"""Renders the Scenario Export workbook (ADR-0065).

One ``.xlsx`` with one sheet per Scenario (model A2), each sheet's rows shaped by
``domain.scenario_export`` and painted with the Monday-style branding in
``infrastructure.xlsx.branding``. Programmatic openpyxl (no template) so a
dynamic number of scenario sheets is handled natively.
"""

from __future__ import annotations

import re
from typing import Sequence

from openpyxl import Workbook

from domain.scenario_export.scenario_sheet import ExportSheet
from infrastructure.xlsx.branding import style_sheet

# Excel forbids these in a sheet title and caps titles at 31 characters.
_ILLEGAL_SHEET_CHARS = re.compile(r"[:\\/?*\[\]]")
_MAX_SHEET_NAME = 31


def _safe_sheet_name(name: str, used: set[str]) -> str:
    """An Excel-legal, unique sheet name: illegal characters stripped, capped at
    31 chars, and suffixed on collision (two scenarios can share a name)."""
    clean = _ILLEGAL_SHEET_CHARS.sub("", name or "scenario").strip() or "scenario"
    clean = clean[:_MAX_SHEET_NAME]
    base, index = clean, 1
    while clean in used:
        suffix = f" ({index})"
        clean = base[: _MAX_SHEET_NAME - len(suffix)] + suffix
        index += 1
    used.add(clean)
    return clean


def render_workbook(
    sheets: Sequence[tuple[str, ExportSheet]], destination_path: str
) -> None:
    """Render the scenario sheets into a single branded ``.xlsx`` at
    ``destination_path``. Each tuple is a Scenario name and its shaped sheet;
    sheet order follows the input (the requested ``scenario_ids`` order).

    Saves straight to disk (``Workbook.save(path)``) so the caller can
    ``S3Client.upload_file`` it with multipart — the workbook is never also held
    as an in-memory ``bytes`` copy (ADR-0065; the OOM path the 4 GB sizing was
    against at the 100k-row cap). The further memory win is openpyxl
    ``write_only`` mode; that switch would live at this seam.
    """
    workbook = Workbook()
    default = workbook.active
    if default is not None:
        workbook.remove(default)

    used_names: set[str] = set()
    for name, sheet in sheets:
        worksheet = workbook.create_sheet(title=_safe_sheet_name(name, used_names))
        worksheet.append(list(sheet.columns))
        for row in sheet.rows:
            worksheet.append([row.get(column, "") for column in sheet.columns])
        style_sheet(worksheet)

    workbook.save(destination_path)