import uuid

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

from app.models.skill import Skill


async def get_accessible_skills(
    db: AsyncSession, user_id: uuid.UUID, include_general: bool = True
) -> list[Skill]:
    conditions = [Skill.user_id == user_id]
    if include_general:
        conditions.append(Skill.user_id.is_(None))
    stmt = select(Skill).where(or_(*conditions), Skill.is_active == True).order_by(Skill.sort_order)  # noqa: E712
    result = await db.execute(stmt)
    return list(result.scalars().all())


async def get_skill(db: AsyncSession, skill_id: uuid.UUID, user_id: uuid.UUID | None = None) -> Skill:
    result = await db.execute(select(Skill).where(Skill.id == skill_id))
    skill = result.scalar_one_or_none()
    if not skill:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Skill not found")
    # Access check: must be general or owned by user
    if user_id and skill.user_id is not None and skill.user_id != user_id:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Skill not found")
    return skill


async def validate_skill_accessible(db: AsyncSession, skill_id: uuid.UUID, user_id: uuid.UUID) -> None:
    """Validate skill exists and is accessible by user (general or owned). Raises 404 if not."""
    await get_skill(db, skill_id, user_id)


# --- Personal skills ---

async def create_personal_skill(db: AsyncSession, user_id: uuid.UUID, **kwargs) -> Skill:
    skill = Skill(user_id=user_id, **kwargs)
    db.add(skill)
    await db.flush()
    return skill


async def update_personal_skill(db: AsyncSession, skill_id: uuid.UUID, user_id: uuid.UUID, **kwargs) -> Skill:
    skill = await get_skill(db, skill_id, user_id)
    if skill.user_id != user_id:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Cannot edit general skills")
    for key, value in kwargs.items():
        if value is not None:
            setattr(skill, key, value)
    await db.flush()
    return skill


async def delete_personal_skill(db: AsyncSession, skill_id: uuid.UUID, user_id: uuid.UUID) -> None:
    skill = await get_skill(db, skill_id, user_id)
    if skill.user_id != user_id:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Cannot delete general skills")
    await db.delete(skill)


# --- General (admin) skills ---

async def get_general_skills(db: AsyncSession) -> list[Skill]:
    result = await db.execute(
        select(Skill).where(Skill.user_id.is_(None)).order_by(Skill.sort_order)
    )
    return list(result.scalars().all())


async def create_general_skill(db: AsyncSession, **kwargs) -> Skill:
    skill = Skill(user_id=None, **kwargs)
    db.add(skill)
    await db.flush()
    return skill


async def update_general_skill(db: AsyncSession, skill_id: uuid.UUID, **kwargs) -> Skill:
    result = await db.execute(select(Skill).where(Skill.id == skill_id, Skill.user_id.is_(None)))
    skill = result.scalar_one_or_none()
    if not skill:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="General skill not found")
    for key, value in kwargs.items():
        if value is not None:
            setattr(skill, key, value)
    await db.flush()
    return skill


async def delete_general_skill(db: AsyncSession, skill_id: uuid.UUID) -> None:
    result = await db.execute(select(Skill).where(Skill.id == skill_id, Skill.user_id.is_(None)))
    skill = result.scalar_one_or_none()
    if not skill:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="General skill not found")
    await db.delete(skill)