"""Регистрация TTF с кириллицей для reportlab (Linux / macOS / Windows)."""

from __future__ import annotations

import os
from pathlib import Path

from reportlab.pdfbase import pdfmetrics
from reportlab.pdfbase.ttfonts import TTFont

_FONT_REGISTERED = False
_FONT_BOLD_REGISTERED = False
_PROJECT_ROOT = Path(__file__).resolve().parents[2]


def _windows_fonts_dir() -> Path:
    windir = os.environ.get("WINDIR", r"C:\Windows")
    return Path(windir) / "Fonts"


def _cyrillic_font_candidates(*, bold: bool = False) -> list[Path]:
    bundled = (
        _PROJECT_ROOT / "vendor" / "fonts" / ("DejaVuSans-Bold.ttf" if bold else "DejaVuSans.ttf")
    )
    candidates: list[Path] = [bundled]

    if os.name == "nt":
        win = _windows_fonts_dir()
        if bold:
            candidates.extend(
                [
                    win / "arialbd.ttf",
                    win / "segoeuib.ttf",
                    win / "calibrib.ttf",
                    win / "timesbd.ttf",
                ]
            )
        else:
            candidates.extend(
                [
                    win / "arial.ttf",
                    win / "segoeui.ttf",
                    win / "calibri.ttf",
                    win / "times.ttf",
                ]
            )

    if bold:
        candidates.extend(
            [
                Path("/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf"),
                Path("/usr/share/fonts/dejavu/DejaVuSans-Bold.ttf"),
                Path("/System/Library/Fonts/Supplemental/Arial Bold.ttf"),
                Path("/Library/Fonts/Arial Bold.ttf"),
            ]
        )
    else:
        candidates.extend(
            [
                Path("/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf"),
                Path("/usr/share/fonts/dejavu/DejaVuSans.ttf"),
                Path("/System/Library/Fonts/Supplemental/Arial Unicode.ttf"),
                Path("/Library/Fonts/Arial Unicode.ttf"),
                Path("/System/Library/Fonts/Supplemental/Arial.ttf"),
            ]
        )

    seen: set[str] = set()
    unique: list[Path] = []
    for path in candidates:
        key = str(path).lower()
        if key in seen:
            continue
        seen.add(key)
        unique.append(path)
    return unique


def register_cyrillic_font() -> str:
    """Возвращает имя зарегистрированного шрифта reportlab или Helvetica (без кириллицы)."""
    global _FONT_REGISTERED
    if _FONT_REGISTERED:
        return "WespCyr"
    for path in _cyrillic_font_candidates(bold=False):
        if not path.is_file():
            continue
        try:
            pdfmetrics.registerFont(TTFont("WespCyr", str(path)))
            _FONT_REGISTERED = True
            return "WespCyr"
        except Exception:
            continue
    return "Helvetica"


def register_cyrillic_font_bold() -> str:
    global _FONT_BOLD_REGISTERED
    if _FONT_BOLD_REGISTERED:
        return "WespCyrBold"
    for path in _cyrillic_font_candidates(bold=True):
        if not path.is_file():
            continue
        try:
            pdfmetrics.registerFont(TTFont("WespCyrBold", str(path)))
            _FONT_BOLD_REGISTERED = True
            return "WespCyrBold"
        except Exception:
            continue
    return register_cyrillic_font()