/// Normalized rectangle (0–1) on the receipt photo for review highlights.
library;

class ReceiptBounds {
  const ReceiptBounds({
    required this.left,
    required this.top,
    required this.right,
    required this.bottom,
  });

  final double left;
  final double top;
  final double right;
  final double bottom;

  bool get isEmpty => right <= left || bottom <= top;

  ReceiptBounds union(ReceiptBounds other) {
    if (isEmpty) return other;
    if (other.isEmpty) return this;
    return ReceiptBounds(
      left: left < other.left ? left : other.left,
      top: top < other.top ? top : other.top,
      right: right > other.right ? right : other.right,
      bottom: bottom > other.bottom ? bottom : other.bottom,
    );
  }

  static ReceiptBounds? merge(Iterable<ReceiptBounds> bounds) {
    ReceiptBounds? merged;
    for (final box in bounds) {
      if (box.isEmpty) continue;
      merged = merged == null ? box : merged.union(box);
    }
    return merged;
  }

  static ReceiptBounds fromPixelRect({
    required double left,
    required double top,
    required double right,
    required double bottom,
    required double imageWidth,
    required double imageHeight,
  }) {
    if (imageWidth <= 0 || imageHeight <= 0) {
      return const ReceiptBounds(left: 0, top: 0, right: 0, bottom: 0);
    }
    return ReceiptBounds(
      left: left / imageWidth,
      top: top / imageHeight,
      right: right / imageWidth,
      bottom: bottom / imageHeight,
    );
  }
}