"""Repositories for durable async job rows (活动分析 / 周期对比).

DB 行是任务的持久权威：queued/generating/completed/failed 状态机与
claim 竞争都住在这里；进程内任务句柄另由 TaskRegistry 管理。
"""

from dataclasses import dataclass
from enum import Enum
from typing import Generic, Optional, TypeVar

from sqlalchemy import update as sql_update
from sqlmodel import Session, select

from agenteval.storage.db import CampaignAnalysisDB, CampaignPeriodComparisonDB, get_session, utc_now

DB = TypeVar("DB")  # persisted table row


class AsyncJobClaimStatus(str, Enum):
    CLAIMED = "claimed"
    NOT_FOUND = "not_found"
    ALREADY_CLAIMED = "already_claimed"
    NOT_QUEUED = "not_queued"


@dataclass(frozen=True)
class AsyncJobClaimResult:
    status: AsyncJobClaimStatus

    @property
    def claimed(self) -> bool:
        return self.status is AsyncJobClaimStatus.CLAIMED


class AsyncJobRepository(Generic[DB]):
    """Base class for async job repositories (analysis, comparison).

    Provides common pattern: get_by_campaign, mark_orphans_failed.
    Subclasses implement upsert with their specific fields.
    """

    _table: type[DB]

    def __init__(self, session: Optional[Session] = None):
        self.session = session or get_session()

    def get_by_campaign(self, campaign_id: str) -> Optional[DB]:
        statement = select(self._table).where(self._table.campaign_id == campaign_id)  # type: ignore[attr-defined]
        return self.session.exec(statement).first()

    def list_queued(self) -> list[DB]:
        statement = select(self._table).where(self._table.status == "queued")  # type: ignore[attr-defined]
        return list(self.session.exec(statement).all())

    def claim_queued(self, campaign_id: str) -> AsyncJobClaimResult:
        """Atomically move one queued job to generating.

        The status predicate is the durable idempotency authority. Competing
        workers may observe the same queued row, but only one can claim it.
        """
        statement = (
            sql_update(self._table)
            .where(
                self._table.campaign_id == campaign_id,  # type: ignore[attr-defined]
                self._table.status == "queued",  # type: ignore[attr-defined]
            )
            .values(status="generating", error=None, updated_at=utc_now())
        )
        result = self.session.exec(statement)
        self.session.commit()
        self.session.expire_all()
        if result.rowcount == 1:
            return AsyncJobClaimResult(AsyncJobClaimStatus.CLAIMED)
        row = self.get_by_campaign(campaign_id)
        if row is None:
            return AsyncJobClaimResult(AsyncJobClaimStatus.NOT_FOUND)
        if row.status == "generating":  # type: ignore[attr-defined]
            return AsyncJobClaimResult(AsyncJobClaimStatus.ALREADY_CLAIMED)
        return AsyncJobClaimResult(AsyncJobClaimStatus.NOT_QUEUED)

    def prepare_queued_recovery(self, max_attempts: int, exhausted_error: str) -> list[DB]:
        """Increment queued recovery attempts and fail exhausted jobs."""
        recoverable: list[DB] = []
        rows = self.list_queued()
        for row in rows:
            if row.recovery_attempts >= max_attempts:  # type: ignore[attr-defined]
                row.status = "failed"  # type: ignore[attr-defined]
                row.error = exhausted_error  # type: ignore[attr-defined]
            else:
                row.recovery_attempts += 1  # type: ignore[attr-defined]
                recoverable.append(row)
            row.updated_at = utc_now()  # type: ignore[attr-defined]
            self.session.add(row)
        if rows:
            self.session.commit()
            self.session.expire_all()
        return recoverable

    def mark_orphans_failed(self, error_message: str) -> int:
        """服务启动时清理：把滞留的 generating 行标记为 failed。

        异步任务是进程内 asyncio 任务，服务重启后不会恢复；不清理则这些
        行永远停留在 generating（僵尸状态）。
        """
        rows = self.session.exec(
            select(self._table).where(self._table.status == "generating")  # type: ignore[attr-defined]
        ).all()
        for row in rows:
            row.status = "failed"  # type: ignore[attr-defined]
            row.error = error_message  # type: ignore[attr-defined]
            row.updated_at = utc_now()  # type: ignore[attr-defined]
            self.session.add(row)
        if rows:
            self.session.commit()
        return len(rows)


class CampaignAnalysisRepository(AsyncJobRepository[CampaignAnalysisDB]):
    """Repository for campaign analysis rows (one per campaign, upserted)."""

