from datetime import datetime

from sqlalchemy import func, select
from sqlalchemy.orm import Session

from core_domain import TeamRunStatus, TeamStatus, TeamVersionStatus
from core_shared import JSONValue

from app.db.models import TeamDefinition, TeamRun, TeamVersion


class TeamDefinitionRepository:
    def __init__(self, db: Session) -> None:
        self.db = db

    def create(
        self,
        *,
        code: str,
        name: str,
        description: str | None,
        team_type: str,
        owner_user_id: str | None,
        metadata_json: dict[str, JSONValue] | None) -> TeamDefinition:
        entity = TeamDefinition(
            code=code,
            name=name,
            description=description,
            team_type=team_type,
            owner_user_id=owner_user_id,
            metadata_json=metadata_json)
        self.db.add(entity)
        self.db.commit()
        self.db.refresh(entity)
        return entity

    def list_all(self) -> list[TeamDefinition]:
        stmt = (
            select(TeamDefinition)
            .order_by(TeamDefinition.created_time.desc())
        )
        return list(self.db.scalars(stmt))

    def get_by_id(self, *, team_id: str) -> TeamDefinition | None:
        stmt = (
            select(TeamDefinition)
            .where(TeamDefinition.id == team_id)
        )
        return self.db.scalar(stmt)

    def update_status(
        self,
        *,
        team_id: str,
        status: TeamStatus) -> TeamDefinition | None:
        entity = self.get_by_id(team_id=team_id)
        if entity is None:
            return None
        entity.status = status
        self.db.commit()
        self.db.refresh(entity)
        return entity


class TeamVersionRepository:
    def __init__(self, db: Session) -> None:
        self.db = db

    def create(
        self,
        *,
        team_id: str,
        status: TeamVersionStatus,
        coordination_mode: str,
        objective: str | None,
        member_refs_json: list[dict[str, JSONValue]],
        policy_json: dict[str, JSONValue]) -> TeamVersion:
        version_no = self._next_version_no(team_id)
        entity = TeamVersion(
            team_id=team_id,
            version_no=version_no,
            status=status,
            coordination_mode=coordination_mode,
            objective=objective,
            member_refs_json=member_refs_json,
            policy_json=policy_json,
            published_time=datetime.utcnow() if status == "published" else None)
        self.db.add(entity)
        self.db.commit()
        self.db.refresh(entity)
        return entity

    def list_by_team(self, *, team_id: str) -> list[TeamVersion]:
        stmt = (
            select(TeamVersion)
            .where(TeamVersion.team_id == team_id)
            .order_by(TeamVersion.version_no.desc())
        )
        return list(self.db.scalars(stmt))

    def get_by_id(self, *, team_version_id: str) -> TeamVersion | None:
        stmt = (
            select(TeamVersion)
            .where(TeamVersion.id == team_version_id)
        )
        return self.db.scalar(stmt)

    def get_latest_published(self, *, team_id: str) -> TeamVersion | None:
        stmt = (
            select(TeamVersion)
            .where(TeamVersion.team_id == team_id)
            .where(TeamVersion.status == "published")
            .order_by(TeamVersion.version_no.desc())
            .limit(1)
        )
        return self.db.scalar(stmt)

    def _next_version_no(self, team_id: str) -> int:
        stmt = select(func.max(TeamVersion.version_no)).where(TeamVersion.team_id == team_id)
        current_max = self.db.scalar(stmt)
        return (current_max or 0) + 1


class TeamRunRepository:
    def __init__(self, db: Session) -> None:
        self.db = db

    def create(
        self,
        *,
        team_id: str,
        team_version_id: str,
        session_id: str | None,
        input_text: str | None,
        input_json: dict[str, JSONValue] | None) -> TeamRun:
        now = datetime.utcnow()
        entity = TeamRun(
            team_id=team_id,
            team_version_id=team_version_id,
            session_id=session_id,
            input_text=input_text,
            input_json=input_json,
            status="queued",
            queued_time=now)
        self.db.add(entity)
        self.db.commit()
        self.db.refresh(entity)
        return entity

    def list_by_scope(
        self,
        *,
        team_id: str | None = None,
        session_id: str | None = None) -> list[TeamRun]:
        stmt = select(TeamRun)
        if team_id is not None:
            stmt = stmt.where(TeamRun.team_id == team_id)
        if session_id is not None:
            stmt = stmt.where(TeamRun.session_id == session_id)
        stmt = stmt.order_by(TeamRun.created_time.desc())
        return list(self.db.scalars(stmt))

    def get_by_id(self, *, team_run_id: str) -> TeamRun | None:
        stmt = (
            select(TeamRun)
            .where(TeamRun.id == team_run_id)
        )
        return self.db.scalar(stmt)

    def claim_next_queued(
        self,
        *,
        worker_key: str,
        lease_expire_time: datetime) -> TeamRun | None:
        stmt = (
            select(TeamRun)
            .where(TeamRun.status == "queued")
            .order_by(TeamRun.created_time.asc())
            .with_for_update(skip_locked=True)
            .limit(1)
        )
        entity = self.db.scalar(stmt)
        if entity is None:
            return None

        now = datetime.utcnow()
        entity.status = "running"
        entity.worker_key = worker_key
        entity.started_time = entity.started_time or now
        entity.lease_expire_time = lease_expire_time
        self.db.commit()
        self.db.refresh(entity)
        return entity

    def release_expired_leases(self, *, now_time: datetime, max_items: int = 100) -> int:
        stmt = (
            select(TeamRun)
            .where(TeamRun.status == "running")
            .where(TeamRun.lease_expire_time.is_not(None))
            .where(TeamRun.lease_expire_time <= now_time)
            .order_by(TeamRun.lease_expire_time.asc())
            .limit(max_items)
        )
        entities = list(self.db.scalars(stmt))
        for entity in entities:
            entity.status = "queued"
            entity.worker_key = None
            entity.lease_expire_time = None
            entity.queued_time = now_time
            entity.started_time = None
            entity.finished_time = None

        if entities:
            self.db.commit()

        return len(entities)

    def update_status(
        self,
        *,
        team_run_id: str,
        status: TeamRunStatus,
        worker_key: str | None = None,
        output_text: str | None = None,
        output_json: dict[str, JSONValue] | None = None,
        error_code: str | None = None,
        error_message: str | None = None) -> TeamRun | None:
        entity = self.db.get(TeamRun, team_run_id)
        if entity is None:
            return None

        now = datetime.utcnow()
        entity.status = status
        entity.worker_key = worker_key
        entity.output_text = output_text
        entity.output_json = output_json
        entity.error_code = error_code
        entity.error_message = error_message
        if status == "running" and entity.started_time is None:
            entity.started_time = now
        if status != "running":
            entity.lease_expire_time = None
        if status in {"completed", "failed", "cancelled"}:
            entity.finished_time = now

        self.db.commit()
        self.db.refresh(entity)
        return entity