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"""GlyphSets returned by a TTFont."""

from abc import ABC, abstractmethod
from collections.abc import Mapping
from contextlib import contextmanager
from copy import copy, deepcopy
from types import SimpleNamespace
from fontTools.misc.vector import Vector
from fontTools.misc.fixedTools import otRound, fixedToFloat as fi2fl
from fontTools.misc.loggingTools import deprecateFunction
from fontTools.misc.transform import Transform, DecomposedTransform
from fontTools.pens.transformPen import TransformPen, TransformPointPen
from fontTools.pens.recordingPen import (
    DecomposingRecordingPen,
    lerpRecordings,
    replayRecording,
)


def _getVariationAxes(font):
    if "fvar" in font:
        return font["fvar"].axes

    # VARC permits static fonts to retain gvar or CFF2 variation data for
    # component-internal coordinates without exposing axes through fvar.
    axisCount = 0
    gvar = font.get("GVAR" if "GVAR" in font else "gvar")
    if gvar is not None:
        axisCount = gvar.axisCount
    if "CFF2" in font:
        cff = next(iter(font["CFF2"].cff.values()))
        varStore = getattr(cff.CharStrings, "varStore", None)
        if varStore is not None:
            axisCount = max(
                axisCount, varStore.otVarStore.VarRegionList.RegionAxisCount
            )
    return [SimpleNamespace(axisTag=i) for i in range(axisCount)]


class _TTGlyphSet(Mapping):
    """Generic dict-like GlyphSet class that pulls metrics from hmtx and
    glyph shape from TrueType or CFF.
    """

    def __init__(
        self,
        font,
        location,
        glyphsMapping,
        *,
        hMetricsTag="hmtx",
        vMetricsTag="vmtx",
        recalcBounds=True,
    ):
        self.recalcBounds = recalcBounds
        self.font = font
        self.axes = _getVariationAxes(font)
        self.location = location if location is not None else {}
        self.rawLocation = {}  # VarComponent-only location
        self.originalLocation = location if location is not None else {}
        self.depth = 0
        self.locationStack = []
        self.rawLocationStack = []
        self.glyphsMapping = glyphsMapping
        self._hMetricsTag = hMetricsTag
        self._vMetricsTag = vMetricsTag
        self.hMetrics = font[hMetricsTag].metrics
        self.vMetrics = getattr(font.get(vMetricsTag), "metrics", None)
        self.hvarTable = None
        self.vvarTable = None
        if location:
            from fontTools.varLib.varStore import VarStoreInstancer

            self.hvarTable = getattr(font.get("HVAR"), "table", None)
            if self.hvarTable is not None:
                self.hvarInstancer = VarStoreInstancer(
                    self.hvarTable.VarStore, self.axes, location
                )
            self.vvarTable = getattr(font.get("VVAR"), "table", None)
            if self.vvarTable is not None:
                self.vvarInstancer = VarStoreInstancer(
                    self.vvarTable.VarStore, self.axes, location
                )
            # TODO VORG

    @contextmanager
    def pushLocation(self, location, reset: bool):
        self.locationStack.append(self.location)
        self.rawLocationStack.append(self.rawLocation)
        if reset:
            self.location = self.originalLocation.copy()
            self.rawLocation = {}
        else:
            self.location = self.location.copy()
            self.rawLocation = {}
        self.location.update(location)
        self.rawLocation.update(location)

        try:
            yield None
        finally:
            self.location = self.locationStack.pop()
            self.rawLocation = self.rawLocationStack.pop()

    @contextmanager
    def pushDepth(self):
        try:
            depth = self.depth
            self.depth += 1
            yield depth
        finally:
            self.depth -= 1

    def __contains__(self, glyphName):
        return glyphName in self.glyphsMapping

    def __iter__(self):
        return iter(self.glyphsMapping.keys())

    def __len__(self):
        return len(self.glyphsMapping)

