"""实验结果同步服务（P1）"""

from datetime import datetime, timezone
from typing import Any, Dict, Optional, Set

from sqlalchemy import and_, select
from sqlalchemy.ext.asyncio import AsyncSession

from ..models import Experiment, ExperimentTruthNodeSync, TruthNode


from ..utils.timezone import now_cn_aware, now_cn_naive
class ExperimentSyncService:
    """实验结果 -> 宪章同步，支持自动应用、人工审核与回滚。"""

    def __init__(self, db: AsyncSession):
        self.db = db

    async def auto_sync_experiment_result(
        self,
        experiment_id: int,
        truth_node_id: int,
        tenant_id: int,
        project_id: Optional[int] = None,
        sync_type: str = "result_sync",
        auto_apply_threshold: float = 0.8,
    ) -> Dict[str, Any]:
        experiment = await self._get_experiment(experiment_id, tenant_id)
        truth_node = await self._get_truth_node(truth_node_id, tenant_id)
        if not experiment or not truth_node:
            raise ValueError("实验或宪章不存在")
        if project_id is not None:
            await self.validate_experiment_truth_same_project(
                experiment=experiment,
                truth_node=truth_node,
                tenant_id=tenant_id,
                project_id=project_id,
            )

        confidence = self._calc_confidence(experiment.current_score)
        sync_data = self._build_sync_data(experiment, truth_node, sync_type)
        auto_apply = confidence >= auto_apply_threshold

        record = ExperimentTruthNodeSync(
            tenant_id=tenant_id,
            experiment_id=experiment.id,
            experiment_external_id=str(experiment.id),
            truth_node_id=truth_node.id,
            sync_type=sync_type,
            sync_data=sync_data,
            confidence_score=confidence,
            auto_applied=auto_apply,
            apply_status="pending",
        )

        if auto_apply:
            await self._apply_sync_to_truth_node(record, truth_node)
            record.apply_status = "applied"

        self.db.add(record)
        await self.db.commit()
        await self.db.refresh(record)

        return {
            "sync_id": record.id,
            "confidence_score": record.confidence_score,
            "auto_applied": record.auto_applied,
            "apply_status": record.apply_status,
            "sync_data": record.sync_data,
        }

    async def validate_experiment_truth_same_project(
        self,
        experiment: Experiment,
        truth_node: TruthNode,
        tenant_id: int,
        project_id: int,
    ) -> None:
        """交叉校验实验与宪章均属于指定项目。

        注意：Experiment 当前无 project_id 字段，使用 linked_context_nodes 与项目宪章集合交叉验证。
        """
        if truth_node.project_id != project_id:
            raise ValueError(
                f"宪章 {truth_node.id} 不属于项目 {project_id}，拒绝跨项目同步"
            )

        # 强约束优先：Experiment.project_id 命中则直接使用。
        if experiment.project_id is not None:
            if int(experiment.project_id) != int(project_id):
                raise ValueError(
                    f"实验 {experiment.id} 不属于项目 {project_id}，拒绝跨项目同步"
                )
            return

        project_truth_nodes = await self._get_project_truth_node_ids(project_id, tenant_id)
        if not project_truth_nodes:
            raise ValueError(f"项目 {project_id} 下无可用宪章，无法校验实验归属")

        linked = experiment.linked_context_nodes or []
        linked_ids = self._normalize_ids(linked)
        if not linked_ids:
            raise ValueError(
                "实验未关联任何上下文节点（linked_context_nodes 为空），无法通过项目归属校验"
            )

        if linked_ids.isdisjoint(project_truth_nodes):
            raise ValueError(
                f"实验 {experiment.id} 未关联项目 {project_id} 下宪章，拒绝跨项目同步"
            )

        # 迁移期兼容：可推断归属时补写 project_id，减少后续重复推断。
        experiment.project_id = project_id

    async def _get_project_truth_node_ids(self, project_id: int, tenant_id: int) -> Set[int]:
        result = await self.db.execute(
            select(TruthNode.id).where(
                and_(
                    TruthNode.tenant_id == tenant_id,
                    TruthNode.project_id == project_id,
                )
            )
        )
        return {int(row[0]) for row in result.all()}

    def _normalize_ids(self, raw: Any) -> Set[int]:
        ids: Set[int] = set()
        if isinstance(raw, list):
            for item in raw:
                try:
                    ids.add(int(item))
                except (TypeError, ValueError):
                    continue
        return ids

    async def review_sync(
        self,
        sync_id: int,
        tenant_id: int,
        reviewer_id: int,
        action: str,
        review_notes: Optional[str] = None,
    ) -> Dict[str, Any]:
        record = await self._get_sync_record(sync_id, tenant_id)
        if not record:
            raise ValueError("同步记录不存在")
        if record.apply_status == "applied" and action == "approve":
            return {"sync_id": record.id, "apply_status": record.apply_status}

        record.reviewed_by = reviewer_id
        record.reviewed_at = now_cn_naive()
        record.review_notes = review_notes

