#
# The Python Imaging Library.
# $Id$
#
# PIL raster font management
#
# History:
# 1996-08-07 fl   created (experimental)
# 1997-08-25 fl   minor adjustments to handle fonts from pilfont 0.3
# 1999-02-06 fl   rewrote most font management stuff in C
# 1999-03-17 fl   take pth files into account in load_path (from Richard Jones)
# 2001-02-17 fl   added freetype support
# 2001-05-09 fl   added TransposedFont wrapper class
# 2002-03-04 fl   make sure we have a "L" or "1" font
# 2002-12-04 fl   skip non-directory entries in the system path
# 2003-04-29 fl   add embedded default font
# 2003-09-27 fl   added support for truetype charmap encodings
#
# Todo:
# Adapt to PILFONT2 format (16-bit fonts, compressed, single file)
#
# Copyright (c) 1997-2003 by Secret Labs AB
# Copyright (c) 1996-2003 by Fredrik Lundh
#
# See the README file for information on usage and redistribution.
#

from . import Image
from ._util import isDirectory, isPath, py3
import os
import sys

LAYOUT_BASIC = 0
LAYOUT_RAQM = 1


class _imagingft_not_installed(object):
    # module placeholder
    def __getattr__(self, id):
        raise ImportError("The _imagingft C module is not installed")


try:
    from . import _imagingft as core
except ImportError:
    core = _imagingft_not_installed()


# FIXME: add support for pilfont2 format (see FontFile.py)

# --------------------------------------------------------------------
# Font metrics format:
#       "PILfont" LF
#       fontdescriptor LF
#       (optional) key=value... LF
#       "DATA" LF
#       binary data: 256*10*2 bytes (dx, dy, dstbox, srcbox)
#
# To place a character, cut out srcbox and paste at dstbox,
# relative to the character position.  Then move the character
# position according to dx, dy.
# --------------------------------------------------------------------


class ImageFont(object):
    "PIL font wrapper"

    def _load_pilfont(self, filename):

        with open(filename, "rb") as fp:
            for ext in (".png", ".gif", ".pbm"):
                try:
                    fullname = os.path.splitext(filename)[0] + ext
                    image = Image.open(fullname)
                except Exception:
                    pass
                else:
                    if image and image.mode in ("1", "L"):
                        break
            else:
                raise IOError("cannot find glyph data file")

            self.file = fullname

            return self._load_pilfont_data(fp, image)

    def _load_pilfont_data(self, file, image):

        # read PILfont header
        if file.readline() != b"PILfont\n":
            raise SyntaxError("Not a PILfont file")
        file.readline().split(b";")
        self.info = []  # FIXME: should be a dictionary
        while True:
            s = file.readline()
            if not s or s == b"DATA\n":
                break
            self.info.append(s)

        # read PILfont metrics
        data = file.read(256 * 20)

        # check image
        if image.mode not in ("1", "L"):
            raise TypeError("invalid font image mode")

        image.load()

        self.font = Image.core.font(image.im, data)

    def getsize(self, text, *args, **kwargs):
        return self.font.getsize(text)

    def getmask(self, text, mode="", *args, **kwargs):
        return self.font.getmask(text, mode)


##
# Wrapper for FreeType fonts.  Application code should use the
# <b>truetype</b> factory function to create font objects.


class FreeTypeFont(object):
    "FreeType font wrapper (requires _imagingft service)"

    def __init__(self, font=None, size=10, index=0, encoding="", layout_engine=None):
        # FIXME: use service provider instead

        self.path = font
        self.size = size
        self.index = index
        self.encoding = encoding

        if layout_engine not in (LAYOUT_BASIC, LAYOUT_RAQM):
            layout_engine = LAYOUT_BASIC
            if core.HAVE_RAQM:
                layout_engine = LAYOUT_RAQM
        elif layout_engine == LAYOUT_RAQM and not core.HAVE_RAQM:
            layout_engine = LAYOUT_BASIC

        self.layout_engine = layout_engine

        def load_from_bytes(f):
            self.font_bytes = f.read()
            self.font = core.getfont(
                "", size, index, encoding, self.font_bytes, layout_engine
            )

        if isPath(font):
            if sys.platform == "win32":
                font_bytes_path = font if isinstance(font, bytes) else font.encode()
                try:
                    font_bytes_path.decode("ascii")
                except UnicodeDecodeError:
                    # FreeType cannot load fonts with non-ASCII characters on Windows
                    # So load it into memory first
                    with open(font, "rb") as f:
                        load_from_bytes(f)
                    return
            self.font = core.getfont(
                font, size, index, encoding, layout_engine=layout_engine
            )
        else:
            load_from_bytes(font)

    def _multiline_split(self, text):
        split_character = "\n" if isinstance(text, str) else b"\n"
        return text.split(split_character)

    def getname(self):
        """
        :return: A tuple of the font family (e.g. Helvetica) and the font style
            (e.g. Bold)
        """
        return self.font.family, self.font.style

    def getmetrics(self):
        """
        :return: A tuple of the font ascent (the distance from the baseline to
            the highest outline point) and descent (the distance from the
            baseline to the lowest outline point, a negative value)
        """
        return self.font.ascent, self.font.descent

    def getsize(self, text, direction=None, features=None, language=None):
        """
        Returns width and height (in pixels) of given text if rendered in font with
        provided direction, features, and language.

