# -*- coding: utf-8 -*-

# This work is licensed under the MIT License.
# To view a copy of this license, visit https://opensource.org/licenses/MIT

# Written by Abdullah Diab (mpcabd)
# Email: mpcabd@gmail.com
# Website: http://mpcabd.xyz

import os

from configparser import ConfigParser

from .letters import (UNSHAPED, ISOLATED, LETTERS_ARABIC)
from .ligatures import (SENTENCES_LIGATURES,
                        WORDS_LIGATURES,
                        LETTERS_LIGATURES)

try:
    from fontTools.ttLib import TTFont
    with_font_config = True
except ImportError:
    with_font_config = False

class ArabicReshaperConfigurationError(ValueError):
    """Raised when the reshaper configuration is invalid or missing."""


ENABLE_NO_LIGATURES = 0b000
ENABLE_SENTENCES_LIGATURES = 0b001
ENABLE_WORDS_LIGATURES = 0b010
ENABLE_LETTERS_LIGATURES = 0b100
ENABLE_ALL_LIGATURES = 0b111

default_config = {
    # Supported languages are: [Arabic, ArabicV2, Kurdish]
    # More languages might be supported soon.
    # `Arabic` is default and recommended to work in most of the cases and
    # supports (Arabic, Urdu and Farsi)
    # `ArabicV2` is only to be used with certain font that you run into missing
    # chars `Kurdish` if you are using Kurdish Sarchia font is recommended,
    # work with both unicode and classic Arabic-Kurdish keybouard
    'language': 'Arabic',

    # Whether to delete the Harakat (Tashkeel) before reshaping or not.
    'delete_harakat': True,

    # Whether to shift the Harakat (Tashkeel) one position so they appear
    # correctly when string is reversed
    'shift_harakat_position': False,

    # Whether to delete the Tatweel (U+0640) before reshaping or not.
    'delete_tatweel': False,

    # Whether to support ZWJ (U+200D) or not.
    'support_zwj': True,

    # Use unshaped form instead of isolated form.
    'use_unshaped_instead_of_isolated': False,

    # Whether to use ligatures or not.
    # Serves as a shortcut to disable all ligatures.
    'support_ligatures': True,

    # When `support_ligatures` is enabled.
    # Separate ligatures configuration take precedence over it.
    # When `support_ligatures` is disabled,
    # separate ligatures configurations are ignored.

    # ------------------- Begin: Ligatures Configurations ------------------ #

    # Sentences (Enabled on top)
    'ARABIC LIGATURE BISMILLAH AR-RAHMAN AR-RAHEEM': False,
    'ARABIC LIGATURE JALLAJALALOUHOU': False,
    'ARABIC LIGATURE SALLALLAHOU ALAYHE WASALLAM': False,

    # Words (Enabled on top)
    'ARABIC LIGATURE ALLAH': True,
    'ARABIC LIGATURE AKBAR': False,
    'ARABIC LIGATURE ALAYHE': False,
    'ARABIC LIGATURE MOHAMMAD': False,
    'ARABIC LIGATURE RASOUL': False,
    'ARABIC LIGATURE SALAM': False,
    'ARABIC LIGATURE SALLA': False,
    'ARABIC LIGATURE WASALLAM': False,
    'RIAL SIGN': False,

