentVal != null ? currentVal : 0.0);
    double max =
        (pts != null && !pts.isEmpty())
            ? pts.stream().mapToDouble(ChartPoint::y).max().orElse(100.0)
            : (currentVal != null ? currentVal : 100.0);

    if (currentVal != null) {
      min = Math.min(min, currentVal);
      max = Math.max(max, currentVal);
    }

    if (max <= 0 && min <= 0) {
      double absMax = Math.abs(min);
      double unit = niceNum(absMax / 4.0, true);
      if (unit <= 0) unit = 50;
      double lower = Math.floor(min / unit) * unit - unit;
      yAxis.setAutoRanging(false);
      yAxis.setLowerBound(lower);
      yAxis.setUpperBound(0.0);
      yAxis.setTickUnit(unit);
      return;
    }

    double targetMax = max > 0 ? max * 1.15 : 100.0;
    double targetMin = min < 0 ? min * 1.20 : 0.0;
    double range = targetMax - targetMin;
    double unit = niceNum(range / 5.0, true);
    if (unit <= 0) unit = 50;

    double lower = targetMin < 0 ? Math.floor(targetMin / unit) * unit : 0.0;
    double upper = Math.ceil(targetMax / unit) * unit;
    if (upper <= max) {
      upper += unit;
    }

    yAxis.setAutoRanging(false);
    yAxis.setLowerBound(lower);
    yAxis.setUpperBound(upper);
    yAxis.setTickUnit(unit);
  }

  private static double niceNum(double range, boolean round) {
    if (range <= 0) return 1.0;
    double exponent = Math.floor(Math.log10(range));
    double fraction = range / Math.pow(10, exponent);
    double niceFraction;

    if (round) {
      if (fraction < 1.5) niceFraction = 1.0;
      else if (fraction < 3.0) niceFraction = 2.0;
      else if (fraction < 7.0) niceFraction = 5.0;
      else niceFraction = 10.0;
    } else {
      if (fraction <= 1.0) niceFraction = 1.0;
      else if (fraction <= 2.0) niceFraction = 2.0;
      else if (fraction <= 5.0) niceFraction = 5.0;
      else niceFraction = 10.0;
    }

    return niceFraction * Math.pow(10, exponent);
  }

  private static XYChart.Series<Number, Number> series(String name, List<ChartPoint> pts) {
    var s = new XYChart.Series<Number, Number>();
    s.setName(name);
    if (pts != null) {
      for (var p : pts) {
        s.getData().add(new XYChart.Data<>(toEpochSecond(p.x()), p.y()));
      }
    }
    return s;
  }
}