"""Small right-aligned mathematical annotations shared by Qt plots."""
try:
    from PySide6.QtCore import QRectF, Qt
    from PySide6.QtGui import QColor
except ImportError:
    from PySide2.QtCore import QRectF, Qt
    from PySide2.QtGui import QColor


def paint_formulas(painter, rect, entries):
    """Draw (color, text) entries in the right half, wrapping long formulas."""
    painter.save()
    painter.setClipRect(rect)
    metrics = painter.fontMetrics()
    width = max(1., rect.width() * .48 - 12)
    top = rect.top() + 5
    flags = int(Qt.AlignRight | Qt.AlignTop | Qt.TextWordWrap)
    for color, text in entries:
        box = QRectF(rect.right() - width - 6, top, width, max(1., rect.bottom() - top))
        height = painter.boundingRect(box, flags, text).height()
        box.setHeight(height)
        painter.fillRect(box.adjusted(-3, -1, 3, 1), QColor('#0b1119'))
        painter.setPen(QColor(color))
        painter.drawText(box, flags, text)
        top += height + metrics.height() * .4
        if top >= rect.bottom():
            break
    painter.restore()