    # Letters (Enabled on top)
    'ARABIC LIGATURE LAM WITH ALEF': True,
    'ARABIC LIGATURE LAM WITH ALEF WITH HAMZA ABOVE': True,
    'ARABIC LIGATURE LAM WITH ALEF WITH HAMZA BELOW': True,
    'ARABIC LIGATURE LAM WITH ALEF WITH MADDA ABOVE': True,
    'ARABIC LIGATURE AIN WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE AIN WITH JEEM': False,
    'ARABIC LIGATURE AIN WITH JEEM WITH MEEM': False,
    'ARABIC LIGATURE AIN WITH MEEM': False,
    'ARABIC LIGATURE AIN WITH MEEM WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE AIN WITH MEEM WITH MEEM': False,
    'ARABIC LIGATURE AIN WITH MEEM WITH YEH': False,
    'ARABIC LIGATURE AIN WITH YEH': False,
    'ARABIC LIGATURE ALEF MAKSURA WITH SUPERSCRIPT ALEF': False,
    'ARABIC LIGATURE ALEF WITH FATHATAN': False,
    'ARABIC LIGATURE BEH WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE BEH WITH HAH': False,
    'ARABIC LIGATURE BEH WITH HAH WITH YEH': False,
    'ARABIC LIGATURE BEH WITH HEH': False,
    'ARABIC LIGATURE BEH WITH JEEM': False,
    'ARABIC LIGATURE BEH WITH KHAH': False,
    'ARABIC LIGATURE BEH WITH KHAH WITH YEH': False,
    'ARABIC LIGATURE BEH WITH MEEM': False,
    'ARABIC LIGATURE BEH WITH NOON': False,
    'ARABIC LIGATURE BEH WITH REH': False,
    'ARABIC LIGATURE BEH WITH YEH': False,
    'ARABIC LIGATURE BEH WITH ZAIN': False,
    'ARABIC LIGATURE DAD WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE DAD WITH HAH': False,
    'ARABIC LIGATURE DAD WITH HAH WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE DAD WITH HAH WITH YEH': False,
    'ARABIC LIGATURE DAD WITH JEEM': False,
    'ARABIC LIGATURE DAD WITH KHAH': False,
    'ARABIC LIGATURE DAD WITH KHAH WITH MEEM': False,
    'ARABIC LIGATURE DAD WITH MEEM': False,
    'ARABIC LIGATURE DAD WITH REH': False,
    'ARABIC LIGATURE DAD WITH YEH': False,
    'ARABIC LIGATURE FEH WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE FEH WITH HAH': False,
    'ARABIC LIGATURE FEH WITH JEEM': False,
    'ARABIC LIGATURE FEH WITH KHAH': False,
    'ARABIC LIGATURE FEH WITH KHAH WITH MEEM': False,
    'ARABIC LIGATURE FEH WITH MEEM': False,
    'ARABIC LIGATURE FEH WITH MEEM WITH YEH': False,
    'ARABIC LIGATURE FEH WITH YEH': False,
    'ARABIC LIGATURE GHAIN WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE GHAIN WITH JEEM': False,
    'ARABIC LIGATURE GHAIN WITH MEEM': False,
    'ARABIC LIGATURE GHAIN WITH MEEM WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE GHAIN WITH MEEM WITH MEEM': False,
    'ARABIC LIGATURE GHAIN WITH MEEM WITH YEH': False,
    'ARABIC LIGATURE GHAIN WITH YEH': False,
    'ARABIC LIGATURE HAH WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE HAH WITH JEEM': False,
    'ARABIC LIGATURE HAH WITH JEEM WITH YEH': False,
    'ARABIC LIGATURE HAH WITH MEEM': False,
    'ARABIC LIGATURE HAH WITH MEEM WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE HAH WITH MEEM WITH YEH': False,
    'ARABIC LIGATURE HAH WITH YEH': False,
    'ARABIC LIGATURE HEH WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE HEH WITH JEEM': False,
    'ARABIC LIGATURE HEH WITH MEEM': False,
    'ARABIC LIGATURE HEH WITH MEEM WITH JEEM': False,
    'ARABIC LIGATURE HEH WITH MEEM WITH MEEM': False,
    'ARABIC LIGATURE HEH WITH SUPERSCRIPT ALEF': False,
    'ARABIC LIGATURE HEH WITH YEH': False,
    'ARABIC LIGATURE JEEM WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE JEEM WITH HAH': False,
    'ARABIC LIGATURE JEEM WITH HAH WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE JEEM WITH HAH WITH YEH': False,
    'ARABIC LIGATURE JEEM WITH MEEM': False,
