# Orca
#
# Copyright 2024 Igalia, S.L.
# Copyright 2024 GNOME Foundation Inc.
# Author: Joanmarie Diggs <jdiggs@igalia.com>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the
# Free Software Foundation, Inc., Franklin Street, Fifth Floor,
# Boston MA  02110-1301 USA.

# pylint: disable=too-many-public-methods
# pylint: disable=too-many-lines
# pylint: disable=too-many-branches
# pylint: disable=too-many-return-statements

"""Wrapper for the Atspi.Text interface."""

from __future__ import annotations

import contextlib
import enum
import locale
import re

import gi

gi.require_version("Atspi", "2.0")
from gi.repository import Atspi, GLib

from . import (
    ax_cache_manager,
    colornames,
    debug,
    language_utilities,
    messages,
    object_properties,
    text_attribute_names,
)
from .ax_object import AXObject
from .ax_utilities_role import AXUtilitiesRole
from .ax_utilities_state import AXUtilitiesState

_TEXT_ATTRIBUTE_ALIASES: dict[str, str] = {
    "font-style": "style",
    "font-weight": "weight",
    "font-size": "size",
    "font-family": "family-name",
    "text-decoration-line": "text-decoration",
}


class AXTextAttribute(enum.Enum):
    """Enum representing an accessible text attribute."""

    # Note: Anything added here should also have an entry in text_attribute_names.py.
    # The tuple is (non-localized name, enable by default).
    BG_COLOR = ("bg-color", True)
    BG_FULL_HEIGHT = ("bg-full-height", False)
    BG_STIPPLE = ("bg-stipple", False)
    DIRECTION = ("direction", False)
    EDITABLE = ("editable", False)
    FAMILY_NAME = ("family-name", True)
    FG_COLOR = ("fg-color", True)
    FG_STIPPLE = ("fg-stipple", False)
    FONT_EFFECT = ("font-effect", True)
    INDENT = ("indent", True)
    INVALID = ("invalid", True)
    INVISIBLE = ("invisible", False)
    JUSTIFICATION = ("justification", True)
    LANGUAGE = ("language", False)
    LEFT_MARGIN = ("left-margin", False)
    LINE_HEIGHT = ("line-height", False)
    MARK = ("mark", True)
    PARAGRAPH_STYLE = ("paragraph-style", True)
    PIXELS_ABOVE_LINES = ("pixels-above-lines", False)
    PIXELS_BELOW_LINES = ("pixels-below-lines", False)
    PIXELS_INSIDE_WRAP = ("pixels-inside-wrap", False)
    RIGHT_MARGIN = ("right-margin", False)
    RISE = ("rise", False)
    SCALE = ("scale", False)
    SIZE = ("size", True)
    STRETCH = ("stretch", False)
    STRIKETHROUGH = ("strikethrough", True)
    STYLE = ("style", True)
    TEXT_DECORATION = ("text-decoration", True)
    TEXT_POSITION = ("text-position", False)
    TEXT_ROTATION = ("text-rotation", True)
    TEXT_SHADOW = ("text-shadow", False)
    UNDERLINE = ("underline", True)
    VARIANT = ("variant", False)
    VERTICAL_ALIGN = ("vertical-align", False)
    WEIGHT = ("weight", True)
    WRAP_MODE = ("wrap-mode", False)
    WRITING_MODE = ("writing-mode", False)

    @classmethod
    def from_string(cls, string: str) -> AXTextAttribute | None:
        """Returns the AXTextAttribute for the specified string."""

        canonical = _TEXT_ATTRIBUTE_ALIASES.get(string, string)
        for attribute in cls:
            if attribute.get_attribute_name() == canonical:
                return attribute

        return None

    @classmethod
    def from_localized_string(cls, string: str) -> AXTextAttribute | None:
        """Returns the AXTextAttribute for the specified localized string."""

        for attribute in cls:
            if attribute.get_localized_name() == string:
                return attribute

        return None

    def get_attribute_name(self) -> str:
        """Returns the non-localized name of the attribute."""

        return self.value[0]

    def get_value_from_attrs(self, attrs: dict[str, str]) -> str | None:
        """Returns the value for this attribute from an attrs dict, checking aliases."""

        key = self.value[0]
        value = attrs.get(key)
        if value is not None:
            return value
        for alias, canonical in _TEXT_ATTRIBUTE_ALIASES.items():
            if canonical == key:
                value = attrs.get(alias)
                if value is not None:
                    return value
        return None

    def get_localized_name(self) -> str:
        """Returns the localized name of the attribute."""

