# Source code for fontTools.afmLib

    """Module for reading and writing AFM (Adobe Font Metrics) files.

    Note that this has been designed to read in AFM files generated by Fontographer
    and has not been tested on many other files. In particular, it does not
    implement the whole Adobe AFM specification [#f1]_ but, it should read most
    "common" AFM files.

    Here is an example of using `afmLib` to read, modify and write an AFM file:

    	>>> from fontTools.afmLib import AFM
    	>>> f = AFM("Tests/afmLib/data/TestAFM.afm")
    	>>>
    	>>> # Accessing a pair gets you the kern value
    	>>> f[("V","A")]
    	-60
    	>>>
    	>>> # Accessing a glyph name gets you metrics
    	>>> f["A"]
    	(65, 668, (8, -25, 660, 666))
    	>>> # (charnum, width, bounding box)
    	>>>
    	>>> # Accessing an attribute gets you metadata
    	>>> f.FontName
    	'TestFont-Regular'
    	>>> f.FamilyName
    	'TestFont'
    	>>> f.Weight
    	'Regular'
    	>>> f.XHeight
    	500
    	>>> f.Ascender
    	750
    	>>>
    	>>> # Attributes and items can also be set
    	>>> f[("A","V")] = -150 # Tighten kerning
    	>>> f.FontName = "TestFont Squished"
    	>>>
    	>>> # And the font written out again (remove the # in front)
    	>>> #f.write("testfont-squished.afm")

    .. rubric:: Footnotes

    .. [#f1] `Adobe Technote 5004 <https://www.adobe.com/content/dam/acom/en/devnet/font/pdfs/5004.AFM_Spec.pdf>`_,
       Adobe Font Metrics File Format Specification.

    """

    import re

    # every single line starts with a "word"
    identifierRE = re.compile(r"^([A-Za-z]+).*")

    # regular expression to parse char lines
    charRE = re.compile(
        r"(-?\d+)"  # charnum
        r"\s*;\s*WX\s+"  # ; WX
        r"(-?\d+)"  # width
        r"\s*;\s*N\s+"  # ; N
        r"([.A-Za-z0-9_]+)"  # charname
        r"\s*;\s*B\s+"  # ; B
        r"(-?\d+)"  # left
        r"\s+"
        r"(-?\d+)"  # bottom
        r"\s+"
        r"(-?\d+)"  # right
        r"\s+"
        r"(-?\d+)"  # top
        r"\s*;\s*"  # ;
    )

    # regular expression to parse kerning lines
    kernRE = re.compile(
        r"([.A-Za-z0-9_]+)"  # leftchar
        r"\s+"
        r"([.A-Za-z0-9_]+)"  # rightchar
        r"\s+"
        r"(-?\d+)"  # value
        r"\s*"
    )

    # regular expressions to parse composite info lines of the form:
    # Aacute 2 ; PCC A 0 0 ; PCC acute 182 211 ;
    compositeRE = re.compile(
        r"([.A-Za-z0-9_]+)"  # char name
        r"\s+"
        r"(\d+)"  # number of parts
        r"\s*;\s*"
    )
    componentRE = re.compile(
        r"PCC\s+"  # PPC
        r"([.A-Za-z0-9_]+)"  # base char name
        r"\s+"
        r"(-?\d+)"  # x offset
        r"\s+"
        r"(-?\d+)"  # y offset
        r"\s*;\s*"
    )

    preferredAttributeOrder = [
        "FontName",
        "FullName",
        "FamilyName",
        "Weight",
        "ItalicAngle",
        "IsFixedPitch",
        "FontBBox",
        "UnderlinePosition",
        "UnderlineThickness",
        "Version",
        "Notice",
        "EncodingScheme",
        "CapHeight",
        "XHeight",
        "Ascender",
        "Descender",
    ]

    class error(Exception):
        pass

    class AFM(object):
        _attrs = None

        _keywords = [
            "StartFontMetrics",
            "EndFontMetrics",
            "StartCharMetrics",
            "EndCharMetrics",
            "StartKernData",
            "StartKernPairs",
            "EndKernPairs",
            "EndKernData",
            "StartComposites",
            "EndComposites",
        ]

        def __init__(self, path=None):
            """AFM file reader.