    'ARABIC LIGATURE JEEM WITH MEEM WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE JEEM WITH MEEM WITH HAH': False,
    'ARABIC LIGATURE JEEM WITH MEEM WITH YEH': False,
    'ARABIC LIGATURE JEEM WITH YEH': False,
    'ARABIC LIGATURE KAF WITH ALEF': False,
    'ARABIC LIGATURE KAF WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE KAF WITH HAH': False,
    'ARABIC LIGATURE KAF WITH JEEM': False,
    'ARABIC LIGATURE KAF WITH KHAH': False,
    'ARABIC LIGATURE KAF WITH LAM': False,
    'ARABIC LIGATURE KAF WITH MEEM': False,
    'ARABIC LIGATURE KAF WITH MEEM WITH MEEM': False,
    'ARABIC LIGATURE KAF WITH MEEM WITH YEH': False,
    'ARABIC LIGATURE KAF WITH YEH': False,
    'ARABIC LIGATURE KHAH WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE KHAH WITH HAH': False,
    'ARABIC LIGATURE KHAH WITH JEEM': False,
    'ARABIC LIGATURE KHAH WITH MEEM': False,
    'ARABIC LIGATURE KHAH WITH YEH': False,
    'ARABIC LIGATURE LAM WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE LAM WITH HAH': False,
    'ARABIC LIGATURE LAM WITH HAH WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE LAM WITH HAH WITH MEEM': False,
    'ARABIC LIGATURE LAM WITH HAH WITH YEH': False,
    'ARABIC LIGATURE LAM WITH HEH': False,
    'ARABIC LIGATURE LAM WITH JEEM': False,
    'ARABIC LIGATURE LAM WITH JEEM WITH JEEM': False,
    'ARABIC LIGATURE LAM WITH JEEM WITH MEEM': False,
    'ARABIC LIGATURE LAM WITH JEEM WITH YEH': False,
    'ARABIC LIGATURE LAM WITH KHAH': False,
    'ARABIC LIGATURE LAM WITH KHAH WITH MEEM': False,
    'ARABIC LIGATURE LAM WITH MEEM': False,
    'ARABIC LIGATURE LAM WITH MEEM WITH HAH': False,
    'ARABIC LIGATURE LAM WITH MEEM WITH YEH': False,
    'ARABIC LIGATURE LAM WITH YEH': False,
    'ARABIC LIGATURE MEEM WITH ALEF': False,
    'ARABIC LIGATURE MEEM WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE MEEM WITH HAH': False,
    'ARABIC LIGATURE MEEM WITH HAH WITH JEEM': False,
    'ARABIC LIGATURE MEEM WITH HAH WITH MEEM': False,
    'ARABIC LIGATURE MEEM WITH HAH WITH YEH': False,
    'ARABIC LIGATURE MEEM WITH JEEM': False,
    'ARABIC LIGATURE MEEM WITH JEEM WITH HAH': False,
    'ARABIC LIGATURE MEEM WITH JEEM WITH KHAH': False,
    'ARABIC LIGATURE MEEM WITH JEEM WITH MEEM': False,
    'ARABIC LIGATURE MEEM WITH JEEM WITH YEH': False,
    'ARABIC LIGATURE MEEM WITH KHAH': False,
    'ARABIC LIGATURE MEEM WITH KHAH WITH JEEM': False,
    'ARABIC LIGATURE MEEM WITH KHAH WITH MEEM': False,
    'ARABIC LIGATURE MEEM WITH KHAH WITH YEH': False,
    'ARABIC LIGATURE MEEM WITH MEEM': False,
    'ARABIC LIGATURE MEEM WITH MEEM WITH YEH': False,
    'ARABIC LIGATURE MEEM WITH YEH': False,
    'ARABIC LIGATURE NOON WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE NOON WITH HAH': False,
    'ARABIC LIGATURE NOON WITH HAH WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE NOON WITH HAH WITH MEEM': False,
    'ARABIC LIGATURE NOON WITH HAH WITH YEH': False,
    'ARABIC LIGATURE NOON WITH HEH': False,
    'ARABIC LIGATURE NOON WITH JEEM': False,
    'ARABIC LIGATURE NOON WITH JEEM WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE NOON WITH JEEM WITH HAH': False,
    'ARABIC LIGATURE NOON WITH JEEM WITH MEEM': False,
    'ARABIC LIGATURE NOON WITH JEEM WITH YEH': False,
    'ARABIC LIGATURE NOON WITH KHAH': False,
    'ARABIC LIGATURE NOON WITH MEEM': False,
    'ARABIC LIGATURE NOON WITH MEEM WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE NOON WITH MEEM WITH YEH': False,
    'ARABIC LIGATURE NOON WITH NOON': False,
    'ARABIC LIGATURE NOON WITH REH': False,