        name = self.value[0]
        return text_attribute_names.attribute_names.get(name, name)

    def get_localized_value(self, value) -> str:
        """Returns the localized value of the attribute."""

        if value is None:
            return ""

        if value.endswith("px"):
            value = value.split("px")[0]
            if locale.localeconv()["decimal_point"] in value:
                return messages.pixel_count(float(value))
            return messages.pixel_count(int(value))

        if self in [AXTextAttribute.BG_COLOR, AXTextAttribute.FG_COLOR]:
            return colornames.get_presentable_color_name(value)

        # TODO - JD: Is this still needed?
        value = value.replace("-moz", "")

        # TODO - JD: Are these still needed?
        if self == AXTextAttribute.JUSTIFICATION:
            value = value.replace("justify", "fill")
        elif self == AXTextAttribute.FAMILY_NAME:
            value = value.split(",")[0].strip().strip('"')

        return text_attribute_names.attribute_values.get(value, value)

    def should_present_by_default(self) -> bool:
        """Returns True if the attribute should be presented by default."""

        return self.value[1]

    def value_is_default(self, value) -> bool:
        """Returns True if value should be treated as the default value for this attribute."""

        null_values = ["0", "0mm", "0px", "none", "false", "normal", "", None]
        if value in null_values:
            return True

        if self == AXTextAttribute.SCALE:
            return float(value) == 1.0
        if self in (AXTextAttribute.TEXT_POSITION, AXTextAttribute.VERTICAL_ALIGN):
            return value == "baseline"
        if self == AXTextAttribute.WEIGHT:
            return value == "400"
        if self == AXTextAttribute.LANGUAGE:
            return value == language_utilities.get_current_language()

        return False

    def get_change_description(self, new_value: str | None) -> str:
        """Returns a localized description for announcing a change."""

        if self == AXTextAttribute.WEIGHT:
            if new_value and (
                new_value == "bold" or (new_value.isdigit() and int(new_value) > 400)
            ):
                return messages.BOLD
            return messages.TEXT_ATTRIBUTE_OFF % messages.BOLD

        if self == AXTextAttribute.STYLE:
            localized_italic = self.get_localized_value("italic")
            if new_value in ("italic", "oblique"):
                return self.get_localized_value(new_value)
            return messages.TEXT_ATTRIBUTE_OFF % localized_italic

        if self in (AXTextAttribute.UNDERLINE, AXTextAttribute.STRIKETHROUGH):
            if self.value_is_default(new_value):
                return messages.TEXT_ATTRIBUTE_OFF % self.get_localized_name()
            if new_value in ("single", "solid", "true"):
                return self.get_localized_name()
            return f"{self.get_localized_name()}: {self.get_localized_value(new_value)}"

        if self == AXTextAttribute.MARK:
            if self.value_is_default(new_value):
                return messages.TEXT_ATTRIBUTE_OFF % self.get_localized_name()
            return self.get_localized_name()

        if self == AXTextAttribute.INVALID:
            if new_value == "spelling":
                return messages.MISSPELLED
            if new_value == "grammar":
                return object_properties.STATE_INVALID_GRAMMAR_SPEECH
            return ""

        if self in (AXTextAttribute.TEXT_POSITION, AXTextAttribute.VERTICAL_ALIGN):
            if self.value_is_default(new_value):
                return messages.TEXT_ATTRIBUTE_OFF % self.get_localized_name()
            localized = self.get_localized_value(new_value)
            # TODO - JD: LO reports percentages instead of "super"/"sub".
            if localized == new_value and new_value and new_value.endswith("%"):
                value = new_value.removesuffix("%")
                with contextlib.suppress(ValueError):
                    localized = self.get_localized_value("super" if float(value) > 0 else "sub")
            return localized

        return f"{self.get_localized_name()}: {self.get_localized_value(new_value)}"


class AXText:
    """Wrapper for the Atspi.Text interface."""

