# Source code for fontTools.pens.filterPen

    from __future__ import annotations

    from fontTools.pens.basePen import AbstractPen, DecomposingPen
    from fontTools.pens.pointPen import (
        AbstractPointPen,
        DecomposingPointPen,
        ReverseFlipped,
    )
    from fontTools.pens.recordingPen import RecordingPen

    class _PassThruComponentsMixin(object):
        def addComponent(self, glyphName, transformation, **kwargs):
            self._outPen.addComponent(glyphName, transformation, **kwargs)

    class FilterPen(_PassThruComponentsMixin, AbstractPen):
        """Base class for pens that apply some transformation to the coordinates
        they receive and pass them to another pen.

        You can override any of its methods. The default implementation does
        nothing, but passes the commands unmodified to the other pen.

        >>> from fontTools.pens.recordingPen import RecordingPen
        >>> rec = RecordingPen()
        >>> pen = FilterPen(rec)
        >>> v = iter(rec.value)

        >>> pen.moveTo((0, 0))
        >>> next(v)
        ('moveTo', ((0, 0),))

        >>> pen.lineTo((1, 1))
        >>> next(v)
        ('lineTo', ((1, 1),))

        >>> pen.curveTo((2, 2), (3, 3), (4, 4))
        >>> next(v)
        ('curveTo', ((2, 2), (3, 3), (4, 4)))

        >>> pen.qCurveTo((5, 5), (6, 6), (7, 7), (8, 8))
        >>> next(v)
        ('qCurveTo', ((5, 5), (6, 6), (7, 7), (8, 8)))

        >>> pen.closePath()
        >>> next(v)
        ('closePath', ())

        >>> pen.moveTo((9, 9))
        >>> next(v)
        ('moveTo', ((9, 9),))

        >>> pen.endPath()
        >>> next(v)
        ('endPath', ())

        >>> pen.addComponent('foo', (1, 0, 0, 1, 0, 0))
        >>> next(v)
        ('addComponent', ('foo', (1, 0, 0, 1, 0, 0)))
        """

        def __init__(self, outPen):
            self._outPen = outPen
            self.current_pt = None

        def moveTo(self, pt):
            self._outPen.moveTo(pt)
            self.current_pt = pt

        def lineTo(self, pt):
            self._outPen.lineTo(pt)
            self.current_pt = pt

        def curveTo(self, *points):
            self._outPen.curveTo(*points)
            self.current_pt = points[-1]

        def qCurveTo(self, *points):
            self._outPen.qCurveTo(*points)
            self.current_pt = points[-1]

        def closePath(self):
            self._outPen.closePath()
            self.current_pt = None

        def endPath(self):
            self._outPen.endPath()
            self.current_pt = None

    class ContourFilterPen(_PassThruComponentsMixin, RecordingPen):
        """A "buffered" filter pen that accumulates contour data, passes
        it through a ``filterContour`` method when the contour is closed or ended,
        and finally draws the result with the output pen.

        Components are passed through unchanged.
        """

        def __init__(self, outPen):
            super(ContourFilterPen, self).__init__()
            self._outPen = outPen

        def closePath(self):
            super(ContourFilterPen, self).closePath()
            self._flushContour()

        def endPath(self):
            super(ContourFilterPen, self).endPath()
            self._flushContour()

        def _flushContour(self):
            result = self.filterContour(self.value)
            if result is not None:
                self.value = result
            self.replay(self._outPen)
            self.value = []

        def filterContour(self, contour):
            """Subclasses must override this to perform the filtering.

            The contour is a list of pen (operator, operands) tuples.
            Operators are strings corresponding to the AbstractPen methods:
            "moveTo", "lineTo", "curveTo", "qCurveTo", "closePath" and
            "endPath". The operands are the positional arguments that are
            passed to each method.

            If the method doesn't return a value (i.e. returns None), it's
            assumed that the argument was modified in-place.
            Otherwise, the return value is drawn with the output pen.
            """
            return  # or return contour

    class FilterPointPen(_PassThruComponentsMixin, AbstractPointPen):
        """Baseclass for point pens that apply some transformation to the
        coordinates they receive and pass them to another point pen.

        You can override any of its methods. The default implementation does
        nothing, but passes the commands unmodified to the other pen.