    'ARABIC LIGATURE NOON WITH YEH': False,
    'ARABIC LIGATURE NOON WITH ZAIN': False,
    'ARABIC LIGATURE QAF WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE QAF WITH HAH': False,
    'ARABIC LIGATURE QAF WITH MEEM': False,
    'ARABIC LIGATURE QAF WITH MEEM WITH HAH': False,
    'ARABIC LIGATURE QAF WITH MEEM WITH MEEM': False,
    'ARABIC LIGATURE QAF WITH MEEM WITH YEH': False,
    'ARABIC LIGATURE QAF WITH YEH': False,
    'ARABIC LIGATURE QALA USED AS KORANIC STOP SIGN': False,
    'ARABIC LIGATURE REH WITH SUPERSCRIPT ALEF': False,
    'ARABIC LIGATURE SAD WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE SAD WITH HAH': False,
    'ARABIC LIGATURE SAD WITH HAH WITH HAH': False,
    'ARABIC LIGATURE SAD WITH HAH WITH YEH': False,
    'ARABIC LIGATURE SAD WITH KHAH': False,
    'ARABIC LIGATURE SAD WITH MEEM': False,
    'ARABIC LIGATURE SAD WITH MEEM WITH MEEM': False,
    'ARABIC LIGATURE SAD WITH REH': False,
    'ARABIC LIGATURE SAD WITH YEH': False,
    'ARABIC LIGATURE SALLA USED AS KORANIC STOP SIGN': False,
    'ARABIC LIGATURE SEEN WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE SEEN WITH HAH': False,
    'ARABIC LIGATURE SEEN WITH HAH WITH JEEM': False,
    'ARABIC LIGATURE SEEN WITH HEH': False,
    'ARABIC LIGATURE SEEN WITH JEEM': False,
    'ARABIC LIGATURE SEEN WITH JEEM WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE SEEN WITH JEEM WITH HAH': False,
    'ARABIC LIGATURE SEEN WITH KHAH': False,
    'ARABIC LIGATURE SEEN WITH KHAH WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE SEEN WITH KHAH WITH YEH': False,
    'ARABIC LIGATURE SEEN WITH MEEM': False,
    'ARABIC LIGATURE SEEN WITH MEEM WITH HAH': False,
    'ARABIC LIGATURE SEEN WITH MEEM WITH JEEM': False,
    'ARABIC LIGATURE SEEN WITH MEEM WITH MEEM': False,
    'ARABIC LIGATURE SEEN WITH REH': False,
    'ARABIC LIGATURE SEEN WITH YEH': False,
    'ARABIC LIGATURE SHADDA WITH DAMMA': False,
    'ARABIC LIGATURE SHADDA WITH DAMMA ISOLATED FORM': False,
    'ARABIC LIGATURE SHADDA WITH DAMMA MEDIAL FORM': False,
    'ARABIC LIGATURE SHADDA WITH DAMMATAN ISOLATED FORM': False,
    'ARABIC LIGATURE SHADDA WITH FATHA': False,
    'ARABIC LIGATURE SHADDA WITH FATHA ISOLATED FORM': False,
    'ARABIC LIGATURE SHADDA WITH FATHA MEDIAL FORM': False,
    'ARABIC LIGATURE SHADDA WITH KASRA': False,
    'ARABIC LIGATURE SHADDA WITH KASRA ISOLATED FORM': False,
    'ARABIC LIGATURE SHADDA WITH KASRA MEDIAL FORM': False,
    'ARABIC LIGATURE SHADDA WITH KASRATAN ISOLATED FORM': False,
    'ARABIC LIGATURE SHADDA WITH SUPERSCRIPT ALEF': False,
    'ARABIC LIGATURE SHADDA WITH SUPERSCRIPT ALEF ISOLATED FORM': False,
    'ARABIC LIGATURE SHEEN WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE SHEEN WITH HAH': False,
    'ARABIC LIGATURE SHEEN WITH HAH WITH MEEM': False,
    'ARABIC LIGATURE SHEEN WITH HAH WITH YEH': False,
    'ARABIC LIGATURE SHEEN WITH HEH': False,
    'ARABIC LIGATURE SHEEN WITH JEEM': False,
    'ARABIC LIGATURE SHEEN WITH JEEM WITH YEH': False,
    'ARABIC LIGATURE SHEEN WITH KHAH': False,
    'ARABIC LIGATURE SHEEN WITH MEEM': False,
    'ARABIC LIGATURE SHEEN WITH MEEM WITH KHAH': False,
    'ARABIC LIGATURE SHEEN WITH MEEM WITH MEEM': False,
    'ARABIC LIGATURE SHEEN WITH REH': False,
    'ARABIC LIGATURE SHEEN WITH YEH': False,
    'ARABIC LIGATURE TAH WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE TAH WITH HAH': False,
    'ARABIC LIGATURE TAH WITH MEEM': False,
    'ARABIC LIGATURE TAH WITH MEEM WITH HAH': False,
    'ARABIC LIGATURE TAH WITH MEEM WITH MEEM': False,
    'ARABIC LIGATURE TAH WITH MEEM WITH YEH': False,