            Instantiating an object with a path name will cause the file to be opened,
            read, and parsed. Alternatively the path can be left unspecified, and a
            file can be parsed later with the :meth:`read` method."""
            self._attrs = {}
            self._chars = {}
            self._kerning = {}
            self._index = {}
            self._comments = []
            self._composites = {}
            if path is not None:
                self.read(path)

        def read(self, path):
            """Opens, reads and parses a file."""
            lines = readlines(path)
            for line in lines:
                if not line.strip():
                    continue
                m = identifierRE.match(line)
                if m is None:
                    raise error("syntax error in AFM file: " + repr(line))

                pos = m.regs[1][1]
                word = line[:pos]
                rest = line[pos:].strip()
                if word in self._keywords:
                    continue
                if word == "C":
                    self.parsechar(rest)
                elif word == "KPX":
                    self.parsekernpair(rest)
                elif word == "CC":
                    self.parsecomposite(rest)
                else:
                    self.parseattr(word, rest)

        def parsechar(self, rest):
            m = charRE.match(rest)
            if m is None:
                raise error("syntax error in AFM file: " + repr(rest))
            things = []
            for fr, to in m.regs[1:]:
                things.append(rest[fr:to])
            charname = things[2]
            del things[2]
            charnum, width, l, b, r, t = (int(thing) for thing in things)
            self._chars[charname] = charnum, width, (l, b, r, t)

        def parsekernpair(self, rest):
            m = kernRE.match(rest)
            if m is None:
                raise error("syntax error in AFM file: " + repr(rest))
            things = []
            for fr, to in m.regs[1:]:
                things.append(rest[fr:to])
            leftchar, rightchar, value = things
            value = int(value)
            self._kerning[(leftchar, rightchar)] = value

        def parseattr(self, word, rest):
            if word == "FontBBox":
                l, b, r, t = [int(thing) for thing in rest.split()]
                self._attrs[word] = l, b, r, t
            elif word == "Comment":
                self._comments.append(rest)
            else:
                try:
                    value = int(rest)
                except (ValueError, OverflowError):
                    self._attrs[word] = rest
                else:
                    self._attrs[word] = value

        def parsecomposite(self, rest):
            m = compositeRE.match(rest)
            if m is None:
                raise error("syntax error in AFM file: " + repr(rest))
            charname = m.group(1)
            ncomponents = int(m.group(2))
            rest = rest[m.regs[0][1] :]
            components = []
            while True:
                m = componentRE.match(rest)
                if m is None:
                    raise error("syntax error in AFM file: " + repr(rest))
                basechar = m.group(1)
                xoffset = int(m.group(2))
                yoffset = int(m.group(3))
                components.append((basechar, xoffset, yoffset))
                rest = rest[m.regs[0][1] :]
                if not rest:
                    break
            assert len(components) == ncomponents
            self._composites[charname] = components

        def write(self, path, sep="\r"):
            """Writes out an AFM font to the given path."""
            import time

            lines = [
                "StartFontMetrics 2.0",
                "Comment Generated by afmLib; at %s"
                % (time.strftime("%m/%d/%Y %H:%M:%S", time.localtime(time.time()))),
            ]

            # write comments, assuming (possibly wrongly!) they should
            # all appear at the top
            for comment in self._comments:
                lines.append("Comment " + comment)

            # write attributes, first the ones we know about, in
            # a preferred order
            attrs = self._attrs
            for attr in preferredAttributeOrder:
                if attr in attrs:
                    value = attrs[attr]
                    if attr == "FontBBox":
                        value = "%s %s %s %s" % value
                    lines.append(attr + " " + str(value))
            # then write the attributes we don't know about,
            # in alphabetical order
            items = sorted(attrs.items())
            for attr, value in items:
                if attr in preferredAttributeOrder:
                    continue
                lines.append(attr + " " + str(value))

            # write char metrics
            lines.append("StartCharMetrics " + repr(len(self._chars)))
            items = [
                (charnum, (charname, width, box))
                for charname, (charnum, width, box) in self._chars.items()
            ]

            def myKey(a):
                """Custom key function to make sure unencoded chars (-1)
                end up at the end of the list after sorting."""
                if a[0] == -1:
                    a = (0xFFFF,) + a[1:]  # 0xffff is an arbitrary large number
                return a

            items.sort(key=myKey)

            for charnum, (charname, width, (l, b, r, t)) in items:
                lines.append(
                    "C %d ; WX %d ; N %s ; B %d %d %d %d ;"
                    % (charnum, width, charname, l, b, r, t)
                )
            lines.append("EndCharMetrics")