    @deprecateFunction(
        "use 'glyphName in glyphSet' instead", category=DeprecationWarning
    )
    def has_key(self, glyphName):
        return glyphName in self.glyphsMapping


class _TTGlyphSetGlyf(_TTGlyphSet):
    def __init__(self, font, location, glyfTag, recalcBounds=True):
        self.glyfTable = font[glyfTag]
        super().__init__(
            font,
            location,
            self.glyfTable,
            hMetricsTag=self.glyfTable.hmtxTag,
            vMetricsTag=self.glyfTable.vmtxTag,
            recalcBounds=recalcBounds,
        )
        self.gvarTable = font.get(self.glyfTable.gvarTag)

    def __getitem__(self, glyphName):
        return _TTGlyphGlyf(self, glyphName, recalcBounds=self.recalcBounds)


class _TTGlyphSetCFF(_TTGlyphSet):
    def __init__(self, font, location):
        tableTag = "CFF2" if "CFF2" in font else "CFF "
        self.charStrings = list(font[tableTag].cff.values())[0].CharStrings
        super().__init__(
            font,
            location,
            self.charStrings,
            hMetricsTag="HMTX" if "HMTX" in font else "hmtx",
            vMetricsTag="VMTX" if "VMTX" in font else "vmtx",
        )
        self.setLocation(location)

    def __getitem__(self, glyphName):
        return _TTGlyphCFF(self, glyphName)

    def setLocation(self, location):
        self.blender = None
        if location:
            # TODO Optimize by using instancer.setLocation()

            from fontTools.varLib.varStore import VarStoreInstancer

            varStore = getattr(self.charStrings, "varStore", None)
            if varStore is not None:
                instancer = VarStoreInstancer(varStore.otVarStore, self.axes, location)
                self.blender = instancer.interpolateFromDeltas
        else:
            self.blender = None

    @contextmanager
    def pushLocation(self, location, reset: bool):
        try:
            with _TTGlyphSet.pushLocation(self, location, reset) as value:
                self.setLocation(self.location)
                yield value
        finally:
            # Restore the blender after the base context pops the parent location.
            self.setLocation(self.location)


class _TTGlyphSetVARC(_TTGlyphSet):
    def __init__(self, font, location, glyphSet):
        self.glyphSet = glyphSet
        super().__init__(
            font,
            location,
            dict.fromkeys(font.getGlyphOrder()),
            hMetricsTag=glyphSet._hMetricsTag,
            vMetricsTag=glyphSet._vMetricsTag,
        )
        self.varcTable = font["VARC"].table

    def __getitem__(self, glyphName):
        varc = self.varcTable
        if glyphName not in varc.Coverage.glyphs:
            return self.glyphSet[glyphName]
        return _TTGlyphVARC(self, glyphName)


class _TTGlyph(ABC):
    """Glyph object that supports the Pen protocol, meaning that it has
    .draw() and .drawPoints() methods that take a pen object as their only
    argument. Additionally there are 'width' and 'lsb' attributes, read from
    the 'hmtx' table.

    If the font contains a 'vmtx' table, there will also be 'height' and 'tsb'
    attributes.
    """

    def __init__(self, glyphSet, glyphName, *, recalcBounds=True):
        self.glyphSet = glyphSet
        self.name = glyphName
        self.recalcBounds = recalcBounds
        self.width, self.lsb = glyphSet.hMetrics[glyphName]
        if glyphSet.vMetrics is not None:
            self.height, self.tsb = glyphSet.vMetrics[glyphName]
        else:
            self.height, self.tsb = None, None
        if glyphSet.location and glyphSet.hvarTable is not None:
            varidx = (
                glyphSet.font.getGlyphID(glyphName)
                if glyphSet.hvarTable.AdvWidthMap is None
                else glyphSet.hvarTable.AdvWidthMap.mapping[glyphName]
            )
            # An implicit mapping always uses outer index zero. Oversized
            # glyph IDs must not be interpreted as packed variation indices.
            if glyphSet.hvarTable.AdvWidthMap is not None or varidx <= 0xFFFF:
                self.width += glyphSet.hvarInstancer[varidx]
        if self.height is not None and glyphSet.vvarTable is not None:
            varidx = (
                glyphSet.font.getGlyphID(glyphName)
                if glyphSet.vvarTable.AdvHeightMap is None
                else glyphSet.vvarTable.AdvHeightMap.mapping[glyphName]
            )
            if glyphSet.vvarTable.AdvHeightMap is not None or varidx <= 0xFFFF:
                self.height += glyphSet.vvarInstancer[varidx]
        # TODO: VORG