    _CHARACTER_COUNT = "AXText.character-count"
    _ALL_TEXT = "AXText.all-text"
    _CACHE = ax_cache_manager.ScopedCache(
        (_CHARACTER_COUNT, _ALL_TEXT),
        ax_cache_manager.active_stable_tree_scope,
    )
    _ZERO_WIDTH_JOINER = "\u200d"
    _ZERO_WIDTH_NO_BREAK_SPACE = "\ufeff"
    _VARIATION_SELECTOR_RANGE = ("\ufe00", "\ufe0f")
    _EMOJI_MODIFIER_RANGE = ("\U0001f3fb", "\U0001f3ff")
    _REGIONAL_INDICATOR_RANGE = ("\U0001f1e6", "\U0001f1ff")
    # Widest span (in code points) a handled emoji cluster can occupy, including Gecko's
    # interleaved zero-width no-break spaces, with headroom. Bounds the text read for adjustment.
    _WHOLE_CHARACTER_MARGIN = 64

    @staticmethod
    def _extends_previous_character(text: str, offset: int) -> bool:
        """Returns True if text[offset] continues the previous character."""

        char = text[offset]
        if char == AXText._ZERO_WIDTH_NO_BREAK_SPACE:
            return True

        # Gecko interleaves zero-width no-break spaces, so look past them for the real neighbor.
        index = offset - 1
        while index >= 0 and text[index] == AXText._ZERO_WIDTH_NO_BREAK_SPACE:
            index -= 1
        if index < 0:
            return False
        previous = text[index]

        if AXText._ZERO_WIDTH_JOINER in (char, previous):
            return True
        vs_low, vs_high = AXText._VARIATION_SELECTOR_RANGE
        mod_low, mod_high = AXText._EMOJI_MODIFIER_RANGE
        if vs_low <= char <= vs_high or mod_low <= char <= mod_high:
            return True
        ri_low, ri_high = AXText._REGIONAL_INDICATOR_RANGE
        if ri_low <= char <= ri_high and ri_low <= previous <= ri_high:
            # Two regional indicators form one flag, so break only after a complete pair.
            run = 0
            while index >= 0:
                if text[index] == AXText._ZERO_WIDTH_NO_BREAK_SPACE:
                    index -= 1
                    continue
                if not ri_low <= text[index] <= ri_high:
                    break
                run += 1
                index -= 1
            return run % 2 == 1
        return False

    @staticmethod
    def _adjust_to_whole_characters(text: str, start: int, end: int) -> tuple[int, int]:
        """Extends start and end outward so neither falls inside a multi-code-point character."""

        length = len(text)
        start = max(0, min(start, length))
        end = max(start, min(end, length))
        while 0 < start < length and AXText._extends_previous_character(text, start):
            start -= 1
        while 0 < end < length and AXText._extends_previous_character(text, end):
            end += 1
        return start, end

    @staticmethod
    def _whole_character_content(
        obj: Atspi.Accessible, start: int, end: int
    ) -> tuple[str, int, int]:
        """Returns (content, start, end) grown to whole characters from a bounded text window."""

        length = AXText.get_character_count(obj)
        lo = max(0, start - AXText._WHOLE_CHARACTER_MARGIN)
        hi = min(length, end + AXText._WHOLE_CHARACTER_MARGIN)
        text = AXText.get_substring(obj, lo, hi)
        adjusted_start, adjusted_end = AXText._adjust_to_whole_characters(
            text, start - lo, end - lo
        )
        if (adjusted_start == 0 and lo > 0) or (adjusted_end == len(text) and hi < length):
            # The cluster reached the window edge; reread the full text to be safe.
            text = AXText.get_all_text(obj)
            adjusted_start, adjusted_end = AXText._adjust_to_whole_characters(text, start, end)
            return text[adjusted_start:adjusted_end], adjusted_start, adjusted_end
        return text[adjusted_start:adjusted_end], adjusted_start + lo, adjusted_end + lo

    @staticmethod
    def get_character_at_offset(
        obj: Atspi.Accessible,
        offset: int | None = None,
        ensure_whole_characters: bool = False,
    ) -> tuple[str, int, int]:
        """Returns the (character, start, end) for the current or specified offset."""

        length = AXText.get_character_count(obj)
        if not length:
            return "", 0, 0

        if offset is None:
            offset = AXText.get_caret_offset(obj)

        if not 0 <= offset <= length:
            tokens = ["WARNING: Offset", offset, "is not valid. No character can be provided."]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return "", 0, 0

        try:
            result = Atspi.Text.get_string_at_offset(obj, offset, Atspi.TextGranularity.CHAR)
        except GLib.GError as error:
            tokens = ["AXText: Exception in get_character_at_offset:", error]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return "", 0, 0

        if result is None:
            tokens = ["AXText: get_string_at_offset (char) failed for", obj, "at", offset, "."]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return "", 0, 0

        debug_string = result.content.replace("\n", "\\n")
        tokens = [
            "AXText: Character at offset",
            offset,
            "in",
            obj,
            "'",
            debug_string,
            "' (",
            result.start_offset,
            "-",
            result.end_offset,
            ")",
        ]
        debug.print_tokens(debug.LEVEL_INFO, tokens, True)
        content, start, end = result.content, result.start_offset, result.end_offset
        if ensure_whole_characters and start >= 0:
            if end < start:
                # Some engines return a broken boundary inside a multi-code-point
                # character (e.g. Chromium between a flag's regional indicators).
                start, end = offset, offset + 1
            content, start, end = AXText._whole_character_content(obj, start, end)
        return content, start, end