        >>> from fontTools.pens.recordingPen import RecordingPointPen
        >>> rec = RecordingPointPen()
        >>> pen = FilterPointPen(rec)
        >>> v = iter(rec.value)
        >>> pen.beginPath(identifier="abc")
        >>> next(v)
        ('beginPath', (), {'identifier': 'abc'})
        >>> pen.addPoint((1, 2), "line", False)
        >>> next(v)
        ('addPoint', ((1, 2), 'line', False, None), {})
        >>> pen.addComponent("a", (2, 0, 0, 2, 10, -10), identifier="0001")
        >>> next(v)
        ('addComponent', ('a', (2, 0, 0, 2, 10, -10)), {'identifier': '0001'})
        >>> pen.endPath()
        >>> next(v)
        ('endPath', (), {})
        """

        def __init__(self, outPen):
            self._outPen = outPen

        def beginPath(self, identifier=None, **kwargs):
            kwargs = dict(kwargs)
            if identifier is not None:
                kwargs["identifier"] = identifier
            self._outPen.beginPath(**kwargs)

        def endPath(self):
            self._outPen.endPath()

        def addPoint(
            self,
            pt,
            segmentType=None,
            smooth=False,
            name=None,
            identifier=None,
            **kwargs,
        ):
            kwargs = dict(kwargs)
            if identifier is not None:
                kwargs["identifier"] = identifier
            self._outPen.addPoint(pt, segmentType, smooth, name, **kwargs)

    class _DecomposingFilterMixinBase:
        """Base mixin class with common `addComponent` logic for decomposing filter pens."""

        def addComponent(self, baseGlyphName, transformation, **kwargs):
            # only decompose the component if it's included in the set
            if self.include is None or baseGlyphName in self.include:
                # if we're decomposing nested components, temporarily set include to None
                include_bak = self.include
                if self.decomposeNested and self.include:
                    self.include = None
                try:
                    super().addComponent(baseGlyphName, transformation, **kwargs)
                finally:
                    if self.include != include_bak:
                        self.include = include_bak
            else:
                _PassThruComponentsMixin.addComponent(
                    self, baseGlyphName, transformation, **kwargs
                )

    class _DecomposingFilterPenMixin(_DecomposingFilterMixinBase):
        """Mixin class that decomposes components as regular contours for segment pens.

        Used by DecomposingFilterPen.

        Takes two required parameters, another segment pen 'outPen' to draw
        with, and a 'glyphSet' dict of drawable glyph objects to draw components from.

        The 'skipMissingComponents' and 'reverseFlipped' optional arguments work the
        same as in the DecomposingPen. reverseFlipped is bool only (True/False).

        In addition, the decomposing filter pens also take the following two options:

        'include' is an optional set of component base glyph names to consider for
        decomposition; the default include=None means decompose all components no matter
        the base glyph name).

        'decomposeNested' (bool) controls whether to recurse decomposition into nested
        components of components (this only matters when 'include' was also provided);
        if False, only decompose top-level components included in the set, but not
        also their children.
        """

        # raises MissingComponentError if base glyph is not found in glyphSet
        skipMissingComponents = False

        def __init__(
            self,
            outPen,
            glyphSet,
            skipMissingComponents=None,
            reverseFlipped: bool = False,
            include: set[str] | None = None,
            decomposeNested: bool = True,
            **kwargs,
        ):
            assert isinstance(
                reverseFlipped, bool
            ), f"Expected bool, got {type(reverseFlipped).__name__}"
            super().__init__(
                outPen=outPen,
                glyphSet=glyphSet,
                skipMissingComponents=skipMissingComponents,
                reverseFlipped=reverseFlipped,
                **kwargs,
            )
            self.include = include
            self.decomposeNested = decomposeNested

    class _DecomposingFilterPointPenMixin(_DecomposingFilterMixinBase):
        """Mixin class that decomposes components as regular contours for point pens.

        Takes two required parameters, another point pen 'outPen' to draw
        with, and a 'glyphSet' dict of drawable glyph objects to draw components from.

        The 'skipMissingComponents' and 'reverseFlipped' optional arguments work the
        same as in the DecomposingPointPen. reverseFlipped accepts bool | ReverseFlipped
        (see DecomposingPointPen).

        In addition, the decomposing filter pens also take the following two options:

        'include' is an optional set of component base glyph names to consider for
        decomposition; the default include=None means decompose all components no matter
        the base glyph name).

