# 接口 3 整批校验与落表。不跑合同作业。
#
# 入参 camelCase，落表 snake_case。幂等键是对方 fid。
# 请求里不录合同。

from __future__ import annotations

from . import messages
from .parse import parse_date, parse_decimal, parse_fid, parse_int, parse_oms_id, parse_str

_STRING_FIELDS = (
    ("supplierId", "supplier_id", 20),
    ("supplierName", "supplier_name", 200),
    ("goodsId", "goods_id", 20),
    ("goodsName", "goods_name", 200),
    ("regNo", "reg_no", 100),
    ("spec", "spec", 100),
    ("unit", "unit", 20),
    ("goodsSourceId", "goods_source_id", 20),
    ("purchaserId", "purchaser_id", 20),
    ("purchaserName", "purchaser_name", 100),
    ("plannerId", "planner_id", 20),
    ("plannerName", "planner_name", 100),
    ("orgCode", "org_code", 10),
    ("goodsMdmCode", "goods_mdm_code", 100),
    ("supplierMdmCode", "supplier_mdm_code", 100),
)

_DATE_FIELDS = (
    ("contractSignDate", "contract_sign_date"),
    ("contractStartDate", "contract_start_date"),
    ("contractEndDate", "contract_end_date"),
)

_DECIMAL_FIELDS = (
    ("qty", "qty"),
    ("purchaseTaxRate", "purchase_tax_rate"),
    ("unitPrice", "unit_price"),
)


# 整批接收采购合同：先校验再落库，返回与入参下标对齐的结果。
def receive_purchase_contracts(rows: list, repo) -> list[dict]:
    results: list[dict | None] = [None] * len(rows)
    pending: list[tuple[int, dict]] = []
    seen: set[int] = set()
    for index, row in enumerate(rows):
        decided = _classify(row, seen)
        if "resultCode" in decided:
            results[index] = decided
        else:
            pending.append((index, decided))
    if pending:
        _persist(results, pending, repo)
    return [item for item in results if item is not None]


# 内存判定：对象/字段/同批 fid 冲突当场出结果，通过则返回待插入记录。
def _classify(row: object, seen: set[int]) -> dict:
    if not isinstance(row, dict):
        return _result(None, "REJECTED", messages.ROW_NOT_OBJECT)

    fid, fid_error = parse_fid(row.get("fid"))
    if fid is not None and fid in seen:
        return _result(fid, "CONFLICT", messages.CONTRACT_CONFLICT)
    if fid is not None:
        seen.add(fid)

    parsed, error = _parse_row(row, fid, fid_error)
    if error:
        _camel, message = error
        return _result(row.get("fid"), "REJECTED", message)
    return parsed


# 对通过校验的行一次查重、一次插入，把 DUPLICATE / ACCEPTED 填回 results。
def _persist(results: list[dict | None], pending: list[tuple[int, dict]], repo) -> None:
    existing = repo.existing_fids([record["fid"] for _index, record in pending])
    to_insert: list[dict] = []
    insert_at: list[int] = []
    for index, record in pending:
        if record["fid"] in existing:
            results[index] = _result(
                record["fid"], "DUPLICATE", messages.CONTRACT_DUPLICATE
            )
        else:
            to_insert.append(record)
            insert_at.append(index)
    collided = repo.insert_many(to_insert) if to_insert else set()
    for index, record in zip(insert_at, to_insert):
        if record["fid"] in collided:
            results[index] = _result(
                record["fid"], "DUPLICATE", messages.CONTRACT_DUPLICATE
            )
        else:
            results[index] = _result(
                record["fid"], "ACCEPTED", messages.CONTRACT_ACCEPTED
            )


# 把一条明细收成表 3 行。失败返回 (None, (字段, 说明))。
def _parse_row(row: dict, fid: int | None, fid_error: str | None):
    if fid_error:
        return None, ("fid", fid_error)

    oms_id, oms_error = parse_oms_id(row.get("omsId"))
    if oms_error:
        return None, ("omsId", oms_error)

    record: dict = {"fid": fid, "oms_id": oms_id, "process_status": 0}
    for camel, snake, max_len in _STRING_FIELDS:
        value, error = parse_str(row.get(camel), camel, max_len)
        if error:
            return None, (camel, error)
        record[snake] = value

    for camel, snake in _DATE_FIELDS:
        value, error = parse_date(row.get(camel), camel)
        if error:
            return None, (camel, error)
        record[snake] = value

    if record["contract_end_date"] < record["contract_start_date"]:
        return None, ("contractEndDate", "contractEndDate 不得早于 contractStartDate")

    payment_term, error = parse_int(row.get("paymentTerm"), "paymentTerm")
    if error:
        return None, ("paymentTerm", error)
    record["payment_term"] = payment_term

    for camel, snake in _DECIMAL_FIELDS:
        value, error = parse_decimal(row.get(camel), camel)
        if error:
            return None, (camel, error)
        record[snake] = value

    customer_type, error = parse_int(row.get("customerType"), "customerType")
    if error:
        return None, ("customerType", error)
    record["customer_type"] = customer_type

    entry_status, error = _parse_entry_status(row.get("contractEntryStatus"))
    if error:
        return None, ("contractEntryStatus", error)
    record["contract_entry_status"] = entry_status

    contract_no, error = _parse_contract_no(row.get("contractNo"), entry_status)
    if error:
        return None, ("contractNo", error)
    record["contract_no"] = contract_no

    return record, None


# 录入合同状态：缺省当 None；有值必须是 0 或 1。
def _parse_entry_status(value) -> tuple[int | None, str | None]:
    if value is None or value == "":
        return None, None
    if type(value) is int and value in (0, 1):
        return value, None
    return None, "contractEntryStatus 必须是 0 或 1"


# contractEntryStatus=0 时合同号必填；其它情况可空。
def _parse_contract_no(value, entry_status: int | None) -> tuple[str | None, str | None]:
    if entry_status == 0:
        return parse_str(value, "contractNo", 40)
    if value is None or value == "":
        return None, None
    return parse_str(value, "contractNo", 40)


# 拼一条接口 3 的 results[] 项。
def _result(fid, result_code: str, message: str) -> dict:
    return {"fid": fid, "resultCode": result_code, "message": message}