    @staticmethod
    def get_word_at_offset(
        obj: Atspi.Accessible,
        offset: int | None = None,
        ensure_whole_characters: bool = False,
    ) -> tuple[str, int, int]:
        """Returns the (word, start, end) for the current or specified offset."""

        length = AXText.get_character_count(obj)
        if not length:
            return "", 0, 0

        if offset is None:
            offset = AXText.get_caret_offset(obj)

        offset = min(max(0, offset), length - 1)
        try:
            result = Atspi.Text.get_string_at_offset(obj, offset, Atspi.TextGranularity.WORD)
        except GLib.GError as error:
            tokens = ["AXText: Exception in get_word_at_offset:", error]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return "", 0, 0

        if result is None:
            tokens = ["AXText: get_string_at_offset (word) failed for", obj, "at", offset, "."]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return "", 0, 0

        tokens = [
            "AXText: Word at offset",
            offset,
            "in",
            obj,
            "'",
            result.content,
            "' (",
            result.start_offset,
            "-",
            result.end_offset,
            ")",
        ]
        debug.print_tokens(debug.LEVEL_INFO, tokens, True)
        content, start, end = result.content, result.start_offset, result.end_offset
        if ensure_whole_characters and start >= 0:
            if end < start:
                # The engine returned a broken word boundary inside a multi-code-point
                # character (e.g. Chromium inside a flag); recover the word from whitespace.
                # Rare and limited to small web objects, so reading the full text is fine.
                text = AXText.get_all_text(obj)
                start = offset
                while start > 0 and not text[start - 1].isspace():
                    start -= 1
                end = offset
                while end < len(text) and not text[end].isspace():
                    end += 1
                start, end = AXText._adjust_to_whole_characters(text, start, end)
                content = text[start:end]
            else:
                content, start, end = AXText._whole_character_content(obj, start, end)
        return content, start, end

    @staticmethod
    def get_line_at_offset(
        obj: Atspi.Accessible,
        offset: int | None = None,
    ) -> tuple[str, int, int]:
        """Returns the (line, start, end) for the current or specified offset."""

        length = AXText.get_character_count(obj)
        if not length:
            return "", 0, 0

        if offset is None:
            offset = AXText.get_caret_offset(obj)

        # Don't adjust the length in multiline text because we want to say "blank" at the end.
        # This may or may not be sufficient. GTK3 seems to give us the correct, empty line. But
        # (at least) Chromium does not. See comment below.
        if (
            not AXUtilitiesState.is_multi_line(obj)
            and not AXUtilitiesRole.is_paragraph(obj)
            and not AXUtilitiesRole.is_section(obj)
        ):
            offset = min(max(0, offset), length - 1)
        else:
            offset = max(0, offset)

        try:
            result = Atspi.Text.get_string_at_offset(obj, offset, Atspi.TextGranularity.LINE)
        except GLib.GError as error:
            tokens = ["AXText: Exception in get_line_at_offset:", error]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return "", 0, 0

        if result is None:
            tokens = ["AXText: get_string_at_offset (line) failed for", obj, "at", offset, "."]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return "", 0, 0

        # Try again, e.g. Chromium returns "", -1, -1.
        if result.start_offset == result.end_offset == -1 and offset == length:
            offset -= 1
            result = Atspi.Text.get_string_at_offset(obj, offset, Atspi.TextGranularity.LINE)

        if (
            debug.debugLevel <= debug.LEVEL_INFO
            and result.start_offset == result.end_offset == -1
            and 0 < offset < length
            and AXObject.get_toolkit_name(obj).startswith("chromium")
        ):
            tokens = [
                "ERROR: Chromium returned invalid line boundary at offset",
                offset,
                ". See https://crbug.com/536662914",
            ]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)

        debug_string = result.content.replace("\n", "\\n")
        tokens = [
            "AXText: Line at offset",
            offset,
            "in",
            obj,
            "'",
            debug_string,
            "' (",
            result.start_offset,
            "-",
            result.end_offset,
            ")",
        ]
        debug.print_tokens(debug.LEVEL_INFO, tokens, True)

