import uuid
from datetime import datetime, timezone

from sqlalchemy import DateTime, JSON, func
from sqlalchemy.ext.asyncio import AsyncSession
from sqlmodel import Field, SQLModel, select


def _now() -> datetime:
    return datetime.now(timezone.utc)


class SavedReports(SQLModel, table=True):
    __tablename__ = "saved_reports"

    id: uuid.UUID = Field(default_factory=uuid.uuid4, primary_key=True)
    user_id: uuid.UUID = Field(index=True, foreign_key="users.id")
    name: str
    description: str | None = Field(default=None)
    report_type: str
    filters: dict = Field(default_factory=dict, sa_type=JSON)
    last_run_at: datetime | None = Field(default=None, sa_type=DateTime(timezone=True))
    created_at: datetime = Field(default_factory=_now, sa_type=DateTime(timezone=True))
    updated_at: datetime = Field(default_factory=_now, sa_type=DateTime(timezone=True))
    is_deleted: bool = Field(default=False)

    @staticmethod
    def _as_uuid(record_id) -> uuid.UUID | None:
        if record_id in (None, ""):
            return None
        try:
            return uuid.UUID(str(record_id))
        except ValueError:
            return None

    @classmethod
    async def get_by_id(cls, session: AsyncSession, record_id, *, user_id=None):
        uid = cls._as_uuid(record_id)
        if uid is None:
            return None
        statement = select(cls).where(cls.id == uid, cls.is_deleted == False)  # noqa: E712
        if user_id is not None:
            statement = statement.where(cls.user_id == user_id)
        result = await session.execute(statement)
        return result.scalars().first()

    @classmethod
    async def fetch_saved_reports(cls, session: AsyncSession, *, user_id):
        statement = select(cls).where(
            cls.user_id == user_id, cls.is_deleted == False  # noqa: E712
        )
        count_statement = select(func.count()).select_from(statement.subquery())
        total = (await session.execute(count_statement)).scalar_one()
        statement = statement.order_by(cls.created_at.desc())
        result = await session.execute(statement)
        return list(result.scalars().all()), total

    @classmethod
    async def insert_saved_report(cls, session: AsyncSession, fields: dict):
        row = cls(**fields)
        session.add(row)
        await session.commit()
        return await cls.get_by_id(session, row.id)

    @classmethod
    async def update_saved_report(cls, session: AsyncSession, record_id, fields: dict, *, user_id):
        row = await cls.get_by_id(session, record_id, user_id=user_id)
        if not row:
            return None
        for key, value in fields.items():
            setattr(row, key, value)
        row.updated_at = _now()
        session.add(row)
        await session.commit()
        await session.refresh(row)
        return row

    @classmethod
    async def soft_delete_saved_report(cls, session: AsyncSession, record_id, *, user_id):
        row = await cls.get_by_id(session, record_id, user_id=user_id)
        if not row:
            return None
        row.is_deleted = True
        row.updated_at = _now()
        session.add(row)
        await session.commit()
        return row

    @classmethod
    async def touch_last_run(cls, session: AsyncSession, record_id, *, user_id):
        row = await cls.get_by_id(session, record_id, user_id=user_id)
        if not row:
            return None
        row.last_run_at = _now()
        session.add(row)
        await session.commit()
        return row


class ReportRuns(SQLModel, table=True):
    __tablename__ = "report_runs"

    id: uuid.UUID = Field(default_factory=uuid.uuid4, primary_key=True)
    saved_report_id: uuid.UUID = Field(index=True, foreign_key="saved_reports.id")
    run_by: uuid.UUID = Field(foreign_key="users.id")
    run_at: datetime = Field(default_factory=_now, sa_type=DateTime(timezone=True))
    params: dict = Field(default_factory=dict, sa_type=JSON)
    row_count: int = Field(default=0)
    status: str = Field(default="completed")

    @classmethod
    async def insert_run(cls, session: AsyncSession, fields: dict):
        row = cls(**fields)
        session.add(row)
        await session.commit()
        return row

    @classmethod
    async def fetch_runs(cls, session: AsyncSession, *, saved_report_id, top: int = 20):
        statement = (
            select(cls)
            .where(cls.saved_report_id == saved_report_id)
            .order_by(cls.run_at.desc())
            .limit(top)
        )
        result = await session.execute(statement)
        return list(result.scalars().all())


import users.models as _users_models  # noqa: E402, F401