import uuid

from fastapi import HTTPException, status
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.models.memory_entry import MemoryEntry


async def create_memory(db: AsyncSession, user_id: uuid.UUID, **kwargs) -> MemoryEntry:
    entry = MemoryEntry(user_id=user_id, **kwargs)
    db.add(entry)
    await db.flush()
    return entry


async def get_memory(db: AsyncSession, entry_id: uuid.UUID, user_id: uuid.UUID) -> MemoryEntry:
    result = await db.execute(
        select(MemoryEntry).where(MemoryEntry.id == entry_id, MemoryEntry.user_id == user_id)
    )
    entry = result.scalar_one_or_none()
    if not entry:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Memory entry not found")
    return entry


async def get_user_memories(
    db: AsyncSession,
    user_id: uuid.UUID,
    category: str | None = None,
    importance: str | None = None,
    is_active: bool | None = None,
) -> list[MemoryEntry]:
    stmt = select(MemoryEntry).where(MemoryEntry.user_id == user_id)
    if category:
        stmt = stmt.where(MemoryEntry.category == category)
    if importance:
        stmt = stmt.where(MemoryEntry.importance == importance)
    if is_active is not None:
        stmt = stmt.where(MemoryEntry.is_active == is_active)
    stmt = stmt.order_by(MemoryEntry.created_at.desc())
    result = await db.execute(stmt)
    return list(result.scalars().all())


ALLOWED_UPDATE_FIELDS = {"category", "title", "content", "importance", "is_active"}


async def update_memory(db: AsyncSession, entry_id: uuid.UUID, user_id: uuid.UUID, **kwargs) -> MemoryEntry:
    entry = await get_memory(db, entry_id, user_id)
    for key, value in kwargs.items():
        if key in ALLOWED_UPDATE_FIELDS:
            setattr(entry, key, value)
    await db.flush()
    return entry


async def delete_memory(db: AsyncSession, entry_id: uuid.UUID, user_id: uuid.UUID) -> None:
    entry = await get_memory(db, entry_id, user_id)
    await db.delete(entry)


async def get_critical_memories(db: AsyncSession, user_id: uuid.UUID) -> list[MemoryEntry]:
    result = await db.execute(
        select(MemoryEntry).where(
            MemoryEntry.user_id == user_id,
            MemoryEntry.is_active == True,  # noqa: E712
            MemoryEntry.importance.in_(["critical", "high"]),
        ).order_by(MemoryEntry.importance, MemoryEntry.created_at.desc())
    )
    return list(result.scalars().all())