    'ARABIC LIGATURE TAH WITH YEH': False,
    'ARABIC LIGATURE TEH WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE TEH WITH HAH': False,
    'ARABIC LIGATURE TEH WITH HAH WITH JEEM': False,
    'ARABIC LIGATURE TEH WITH HAH WITH MEEM': False,
    'ARABIC LIGATURE TEH WITH HEH': False,
    'ARABIC LIGATURE TEH WITH JEEM': False,
    'ARABIC LIGATURE TEH WITH JEEM WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE TEH WITH JEEM WITH MEEM': False,
    'ARABIC LIGATURE TEH WITH JEEM WITH YEH': False,
    'ARABIC LIGATURE TEH WITH KHAH': False,
    'ARABIC LIGATURE TEH WITH KHAH WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE TEH WITH KHAH WITH MEEM': False,
    'ARABIC LIGATURE TEH WITH KHAH WITH YEH': False,
    'ARABIC LIGATURE TEH WITH MEEM': False,
    'ARABIC LIGATURE TEH WITH MEEM WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE TEH WITH MEEM WITH HAH': False,
    'ARABIC LIGATURE TEH WITH MEEM WITH JEEM': False,
    'ARABIC LIGATURE TEH WITH MEEM WITH KHAH': False,
    'ARABIC LIGATURE TEH WITH MEEM WITH YEH': False,
    'ARABIC LIGATURE TEH WITH NOON': False,
    'ARABIC LIGATURE TEH WITH REH': False,
    'ARABIC LIGATURE TEH WITH YEH': False,
    'ARABIC LIGATURE TEH WITH ZAIN': False,
    'ARABIC LIGATURE THAL WITH SUPERSCRIPT ALEF': False,
    'ARABIC LIGATURE THEH WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE THEH WITH HEH': False,
    'ARABIC LIGATURE THEH WITH JEEM': False,
    'ARABIC LIGATURE THEH WITH MEEM': False,
    'ARABIC LIGATURE THEH WITH NOON': False,
    'ARABIC LIGATURE THEH WITH REH': False,
    'ARABIC LIGATURE THEH WITH YEH': False,
    'ARABIC LIGATURE THEH WITH ZAIN': False,
    'ARABIC LIGATURE UIGHUR KIRGHIZ YEH WITH HAMZA ABOVE WITH ALEF MAKSURA': False,  # noqa
    'ARABIC LIGATURE YEH WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE YEH WITH HAH': False,
    'ARABIC LIGATURE YEH WITH HAH WITH YEH': False,
    'ARABIC LIGATURE YEH WITH HAMZA ABOVE WITH AE': False,
    'ARABIC LIGATURE YEH WITH HAMZA ABOVE WITH ALEF': False,
    'ARABIC LIGATURE YEH WITH HAMZA ABOVE WITH ALEF MAKSURA': False,
    'ARABIC LIGATURE YEH WITH HAMZA ABOVE WITH E': False,
    'ARABIC LIGATURE YEH WITH HAMZA ABOVE WITH HAH': False,
    'ARABIC LIGATURE YEH WITH HAMZA ABOVE WITH HEH': False,
    'ARABIC LIGATURE YEH WITH HAMZA ABOVE WITH JEEM': False,
    'ARABIC LIGATURE YEH WITH HAMZA ABOVE WITH KHAH': False,
    'ARABIC LIGATURE YEH WITH HAMZA ABOVE WITH MEEM': False,
    'ARABIC LIGATURE YEH WITH HAMZA ABOVE WITH NOON': False,
    'ARABIC LIGATURE YEH WITH HAMZA ABOVE WITH OE': False,
    'ARABIC LIGATURE YEH WITH HAMZA ABOVE WITH REH': False,
    'ARABIC LIGATURE YEH WITH HAMZA ABOVE WITH U': False,
    'ARABIC LIGATURE YEH WITH HAMZA ABOVE WITH WAW': False,
    'ARABIC LIGATURE YEH WITH HAMZA ABOVE WITH YEH': False,
    'ARABIC LIGATURE YEH WITH HAMZA ABOVE WITH YU': False,
    'ARABIC LIGATURE YEH WITH HAMZA ABOVE WITH ZAIN': False,
    'ARABIC LIGATURE YEH WITH HEH': False,
    'ARABIC LIGATURE YEH WITH JEEM': False,
    'ARABIC LIGATURE YEH WITH JEEM WITH YEH': False,
    'ARABIC LIGATURE YEH WITH KHAH': False,
    'ARABIC LIGATURE YEH WITH MEEM': False,
    'ARABIC LIGATURE YEH WITH MEEM WITH MEEM': False,
    'ARABIC LIGATURE YEH WITH MEEM WITH YEH': False,
    'ARABIC LIGATURE YEH WITH NOON': False,
    'ARABIC LIGATURE YEH WITH REH': False,
    'ARABIC LIGATURE YEH WITH YEH': False,
    'ARABIC LIGATURE YEH WITH ZAIN': False,
    'ARABIC LIGATURE ZAH WITH MEEM': False,
    # -------------------- End: Ligatures Configurations ------------------- #
}