        if 0 <= offset < result.start_offset:
            offset -= 1
            tokens = ["ERROR: Start offset is greater than offset. Trying with offset", offset]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            result = Atspi.Text.get_string_at_offset(obj, offset, Atspi.TextGranularity.LINE)

            debug_string = result.content.replace("\n", "\\n")
            tokens = [
                "AXText: Line at offset",
                offset,
                "in",
                obj,
                "'",
                debug_string,
                "' (",
                result.start_offset,
                "-",
                result.end_offset,
                ")",
            ]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)

        return result.content, result.start_offset, result.end_offset

    @staticmethod
    def _find_sentence_boundaries(text: str) -> list[int]:
        """Returns the offsets in text that should be treated as sentence beginnings."""

        if not text:
            return []

        boundaries = [0]
        pattern = r"[.!?]+(?=\s|\ufffc|$)|\n[^\S\n]*\n"
        for match in re.finditer(pattern, text):
            end_pos = match.end()
            # Skip whitespace to find start of next sentence. Do not skip embedded object
            # characters since they represent child objects that must be traversed.
            while end_pos < len(text) and text[end_pos].isspace():
                end_pos += 1
            # Only add boundary if we haven't reached the end and it's not a duplicate.
            if end_pos < len(text) and end_pos not in boundaries:
                boundaries.append(end_pos)

        if boundaries[-1] != len(text):
            boundaries.append(len(text))

        return boundaries

    @staticmethod
    def _get_sentence_at_offset_fallback(
        obj: Atspi.Accessible,
        offset: int | None = None,
    ) -> tuple[str, int, int]:
        """Fallback sentence detection for broken implementations."""

        if offset is None:
            offset = AXText.get_caret_offset(obj)

        text = AXText.get_all_text(obj)
        if not text or offset < 0 or offset >= len(text):
            return "", 0, 0

        fallback_text, fallback_start, fallback_end = text, 0, len(text)
        boundaries = AXText._find_sentence_boundaries(text)
        for i in range(len(boundaries) - 1):
            start, end = boundaries[i], boundaries[i + 1]
            if start <= offset < end:
                fallback_text, fallback_start, fallback_end = text[start:end], start, end
                break

        tokens = [
            "AXText: Fallback sentence in",
            obj,
            "at offset",
            offset,
            ": '",
            fallback_text,
            "' (",
            fallback_start,
            "-",
            fallback_end,
            ")",
        ]
        debug.print_tokens(debug.LEVEL_INFO, tokens, True)
        return fallback_text, fallback_start, fallback_end

    @staticmethod
    def get_sentence_at_offset(
        obj: Atspi.Accessible,
        offset: int | None = None,
    ) -> tuple[str, int, int]:
        """Returns the (sentence, start, end) for the current or specified offset."""

        length = AXText.get_character_count(obj)
        if not length:
            return "", 0, 0

        if offset is None:
            offset = AXText.get_caret_offset(obj)

        offset = min(max(0, offset), length - 1)
        try:
            result = Atspi.Text.get_string_at_offset(obj, offset, Atspi.TextGranularity.SENTENCE)
        except GLib.GError as error:
            tokens = ["AXText: Exception in get_sentence_at_offset:", error]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return AXText._get_sentence_at_offset_fallback(obj, offset)

        if result is None:
            tokens = ["AXText: get_string_at_offset (sentence) failed for", obj, "at", offset, "."]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return "", 0, 0

        if result.start_offset == result.end_offset == -1 or not result.content:
            return AXText._get_sentence_at_offset_fallback(obj, offset)

        if (
            result.start_offset == result.end_offset
            and result.start_offset in [0, -1]
            and not result.content
        ):
            return AXText._get_sentence_at_offset_fallback(obj, offset)

        if re.search(r"\n[^\S\n]*\n", result.content):
            fallback = AXText._get_sentence_at_offset_fallback(obj, offset)
            if result.start_offset <= fallback[1] <= offset < fallback[
                2
            ] <= result.end_offset and fallback[1:] != (result.start_offset, result.end_offset):
                return fallback

        tokens = [
            "AXText: Sentence at offset",
            offset,
            "in",
            obj,
            "'",
            result.content,
            "' (",
            result.start_offset,
            "-",
            result.end_offset,
            ")",
        ]
        debug.print_tokens(debug.LEVEL_INFO, tokens, True)
        return result.content, result.start_offset, result.end_offset

