"""
Code related to text extraction.

Some parts are still in _page.py. In doubt, they will stay there.
"""

import math
from collections.abc import Mapping
from typing import Any, Callable, Literal, Optional, Union

from .._utils import is_char_neutral, is_char_rtl
from ..generic import DictionaryObject, TextStringObject, encode_pdfdocencoding
from ..generic._font import Font

CUSTOM_RTL_MIN: str = ""
CUSTOM_RTL_MAX: str = ""
CUSTOM_RTL_SPECIAL_CHARS: str = ""
LAYOUT_NEW_BT_GROUP_SPACE_WIDTHS: int = 5
UNICODE_LOWER_LIMIT = 0
UNICODE_UPPER_LIMIT = 0x10FFFF


class OrientationNotFoundError(Exception):
    pass


def set_custom_rtl(
    _min: Union[str, int, None] = "",
    _max: Union[str, int, None] = "",
    specials: Union[str, list[int], None] = None,
) -> tuple[str, str, str]:
    """
    Change the Right-To-Left and special characters custom parameters.

    Args:
        _min: The new minimum value for the range of custom characters that
            will be written right to left.
            If set to ``None``, the value will not be changed.
            If set to a valid integer, it will be converted to its corresponding character.
            The default value is "", which sets no additional range to be converted.
        _max: The new maximum value for the range of custom characters that will
            be written right to left.
            If set to ``None``, the value will not be changed.
            If set to a valid integer, it will be converted to its corresponding character.
            The default value is "", which sets no additional range to be converted.
        specials: The new list of special characters to be inserted in the
            current insertion order.
            If set to ``None``, the current value will not be changed.
            If set to a string, it will be converted to a list of ASCII codes.
            The default value is an empty list.

    Returns:
        A tuple containing the new values for ``CUSTOM_RTL_MIN``,
        ``CUSTOM_RTL_MAX``, and ``CUSTOM_RTL_SPECIAL_CHARS``.

    """
    global CUSTOM_RTL_MIN, CUSTOM_RTL_MAX, CUSTOM_RTL_SPECIAL_CHARS
    if isinstance(_min, int):
        CUSTOM_RTL_MIN = chr(_min) if UNICODE_LOWER_LIMIT <= _min <= UNICODE_UPPER_LIMIT else ""
    elif isinstance(_min, str):
        CUSTOM_RTL_MIN = _min
    if isinstance(_max, int):
        CUSTOM_RTL_MAX = chr(_max) if UNICODE_LOWER_LIMIT <= _max <= UNICODE_UPPER_LIMIT else ""
    elif isinstance(_max, str):
        CUSTOM_RTL_MAX = _max
    if isinstance(specials, str):
        CUSTOM_RTL_SPECIAL_CHARS = specials
    elif isinstance(specials, list):
        CUSTOM_RTL_SPECIAL_CHARS = "".join(
            chr(char) for char in specials if UNICODE_LOWER_LIMIT <= char <= UNICODE_UPPER_LIMIT
        )
    return CUSTOM_RTL_MIN, CUSTOM_RTL_MAX, CUSTOM_RTL_SPECIAL_CHARS


def mult(
    m: list[float],
    n: Union[
        list[float],
        Mapping[Union[int, Literal["is_text", "is_render"]], Union[float, bool]],
    ],
) -> list[float]:
    return [
        m[0] * n[0] + m[1] * n[2],
        m[0] * n[1] + m[1] * n[3],
        m[2] * n[0] + m[3] * n[2],
        m[2] * n[1] + m[3] * n[3],
        m[4] * n[0] + m[5] * n[2] + n[4],
        m[4] * n[1] + m[5] * n[3] + n[5],
    ]


def orient(m: list[float]) -> int:
    if m[3] > 1e-6:
        return 0
    if m[3] < -1e-6:
        return 180
    if m[1] > 0:
        return 90
    return 270


def crlf_space_check(  # noqa: PLR0913, PLR0917
    text: str,
    cmtm_prev: tuple[list[float], list[float]],
    cmtm_matrix: tuple[list[float], list[float]],
    memo_cmtm: tuple[list[float], list[float]],
    font_resource: Optional[DictionaryObject],
    orientations: tuple[int, ...],
    output: str,
    font_size: float,
    visitor_text: Optional[Callable[[Any, Any, Any, Any, Any], None]],
    str_widths: float,
    spacewidth: float,
    str_height: float,
    line_span: Optional[tuple[int, float, float]],
) -> tuple[str, str, list[float], list[float], Optional[tuple[int, float, float]]]:
    cm_prev = cmtm_prev[0]
    tm_prev = cmtm_prev[1]
    cm_matrix = cmtm_matrix[0]
    tm_matrix = cmtm_matrix[1]
    memo_cm = memo_cmtm[0]
    memo_tm = memo_cmtm[1]

    m_prev = mult(tm_prev, cm_prev)
    m = mult(tm_matrix, cm_matrix)
    orientation = orient(m)
    delta_x = m[4] - m_prev[4]
    delta_y = m[5] - m_prev[5]
    # Table 108 of the 1.7 reference ("Text positioning operators")
    # delta_x/delta_y are expressed in the coordinate system produced by
    # text matrix x current transformation matrix, so the scaling factors
    # they get compared against have to be taken from the same combined
    # matrices instead of the text matrices alone.
    scale_prev_x = math.sqrt(m_prev[0]**2 + m_prev[1]**2)
    scale_prev_y = math.sqrt(m_prev[2]**2 + m_prev[3]**2)
    scale_y = math.sqrt(m[2]**2 + m[3]**2)
    cm_prev = m