            # write kerning info
            lines.append("StartKernData")
            lines.append("StartKernPairs " + repr(len(self._kerning)))
            items = sorted(self._kerning.items())
            for (leftchar, rightchar), value in items:
                lines.append("KPX %s %s %d" % (leftchar, rightchar, value))
            lines.append("EndKernPairs")
            lines.append("EndKernData")

            if self._composites:
                composites = sorted(self._composites.items())
                lines.append("StartComposites %s" % len(self._composites))
                for charname, components in composites:
                    line = "CC %s %s ;" % (charname, len(components))
                    for basechar, xoffset, yoffset in components:
                        line = line + " PCC %s %s %s ;" % (basechar, xoffset, yoffset)
                    lines.append(line)
                lines.append("EndComposites")

            lines.append("EndFontMetrics")

            writelines(path, lines, sep)

        def has_kernpair(self, pair):
            """Returns `True` if the given glyph pair (specified as a tuple) exists
            in the kerning dictionary."""
            return pair in self._kerning

        def kernpairs(self):
            """Returns a list of all kern pairs in the kerning dictionary."""
            return list(self._kerning.keys())

        def has_char(self, char):
            """Returns `True` if the given glyph exists in the font."""
            return char in self._chars

        def chars(self):
            """Returns a list of all glyph names in the font."""
            return list(self._chars.keys())

        def comments(self):
            """Returns all comments from the file."""
            return self._comments

        def addComment(self, comment):
            """Adds a new comment to the file."""
            self._comments.append(comment)

        def addComposite(self, glyphName, components):
            """Specifies that the glyph `glyphName` is made up of the given components.
            The components list should be of the following form::

                    [
                            (glyphname, xOffset, yOffset),
                            ...
                    ]

            """
            self._composites[glyphName] = components

        def __getattr__(self, attr):
            if attr in self._attrs:
                return self._attrs[attr]
            else:
                raise AttributeError(attr)

        def __setattr__(self, attr, value):
            # all attrs *not* starting with "_" are consider to be AFM keywords
            if attr[:1] == "_":
                self.__dict__[attr] = value
            else:
                self._attrs[attr] = value

        def __delattr__(self, attr):
            # all attrs *not* starting with "_" are consider to be AFM keywords
            if attr[:1] == "_":
                try:
                    del self.__dict__[attr]
                except KeyError:
                    raise AttributeError(attr)
            else:
                try:
                    del self._attrs[attr]
                except KeyError:
                    raise AttributeError(attr)

        def __getitem__(self, key):
            if isinstance(key, tuple):
                # key is a tuple, return the kernpair
                return self._kerning[key]
            else:
                # return the metrics instead
                return self._chars[key]

        def __setitem__(self, key, value):
            if isinstance(key, tuple):
                # key is a tuple, set kernpair
                self._kerning[key] = value
            else:
                # set char metrics
                self._chars[key] = value

        def __delitem__(self, key):
            if isinstance(key, tuple):
                # key is a tuple, del kernpair
                del self._kerning[key]
            else:
                # del char metrics
                del self._chars[key]

        def __repr__(self):
            if hasattr(self, "FullName"):
                return "<AFM object for %s>" % self.FullName
            else:
                return "<AFM object at %x>" % id(self)

    def readlines(path):
        with open(path, "r", encoding="ascii") as f:
            data = f.read()
        return data.splitlines()

    def writelines(path, lines, sep="\r"):
        with open(path, "w", encoding="ascii", newline=sep) as f:
            f.write("\n".join(lines) + "\n")

    if __name__ == "__main__":
        import EasyDialogs

        path = EasyDialogs.AskFileForOpen()
        if path:
            afm = AFM(path)
            char = "A"
            if afm.has_char(char):
                print(afm[char])  # print charnum, width and boundingbox
            pair = ("A", "V")
            if afm.has_kernpair(pair):
                print(afm[pair])  # print kerning value for pair
            print(afm.Version)  # various other afm entries have become attributes
            print(afm.Weight)
            # afm.comments() returns a list of all Comment lines found in the AFM
            print(afm.comments())
            # print afm.chars()
            # print afm.kernpairs()
            print(afm)
            afm.write(path + ".muck")