# SPDX-License-Identifier: AGPL-3.0-or-later
"""Synthetic-file CRUD + realism config key/value store."""
from __future__ import annotations

from datetime import datetime, timedelta, timezone
from typing import Any, Optional, cast

from sqlalchemy import desc, func, select, update

from decnet.web.db.models import RealismConfig, SyntheticFile
from decnet.web.db.models.realism import SYNTHETIC_FILE_BODY_LIMIT


from decnet.web.db.sqlmodel_repo._helpers import _MixinBase

class RealismMixin(_MixinBase):
    """Mixin: composed onto ``SQLModelRepository``."""

    async def record_synthetic_file(self, data: dict[str, Any]) -> str:
        if "last_body" in data and data["last_body"] is not None:
            data = {**data, "last_body": data["last_body"][:SYNTHETIC_FILE_BODY_LIMIT]}
        async with self._session() as session:
            row = SyntheticFile(**data)
            session.add(row)
            await session.commit()
            await session.refresh(row)
            return row.uuid

    async def update_synthetic_file(
        self, row_uuid: str, data: dict[str, Any],
    ) -> None:
        if "last_body" in data and data["last_body"] is not None:
            data = {**data, "last_body": data["last_body"][:SYNTHETIC_FILE_BODY_LIMIT]}
        async with self._session() as session:
            stmt = (
                update(SyntheticFile)
                .where(SyntheticFile.uuid == row_uuid)
                .values(**data)
            )
            await session.execute(stmt)
            await session.commit()

    async def list_synthetic_files(
        self,
        *,
        decky_uuid: Optional[str] = None,
        persona: Optional[str] = None,
        content_class: Optional[str] = None,
        limit: int = 100,
        offset: int = 0,
    ) -> list[dict[str, Any]]:
        async with self._session() as session:
            stmt = select(SyntheticFile)
            if decky_uuid is not None:
                stmt = stmt.where(SyntheticFile.decky_uuid == decky_uuid)
            if persona is not None:
                stmt = stmt.where(SyntheticFile.persona == persona)
            if content_class is not None:
                stmt = stmt.where(SyntheticFile.content_class == content_class)
            stmt = (
                stmt.order_by(desc(SyntheticFile.last_modified))
                .offset(offset)
                .limit(limit)
            )
            result = await session.execute(stmt)
            return [r.model_dump(mode="json") for r in result.scalars().all()]

    async def count_synthetic_files(
        self,
        *,
        decky_uuid: Optional[str] = None,
        persona: Optional[str] = None,
        content_class: Optional[str] = None,
    ) -> int:
        async with self._session() as session:
            stmt = select(func.count(SyntheticFile.uuid))
            if decky_uuid is not None:
                stmt = stmt.where(SyntheticFile.decky_uuid == decky_uuid)
            if persona is not None:
                stmt = stmt.where(SyntheticFile.persona == persona)
            if content_class is not None:
                stmt = stmt.where(SyntheticFile.content_class == content_class)
            result = await session.execute(stmt)
            return int(result.scalar() or 0)

    async def get_synthetic_file(
        self, uuid: str,
    ) -> Optional[dict[str, Any]]:
        async with self._session() as session:
            stmt = select(SyntheticFile).where(SyntheticFile.uuid == uuid)
            result = await session.execute(stmt)
            row = result.scalars().first()
            if row is None:
                return None
            return cast(dict[str, Any], row.model_dump(mode="json"))

    async def get_realism_config(
        self, key: str,
    ) -> Optional[dict[str, Any]]:
        async with self._session() as session:
            stmt = select(RealismConfig).where(RealismConfig.key == key)
            result = await session.execute(stmt)
            row = result.scalars().first()
            if row is None:
                return None
            return cast(dict[str, Any], row.model_dump(mode="json"))

    async def set_realism_config(
        self, key: str, value: str,
    ) -> None:
        """Upsert one realism_config row. Last-write-wins."""
        async with self._session() as session:
            stmt = select(RealismConfig).where(RealismConfig.key == key)
            result = await session.execute(stmt)
            row = result.scalars().first()
            if row is None:
                session.add(RealismConfig(
                    key=key, value=value,
                    updated_at=datetime.now(timezone.utc),
                ))
            else:
                upd = (
                    update(RealismConfig)
                    .where(RealismConfig.uuid == row.uuid)
                    .values(value=value, updated_at=datetime.now(timezone.utc))
                )
                await session.execute(upd)
            await session.commit()

    async def pick_random_synthetic_file_for_edit(
        self,
        decky_uuid: str,
        *,
        max_age_days: int = 30,
    ) -> Optional[dict[str, Any]]:
        # Editable classes: anything whose body is plain text we can
        # mutate idempotently. Binary canary artifacts are out — they
        # rotate via a fresh plant, not an edit.
        editable = (
            "note", "todo", "draft", "script", "log_cron", "log_daemon",
        )
        cutoff = datetime.now(timezone.utc) - timedelta(days=max_age_days)
        async with self._session() as session:
            stmt = (
                select(SyntheticFile)
                .where(
                    SyntheticFile.decky_uuid == decky_uuid,
                    SyntheticFile.content_class.in_(editable),  # type: ignore[attr-defined]
                    SyntheticFile.last_modified >= cutoff,
                )
                # SQLite + MySQL both support func.random() / RAND() —
                # SQLAlchemy's func.random() compiles per-dialect.
                .order_by(func.random())
                .limit(1)
            )
            result = await session.execute(stmt)
            row = result.scalars().first()
            if row is None:
                return None
            return cast(dict[str, Any], row.model_dump(mode="json"))