"""运输计划多段：内部客户地磅默认值与数量平衡校验"""
from __future__ import annotations

from decimal import Decimal
from typing import Any, Iterable, Literal, Optional, Tuple

from fastapi import HTTPException

from app.services.pl_internal_customer import is_internal_customer_name

StopType = Literal["load", "delivery"]


def resolve_stop_dibang_defaults(
    customer_name: Optional[str],
    stop_type: StopType,
) -> Tuple[bool, str]:
    """地磅默认勾选以本段客户是否为内部客户（山峡/云栋）为准。"""
    if not is_internal_customer_name(customer_name):
        return False, "none"
    if stop_type == "load":
        return True, "outbound"
    if stop_type == "delivery":
        return True, "inbound"
    return False, "none"


def normalize_stop_dibang_fields(
    customer_name: Optional[str],
    stop_type: StopType,
    generate_dibang: Optional[int],
    dibang_direction: Optional[str],
) -> Tuple[int, str]:
    """归一化段次地磅勾选与方向。

    - 非内部客户：强制不生成地磅单
    - 内部客户：尊重显式勾选值（含可选车取消勾选传 0）；仅 None 时用默认
    - 勾选但方向缺失/none 时按本段客户补默认方向
    """
    if not is_internal_customer_name(customer_name):
        return 0, "none"

    default_gen, default_dir = resolve_stop_dibang_defaults(customer_name, stop_type)
    if generate_dibang is None:
        gen = 1 if default_gen else 0
    else:
        gen = 1 if int(generate_dibang) == 1 else 0

    direction = (dibang_direction or "").strip()
    if gen:
        if direction not in ("outbound", "inbound"):
            direction = default_dir if default_dir != "none" else (
                "outbound" if stop_type == "load" else "inbound"
            )
    else:
        direction = "none"
    return gen, direction


def _extract_qty(item: Any, *field_names: str) -> Decimal:
    for name in field_names:
        if isinstance(item, dict):
            value = item.get(name)
        else:
            value = getattr(item, name, None)
        if value is not None:
            return Decimal(str(value))
    return Decimal("0")


def _fmt_qty(qty: Decimal) -> str:
    if qty == qty.to_integral_value():
        return str(int(qty))
    return format(qty.normalize(), "f")


def _row_text(item: Any, *field_names: str) -> str:
    for name in field_names:
        if isinstance(item, dict):
            value = item.get(name)
        else:
            value = getattr(item, name, None)
        text = str(value or "").strip()
        if text:
            return text
    return ""


def _product_key(item: Any) -> str:
    product_id = _row_text(item, "product_id", "productId")
    if product_id:
        return f"id:{product_id}"
    product_no = _row_text(item, "product_no", "productNo")
    if product_no:
        return f"no:{product_no}"
    product_name = _row_text(item, "product_name", "productName")
    if product_name:
        return f"name:{product_name}"
    return ""


def _product_label(item: Any) -> str:
    return _row_text(
        item, "product_name", "productName", "product_no", "productNo", "product_id", "productId"
    ) or "未命名产品"


def _ordered_product_labels(items: Iterable[Any]) -> list[tuple[str, str]]:
    labels: dict[str, str] = {}
    order: list[str] = []
    for item in items or []:
        key = _product_key(item)
        if not key or key in labels:
            continue
        labels[key] = _product_label(item)
        order.append(key)
    return [(key, labels[key]) for key in order]


def _delivery_product_rows(deliveries: Optional[Iterable[Any]]) -> list[Any]:
    rows: list[Any] = []
    for delivery in deliveries or []:
        if isinstance(delivery, dict):
            rows.extend(delivery.get("products") or [])
        else:
            rows.extend(getattr(delivery, "products", None) or [])
    return rows


def load_delivery_product_gap(load: Any, deliveries: Optional[Iterable[Any]]) -> str:
    """装货段与全部送货段的产品种类必须一致。返回空字符串表示一致。"""
    load_rows = []
    if load is not None:
        load_rows = load.get("products") if isinstance(load, dict) else (getattr(load, "products", None) or [])
    load_labels = _ordered_product_labels(load_rows)
    delivery_labels = _ordered_product_labels(_delivery_product_rows(deliveries))
    delivery_keys = {key for key, _label in delivery_labels}
    load_keys = {key for key, _label in load_labels}
    only_load = [label for key, label in load_labels if key not in delivery_keys]
    only_delivery = [label for key, label in delivery_labels if key not in load_keys]
    parts: list[str] = []
    if only_load:
        parts.append(f"装货段有产品 {'、'.join(only_load)}，送货段没有")
    if only_delivery:
        parts.append(f"送货段有产品 {'、'.join(only_delivery)}，装货段没有")
    if not parts:
        return ""
    return f"{'；'.join(parts)}。两边产品必须一致，不能保存"


def assert_load_delivery_same_products(load: Any, deliveries: Optional[Iterable[Any]]) -> None:
    gap = load_delivery_product_gap(load, deliveries)
    if gap:
        raise HTTPException(status_code=422, detail=gap)


def _group_plan_qty(items: Iterable[Any]) -> tuple[list[str], dict[str, tuple[Decimal, str]]]:
    groups: dict[str, tuple[Decimal, str]] = {}
    order: list[str] = []
    for item in items or []:
        key = _product_key(item)
        qty = _extract_qty(item, "plan_qty", "planQty")
        label = _product_label(item) if key else ""
        if key not in groups:
            groups[key] = (Decimal("0"), label)
            order.append(key)
        total, existing = groups[key]
        groups[key] = (total + qty, existing or label)
    return order, groups


def warn_qty_imbalance(
    plan_products: Iterable[Any],
    load_products: Iterable[Any],
    delivery_products: Iterable[Any],
) -> list[str]:
    del plan_products
    load_order, load_groups = _group_plan_qty(load_products)
    delivery_order, delivery_groups = _group_plan_qty(delivery_products)
    warnings: list[str] = []
    seen: set[str] = set()
    for key in [*load_order, *delivery_order]:
        if key in seen:
            continue
        seen.add(key)
        load_qty, load_label = load_groups.get(key, (Decimal("0"), ""))
        delivery_qty, delivery_label = delivery_groups.get(key, (Decimal("0"), ""))
        if load_qty == delivery_qty:
            continue
        label = load_label or delivery_label
        text = f"装货合计({_fmt_qty(load_qty)})与送货合计({_fmt_qty(delivery_qty)})不一致，请核对"
        if label:
            text = f"产品{label}：{text}"
        warnings.append(text)
    return warnings