    if orientation not in orientations:
        raise OrientationNotFoundError
    if orientation in (0, 180):
        moved_height: float = delta_y
        moved_width: float = delta_x
    elif orientation in (90, 270):
        moved_height = delta_x
        moved_width = delta_y
    # Keep track of the baseline range of the current extracted line. A centered
    # row label can fall between the two baselines of a wrapped cell (#4130), so
    # comparing only with the immediately preceding fragment can incorrectly
    # insert a line break. Use the established baseline range for that case.
    axis_index = 5 if orientation in (0, 180) else 4
    axis = m[axis_index]
    if line_span is None or line_span[0] != axis_index:
        distance = abs(moved_height)
    else:
        lower, upper = line_span[1], line_span[2]
        distance = 0.0 if lower <= axis <= upper else min(abs(axis - lower), abs(axis - upper))
    last = (output + text)[-1:]
    if distance > 0.8 * min(str_height * scale_prev_y, font_size * scale_y):
        if last not in ("", "\n"):
            output += text + "\n"
            if visitor_text is not None:
                visitor_text(
                    text + "\n",
                    memo_cm,
                    memo_tm,
                    font_resource,
                    font_size,
                )
            text = ""
        line_span = (axis_index, axis, axis)
    else:
        if (
            (moved_width >= (spacewidth + str_widths) * scale_prev_x)
            and last not in ("", " ")
        ):
            text += " "
        if last in ("", "\n") or line_span is None or line_span[0] != axis_index:
            line_span = (axis_index, axis, axis)
        else:
            line_span = (axis_index, min(line_span[1], axis), max(line_span[2], axis))
    tm_prev = tm_matrix.copy()
    cm_prev = cm_matrix.copy()
    return text, output, cm_prev, tm_prev, line_span


def get_text_operands(
    operands: list[Union[str, TextStringObject]],
    cm_matrix: list[float],
    tm_matrix: list[float],
    font: Font,
    orientations: tuple[int, ...]
) -> tuple[str, bool, float]:
    text: str = ""
    is_str_operands = False
    widths: float = 0.0
    width_cache: dict[str, float] = {}
    m = mult(tm_matrix, cm_matrix)
    orientation = orient(m)
    raw_characters: str = ""
    if orientation in orientations and len(operands) > 0:
        if isinstance(operands[0], str):
            text = operands[0]
            is_str_operands = True
        else:
            text = ""
            tt: bytes = (
                encode_pdfdocencoding(operands[0])
                if isinstance(operands[0], str)
                else operands[0]
            )
            if isinstance(font.encoding, str):  # Apply named encoding
                try:
                    text = tt.decode(font.encoding, "surrogatepass")
                except UnicodeDecodeError:
                    # Fallback for odd byte counts or unmapped 16-bit GIDs/CIDs
                    text = tt.decode(font.encoding, "surrogateescape")
            else:  # Apply dict encoding
                text = "".join(font.encoding.get(x, chr(x)) for x in tt)
                raw_characters = "".join(chr(byte) for byte in tt)
        for char in (raw_characters or text):
            if char == font.space_char:
                widths += font.space_width
            else:
                if char not in width_cache:
                    width_cache[char] = font.get_text_width(char)
                widths += width_cache[char]

    width_cache.clear()
    return (text, is_str_operands, widths)


def get_display_str(
    text: str,
    cm_matrix: list[float],
    tm_matrix: list[float],
    font_resource: Optional[DictionaryObject],
    font: Font,
    text_operands: str,
    font_size: float,
    rtl_dir: bool,
    visitor_text: Optional[Callable[[Any, Any, Any, Any, Any], None]]
) -> tuple[str, bool, str]:
    """
    Add the characters of ``text_operands`` to ``text`` in display order.

    Returns:
        A tuple containing the current text run, its direction, and any text runs completed
        because of a direction change. The completed runs precede the current run in display order.

    """
    # "\u0590 - \u08FF \uFB50 - \uFDFF"
    completed_text: list[str] = []
    neutral_cache: dict[str, bool] = {}
    rtl_cache: dict[str, bool] = {}

    def clear_character_caches() -> None:
        neutral_cache.clear()
        rtl_cache.clear()

    for raw_character in text_operands:
        x = font.character_map.get(raw_character, raw_character)
        # Test whether x is a sequence of bytes; ex: habibi.pdf
        if len(x) == 1:
            if x not in neutral_cache:
                neutral_cache[x] = is_char_neutral(x, CUSTOM_RTL_SPECIAL_CHARS)
            if neutral_cache[x]:
                # Cases where the current inserting order is kept
                text = x + text if rtl_dir else text + x
            else:
                if x not in rtl_cache:
                    rtl_cache[x] = is_char_rtl(x, CUSTOM_RTL_MIN, CUSTOM_RTL_MAX)
                if rtl_cache[x]:
                    # Right-to-left characters
                    if not rtl_dir:
                        rtl_dir = True
                        if visitor_text is not None:
                            visitor_text(text, cm_matrix, tm_matrix, font_resource, font_size)
                            clear_character_caches()
                        completed_text.append(text)
                        text = ""
                    text = x + text
                else:
                    # Left-to-right characters
                    if rtl_dir:
                        rtl_dir = False
                        if visitor_text is not None:
                            visitor_text(text, cm_matrix, tm_matrix, font_resource, font_size)
                            clear_character_caches()
                        completed_text.append(text)
                        text = ""
                    text = text + x
        else:
            # Treat a sequence of bytes as a neutral character.
            text = x + text if rtl_dir else text + x
    return text, rtl_dir, "".join(completed_text)