from __future__ import annotations

from datetime import datetime
from typing import Any, Literal

from pydantic import BaseModel, ConfigDict, Field, field_validator, model_validator

RiskDispositionAction = Literal[
    "confirm",
    "false_positive",
    "request_supplement",
    "start_remediation",
    "resolve",
    "request_waiver",
]
RiskAdjudication = Literal["unreviewed", "confirmed", "false_positive"]
RiskLifecycleStatus = Literal[
    "open",
    "supplement_requested",
    "remediation_in_progress",
    "waiver_requested",
    "resolved",
]


class RiskDispositionActionCreate(BaseModel):
    action: RiskDispositionAction
    expected_version: int = Field(ge=0)
    request_id: str = Field(min_length=8, max_length=120)
    comment: str | None = Field(default=None, max_length=1000)
    assignee: str | None = Field(default=None, max_length=120)
    due_at: datetime | None = None
    resolution: str | None = Field(default=None, max_length=2000)

    @field_validator("request_id", "comment", "assignee", "resolution", mode="before")
    @classmethod
    def normalize_text(cls, value: Any) -> Any:
        if value is None:
            return None
        normalized = str(value).strip()
        return normalized or None

    @model_validator(mode="after")
    def validate_action_fields(self) -> RiskDispositionActionCreate:
        if self.action == "resolve" and not self.resolution:
            raise ValueError("resolve 动作必须填写 resolution")
        if self.action in {"false_positive", "request_supplement", "request_waiver"} and not (
            self.comment
        ):
            raise ValueError(f"{self.action} 动作必须填写 comment")
        if self.action in {"confirm", "false_positive"} and any(
            value is not None for value in (self.assignee, self.due_at, self.resolution)
        ):
            raise ValueError("裁决动作不能同时修改负责人、截止时间或解决说明")
        return self


class RiskDispositionEventRead(BaseModel):
    model_config = ConfigDict(from_attributes=True)

    id: str
    tenant_id: str
    disposition_id: str
    observation_id: str
    version: int
    action: RiskDispositionAction
    actor_id: str
    actor_name: str
    request_id: str
    comment: str | None
    before_json: dict[str, Any]
    after_json: dict[str, Any]
    created_at: datetime


class RiskDispositionRead(BaseModel):
    model_config = ConfigDict(from_attributes=True)

    id: str
    tenant_id: str
    observation_id: str
    adjudication: RiskAdjudication
    lifecycle_status: RiskLifecycleStatus
    version: int
    assignee: str | None
    due_at: datetime | None
    resolution: str | None
    created_at: datetime
    updated_at: datetime
    events: list[RiskDispositionEventRead] = Field(default_factory=list)


class RiskDispositionMutationRead(BaseModel):
    disposition: RiskDispositionRead
    event: RiskDispositionEventRead
    replayed: bool = False