"""Excel 生成/解析服务（openpyxl）：BOM 单、订单导出、业务数据导入导出共用工具。"""
import io
from typing import Any

from openpyxl import Workbook, load_workbook
from openpyxl.styles import Alignment, Border, Font, PatternFill, Side
from openpyxl.utils import get_column_letter

HEADER_FILL = PatternFill("solid", fgColor="2F5B8F")
HEADER_FONT = Font(color="FFFFFF", bold=True, size=11)
TITLE_FONT = Font(bold=True, size=14)
THIN = Side(style="thin", color="C0C0C0")
BORDER = Border(left=THIN, right=THIN, top=THIN, bottom=THIN)


def new_workbook() -> Workbook:
    return Workbook()


def save_bytes(wb: Workbook) -> bytes:
    """工作簿 → xlsx 字节（供响应返回）。"""
    buf = io.BytesIO()
    wb.save(buf)
    return buf.getvalue()


def write_title(ws: Any, row: int, text: str, span: int) -> int:
    """写合并标题行，返回下一行行号。"""
    ws.cell(row=row, column=1, value=text).font = TITLE_FONT
    ws.merge_cells(start_row=row, start_column=1, end_row=row, end_column=span)
    ws.cell(row=row, column=1).alignment = Alignment(horizontal="center", vertical="center")
    ws.row_dimensions[row].height = 24
    return row + 1


def write_table(ws: Any, start_row: int, headers: list[str], rows: list[list[Any]],
                widths: list[int] | None = None) -> int:
    """写带样式表格（表头填充+全边框），返回下一行行号。"""
    for c, head in enumerate(headers, 1):
        cell = ws.cell(row=start_row, column=c, value=head)
        cell.fill = HEADER_FILL
        cell.font = HEADER_FONT
        cell.border = BORDER
        cell.alignment = Alignment(horizontal="center", vertical="center")
    for r, row_data in enumerate(rows, start_row + 1):
        for c, v in enumerate(row_data, 1):
            cell = ws.cell(row=r, column=c, value=v)
            cell.border = BORDER
            if isinstance(v, (int, float)):
                cell.alignment = Alignment(horizontal="right")
    if widths:
        for c, w in enumerate(widths, 1):
            ws.column_dimensions[get_column_letter(c)].width = w
    return start_row + 1 + len(rows)


def order_workbook(order: dict, bom: dict) -> bytes:
    """订单 Excel：基本信息 + BOM 型材表 + 玻璃/五金汇总。"""
    wb = new_workbook()
    ws = wb.active
    ws.title = "订单BOM"

    row = write_title(ws, 1, f"生产订单 — {order['order_no']}", 5)
    info_rows = [
        ["客户", order.get("customer_name") or "-", "电话", order.get("phone") or "-", ""],
        ["地址", order.get("address") or "-", "状态", order.get("status_label") or "-", ""],
        ["面积", f"{order.get('area') or 0} ㎡", "樘数", order.get("count") or 0, ""],
        ["窗型尺寸", f"{bom.get('width_mm', 0)} × {bom.get('height_mm', 0)} mm", "玻璃面积",
         f"{bom.get('glass_area_m2', 0)} ㎡", ""],
        ["下单时间", str(order.get("created_at"))[:19], "金额", f"¥{order.get('money') or 0}", ""],
    ]
    for r in info_rows:
        for c, v in enumerate(r, 1):
            cell = ws.cell(row=row, column=c, value=v)
            if c in (1, 3):
                cell.font = Font(bold=True)
        row += 1

    row += 1
    row = write_title(ws, row, "型材下料清单", 5)
    bar_rows = [[b["note"] or b["kind"], b["length"], b["qty"], b["length"] * b["qty"] / 1000, ""]
                for b in bom.get("bars", [])]
    row = write_table(ws, row, ["用途", "单件长度(mm)", "数量(件)", "总长(m)", "备注"], bar_rows,
                      widths=[18, 16, 12, 12, 20])
    total_m = sum(b["length"] * b["qty"] for b in bom.get("bars", [])) / 1000
    cell = ws.cell(row=row, column=1, value="型材合计")
    cell.font = Font(bold=True)
    ws.cell(row=row, column=4, value=round(total_m, 2)).font = Font(bold=True)
    row += 2

    row = write_title(ws, row, "玻璃/五金", 5)
    glass_hw = [["玻璃", f"{bom.get('glass_area_m2', 0)} ㎡", "", "", ""],
                ["五金", f"{bom.get('sash_count', 0)} 套", "", "", ""]]
    row = write_table(ws, row, ["项目", "数量", "", "", ""], glass_hw)

    row += 1
    ws.cell(row=row, column=1, value="制单：____________　审核：____________　日期：____________")
    return save_bytes(wb)


# ---------------- 导入解析 ----------------

def read_rows(data: bytes, sheet_index: int = 0) -> list[dict]:
    """解析上传的 xlsx → 行字典列表（自动探测表头行，兼容首行大标题的导出格式）。

    探测规则：前 3 行中非空单元格最多的一行视为表头；空行跳过。
    """
    wb = load_workbook(io.BytesIO(data), read_only=True, data_only=True)
    ws = wb.worksheets[sheet_index]
    all_rows = [list(r) for r in ws.iter_rows(values_only=True)]
    if not all_rows:
        return []
    # 探测表头行：取前 3 行中非空单元格数最多的行
    scan = all_rows[:3]
    header_idx = max(range(len(scan)), key=lambda i: sum(1 for v in scan[i] if v is not None and str(v).strip()))
    headers = [str(v).strip() if v is not None else "" for v in all_rows[header_idx]]
    out: list[dict] = []
    for values in all_rows[header_idx + 1:]:
        row = {headers[i]: values[i] for i in range(min(len(headers), len(values)))}
        if any(v is not None and str(v).strip() for v in row.values()):
            out.append(row)
    return out


def pick(row: dict, *names: str, default=None):
    """按候选列名（含中文表头）取值，全部缺失返回 default。"""
    for n in names:
        if n in row and row[n] not in (None, ""):
            return row[n]
    return default


# ---------------- 业务导出工作簿 ----------------

def simple_table_workbook(title: str, headers: list[str], rows: list[list],
                          widths: list[int] | None = None) -> bytes:
    """单表导出（客户/合同/库存等通用）。"""
    wb = new_workbook()
    ws = wb.active
    ws.title = title[:28] or "导出"
    row = write_title(ws, 1, title, len(headers))
    write_table(ws, row, headers, rows, widths)
    return save_bytes(wb)


def statistics_workbook(orders_summary: dict, receipts: dict) -> bytes:
    """统计报表导出：订单汇总 + 收款统计双 Sheet。"""
    wb = new_workbook()
    ws = wb.active
    ws.title = "订单汇总"
    row = write_title(ws, 1, "订单/业务统计", 4)
    rows = [[k, v, "", ""] for k, v in orders_summary.items()]
    row = write_table(ws, row, ["指标", "数值", "", ""], rows, widths=[24, 18, 8, 8])
    ws2 = wb.create_sheet("收款统计")
    row = write_title(ws2, 1, f"收款统计 {receipts['year']} 年", 14)
    row = write_table(ws2, row,
                      ["年度收款", "合同应收", "未收"] + [f"{m}月" for m in range(1, 13)],
                      [[receipts["total_received"], receipts["contract_total"], receipts["unreceived"],
                        *receipts["monthly"]]],
                      widths=[12] * 15)
    return save_bytes(wb)