    @staticmethod
    def get_paragraph_at_offset(
        obj: Atspi.Accessible,
        offset: int | None = None,
    ) -> tuple[str, int, int]:
        """Returns the (paragraph, start, end) for the current or specified offset."""

        length = AXText.get_character_count(obj)
        if not length:
            return "", 0, 0

        if offset is None:
            offset = AXText.get_caret_offset(obj)

        offset = min(max(0, offset), length - 1)
        try:
            result = Atspi.Text.get_string_at_offset(obj, offset, Atspi.TextGranularity.PARAGRAPH)
        except GLib.GError as error:
            tokens = ["AXText: Exception in get_paragraph_at_offset:", error]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return "", 0, 0

        if result is None:
            tokens = ["AXText: get_string_at_offset (paragraph) failed for", obj, "at", offset, "."]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return "", 0, 0

        tokens = [
            "AXText: Paragraph at offset",
            offset,
            "in",
            obj,
            "'",
            result.content,
            "' (",
            result.start_offset,
            "-",
            result.end_offset,
            ")",
        ]
        debug.print_tokens(debug.LEVEL_INFO, tokens, True)
        return result.content, result.start_offset, result.end_offset

    @staticmethod
    def get_character_count(obj: Atspi.Accessible) -> int:
        """Returns the character count of obj."""

        if not AXObject.supports_text(obj):
            return 0

        key = ax_cache_manager.get_object_key(obj)
        cached = AXText._CACHE.get(AXText._CHARACTER_COUNT, key)
        if cached is not ax_cache_manager.MISSING:
            return cached

        try:
            count = Atspi.Text.get_character_count(obj)
        except GLib.GError as error:
            tokens = ["AXText: Exception in get_character_count:", error]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return 0

        tokens = ["AXText:", obj, "reports", count, "characters."]
        debug.print_tokens(debug.LEVEL_INFO, tokens, True)
        AXText._CACHE.set(AXText._CHARACTER_COUNT, key, count)
        return count

    @staticmethod
    def get_caret_offset(obj: Atspi.Accessible) -> int:
        """Returns the caret offset of obj."""

        if not AXObject.supports_text(obj):
            return -1

        try:
            offset = Atspi.Text.get_caret_offset(obj)
        except GLib.GError as error:
            tokens = ["AXText: Exception in get_caret_offset:", error]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return -1

        tokens = ["AXText:", obj, "reports caret offset of", offset, "."]
        debug.print_tokens(debug.LEVEL_INFO, tokens, True)
        return offset

    @staticmethod
    def set_caret_offset(obj: Atspi.Accessible, offset: int) -> bool:
        """Returns False if we definitely failed to set the offset. True cannot be trusted."""

        if not AXObject.supports_text(obj):
            return False

        try:
            result = Atspi.Text.set_caret_offset(obj, offset)
        except GLib.GError as error:
            tokens = ["AXText: Exception in set_caret_offset:", error]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return False

        tokens = ["AXText: Reported result of setting offset to", offset, "in", obj, ":", result]
        debug.print_tokens(debug.LEVEL_INFO, tokens, True)
        return result

    @staticmethod
    def get_substring(obj: Atspi.Accessible, start_offset: int, end_offset: int) -> str:
        """Returns the text of obj within the specified offsets."""

        if not AXObject.supports_text(obj):
            return ""

        if end_offset == -1:
            end_offset = AXText.get_character_count(obj)

        try:
            result = Atspi.Text.get_text(obj, start_offset, end_offset)
        except GLib.GError as error:
            tokens = ["AXText: Exception in get_substring:", error]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return ""

        debug_string = result.replace("\n", "\\n")
        tokens = [
            "AXText: Text of",
            obj,
            "(",
            start_offset,
            "-",
            end_offset,
            "): '",
            debug_string,
            "'",
        ]
        debug.print_tokens(debug.LEVEL_INFO, tokens, True)
        return result

    @staticmethod
    def get_all_text(obj: Atspi.Accessible, length: int | None = None) -> str:
        """Returns the text content of obj."""

