from __future__ import annotations

from dataclasses import dataclass

from app.enums.credit_record import CreditRecordChargeKind
from app.enums.llm_billing import LlmBillingLedgerState
from app.services.generation.billing_service import build_credit_biz_key


class LlmBillingConfigurationError(RuntimeError):
    """LLM 统一账务配置无效，必须在调用模型前终止。"""


class LlmBillingStateError(RuntimeError):
    """当前 attempt 的账务流水状态不允许继续执行。"""


@dataclass(slots=True, frozen=True)
class LlmBillingPolicy:
    enabled: bool
    hold_credits: float
    config_key: str | None = None
    source_key: str | None = None
    valid: bool = True
    error: str | None = None

    @property
    def bypassed(self) -> bool:
        return not self.enabled


@dataclass(slots=True)
class LlmBillingContext:
    user_id: str
    owner_type: str
    owner_id: str
    attempt_no: int
    charge_kind: str = CreditRecordChargeKind.TEXT_PROMPT.value
    billing_scene: str | None = None
    source_module: str | None = None
    source_project_id: str | None = None
    source_step_id: str | None = None
    source_step_code: str | None = None
    related_id: str | None = None
    hold_credits: float | None = None
    hold_config_key: str | None = None
    description_prefix: str = "LLM"
    trace_id: str | None = None
    request_id: str | None = None
    celery_task_id: str | None = None
    provider: str | None = None
    model_name: str | None = None
    token_usage_id: str | None = None

    @property
    def hold_biz_key(self) -> str:
        return build_credit_biz_key(
            owner_type=self.owner_type,
            owner_id=self.owner_id,
            attempt_no=self.attempt_no,
            charge_kind=self.charge_kind,
            action="hold",
        )

    @property
    def hold_release_biz_key(self) -> str:
        return build_credit_biz_key(
            owner_type=self.owner_type,
            owner_id=self.owner_id,
            attempt_no=self.attempt_no,
            charge_kind=self.charge_kind,
            action="hold_release",
        )

    @property
    def charge_biz_key(self) -> str:
        return build_credit_biz_key(
            owner_type=self.owner_type,
            owner_id=self.owner_id,
            attempt_no=self.attempt_no,
            charge_kind=self.charge_kind,
            action="charge",
        )

    @property
    def ledger_biz_keys(self) -> tuple[str, str, str]:
        return self.hold_biz_key, self.hold_release_biz_key, self.charge_biz_key


@dataclass(slots=True, frozen=True)
class LlmHoldResult:
    amount: float
    state: LlmBillingLedgerState
    created: bool = False
    record_id: str | None = None
    reason: str | None = None

    @property
    def bypassed(self) -> bool:
        return self.state == LlmBillingLedgerState.BILLING_BYPASSED


@dataclass(slots=True, frozen=True)
class LlmHoldValidation:
    can_execute: bool
    amount: float
    state: LlmBillingLedgerState
    reason: str | None = None
    hold_record_id: str | None = None

    @property
    def bypassed(self) -> bool:
        return self.state == LlmBillingLedgerState.BILLING_BYPASSED