    @abstractmethod
    def draw(self, pen):
        """Draw the glyph onto ``pen``. See fontTools.pens.basePen for details
        how that works.
        """
        raise NotImplementedError

    def drawPoints(self, pen):
        """Draw the glyph onto ``pen``. See fontTools.pens.pointPen for details
        how that works.
        """
        from fontTools.pens.pointPen import SegmentToPointPen

        self.draw(SegmentToPointPen(pen))


class _TTGlyphGlyf(_TTGlyph):
    def __init__(self, glyphSet, glyphName, *, recalcBounds=True):
        super().__init__(glyphSet, glyphName, recalcBounds=recalcBounds)
        # Without HVAR the advance at a non-default location comes from the
        # gvar phantom points: compute it lazily on first access.
        if (
            glyphSet.location
            and glyphSet.hvarTable is None
            and glyphSet.gvarTable is not None
        ):
            self._width = None

    @property
    def width(self):
        if self._width is None:
            if self.name in self.glyphSet.gvarTable.variations:
                # no HVAR: this also sets self._width from the phantom points
                self._getGlyphInstance()
            else:
                # no gvar entry: glyph doesn't vary, hmtx advance is right
                self._width = self.glyphSet.hMetrics[self.name][0]
        return self._width

    @width.setter
    def width(self, value):
        self._width = value

    def draw(self, pen):
        """Draw the glyph onto ``pen``. See fontTools.pens.basePen for details
        how that works.
        """
        glyph, offset = self._getGlyphAndOffset()

        with self.glyphSet.pushDepth() as depth:
            if depth:
                offset = 0  # Offset should only apply at top-level

            glyph.draw(pen, self.glyphSet.glyfTable, offset)

    def drawPoints(self, pen):
        """Draw the glyph onto ``pen``. See fontTools.pens.pointPen for details
        how that works.
        """
        glyph, offset = self._getGlyphAndOffset()

        with self.glyphSet.pushDepth() as depth:
            if depth:
                offset = 0  # Offset should only apply at top-level

            glyph.drawPoints(pen, self.glyphSet.glyfTable, offset)

    def _getGlyphAndOffset(self):
        if self.glyphSet.location and self.glyphSet.gvarTable is not None:
            glyph = self._getGlyphInstance()
        else:
            glyph = self.glyphSet.glyfTable[self.name]

        offset = self.lsb - glyph.xMin if hasattr(glyph, "xMin") else 0
        return glyph, offset

    def _getGlyphInstance(self):
        from fontTools.varLib.iup import iup_delta
        from fontTools.ttLib.tables._g_l_y_f import GlyphCoordinates
        from fontTools.varLib.models import supportScalar

        glyphSet = self.glyphSet
        glyfTable = glyphSet.glyfTable
        variations = glyphSet.gvarTable.variations[self.name]
        hMetrics = glyphSet.hMetrics
        vMetrics = glyphSet.vMetrics
        coordinates, _ = glyfTable._getCoordinatesAndControls(
            self.name, hMetrics, vMetrics
        )
        origCoords, endPts = None, None
        for var in variations:
            scalar = supportScalar(glyphSet.location, var.axes)
            if not scalar:
                continue
            delta = var.coordinates
            if None in delta:
                if origCoords is None:
                    origCoords, control = glyfTable._getCoordinatesAndControls(
                        self.name, hMetrics, vMetrics
                    )
                    endPts = (
                        control[1] if control[0] >= 1 else list(range(len(control[1])))
                    )
                delta = iup_delta(delta, origCoords, endPts)
            coordinates += GlyphCoordinates(delta) * scalar

