import 'package:flutter/material.dart';

/// Barre de puissance horizontale normalisée.
///
/// Affiche une barre colorée proportionnelle à [value] / [maxValue].
/// Si [signed] = true, la barre est centrée (positif = droite, négatif = gauche).
class PowerBar extends StatelessWidget {
  final double value;
  final double maxValue;
  final Color color;
  final bool signed;
  final double height;
  final double borderRadius;

  const PowerBar({
    super.key,
    required this.value,
    required this.maxValue,
    required this.color,
    this.signed       = false,
    this.height       = 8,
    this.borderRadius = 4,
  });

  @override
  Widget build(BuildContext context) {
    final frac = maxValue > 0
        ? (value.abs() / maxValue).clamp(0.0, 1.0)
        : 0.0;

    return LayoutBuilder(
      builder: (context, constraints) {
        final w = constraints.maxWidth;
        if (signed) {
          return Stack(
            children: [
              Container(
                height: height,
                decoration: BoxDecoration(
                  color: Colors.grey.withValues(alpha: 0.15),
                  borderRadius: BorderRadius.circular(borderRadius),
                ),
              ),
              Positioned(
                left:  value >= 0 ? w / 2 : w / 2 - frac * w / 2,
                child: Container(
                  width:  frac * w / 2,
                  height: height,
                  decoration: BoxDecoration(
                    color: color,
                    borderRadius: BorderRadius.circular(borderRadius),
                  ),
                ),
              ),
            ],
          );
        }

        return Stack(
          children: [
            Container(
              height: height,
              decoration: BoxDecoration(
                color: Colors.grey.withValues(alpha: 0.15),
                borderRadius: BorderRadius.circular(borderRadius),
              ),
            ),
            FractionallySizedBox(
              widthFactor: frac,
              child: Container(
                height: height,
                decoration: BoxDecoration(
                  color: color,
                  borderRadius: BorderRadius.circular(borderRadius),
                ),
              ),
            ),
          ],
        );
      },
    );
  }
}