def auto_config(
    configuration: dict | None = None,
    configuration_file: str | None = None,
):
    loaded_from_envvar = False

    configuration_parser = ConfigParser()
    configuration_parser.read_dict({
        'ArabicReshaper': default_config
    })

    if not configuration_file:
        configuration_file = os.getenv(
            'PYTHON_ARABIC_RESHAPER_CONFIGURATION_FILE'
        )
        if configuration_file:
            loaded_from_envvar = True

    if configuration_file:
        if not os.path.exists(configuration_file):
            env_note = (
                ' (set via PYTHON_ARABIC_RESHAPER_CONFIGURATION_FILE)'
                if loaded_from_envvar else ''
            )
            raise ArabicReshaperConfigurationError(
                f'Configuration file not found: {configuration_file}{env_note}'
            )
        configuration_parser.read((configuration_file,))

    if configuration:
        configuration_parser.read_dict({
            'ArabicReshaper': configuration
        })

    if 'ArabicReshaper' not in configuration_parser:
        raise ArabicReshaperConfigurationError(
            'Invalid configuration: '
            'A section with the name ArabicReshaper was not found'
        )

    return configuration_parser['ArabicReshaper']


def config_for_true_type_font(font_file_path: str, ligatures_config: int = ENABLE_ALL_LIGATURES) -> dict:
    """Return a reshaper configuration dict tuned to the capabilities of a TrueType font.

    Inspects the font's cmap table to determine which positional Arabic letter
    forms are present, and checks each ligature glyph so that only ligatures
    the font actually supports are enabled.

    Args:
        font_file_path: Path to the .ttf/.otf font file.
        ligatures_config: Bitmask of ENABLE_*_LIGATURES flags controlling which
            ligature categories to probe. Defaults to ENABLE_ALL_LIGATURES.

    Returns:
        A configuration dict suitable for passing to ArabicReshaper().

    Raises:
        ImportError: If fonttools is not installed.
        ArabicReshaperConfigurationError: If the font path is invalid.
    """
    if not with_font_config:
        raise ImportError(
            'fonttools is not installed. '
            'Install it with: pip install arabic-reshaper[with-fonttools]'
        )
    if not font_file_path or not os.path.exists(font_file_path):
        raise ArabicReshaperConfigurationError(f'Invalid path to font file: {font_file_path}')
    ttfont = TTFont(font_file_path)
    has_isolated = True
    for k, v in LETTERS_ARABIC.items():
        for table in ttfont['cmap'].tables:
            if ord(v[ISOLATED]) in table.cmap:
                break
        else:
            has_isolated = False
            break

    configuration = {
        'use_unshaped_instead_of_isolated': not has_isolated,
    }

    def process_ligatures(ligatures):
        for ligature in ligatures:
            forms = list(filter(lambda form: form != '', ligature[1][1]))
            n = len(forms)
            for form in forms:
                for table in ttfont['cmap'].tables:
                    if ord(form) in table.cmap:
                        n -= 1
                        break
            configuration[ligature[0]] = (n == 0)

    if ENABLE_SENTENCES_LIGATURES & ligatures_config:
        process_ligatures(SENTENCES_LIGATURES)

    if ENABLE_WORDS_LIGATURES & ligatures_config:
        process_ligatures(WORDS_LIGATURES)

    if ENABLE_LETTERS_LIGATURES & ligatures_config:
        process_ligatures(LETTERS_LIGATURES)

    return configuration