        key = ax_cache_manager.get_object_key(obj)
        cached = AXText._CACHE.get(AXText._ALL_TEXT, key)
        if cached is not ax_cache_manager.MISSING:
            return cached

        if length is None:
            length = AXText.get_character_count(obj)
        if not length:
            return ""

        try:
            result = Atspi.Text.get_text(obj, 0, length)
        except GLib.GError as error:
            tokens = ["AXText: Exception in get_all_text:", error]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return ""

        if debug.debugLevel <= debug.LEVEL_INFO:
            words = result.split()
            if len(words) > 20:
                debug_string = f"{' '.join(words[:5])} ... {' '.join(words[-5:])}"
            else:
                debug_string = result

            debug_string = debug_string.replace("\n", "\\n")
            tokens = ["AXText: Text of", obj, "'", debug_string, "'"]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
        AXText._CACHE.set(AXText._ALL_TEXT, key, result)
        return result

    @staticmethod
    def get_n_selections(obj: Atspi.Accessible) -> int:
        """Returns the number of reported selected substrings in obj."""

        if not AXObject.supports_text(obj):
            return 0

        try:
            result = Atspi.Text.get_n_selections(obj)
        except GLib.GError as error:
            tokens = ["AXText: Exception in get_n_selections:", error]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return 0

        tokens = ["AXText:", obj, "reports", result, "selection(s)."]
        debug.print_tokens(debug.LEVEL_INFO, tokens, True)
        return result

    @staticmethod
    def remove_selection(obj: Atspi.Accessible, selection_number: int) -> None:
        """Attempts to remove the specified selection."""

        if not AXObject.supports_text(obj):
            return

        try:
            Atspi.Text.remove_selection(obj, selection_number)
        except GLib.GError as error:
            tokens = ["AXText: Exception in remove_selection:", error]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return

    @staticmethod
    def get_selected_ranges(obj: Atspi.Accessible) -> list[tuple[int, int]]:
        """Returns a list of (start_offset, end_offset) tuples reflecting the selected text."""

        count = AXText.get_n_selections(obj)
        if not count:
            return []

        selections = []
        for i in range(count):
            try:
                result = Atspi.Text.get_selection(obj, i)
            except GLib.GError as error:
                tokens = ["AXText: Exception in get_selected_ranges:", error]
                debug.print_tokens(debug.LEVEL_INFO, tokens, True)
                break
            if 0 <= result.start_offset < result.end_offset:
                selections.append((result.start_offset, result.end_offset))

        tokens = ["AXText:", obj, "reports selected ranges:", selections]
        debug.print_tokens(debug.LEVEL_INFO, tokens, True)
        return selections

    @staticmethod
    def add_new_selection(obj: Atspi.Accessible, start_offset: int, end_offset: int) -> bool:
        """Creates a new selection for the specified range in obj."""

        if not AXObject.supports_text(obj):
            return False

        try:
            result = Atspi.Text.add_selection(obj, start_offset, end_offset)
        except GLib.GError as error:
            tokens = ["AXText: Exception in add_new_selection:", error]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return False

        return result

    @staticmethod
    def update_existing_selection(
        obj: Atspi.Accessible,
        start_offset: int,
        end_offset: int,
        selection_number: int = 0,
    ) -> bool:
        """Modifies specified selection in obj to the specified range."""

        if not AXObject.supports_text(obj):
            return False

        try:
            result = Atspi.Text.set_selection(obj, selection_number, start_offset, end_offset)
        except GLib.GError as error:
            tokens = ["AXText: Exception in update_existing_selection:", error]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return False

        return result

    # TODO - JD: This should be converted to return AXTextAttribute values.
    @staticmethod
    def get_text_attributes_at_offset(
        obj: Atspi.Accessible,
        offset: int | None = None,
    ) -> tuple[dict[str, str], int, int]:
        """Returns a (dict, start, end) tuple for attributes at offset in obj."""

        if not AXObject.supports_text(obj):
            return {}, 0, 0

        if offset is None:
            offset = AXText.get_caret_offset(obj)

        try:
            result = Atspi.Text.get_attribute_run(obj, offset, include_defaults=True)
        except GLib.GError as error:
            tokens = ["AXText: Exception in get_text_attributes_at_offset:", error]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return {}, 0, AXText.get_character_count(obj)

        if result is None or result[0] is None:
            tokens = ["AXText: get_attribute_run failed for", obj, "at offset", offset, "."]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return {}, 0, AXText.get_character_count(obj)

        tokens = ["AXText: Attributes for", obj, "at offset", offset, ":", result]
        debug.print_tokens(debug.LEVEL_INFO, tokens, True)

