from datetime import datetime
from typing import Any, List, Optional

from pydantic import BaseModel, ConfigDict, Field, field_validator

from app.core.utils import parse_datetime


def _coerce_optional_datetime(value: Any) -> Optional[datetime]:
    """兼容前端 date-picker 的 YYYY-MM-DD 与完整日期时间字符串。"""
    if value is None or value == "":
        return None
    if isinstance(value, datetime):
        return value
    if isinstance(value, str):
        parsed = parse_datetime(value.strip())
        if parsed is not None:
            return parsed
        raise ValueError("无效的日期格式")
    return value


class CellProductBatchItem(BaseModel):
    """批量入库时每一份产品的编码与储物格。"""

    model_config = ConfigDict(populate_by_name=True)

    product_code: str = Field(..., alias="productCode")
    storage_slot_id: Optional[str] = Field(None, alias="storageSlotId")
    passage: Optional[str] = None
    spec_name: Optional[str] = Field(None, alias="specName")
    expected_cell_count: Optional[float] = Field(None, alias="expectedCellCount")
    viability: Optional[float] = None

    @field_validator("passage")
    @classmethod
    def validate_item_passage(cls, v):
        if v is not None and v != "":
            valid = {f"P{i}" for i in range(1, 9)}
            if v.upper() not in valid:
                raise ValueError("代次必须为 P1~P8")
            return v.upper()
        return v

    @field_validator("viability")
    @classmethod
    def validate_item_viability(cls, v):
        if v is not None and (v < 0 or v > 100):
            raise ValueError("活性必须在 0~100 之间")
        return v


class CellProductCreate(BaseModel):
    model_config = ConfigDict(populate_by_name=True)

    product_code: Optional[str] = Field(None, alias="productCode")
    product_name: str = Field(..., alias="productName")
    product_type_id: Optional[str] = Field(None, alias="productTypeId")
    spec_id: Optional[str] = Field(None, alias="specId")
    spec_name: Optional[str] = Field(None, alias="specName")
    batch_no: Optional[str] = Field(None, alias="batchNo")
    storage_slot_id: Optional[str] = Field(None, alias="storageSlotId")
    passage: Optional[str] = None
    freeze_date: Optional[datetime] = Field(None, alias="freezeDate")
    expected_cell_count: Optional[float] = Field(None, alias="expectedCellCount")
    viability: Optional[float] = None
    product_status: Optional[str] = Field("frozen", alias="productStatus")
    source_type: Optional[str] = Field("manual", alias="sourceType")
    quantity: Optional[float] = None
    unit: Optional[str] = None
    expiry_date: Optional[datetime] = Field(None, alias="expiryDate")
    product_images: Optional[str] = Field(None, alias="productImages")
    remark: Optional[str] = None
    items: Optional[List[CellProductBatchItem]] = Field(None, alias="items")

    @field_validator("freeze_date", "expiry_date", mode="before")
    @classmethod
    def coerce_date_fields(cls, v):
        return _coerce_optional_datetime(v)

    @field_validator("viability")
    @classmethod
    def validate_viability(cls, v):
        if v is not None and (v < 0 or v > 100):
            raise ValueError("活性必须在 0~100 之间")
        return v

    @field_validator("passage")
    @classmethod
    def validate_passage(cls, v):
        if v is not None:
            valid = {f"P{i}" for i in range(1, 9)}
            if v.upper() not in valid:
                raise ValueError("代次必须为 P1~P8")
            return v.upper()
        return v


class CellProductUpdate(BaseModel):
    model_config = ConfigDict(populate_by_name=True)

    product_code: Optional[str] = Field(None, alias="productCode")
    product_name: Optional[str] = Field(None, alias="productName")
    product_type_id: Optional[str] = Field(None, alias="productTypeId")
    spec_id: Optional[str] = Field(None, alias="specId")
    spec_name: Optional[str] = Field(None, alias="specName")
    batch_no: Optional[str] = Field(None, alias="batchNo")
    storage_slot_id: Optional[str] = Field(None, alias="storageSlotId")
    passage: Optional[str] = None
    freeze_date: Optional[datetime] = Field(None, alias="freezeDate")
    expected_cell_count: Optional[float] = Field(None, alias="expectedCellCount")
    viability: Optional[float] = None
    product_status: Optional[str] = Field(None, alias="productStatus")
    quantity: Optional[float] = None
    unit: Optional[str] = None
    expiry_date: Optional[datetime] = Field(None, alias="expiryDate")
    product_images: Optional[str] = Field(None, alias="productImages")
    remark: Optional[str] = None

    @field_validator("freeze_date", "expiry_date", mode="before")
    @classmethod
    def coerce_date_fields(cls, v):
        return _coerce_optional_datetime(v)

    @field_validator("viability")
    @classmethod
    def validate_viability(cls, v):
        if v is not None and (v < 0 or v > 100):
            raise ValueError("活性必须在 0~100 之间")
        return v

    @field_validator("passage")
    @classmethod
    def validate_passage(cls, v):
        if v is not None:
            valid = {f"P{i}" for i in range(1, 9)}
            if v.upper() not in valid:
                raise ValueError("代次必须为 P1~P8")
            return v.upper()
        return v

    @field_validator("product_status")
    @classmethod
    def validate_status(cls, v):
        allowed = ("frozen", "sold", "used", "voided", "in_production", "thawed")
        if v is not None and v not in allowed:
            raise ValueError(f"状态必须为 {'/'.join(allowed)}")
        return v


class CellProductListQuery(BaseModel):
    model_config = ConfigDict(populate_by_name=True)

    page: int = 1
    page_size: int = Field(20, alias="pageSize")
    keyword: Optional[str] = None
    product_code: Optional[str] = Field(None, alias="productCode")
    product_name: Optional[str] = Field(None, alias="productName")
    product_type_id: Optional[str] = Field(None, alias="productTypeId")
    product_status: Optional[str] = Field(None, alias="productStatus")
    passage: Optional[str] = None
    source_type: Optional[str] = Field(None, alias="sourceType")