# Source code for PIL.PcfFontFile

    #
    # THIS IS WORK IN PROGRESS
    #
    # The Python Imaging Library
    # $Id$
    #
    # portable compiled font file parser
    #
    # history:
    # 1997-08-19 fl   created
    # 2003-09-13 fl   fixed loading of unicode fonts
    #
    # Copyright (c) 1997-2003 by Secret Labs AB.
    # Copyright (c) 1997-2003 by Fredrik Lundh.
    #
    # See the README file for information on usage and redistribution.
    #

    import io

    from . import FontFile, Image
    from ._binary import i8
    from ._binary import i16be as b16
    from ._binary import i16le as l16
    from ._binary import i32be as b32
    from ._binary import i32le as l32

    # --------------------------------------------------------------------
    # declarations

    PCF_MAGIC = 0x70636601  # "\x01fcp"

    PCF_PROPERTIES = 1 << 0
    PCF_ACCELERATORS = 1 << 1
    PCF_METRICS = 1 << 2
    PCF_BITMAPS = 1 << 3
    PCF_INK_METRICS = 1 << 4
    PCF_BDF_ENCODINGS = 1 << 5
    PCF_SWIDTHS = 1 << 6
    PCF_GLYPH_NAMES = 1 << 7
    PCF_BDF_ACCELERATORS = 1 << 8

    BYTES_PER_ROW = [
        lambda bits: ((bits + 7) >> 3),
        lambda bits: ((bits + 15) >> 3) & ~1,
        lambda bits: ((bits + 31) >> 3) & ~3,
        lambda bits: ((bits + 63) >> 3) & ~7,
    ]

    def sz(s, o):
        return s[o : s.index(b"\0", o)]

    class PcfFontFile(FontFile.FontFile):
        """Font file plugin for the X11 PCF format."""

        name = "name"

        def __init__(self, fp, charset_encoding="iso8859-1"):

            self.charset_encoding = charset_encoding

            magic = l32(fp.read(4))
            if magic != PCF_MAGIC:
                raise SyntaxError("not a PCF file")

            super().__init__()

            count = l32(fp.read(4))
            self.toc = {}
            for i in range(count):
                type = l32(fp.read(4))
                self.toc[type] = l32(fp.read(4)), l32(fp.read(4)), l32(fp.read(4))

            self.fp = fp

            self.info = self._load_properties()

            metrics = self._load_metrics()
            bitmaps = self._load_bitmaps(metrics)
            encoding = self._load_encoding()

            #
            # create glyph structure

            for ch in range(256):
                ix = encoding[ch]
                if ix is not None:
                    x, y, l, r, w, a, d, f = metrics[ix]
                    glyph = (w, 0), (l, d - y, x + l, d), (0, 0, x, y), bitmaps[ix]
                    self.glyph[ch] = glyph

        def _getformat(self, tag):

            format, size, offset = self.toc[tag]

            fp = self.fp
            fp.seek(offset)

            format = l32(fp.read(4))

            if format & 4:
                i16, i32 = b16, b32
            else:
                i16, i32 = l16, l32

            return fp, format, i16, i32

        def _load_properties(self):

            #
            # font properties

            properties = {}

            fp, format, i16, i32 = self._getformat(PCF_PROPERTIES)

            nprops = i32(fp.read(4))

            # read property description
            p = []
            for i in range(nprops):
                p.append((i32(fp.read(4)), i8(fp.read(1)), i32(fp.read(4))))
            if nprops & 3:
                fp.seek(4 - (nprops & 3), io.SEEK_CUR)  # pad

            data = fp.read(i32(fp.read(4)))

            for k, s, v in p:
                k = sz(data, k)
                if s:
                    v = sz(data, v)
                properties[k] = v

            return properties

        def _load_metrics(self):

            #
            # font metrics

            metrics = []

            fp, format, i16, i32 = self._getformat(PCF_METRICS)

            append = metrics.append

            if (format & 0xFF00) == 0x100:

                # "compressed" metrics
                for i in range(i16(fp.read(2))):
                    left = i8(fp.read(1)) - 128
                    right = i8(fp.read(1)) - 128
                    width = i8(fp.read(1)) - 128
                    ascent = i8(fp.read(1)) - 128
                    descent = i8(fp.read(1)) - 128
                    xsize = right - left
                    ysize = ascent + descent
                    append((xsize, ysize, left, right, width, ascent, descent, 0))

            else:

                # "jumbo" metrics
                for i in range(i32(fp.read(4))):
                    left = i16(fp.read(2))
                    right = i16(fp.read(2))
                    width = i16(fp.read(2))
                    ascent = i16(fp.read(2))
                    descent = i16(fp.read(2))
                    attributes = i16(fp.read(2))
                    xsize = right - left
                    ysize = ascent + descent
                    append((xsize, ysize, left, right, width, ascent, descent, attributes))

            return metrics

        def _load_bitmaps(self, metrics):

            #
            # bitmap data

            bitmaps = []

            fp, format, i16, i32 = self._getformat(PCF_BITMAPS)

            nbitmaps = i32(fp.read(4))

            if nbitmaps != len(metrics):
                raise OSError("Wrong number of bitmaps")

            offsets = []
            for i in range(nbitmaps):
                offsets.append(i32(fp.read(4)))

            bitmapSizes = []
            for i in range(4):
                bitmapSizes.append(i32(fp.read(4)))

            # byteorder = format & 4  # non-zero => MSB
            bitorder = format & 8  # non-zero => MSB
            padindex = format & 3

            bitmapsize = bitmapSizes[padindex]
            offsets.append(bitmapsize)

            data = fp.read(bitmapsize)

            pad = BYTES_PER_ROW[padindex]
            mode = "1;R"
            if bitorder:
                mode = "1"

            for i in range(nbitmaps):
                x, y, l, r, w, a, d, f = metrics[i]
                b, e = offsets[i], offsets[i + 1]
                bitmaps.append(Image.frombytes("1", (x, y), data[b:e], "raw", mode, pad(x)))

            return bitmaps

        def _load_encoding(self):

            # map character code to bitmap index
            encoding = [None] * 256

            fp, format, i16, i32 = self._getformat(PCF_BDF_ENCODINGS)

            firstCol, lastCol = i16(fp.read(2)), i16(fp.read(2))
            firstRow, lastRow = i16(fp.read(2)), i16(fp.read(2))

            i16(fp.read(2))  # default

            nencoding = (lastCol - firstCol + 1) * (lastRow - firstRow + 1)

            encodingOffsets = [i16(fp.read(2)) for _ in range(nencoding)]

            for i in range(firstCol, len(encoding)):
                try:
                    encodingOffset = encodingOffsets[
                        ord(bytearray([i]).decode(self.charset_encoding))
                    ]
                    if encodingOffset != 0xFFFF:
                        encoding[i] = encodingOffset
                except UnicodeDecodeError:
                    # character is not supported in selected encoding
                    pass

            return encoding