from typing import Any

import sqlalchemy
from fastapi import APIRouter, HTTPException, status
from sqlmodel import func, select, and_, or_, SQLModel
from sqlalchemy.orm import joinedload

from app.api.deps import CurrentUser, SessionDep
from app.models.base import (
    ApiTags,
    Message,
    RowId,
)
from app.models.member import (
    Member,
    MemberCreate,
    MemberUpdate,
    MemberPublic,
    MembersPublic,
    MemberTeamLink,
)

from app.models.event import Event, EventUserLink
from app.models.team import Team
from app.models.user import (
    PermissionModule,
    PermissionPart,
    PermissionRight,
)

router = APIRouter(prefix="/members", tags=[ApiTags.MEMBERS])


# region # Members #############################################################

def load_member(
    session: SessionDep,
    current_user: CurrentUser,
    id: RowId | None = None,
    module: PermissionModule = PermissionModule.MEMBER,
    part: PermissionPart = PermissionPart.ADMIN,
    user_rights: PermissionRight | None = None,
    event_rights: PermissionRight | None = PermissionRight.MANAGE_MEMBERS,
) -> Member | None:
    member = session.get(Member, id)

    if id and not member:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Member not found")

    no_links = True
    valid = False
    # Global member permissions
    if current_user.has_permissions(module=module, part=part, rights=user_rights):
        # Also valid for create new
        valid = True

    # Own member items
    elif hasattr(member, "user") and member.user and member.user == current_user:
        valid = True

    # Event member permissions
    elif hasattr(member, "team_links"):
        for link in member.team_links:
            team = link.team
            if team and team.event:
                no_links = False
                if team.event.user_has_rights(user=current_user, rights=event_rights):
                    valid = True
                    break

    # Not yet linked, or unlinked member
    if no_links and hasattr(member, "created_by") and member.created_by == current_user.id:
        valid = True

    if not valid:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Not enough permissions")

    return member


@router.get("/", response_model=MembersPublic)
def read_members(
    session: SessionDep, current_user: CurrentUser, skip: int = 0, limit: int = 100
) -> Any:
    """
    Retrieve all members.
    """

    if current_user.has_permissions(
        module=PermissionModule.MEMBER,
        part=PermissionPart.ADMIN,
        rights=PermissionRight.READ,
    ):
        data_query = (
            select(Member)
        )
    else:
        data_query = (
            select(Member)
            .outerjoin(MemberTeamLink, MemberTeamLink.member_id == Member.id)
            .outerjoin(Team, MemberTeamLink.team_id == Team.id)
            .outerjoin(Event, Team.event_id == Event.id)
            .outerjoin(EventUserLink, EventUserLink.event_id == Event.id)
            .where(
                or_(
                    # Own member
                    Member.id == current_user.member_id,

                    # Created by user and unlinked
                    and_(
                        Member.created_by == current_user.id,
                        MemberTeamLink.team_id == None
                    ),

                    # Event permissions via team -> event -> EventUserLink
                    and_(
                        EventUserLink.user_id == current_user.id,
                        # FIXME: EventUserLink.rights.op("&")(PermissionRight.MANAGE_MEMBERS) != 0
                    ),
                )
            )
        )

    # Cache as subquery
    data_sub_query = data_query.subquery()
    aliased_member = sqlalchemy.orm.aliased(Member, data_sub_query)

    # Count using subquery
    count = session.exec(
        select(func.count()).select_from(data_sub_query)
    ).one()

    # Paginated data query using same subquery
    data = session.exec(
        select(aliased_member).offset(skip).limit(limit)
    ).all()

    return MembersPublic(count=count, data=data)


@router.get("/{id}", response_model=MemberPublic)
def read_member(session: SessionDep, current_user: CurrentUser, id: RowId) -> Any:
    """
    Get member by ID.
    """
    member = load_member(
        session=session,
        current_user=current_user,
        id=id,
        user_rights=PermissionRight.READ,
    )

    return member


@router.post("/", response_model=MemberPublic)
def create_member(
    *, session: SessionDep, current_user: CurrentUser, member_in: MemberCreate
) -> Any:
    """
    Create new member.
    """

    load_member(
        session=session,
        current_user=current_user,
        user_rights=PermissionRight.CREATE,
    )

    member = Member.create(create_obj=member_in, session=session, user=current_user)
    return member


@router.put("/{id}", response_model=MemberPublic)
def update_member(
    *, session: SessionDep, current_user: CurrentUser, id: RowId, member_in: MemberUpdate
) -> Any:
    """
    Update a member.
    """
    member = load_member(
        session=session,
        current_user=current_user,
        id=id,
        user_rights=PermissionRight.UPDATE,
    )

    member = Member.update(db_obj=member, in_obj=member_in, session=session)
    return member


@router.delete("/{id}")
def delete_member(session: SessionDep,current_user: CurrentUser, id: RowId) -> Message:
    """
    Delete a member.
    """
    member = load_member(
        session=session,
        current_user=current_user,
        id=id,
        user_rights=PermissionRight.DELETE,
    )

    session.delete(member)
    session.commit()
    return Message(message="Member deleted successfully")

# endregion