from __future__ import annotations

from datetime import UTC, datetime
from enum import StrEnum
from typing import Annotated, Literal

from annotated_types import MinLen
from pydantic import BaseModel, Field
from pydantic_extra_types.currency_code import Currency
from ulid import ULID

from .ref import AccountRef


class AccountType(StrEnum):
    """资金性质"""

    ASSET = "ASSET"
    LIABILITY = "LIABILITY"
    EQUITY = "EQUITY"


class BaseAccount(BaseModel):
    """基础账户模型"""

    id: ULID = Field(default_factory=ULID)
    name: Annotated[str, "用户自定义名称", MinLen(1)]
    account_type: AccountType
    primary_currency: Annotated[Currency | None, "主币种（可选）", Field(default=None)]
    supported_currencies: Annotated[
        list[Currency] | None, "支持的币种列表（None=全币种）", Field(default=None)
    ]
    is_active: Annotated[bool, "是否启用", Field(default=True)]
    remark: Annotated[str | None, "备注", Field(default=None)]
    created_at: Annotated[datetime, "创建时间", Field(default_factory=lambda: datetime.now(UTC))]
    updated_at: Annotated[datetime, "更新时间", Field(default_factory=lambda: datetime.now(UTC))]
    deleted_at: Annotated[datetime | None, "软删除时间（None=未删除）", Field(default=None)]


class BankAccount(BaseAccount):
    """银行账户"""

    account_type: Literal[AccountType.ASSET, AccountType.LIABILITY] = AccountType.ASSET
    issuer_name: Annotated[str, "银行名称", MinLen(1)]
    account_number: Annotated[str | None, "完整账户号（敏感信息）", Field(default=None)]
    account_suffix: Annotated[
        str | None, "账户号末尾部分，用于识别", MinLen(1), Field(default=None)
    ]
    sub_accounts: Annotated[list[AccountRef], "子账户引用", Field(default_factory=list)]


class EWalletAccount(BaseAccount):
    """电子钱包账户"""

    account_type: Literal[AccountType.ASSET] = AccountType.ASSET
    platform: Annotated[
        str,
        "平台名称: Alipay/WeChat/PayMe/AlipayHK/MPay/Octopus/Tap&Go/AlipayMO",
        MinLen(1),
    ]
    account_id: Annotated[str | None, "平台账户ID", Field(default=None)]


class CashAccount(BaseAccount):
    """现金账户"""

    account_type: Literal[AccountType.ASSET] = AccountType.ASSET
    location: Annotated[str | None, "存放位置描述", Field(default=None)]


type Account = Annotated[
    BankAccount | EWalletAccount | CashAccount,
    Field(discriminator="account_type"),
]