# 合同班合单：可录判定、按供应商+货主+三个日期分组、草稿映射。

from __future__ import annotations

from collections import OrderedDict
from datetime import date, datetime
from decimal import Decimal, ROUND_HALF_UP

from contract_draft import ContractDraft
from contract_flow_steps import ContractGoodsLine
from persist import LOOKUP_ONLY_RESULT
from repo import PurchaseContractRow


# 判断是否只录协议行：contract_entry_status=0 且已有合同号。
#
# 合同班跳过这些行，留给返利班。
def is_protocol_rerun(row: PurchaseContractRow) -> bool:
    if row.contract_entry_status is not None and int(row.contract_entry_status) == 0:
        return bool((row.contract_no or "").strip())
    return False


# 判断是否可领：process_status=0 且不是协议重录行。
#
# 过期的 process_status=3 由仓库租约逻辑另判，本函数只认新鲜待领。
def is_claimable(row: PurchaseContractRow) -> bool:
    if int(row.process_status or 0) != 0:
        return False
    return not is_protocol_rerun(row)


# 合单键：供应商、货主、签订日、开始日、结束日。任一不同则各自成组。
def _group_key(row: PurchaseContractRow) -> tuple:
    return (
        row.supplier_id,
        row.org_code,
        row.contract_sign_date,
        row.contract_start_date,
        row.contract_end_date,
    )


# 按合单键分组，组内按 fid 升序，头字段取该组第一行。
def group_by_supplier(rows: list[PurchaseContractRow]) -> list[list[PurchaseContractRow]]:
    groups: OrderedDict[tuple, list[PurchaseContractRow]] = OrderedDict()
    for row in sorted(rows, key=lambda item: item.fid):
        groups.setdefault(_group_key(row), []).append(row)
    return list(groups.values())


# 检查合单是否缺供应商或货品 MDM 码。缺则返回原因，齐则返回 None。
def missing_mdm_reason(rows: list[PurchaseContractRow]) -> str | None:
    if not rows:
        return "缺少供应商MDM码"
    if not (rows[0].supplier_mdm_code or "").strip():
        return "缺少供应商MDM码"
    for row in rows:
        if not (row.goods_mdm_code or "").strip():
            return "缺少货品MDM码"
    return None


# 把金额收成四位小数字符串，四舍五入。
def money4(value) -> str:
    amount = Decimal(str(value)).quantize(Decimal("0.0001"), rounding=ROUND_HALF_UP)
    return f"{amount:.4f}"


# 把日期收成 YYYY-MM-DD。空值返回空字符串。
def iso_date(value) -> str:
    if value is None:
        return ""
    if isinstance(value, datetime):
        return value.date().isoformat()
    if isinstance(value, date):
        return value.isoformat()
    return str(value)[:10]


def draft_from_group(rows: list[PurchaseContractRow]) -> ContractDraft:
    """把同一供应商一组表 3 行收成页面草稿。头字段取第一行。

    结果里已有「只查号」时，下一班只查已有合同，不再起草。
    """
    first = rows[0]
    sign = iso_date(first.contract_sign_date)
    total = sum(
        (Decimal(str(row.qty)) * Decimal(str(row.unit_price)) for row in rows),
        Decimal("0"),
    )
    goods = [
        ContractGoodsLine(
            operation_code=(row.goods_mdm_code or "").strip(),
            goods_code=(row.goods_mdm_code or "").strip(),
            goods_name=row.goods_name,
            approval_no=row.reg_no,
            spec=row.spec,
            unit=row.unit,
            quantity=float(row.qty),
            mdm_code=(row.goods_mdm_code or "").strip(),
            unit_price=money4(row.unit_price),
        )
        for row in rows
    ]
    return ContractDraft(
        supplier_name=first.supplier_name,
        order_date=sign,
        source_type="",
        customer_code=(first.supplier_mdm_code or "").strip(),
        customer_name=first.supplier_name,
        contract_category="采购协议",
        amount=money4(total),
        contract_sign_date=sign,
        contract_start_date=iso_date(first.contract_start_date),
        contract_end_date=iso_date(first.contract_end_date),
        is_prepayment="否",
        belong_year=sign[:4],
        payment_method="账期支付",
        payment_days=str(first.payment_term),
        goods_lines=goods,
        lookup_only=any(LOOKUP_ONLY_RESULT in (row.process_result or "") for row in rows),
    )