        'decomposeNested' (bool) controls whether to recurse decomposition into nested
        components of components (this only matters when 'include' was also provided);
        if False, only decompose top-level components included in the set, but not
        also their children.
        """

        # raises MissingComponentError if base glyph is not found in glyphSet
        skipMissingComponents = False

        def __init__(
            self,
            outPen,
            glyphSet,
            skipMissingComponents=None,
            reverseFlipped: bool | ReverseFlipped = False,
            include: set[str] | None = None,
            decomposeNested: bool = True,
            **kwargs,
        ):
            super().__init__(
                outPen=outPen,
                glyphSet=glyphSet,
                skipMissingComponents=skipMissingComponents,
                reverseFlipped=reverseFlipped,
                **kwargs,
            )
            self.include = include
            self.decomposeNested = decomposeNested

    class DecomposingFilterPen(_DecomposingFilterPenMixin, DecomposingPen, FilterPen):
        """Filter pen that draws components as regular contours."""

        pass

    class DecomposingFilterPointPen(
        _DecomposingFilterPointPenMixin, DecomposingPointPen, FilterPointPen
    ):
        """Filter point pen that draws components as regular contours."""

        pass

    class ContourFilterPointPen(_PassThruComponentsMixin, AbstractPointPen):
        """A "buffered" filter point pen that accumulates contour data, passes
        it through a ``filterContour`` method when the contour is closed or ended,
        and finally draws the result with the output point pen.

        Components are passed through unchanged.

        The ``filterContour`` method can modify the contour in-place (return None)
        or return a new contour to replace it.
        """

        def __init__(self, outPen):
            self._outPen = outPen
            self.currentContour = None
            self.currentContourKwargs = None

        def beginPath(self, identifier=None, **kwargs):
            if self.currentContour is not None:
                raise ValueError("Path already begun")
            kwargs = dict(kwargs)
            if identifier is not None:
                kwargs["identifier"] = identifier
            self.currentContour = []
            self.currentContourKwargs = kwargs

        def endPath(self):
            if self.currentContour is None:
                raise ValueError("Path not begun")
            self._flushContour()
            self.currentContour = None
            self.currentContourKwargs = None

        def _flushContour(self):
            """Flush the current contour to the output pen."""
            result = self.filterContour(self.currentContour)
            if result is not None:
                self.currentContour = result

            # Draw the filtered contour
            self._outPen.beginPath(**self.currentContourKwargs)
            for pt, segmentType, smooth, name, kwargs in self.currentContour:
                self._outPen.addPoint(pt, segmentType, smooth, name, **kwargs)
            self._outPen.endPath()

        def filterContour(self, contour):
            """Subclasses must override this to perform the filtering.

            The contour is a list of (pt, segmentType, smooth, name, kwargs) tuples.
            If the method doesn't return a value (i.e. returns None), it's
            assumed that the contour was modified in-place.
            Otherwise, the return value replaces the original contour.
            """
            return  # or return contour

        def addPoint(
            self,
            pt,
            segmentType=None,
            smooth=False,
            name=None,
            identifier=None,
            **kwargs,
        ):
            if self.currentContour is None:
                raise ValueError("Path not begun")
            kwargs = dict(kwargs)
            if identifier is not None:
                kwargs["identifier"] = identifier
            self.currentContour.append((pt, segmentType, smooth, name, kwargs))

    class OnCurveFirstPointPen(ContourFilterPointPen):
        """Filter point pen that ensures closed contours start with an on-curve point.

        If a closed contour starts with an off-curve point (segmentType=None), it rotates
        the points list so that the first on-curve point (segmentType != None) becomes
        the start point. Open contours and contours already starting with on-curve points
        are passed through unchanged.

        >>> from fontTools.pens.recordingPen import RecordingPointPen
        >>> rec = RecordingPointPen()
        >>> pen = OnCurveFirstPointPen(rec)
        >>> # Closed contour starting with off-curve - will be rotated
        >>> pen.beginPath()
        >>> pen.addPoint((0, 0), None)  # off-curve
        >>> pen.addPoint((100, 100), "line")  # on-curve - will become start
        >>> pen.addPoint((200, 0), None)  # off-curve
        >>> pen.addPoint((300, 100), "curve")  # on-curve
        >>> pen.endPath()
        >>> # The contour should now start with (100, 100) "line"
        >>> rec.value[0]
        ('beginPath', (), {})
        >>> rec.value[1]
        ('addPoint', ((100, 100), 'line', False, None), {})
        >>> rec.value[2]
        ('addPoint', ((200, 0), None, False, None), {})
        >>> rec.value[3]
        ('addPoint', ((300, 100), 'curve', False, None), {})
        >>> rec.value[4]
        ('addPoint', ((0, 0), None, False, None), {})
        """

        def filterContour(self, contour):
            """Rotate closed contour to start with first on-curve point if needed."""
            if not contour:
                return

            # Check if it's a closed contour (no "move" segmentType)
            is_closed = contour[0][1] != "move"

            if is_closed and contour[0][1] is None:
                # Closed contour starting with off-curve - need to rotate
                # Find the first on-curve point
                for i, (pt, segmentType, smooth, name, kwargs) in enumerate(contour):
                    if segmentType is not None:
                        # Rotate the points list so it starts with the first on-curve point
                        return contour[i:] + contour[:i]