"""通用 DTO：与 openapi/openapi.yaml 契约对齐的 Pydantic 类型。

对齐由 tests/test_dto_contract.py 用 bundled 契约校验关键字段；
禁止在此复制会漂移的完整值集（以契约为准）。
"""

from typing import Annotated

from pydantic import BaseModel, ConfigDict, Field


def _id_pattern(prefix: str, version: int) -> str:
    ver = "7" if version == 7 else "4"
    tail = r"[0-9a-f]{12}-[0-9a-f]{4}-" + ver + r"[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$"
    return f"^{prefix}" + tail


UserId = Annotated[str, Field(pattern=_id_pattern("user_", 7))]
PersonalDomainId = Annotated[str, Field(pattern=_id_pattern("domain_", 7))]
ConversationId = Annotated[str, Field(pattern=_id_pattern("conversation_", 7))]
BranchId = Annotated[str, Field(pattern=_id_pattern("branch_", 7))]
MessageId = Annotated[str, Field(pattern=_id_pattern("message_", 7))]
ContentBlockId = Annotated[str, Field(pattern=_id_pattern("block_", 7))]
RunId = Annotated[str, Field(pattern=_id_pattern("run_", 7))]
TurnId = Annotated[str, Field(pattern=_id_pattern("turn_", 7))]
RequestId = Annotated[str, Field(pattern=_id_pattern("request_", 4))]


class Money(BaseModel):
    """金额：最小货币单位整数 + ISO 4217 币种；禁止浮点（契约第 4 节）。"""

    model_config = ConfigDict(extra="forbid")

    amount_minor: int = Field(ge=0)
    currency: str = Field(pattern=r"^[A-Z]{3}$")


class CursorPage[T](BaseModel):
    """opaque cursor 分页（契约第 4.1 节）；客户端不得解析 cursor。"""

    data: list[T]
    next_cursor: str | None
    has_more: bool