        glyph = copy(glyfTable[self.name])  # Shallow copy
        width, lsb, height, tsb = _setCoordinates(
            glyph, coordinates, glyfTable, recalcBounds=self.recalcBounds
        )
        self.lsb = lsb
        self.tsb = tsb
        if glyphSet.hvarTable is None:
            # no HVAR: let's set metrics from the phantom points
            self.width = width
        if glyphSet.vvarTable is None:
            self.height = height
        return glyph


class _TTGlyphCFF(_TTGlyph):
    def draw(self, pen):
        """Draw the glyph onto ``pen``. See fontTools.pens.basePen for details
        how that works.
        """
        self.glyphSet.charStrings[self.name].draw(pen, self.glyphSet.blender)


def _evaluateCondition(condition, axes, location, instancer):
    if condition is None:
        # A null condition offset denotes True.
        return True

    if condition.Format == 1:
        # ConditionAxisRange
        axisIndex = condition.AxisIndex
        axisTag = axes[axisIndex].axisTag
        axisValue = location.get(axisTag, 0)
        minValue = condition.FilterRangeMinValue
        maxValue = condition.FilterRangeMaxValue
        return minValue <= axisValue <= maxValue
    elif condition.Format == 2:
        # ConditionValue
        from fontTools.ttLib.tables.otTables import NO_VARIATION_INDEX

        value = condition.DefaultValue
        if condition.VarIdx != NO_VARIATION_INDEX:
            deltas = instancer[condition.VarIdx]
            if deltas:
                value += deltas[0]
        return value > 0
    elif condition.Format == 3:
        # ConditionAnd
        for subcondition in condition.ConditionTable:
            if not _evaluateCondition(subcondition, axes, location, instancer):
                return False
        return True
    elif condition.Format == 4:
        # ConditionOr
        for subcondition in condition.ConditionTable:
            if _evaluateCondition(subcondition, axes, location, instancer):
                return True
        return False
    elif condition.Format == 5:
        # ConditionNegate
        return not _evaluateCondition(
            condition.ConditionTable, axes, location, instancer
        )
    else:
        return False  # Unkonwn condition format


class _TTGlyphVARC(_TTGlyph):
    def _draw(self, pen, isPointPen):
        """Draw the glyph onto ``pen``. See fontTools.pens.basePen for details
        how that works.
        """
        from fontTools.ttLib.tables.otTables import (
            VarComponentFlags,
            NO_VARIATION_INDEX,
        )

        glyphSet = self.glyphSet
        varc = glyphSet.varcTable
        idx = varc.Coverage.glyphs.index(self.name)
        glyph = varc.VarCompositeGlyphs.VarCompositeGlyph[idx]

        from fontTools.varLib.multiVarStore import MultiVarStoreInstancer
        from fontTools.varLib.varStore import VarStoreInstancer

        axes = glyphSet.axes
        instancer = MultiVarStoreInstancer(
            varc.MultiVarStore, axes, self.glyphSet.location
        )

        for comp in glyph.components:
            if comp.conditionIndex is not None:
                condition = varc.ConditionList.ConditionTable[comp.conditionIndex]
                if not _evaluateCondition(
                    condition, axes, self.glyphSet.location, instancer
                ):
                    continue

            location = {}
            if comp.axisIndicesIndex is not None:
                axisIndices = varc.AxisIndicesList.Item[comp.axisIndicesIndex]
                axisValues = Vector(comp.axisValues)
                if comp.axisValuesVarIndex != NO_VARIATION_INDEX:
                    axisValues += fi2fl(instancer[comp.axisValuesVarIndex], 14)
                assert len(axisIndices) == len(axisValues), (
                    len(axisIndices),
                    len(axisValues),
                )
                location = {axes[i].axisTag: v for i, v in zip(axisIndices, axisValues)}

            if comp.transformVarIndex != NO_VARIATION_INDEX:
                deltas = instancer[comp.transformVarIndex]
                comp = deepcopy(comp)
                comp.applyTransformDeltas(deltas)
            transform = comp.transform

            reset = comp.flags & VarComponentFlags.RESET_UNSPECIFIED_AXES
            with self.glyphSet.glyphSet.pushLocation(location, reset):
                with self.glyphSet.pushLocation(location, reset):
                    shouldDecompose = self.name == comp.glyphName

