from __future__ import annotations

from PySide6.QtCore import QMargins, QPoint, QRect, QSize, Qt
from PySide6.QtWidgets import QLayout, QSizePolicy, QWidgetItem


class FlowLayout(QLayout):
    def __init__(self, parent=None, center=False):
        super().__init__(parent)

        if parent is not None:
            self.setContentsMargins(QMargins(0, 0, 0, 0))

        self._item_list: list[QWidgetItem] = []
        self.center = center

    def __del__(self):
        item = self.takeAt(0)
        while item:
            item = self.takeAt(0)

    def addItem(self, item):
        self._item_list.append(item)

    def count(self):
        return len(self._item_list)

    def itemAt(self, index):
        if 0 <= index < len(self._item_list):
            return self._item_list[index]

        return None

    def takeAt(self, index):
        if 0 <= index < len(self._item_list):
            return self._item_list.pop(index)

        return None

    def expandingDirections(self):
        return Qt.Orientation(0)

    def hasHeightForWidth(self):
        return True

    def heightForWidth(self, width):
        height = self._do_layout(QRect(0, 0, width, 0), True)
        return height

    def setGeometry(self, rect):
        super().setGeometry(rect)
        self._do_layout(rect, False)

    def sizeHint(self):
        return self.minimumSize()

    def minimumSize(self):
        size = QSize()

        for item in self._item_list:
            size = size.expandedTo(item.minimumSize())

        size += QSize(2 * self.contentsMargins().top(), 2 * self.contentsMargins().top())
        return size

    def _do_layout(self, rect, test_only):
        x = rect.x()
        y = rect.y()
        line_height = 0
        spacing = self.spacing()

        rows: list[tuple[list[QWidgetItem], int, int]] = []

        row = []
        for item in self._item_list:
            style = item.widget().style()
            layout_spacing_x = style.layoutSpacing(QSizePolicy.PushButton, QSizePolicy.PushButton, Qt.Horizontal)
            layout_spacing_y = style.layoutSpacing(QSizePolicy.PushButton, QSizePolicy.PushButton, Qt.Vertical)
            space_x = (
                spacing + layout_spacing_x
            ) * item.widget().isVisible()  # If an item isn't visible, it does not have any influence on the next
            space_y = spacing + layout_spacing_y
            next_x = x + item.sizeHint().width() + space_x
            if next_x - space_x > rect.right() and line_height > 0:
                rows.append(
                    (row, rect.right() - x - space_x, line_height)
                )  # We need to remove the unnecessary extra padding from all rows, not just the last
                row = []
                x = rect.x()
                y = y + line_height + space_y
                next_x = x + item.sizeHint().width() + space_x
                line_height = 0

            if not test_only:
                item.setGeometry(QRect(QPoint(x, y), item.sizeHint()))

            x = next_x
            line_height = max(line_height, item.sizeHint().height())
            row.append(item)

        rows.append((row, rect.right() - x - space_x, line_height))

        if not test_only and self.center:
            for items, x_margin, y_size in rows:
                x_margin /= 2
                for item in items:
                    r = item.geometry()
                    new_y = r.y()
                    if r.height() < y_size:
                        new_y += (y_size - r.height()) / 2
                    item.setGeometry(QRect(QPoint(r.x() + x_margin, new_y), item.sizeHint()))

        return y + line_height - rect.y()
