# Source code for PIL.IptcImagePlugin

    #
    # The Python Imaging Library.
    # $Id$
    #
    # IPTC/NAA file handling
    #
    # history:
    # 1995-10-01 fl   Created
    # 1998-03-09 fl   Cleaned up and added to PIL
    # 2002-06-18 fl   Added getiptcinfo helper
    #
    # Copyright (c) Secret Labs AB 1997-2002.
    # Copyright (c) Fredrik Lundh 1995.
    #
    # See the README file for information on usage and redistribution.
    #
    from __future__ import annotations

    from io import BytesIO
    from typing import Sequence

    from . import Image, ImageFile
    from ._binary import i16be as i16
    from ._binary import i32be as i32
    from ._deprecate import deprecate

    COMPRESSION = {1: "raw", 5: "jpeg"}

    def __getattr__(name: str) -> bytes:
        if name == "PAD":
            deprecate("IptcImagePlugin.PAD", 12)
            return b"\0\0\0\0"
        msg = f"module '{__name__}' has no attribute '{name}'"
        raise AttributeError(msg)

    #
    # Helpers

    def _i(c: bytes) -> int:
        return i32((b"\0\0\0\0" + c)[-4:])

    def _i8(c: int | bytes) -> int:
        return c if isinstance(c, int) else c[0]

    def i(c: bytes) -> int:
        """.. deprecated:: 10.2.0"""
        deprecate("IptcImagePlugin.i", 12)
        return _i(c)

    def dump(c: Sequence[int | bytes]) -> None:
        """.. deprecated:: 10.2.0"""
        deprecate("IptcImagePlugin.dump", 12)
        for i in c:
            print("%02x" % _i8(i), end=" ")
        print()

    ##
    # Image plugin for IPTC/NAA datastreams.  To read IPTC/NAA fields
    # from TIFF and JPEG files, use the <b>getiptcinfo</b> function.

    class IptcImageFile(ImageFile.ImageFile):
        format = "IPTC"
        format_description = "IPTC/NAA"

        def getint(self, key: tuple[int, int]) -> int:
            return _i(self.info[key])

        def field(self) -> tuple[tuple[int, int] | None, int]:
            #
            # get a IPTC field header
            s = self.fp.read(5)
            if not s.strip(b"\x00"):
                return None, 0

            tag = s[1], s[2]

            # syntax
            if s[0] != 0x1C or tag[0] not in [1, 2, 3, 4, 5, 6, 7, 8, 9, 240]:
                msg = "invalid IPTC/NAA file"
                raise SyntaxError(msg)

            # field size
            size = s[3]
            if size > 132:
                msg = "illegal field length in IPTC/NAA file"
                raise OSError(msg)
            elif size == 128:
                size = 0
            elif size > 128:
                size = _i(self.fp.read(size - 128))
            else:
                size = i16(s, 3)

            return tag, size

        def _open(self) -> None:
            # load descriptive fields
            while True:
                offset = self.fp.tell()
                tag, size = self.field()
                if not tag or tag == (8, 10):
                    break
                if size:
                    tagdata = self.fp.read(size)
                else:
                    tagdata = None
                if tag in self.info:
                    if isinstance(self.info[tag], list):
                        self.info[tag].append(tagdata)
                    else:
                        self.info[tag] = [self.info[tag], tagdata]
                else:
                    self.info[tag] = tagdata

            # mode
            layers = self.info[(3, 60)][0]
            component = self.info[(3, 60)][1]
            if (3, 65) in self.info:
                id = self.info[(3, 65)][0] - 1
            else:
                id = 0
            if layers == 1 and not component:
                self._mode = "L"
            elif layers == 3 and component:
                self._mode = "RGB"[id]
            elif layers == 4 and component:
                self._mode = "CMYK"[id]

            # size
            self._size = self.getint((3, 20)), self.getint((3, 30))

            # compression
            try:
                compression = COMPRESSION[self.getint((3, 120))]
            except KeyError as e:
                msg = "Unknown IPTC image compression"
                raise OSError(msg) from e

            # tile
            if tag == (8, 10):
                self.tile = [("iptc", (0, 0) + self.size, offset, compression)]

        def load(self):
            if len(self.tile) != 1 or self.tile[0][0] != "iptc":
                return ImageFile.ImageFile.load(self)

            offset, compression = self.tile[0][2:]

            self.fp.seek(offset)

            # Copy image data to temporary file
            o = BytesIO()
            if compression == "raw":
                # To simplify access to the extracted file,
                # prepend a PPM header
                o.write(b"P5\n%d %d\n255\n" % self.size)
            while True:
                type, size = self.field()
                if type != (8, 10):
                    break
                while size > 0:
                    s = self.fp.read(min(size, 8192))
                    if not s:
                        break
                    o.write(s)
                    size -= len(s)

            with Image.open(o) as _im:
                _im.load()
                self.im = _im.im

    Image.register_open(IptcImageFile.format, IptcImageFile)

    Image.register_extension(IptcImageFile.format, ".iim")

    def getiptcinfo(im):
        """
        Get IPTC information from TIFF, JPEG, or IPTC file.

        :param im: An image containing IPTC data.
        :returns: A dictionary containing IPTC information, or None if
            no IPTC information block was found.
        """
        from . import JpegImagePlugin, TiffImagePlugin

        data = None

        if isinstance(im, IptcImageFile):
            # return info dictionary right away
            return im.info

        elif isinstance(im, JpegImagePlugin.JpegImageFile):
            # extract the IPTC/NAA resource
            photoshop = im.info.get("photoshop")
            if photoshop:
                data = photoshop.get(0x0404)

        elif isinstance(im, TiffImagePlugin.TiffImageFile):
            # get raw data from the IPTC/NAA tag (PhotoShop tags the data
            # as 4-byte integers, so we cannot use the get method...)
            try:
                data = im.tag.tagdata[TiffImagePlugin.IPTC_NAA_CHUNK]
            except (AttributeError, KeyError):
                pass

        if data is None:
            return None  # no properties

        # create an IptcImagePlugin object without initializing it
        class FakeImage:
            pass

        im = FakeImage()
        im.__class__ = IptcImageFile

        # parse the IPTC information chunk
        im.info = {}
        im.fp = BytesIO(data)

        try:
            im._open()
        except (IndexError, KeyError):
            pass  # expected failure

        return im.info