#!/usr/bin/env python3
"""将 XLSX 工作簿的二维数据转换为 Markdown。"""

from __future__ import annotations

import argparse
import datetime as dt
import sys
from pathlib import Path

from openpyxl import load_workbook


def display(value: object) -> str:
    """将单元格值转换为稳定、可读且适合表格的文本。"""

    if value is None:
        return ""
    if isinstance(value, dt.datetime):
        value = value.isoformat(sep=" ", timespec="seconds")
    elif isinstance(value, (dt.date, dt.time)):
        value = value.isoformat()
    elif isinstance(value, bool):
        value = "TRUE" if value else "FALSE"
    text = str(value).replace("\\", "\\\\").replace("|", "\\|")
    return text.replace("\r\n", "<br>").replace("\n", "<br>").replace("\r", "<br>")


def matrix_for(sheet, merged_mode: str) -> tuple[list[list[str]], int]:
    """读取有效区域，并按选择的策略表达合并单元格。"""

    values = [[cell.value for cell in row] for row in sheet.iter_rows()]
    merged_count = len(sheet.merged_cells.ranges)
    if merged_mode == "fill":
        for merged in sheet.merged_cells.ranges:
            anchor = values[merged.min_row - 1][merged.min_col - 1]
            for row in range(merged.min_row - 1, merged.max_row):
                for column in range(merged.min_col - 1, merged.max_col):
                    values[row][column] = anchor
    while values and all(value is None for value in values[-1]):
        values.pop()
    width = max((max((i + 1 for i, value in enumerate(row) if value is not None), default=0) for row in values), default=0)
    return [[display(value) for value in row[:width]] for row in values], merged_count


def render_sheet(title: str, rows: list[list[str]]) -> str:
    """将单个工作表渲染为 Markdown 章节。"""

    lines = [f"## {title}", ""]
    if not rows or not rows[0]:
        return "\n".join(lines + ["_空工作表_"])
    width = max(map(len, rows))
    normalized = [row + [""] * (width - len(row)) for row in rows]
    lines.extend((f"| {' | '.join(normalized[0])} |", f"| {' | '.join(['---'] * width)} |"))
    lines.extend(f"| {' | '.join(row)} |" for row in normalized[1:])
    return "\n".join(lines)


def convert(source: Path, output: Path, values_only: bool, merged_mode: str) -> tuple[int, int, int, list[str]]:
    """打开工作簿、转换全部工作表并写入 UTF-8 Markdown。"""

    workbook = load_workbook(source, read_only=False, data_only=values_only)
    sections = [f"# {source.stem}"]
    row_count = merged_count = 0
    warnings: list[str] = []
    for sheet in workbook.worksheets:
        rows, merged = matrix_for(sheet, merged_mode)
        sections.append(render_sheet(sheet.title, rows))
        row_count += len(rows)
        merged_count += merged
        if not rows or not rows[0]:
            warnings.append(f"空工作表：{sheet.title}")
    sheet_count = len(workbook.worksheets)
    workbook.close()
    output.write_text("\n\n".join(sections).rstrip() + "\n", encoding="utf-8")
    return sheet_count, row_count, merged_count, warnings


def main(argv: list[str] | None = None) -> int:
    """校验文件类型、覆盖授权和输出路径后执行转换。"""

    parser = argparse.ArgumentParser(description="将 XLSX 工作簿转换为 Markdown")
    parser.add_argument("input", type=Path)
    parser.add_argument("--output", type=Path)
    parser.add_argument("--values", action="store_true", help="读取缓存值而不是公式文本")
    parser.add_argument("--merged", choices=("fill", "anchor"), default="fill")
    parser.add_argument("--force", action="store_true")
    args = parser.parse_args(argv)
    source = args.input.resolve()
    output = (args.output or source.with_suffix(".md")).resolve()
    if not source.is_file() or source.suffix.lower() != ".xlsx":
        print("错误：只支持存在的 .xlsx 文件；旧版 .xls 不受支持", file=sys.stderr); return 2
    if output.suffix.lower() not in {".md", ".markdown"}:
        print("错误：输出文件必须是 Markdown", file=sys.stderr); return 2
    if output.exists() and not args.force:
        print(f"错误：输出文件已存在：{output}", file=sys.stderr); return 1
    output.parent.mkdir(parents=True, exist_ok=True)
    try:
        sheets, rows, merged, warnings = convert(source, output, args.values, args.merged)
    except (OSError, ValueError) as error:
        print(f"错误：{error}", file=sys.stderr); return 1
    print(f"Markdown：{output}")
    print(f"工作表：{sheets}，数据行：{rows}，合并区域：{merged}")
    for warning in warnings: print(f"警告：{warning}")
    return 0


if __name__ == "__main__":
    raise SystemExit(main())