        :param text: Text to measure.

        :param direction: Direction of the text. It can be 'rtl' (right to
                          left), 'ltr' (left to right) or 'ttb' (top to bottom).
                          Requires libraqm.

                          .. versionadded:: 4.2.0

        :param features: A list of OpenType font features to be used during text
                         layout. This is usually used to turn on optional
                         font features that are not enabled by default,
                         for example 'dlig' or 'ss01', but can be also
                         used to turn off default font features for
                         example '-liga' to disable ligatures or '-kern'
                         to disable kerning.  To get all supported
                         features, see
                         https://docs.microsoft.com/en-us/typography/opentype/spec/featurelist
                         Requires libraqm.

                         .. versionadded:: 4.2.0

        :param language: Language of the text. Different languages may use
                         different glyph shapes or ligatures. This parameter tells
                         the font which language the text is in, and to apply the
                         correct substitutions as appropriate, if available.
                         It should be a `BCP 47 language code
                         <https://www.w3.org/International/articles/language-tags/>`
                         Requires libraqm.

                         .. versionadded:: 6.0.0

        :return: (width, height)
        """
        size, offset = self.font.getsize(text, direction, features, language)
        return (size[0] + offset[0], size[1] + offset[1])

    def getsize_multiline(
        self, text, direction=None, spacing=4, features=None, language=None
    ):
        """
        Returns width and height (in pixels) of given text if rendered in font
        with provided direction, features, and language, while respecting
        newline characters.

        :param text: Text to measure.

        :param direction: Direction of the text. It can be 'rtl' (right to
                          left), 'ltr' (left to right) or 'ttb' (top to bottom).
                          Requires libraqm.

        :param spacing: The vertical gap between lines, defaulting to 4 pixels.

        :param features: A list of OpenType font features to be used during text
                         layout. This is usually used to turn on optional
                         font features that are not enabled by default,
                         for example 'dlig' or 'ss01', but can be also
                         used to turn off default font features for
                         example '-liga' to disable ligatures or '-kern'
                         to disable kerning.  To get all supported
                         features, see
                         https://docs.microsoft.com/en-us/typography/opentype/spec/featurelist
                         Requires libraqm.

        :param language: Language of the text. Different languages may use
                         different glyph shapes or ligatures. This parameter tells
                         the font which language the text is in, and to apply the
                         correct substitutions as appropriate, if available.
                         It should be a `BCP 47 language code
                         <https://www.w3.org/International/articles/language-tags/>`
                         Requires libraqm.

                         .. versionadded:: 6.0.0

        :return: (width, height)
        """
        max_width = 0
        lines = self._multiline_split(text)
        line_spacing = self.getsize("A")[1] + spacing
        for line in lines:
            line_width, line_height = self.getsize(line, direction, features, language)
            max_width = max(max_width, line_width)

        return max_width, len(lines) * line_spacing - spacing

    def getoffset(self, text):
        """
        Returns the offset of given text. This is the gap between the
        starting coordinate and the first marking. Note that this gap is
        included in the result of :py:func:`~PIL.ImageFont.FreeTypeFont.getsize`.

        :param text: Text to measure.

        :return: A tuple of the x and y offset
        """
        return self.font.getsize(text)[1]

    def getmask(self, text, mode="", direction=None, features=None, language=None):
        """
        Create a bitmap for the text.

        If the font uses antialiasing, the bitmap should have mode ``L`` and use a
        maximum value of 255. Otherwise, it should have mode ``1``.

        :param text: Text to render.
        :param mode: Used by some graphics drivers to indicate what mode the
                     driver prefers; if empty, the renderer may return either
                     mode. Note that the mode is always a string, to simplify
                     C-level implementations.

                     .. versionadded:: 1.1.5

        :param direction: Direction of the text. It can be 'rtl' (right to
                          left), 'ltr' (left to right) or 'ttb' (top to bottom).
                          Requires libraqm.

                          .. versionadded:: 4.2.0

        :param features: A list of OpenType font features to be used during text
                         layout. This is usually used to turn on optional
                         font features that are not enabled by default,
                         for example 'dlig' or 'ss01', but can be also
                         used to turn off default font features for
                         example '-liga' to disable ligatures or '-kern'
                         to disable kerning.  To get all supported
                         features, see
                         https://docs.microsoft.com/en-us/typography/opentype/spec/featurelist
                         Requires libraqm.

                         .. versionadded:: 4.2.0

        :param language: Language of the text. Different languages may use
                         different glyph shapes or ligatures. This parameter tells
                         the font which language the text is in, and to apply the
                         correct substitutions as appropriate, if available.
                         It should be a `BCP 47 language code
                         <https://www.w3.org/International/articles/language-tags/>`
                         Requires libraqm.

                         .. versionadded:: 6.0.0

        :return: An internal PIL storage memory instance as defined by the
                 :py:mod:`PIL.Image.core` interface module.
        """
        return self.getmask2(
            text, mode, direction=direction, features=features, language=language
        )[0]

    def getmask2(
        self,
        text,
        mode="",
        fill=Image.core.fill,
        direction=None,
        features=None,
        language=None,
        *args,