    _table = CampaignAnalysisDB

    def enqueue(self, campaign_id: str, *, triggered_by: str = "manual") -> CampaignAnalysisDB:
        """Persist an analysis job before launching its process-local task."""
        row = self.get_by_campaign(campaign_id)
        if row is None:
            row = CampaignAnalysisDB(campaign_id=campaign_id, status="queued", triggered_by=triggered_by)
        elif row.status in {"queued", "generating"}:
            return row
        else:
            row.status = "queued"
            row.result = None
            row.model_config_id = None
            row.error = None
            row.triggered_by = triggered_by
            row.recovery_attempts = 0
            row.updated_at = utc_now()
        self.session.add(row)
        self.session.commit()
        self.session.refresh(row)
        return row

    def upsert(
        self,
        campaign_id: str,
        *,
        status: str,
        result: Optional[dict] = None,
        model_config_id: Optional[str] = None,
        error: Optional[str] = None,
        triggered_by: str = "manual",
    ) -> CampaignAnalysisDB:
        row = self.get_by_campaign(campaign_id)
        if row is None:
            row = CampaignAnalysisDB(campaign_id=campaign_id)
        row.status = status
        if result is not None:
            row.set_result(result)
        else:
            row.result = None
        row.model_config_id = model_config_id
        row.error = error
        row.triggered_by = triggered_by
        row.updated_at = utc_now()
        self.session.add(row)
        self.session.commit()
        self.session.refresh(row)
        return row

    def mark_orphans_failed(self) -> int:
        """服务启动时清理：把滞留的 generating 分析行标记为 failed。"""
        return super().mark_orphans_failed("服务重启导致分析生成中断")


class CampaignPeriodComparisonRepository(AsyncJobRepository[CampaignPeriodComparisonDB]):
    """Repository for period-comparison rows (one per campaign, upserted)."""

    _table = CampaignPeriodComparisonDB

    def enqueue(
        self,
        campaign_id: str,
        *,
        baseline_campaign_id: str,
        triggered_by: str = "manual",
    ) -> CampaignPeriodComparisonDB:
        """Persist a comparison job before launching its process-local task."""
        row = self.get_by_campaign(campaign_id)
        if row is None:
            row = CampaignPeriodComparisonDB(
                campaign_id=campaign_id,
                baseline_campaign_id=baseline_campaign_id,
                status="queued",
                triggered_by=triggered_by,
            )
        elif row.status in {"queued", "generating"}:
            return row
        else:
            row.baseline_campaign_id = baseline_campaign_id
            row.status = "queued"
            row.result = None
            row.model_config_id = None
            row.error = None
            row.triggered_by = triggered_by
            row.recovery_attempts = 0
            row.updated_at = utc_now()
        self.session.add(row)
        self.session.commit()
        self.session.refresh(row)
        return row

    def upsert(
        self,
        campaign_id: str,
        *,
        status: str,
        baseline_campaign_id: Optional[str] = None,
        result: Optional[dict] = None,
        model_config_id: Optional[str] = None,
        error: Optional[str] = None,
        triggered_by: str = "manual",
    ) -> CampaignPeriodComparisonDB:
        row = self.get_by_campaign(campaign_id)
        if row is None:
            row = CampaignPeriodComparisonDB(
                campaign_id=campaign_id,
                baseline_campaign_id=baseline_campaign_id or "",
            )
        row.status = status
        if baseline_campaign_id is not None:
            row.baseline_campaign_id = baseline_campaign_id
        if result is not None:
            row.set_result(result)
        else:
            row.result = None
        row.model_config_id = model_config_id
        row.error = error
        row.triggered_by = triggered_by
        row.updated_at = utc_now()
        self.session.add(row)
        self.session.commit()
        self.session.refresh(row)
        return row

    def mark_orphans_failed(self) -> int:
        """服务启动时清理：把滞留的 generating 周期对比行标记为 failed。"""
        return super().mark_orphans_failed("服务重启导致周期对比生成中断")