        if action == "approve":
            truth_node = await self._get_truth_node(record.truth_node_id, tenant_id)
            if truth_node:
                await self._apply_sync_to_truth_node(record, truth_node)
            record.apply_status = "applied"
        else:
            record.apply_status = "rejected"

        await self.db.commit()
        await self.db.refresh(record)
        return {
            "sync_id": record.id,
            "apply_status": record.apply_status,
            "reviewed_at": record.reviewed_at.isoformat() if record.reviewed_at else None,
        }

    async def rollback_sync(
        self,
        sync_id: int,
        tenant_id: int,
        reviewer_id: int,
        rollback_notes: Optional[str] = None,
    ) -> Dict[str, Any]:
        record = await self._get_sync_record(sync_id, tenant_id)
        if not record:
            raise ValueError("同步记录不存在")
        if record.apply_status != "applied":
            raise ValueError("仅已应用记录支持回滚")

        truth_node = await self._get_truth_node(record.truth_node_id, tenant_id)
        if not truth_node:
            raise ValueError("关联宪章不存在")

        snapshot = (record.sync_data or {}).get("previous_truth_content")
        if snapshot is None:
            raise ValueError("缺少回滚快照，无法回滚")

        truth_node.content = snapshot
        truth_node.version = int(truth_node.version or 1) + 1

        record.apply_status = "requires_review"
        record.reviewed_by = reviewer_id
        record.reviewed_at = now_cn_naive()
        record.review_notes = rollback_notes or "manual rollback"

        await self.db.commit()
        await self.db.refresh(record)
        return {
            "sync_id": record.id,
            "apply_status": record.apply_status,
            "rolled_back": True,
        }

    async def list_sync_records(
        self,
        tenant_id: int,
        truth_node_id: Optional[int] = None,
        limit: int = 50,
    ) -> Dict[str, Any]:
        query = select(ExperimentTruthNodeSync).where(
            ExperimentTruthNodeSync.tenant_id == tenant_id
        )
        if truth_node_id is not None:
            query = query.where(ExperimentTruthNodeSync.truth_node_id == truth_node_id)
        query = query.order_by(ExperimentTruthNodeSync.created_at.desc()).limit(limit)

        result = await self.db.execute(query)
        items = result.scalars().all()
        return {
            "items": [
                {
                    "id": i.id,
                    "experiment_id": i.experiment_id,
                    "truth_node_id": i.truth_node_id,
                    "sync_type": i.sync_type,
                    "confidence_score": i.confidence_score,
                    "auto_applied": i.auto_applied,
                    "apply_status": i.apply_status,
                    "created_at": i.created_at.isoformat() if i.created_at else None,
                }
                for i in items
            ]
        }

    async def _get_experiment(self, experiment_id: int, tenant_id: int) -> Optional[Experiment]:
        result = await self.db.execute(
            select(Experiment).where(
                and_(Experiment.id == experiment_id, Experiment.tenant_id == tenant_id)
            )
        )
        return result.scalar_one_or_none()

    async def _get_truth_node(self, truth_node_id: int, tenant_id: int) -> Optional[TruthNode]:
        result = await self.db.execute(
            select(TruthNode).where(
                and_(TruthNode.id == truth_node_id, TruthNode.tenant_id == tenant_id)
            )
        )
        return result.scalar_one_or_none()

    async def _get_sync_record(
        self, sync_id: int, tenant_id: int
    ) -> Optional[ExperimentTruthNodeSync]:
        result = await self.db.execute(
            select(ExperimentTruthNodeSync).where(
                and_(ExperimentTruthNodeSync.id == sync_id, ExperimentTruthNodeSync.tenant_id == tenant_id)
            )
        )
        return result.scalar_one_or_none()

    def _calc_confidence(self, current_score: Optional[float]) -> float:
        score = float(current_score or 0.0)
        if score > 1:
            score /= 100.0
        return round(max(0.0, min(1.0, score)), 2)

    def _build_sync_data(
        self, experiment: Experiment, truth_node: TruthNode, sync_type: str
    ) -> Dict[str, Any]:
        return {
            "sync_type": sync_type,
            "experiment_summary": {
                "id": experiment.id,
                "title": experiment.title,
                "status": experiment.status,
                "target_metric": experiment.target_metric,
                "current_score": experiment.current_score,
            },
            "previous_truth_content": truth_node.content,
        }

    async def _apply_sync_to_truth_node(
        self, record: ExperimentTruthNodeSync, truth_node: TruthNode
    ) -> None:
        content = truth_node.content if isinstance(truth_node.content, dict) else {}
        if not isinstance(content, dict):
            content = {"raw": str(truth_node.content)}
        sync_section = content.get("experiment_sync", {})
        sync_section["last_sync"] = {
            "sync_id": record.id,
            "sync_type": record.sync_type,
            "confidence_score": record.confidence_score,
            "experiment_summary": (record.sync_data or {}).get("experiment_summary", {}),
            "applied_at": now_cn_aware().isoformat(),
        }
        content["experiment_sync"] = sync_section
        truth_node.content = content
        truth_node.version = int(truth_node.version or 1) + 1