        # Adjust for web browsers that report indentation and justification at object attributes
        # rather than text attributes.
        obj_attributes = AXObject.get_attributes_dict(obj, False)
        if not result[0].get("justification"):
            alternative = obj_attributes.get("text-align")
            if alternative:
                result[0]["justification"] = alternative
        if not result[0].get("indent"):
            alternative = obj_attributes.get("text-indent")
            if alternative:
                result[0]["indent"] = alternative

        return result[0] or {}, result[1] or 0, result[2] or AXText.get_character_count(obj)

    @staticmethod
    def get_offset_at_point(obj: Atspi.Accessible, x: int, y: int) -> int:
        """Returns the character offset in obj at the specified point."""

        if not AXObject.supports_text(obj):
            return -1

        try:
            offset = Atspi.Text.get_offset_at_point(obj, x, y, Atspi.CoordType.WINDOW)
        except GLib.GError as error:
            tokens = ["AXText: Exception in get_offset_at_point:", error]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return -1

        tokens = ["AXText: Offset in", obj, "at", x, ",", y, "is", offset]
        debug.print_tokens(debug.LEVEL_INFO, tokens, True)
        return offset

    @staticmethod
    def get_character_rect(obj: Atspi.Accessible, offset: int | None = None) -> Atspi.Rect:
        """Returns the Atspi rect of the character at the specified offset in obj."""

        if not AXObject.supports_text(obj):
            return Atspi.Rect()

        if offset is None:
            offset = AXText.get_caret_offset(obj)

        try:
            rect = Atspi.Text.get_character_extents(obj, offset, Atspi.CoordType.WINDOW)
        except GLib.GError as error:
            tokens = ["AXText: Exception in get_character_rect:", error]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return Atspi.Rect()

        tokens = ["AXText: Offset", offset, "in", obj, "has rect", rect]
        debug.print_tokens(debug.LEVEL_INFO, tokens, True)
        return rect

    @staticmethod
    def get_range_rect(obj: Atspi.Accessible, start: int, end: int) -> Atspi.Rect:
        """Returns the Atspi rect of the string at the specified range in obj."""

        if not AXObject.supports_text(obj):
            return Atspi.Rect()

        if end <= 0:
            end = AXText.get_character_count(obj)

        try:
            rect = Atspi.Text.get_range_extents(obj, start, end, Atspi.CoordType.WINDOW)
        except GLib.GError as error:
            tokens = ["AXText: Exception in get_range_rect:", error]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return Atspi.Rect()

        tokens = ["AXText: Range", start, "-", end, "in", obj, "has rect", rect]
        debug.print_tokens(debug.LEVEL_INFO, tokens, True)
        return rect

    @staticmethod
    def scroll_substring_to_point(
        obj: Atspi.Accessible,
        x: int,
        y: int,
        start_offset: int | None = None,
        end_offset: int | None = None,
    ) -> bool:
        """Attempts to scroll obj to the specified point."""

        length = AXText.get_character_count(obj)
        if not length:
            return False

        if start_offset is None:
            start_offset = 0
        if end_offset is None:
            end_offset = length - 1

        try:
            result = Atspi.Text.scroll_substring_to_point(
                obj,
                start_offset,
                end_offset,
                Atspi.CoordType.WINDOW,
                x,
                y,
            )
        except GLib.GError as error:
            tokens = ["AXText: Exception in scroll_substring_to_point:", error]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return False

        tokens = [
            "AXText: Scrolled",
            obj,
            "substring (",
            start_offset,
            "-",
            end_offset,
            ") to",
            x,
            ",",
            y,
            ":",
            result,
        ]
        debug.print_tokens(debug.LEVEL_INFO, tokens, True)
        return result

    @staticmethod
    def scroll_substring_to_location(
        obj: Atspi.Accessible,
        location: Atspi.ScrollType,
        start_offset: int | None = None,
        end_offset: int | None = None,
    ) -> bool:
        """Attempts to scroll the substring to the specified Atspi.ScrollType location."""

        length = AXText.get_character_count(obj)
        if not length:
            return False

        if start_offset is None:
            start_offset = 0
        if end_offset is None:
            end_offset = length - 1

        try:
            result = Atspi.Text.scroll_substring_to(obj, start_offset, end_offset, location)
        except GLib.GError as error:
            tokens = ["AXText: Exception in scroll_substring_to_location:", error]
            debug.print_tokens(debug.LEVEL_INFO, tokens, True)
            return False

        tokens = [
            "AXText: Scrolled",
            obj,
            "substring (",
            start_offset,
            "-",
            end_offset,
            ") to",
            location,
            ":",
            result,
        ]
        debug.print_tokens(debug.LEVEL_INFO, tokens, True)
        return result
