"""Выгрузка таблиц экранов в .xlsx (D13) — без БД и сети.

Числа и даты пишутся значениями, не текстом: в Excel по ним можно считать.
"""

from __future__ import annotations

import io
from collections.abc import Sequence
from dataclasses import asdict, is_dataclass
from datetime import date, datetime, timedelta, timezone
from decimal import Decimal
from typing import Any

from openpyxl import Workbook
from openpyxl.styles import Font
from openpyxl.utils import get_column_letter

MIME = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"

# Время аудита в БД — с часовым поясом, в Excel пояса нет: пишем московское.
_MSK = timezone(timedelta(hours=3))
_DATE_FORMAT = "DD.MM.YYYY"
_DATETIME_FORMAT = "DD.MM.YYYY HH:MM:SS"
_MAX_WIDTH = 60
_SHEET_TITLE_MAX = 31  # ограничение Excel


def table_xlsx(rows: Sequence[Any], columns: dict[str, str], sheet: str) -> bytes:
    """Список dataclass/dict -> .xlsx с одним листом. columns: поле -> заголовок,
    в том же порядке, что на экране."""
    workbook = Workbook()
    ws = workbook.active
    ws.title = sheet[:_SHEET_TITLE_MAX]
    ws.append(list(columns.values()))
    for cell in ws[1]:
        cell.font = Font(bold=True)
    ws.freeze_panes = "A2"

    widths = [len(title) for title in columns.values()]
    for row in rows:
        data = asdict(row) if is_dataclass(row) else dict(row)
        values = [_cell_value(data.get(name)) for name in columns]
        ws.append(values)
        for index, value in enumerate(values):
            widths[index] = max(widths[index], _width(value))
    for column, width in enumerate(widths, start=1):
        ws.column_dimensions[get_column_letter(column)].width = min(
            width + 2, _MAX_WIDTH
        )
    for row_cells in ws.iter_rows(min_row=2):
        for cell in row_cells:
            if isinstance(cell.value, datetime):
                cell.number_format = _DATETIME_FORMAT
            elif isinstance(cell.value, date):
                cell.number_format = _DATE_FORMAT

    buffer = io.BytesIO()
    workbook.save(buffer)
    return buffer.getvalue()


def _cell_value(value: Any) -> Any:
    if isinstance(value, datetime) and value.tzinfo is not None:
        return value.astimezone(_MSK).replace(tzinfo=None)
    return value


def _width(value: Any) -> int:
    if value is None:
        return 0
    if isinstance(value, datetime):
        return len(_DATETIME_FORMAT)
    if isinstance(value, date):
        return len(_DATE_FORMAT)
    if isinstance(value, Decimal):
        return len(format(value.normalize(), "f"))
    return len(str(value))