                    if not shouldDecompose:
                        try:
                            kwargs = {"resetUnspecifiedAxes": True} if reset else {}
                            pen.addVarComponent(
                                comp.glyphName,
                                transform,
                                self.glyphSet.rawLocation,
                                **kwargs,
                            )
                        except AttributeError:
                            shouldDecompose = True

                    if shouldDecompose:
                        t = transform.toTransform()
                        compGlyphSet = (
                            self.glyphSet
                            if comp.glyphName != self.name
                            else glyphSet.glyphSet
                        )
                        g = compGlyphSet[comp.glyphName]
                        if isPointPen:
                            tPen = TransformPointPen(pen, t)
                            g.drawPoints(tPen)
                        else:
                            tPen = TransformPen(pen, t)
                            g.draw(tPen)

    def draw(self, pen):
        self._draw(pen, False)

    def drawPoints(self, pen):
        self._draw(pen, True)


def _setCoordinates(glyph, coord, glyfTable, *, recalcBounds=True):
    # Handle phantom points for (left, right, top, bottom) positions.
    assert len(coord) >= 4
    leftSideX = coord[-4][0]
    rightSideX = coord[-3][0]
    topSideY = coord[-2][1]
    bottomSideY = coord[-1][1]

    for _ in range(4):
        del coord[-1]

    if glyph.isComposite():
        assert len(coord) == len(glyph.components)
        glyph.components = [copy(comp) for comp in glyph.components]  # Shallow copy
        for p, comp in zip(coord, glyph.components):
            if hasattr(comp, "x"):
                comp.x, comp.y = p
    elif glyph.numberOfContours == 0:
        assert len(coord) == 0
    else:
        assert len(coord) == len(glyph.coordinates)
        glyph.coordinates = coord

    if recalcBounds:
        glyph.recalcBounds(glyfTable)

    horizontalAdvanceWidth = otRound(rightSideX - leftSideX)
    verticalAdvanceWidth = otRound(topSideY - bottomSideY)
    leftSideBearing = otRound(glyph.xMin - leftSideX)
    topSideBearing = otRound(topSideY - glyph.yMax)
    return (
        horizontalAdvanceWidth,
        leftSideBearing,
        verticalAdvanceWidth,
        topSideBearing,
    )


class LerpGlyphSet(Mapping):
    """A glyphset that interpolates between two other glyphsets.

    Factor is typically between 0 and 1. 0 means the first glyphset,
    1 means the second glyphset, and 0.5 means the average of the
    two glyphsets. Other values are possible, and can be useful to
    extrapolate. Defaults to 0.5.
    """

    def __init__(self, glyphset1, glyphset2, factor=0.5):
        self.glyphset1 = glyphset1
        self.glyphset2 = glyphset2
        self.factor = factor

    def __getitem__(self, glyphname):
        if glyphname in self.glyphset1 and glyphname in self.glyphset2:
            return LerpGlyph(glyphname, self)
        raise KeyError(glyphname)

    def __contains__(self, glyphname):
        return glyphname in self.glyphset1 and glyphname in self.glyphset2

    def __iter__(self):
        set1 = set(self.glyphset1)
        set2 = set(self.glyphset2)
        return iter(set1.intersection(set2))

    def __len__(self):
        set1 = set(self.glyphset1)
        set2 = set(self.glyphset2)
        return len(set1.intersection(set2))


class LerpGlyph:
    def __init__(self, glyphname, glyphset):
        self.glyphset = glyphset
        self.glyphname = glyphname

    def draw(self, pen):
        recording1 = DecomposingRecordingPen(self.glyphset.glyphset1)
        self.glyphset.glyphset1[self.glyphname].draw(recording1)
        recording2 = DecomposingRecordingPen(self.glyphset.glyphset2)
        self.glyphset.glyphset2[self.glyphname].draw(recording2)

        factor = self.glyphset.factor

        replayRecording(lerpRecordings(recording1.value, recording2.value, factor), pen)