arbret/backend/routes/invites.py

"""Invite routes for public check, user invites, and admin management."""

from datetime import UTC, datetime

from fastapi import APIRouter, Depends, HTTPException, Query, status
from sqlalchemy import desc, func, select
from sqlalchemy.exc import IntegrityError
from sqlalchemy.ext.asyncio import AsyncSession

from auth import require_permission
from database import get_db
from invite_utils import (
    generate_invite_identifier,
    is_valid_identifier_format,
    normalize_identifier,
)
from models import Invite, InviteStatus, Permission, User
from pagination import calculate_offset, create_paginated_response
from schemas import (
    AdminUserResponse,
    InviteCheckResponse,
    InviteCreate,
    InviteResponse,
    PaginatedInviteRecords,
    UserInviteResponse,
)

router = APIRouter(prefix="/api/invites", tags=["invites"])
admin_router = APIRouter(prefix="/api/admin", tags=["admin"])

MAX_INVITE_COLLISION_RETRIES = 3


def build_invite_response(invite: Invite) -> InviteResponse:
    """Build an InviteResponse from an Invite with loaded relationships."""
    return InviteResponse(
        id=invite.id,
        identifier=invite.identifier,
        godfather_id=invite.godfather_id,
        godfather_email=invite.godfather.email,
        status=invite.status.value,
        used_by_id=invite.used_by_id,
        used_by_email=invite.used_by.email if invite.used_by else None,
        created_at=invite.created_at,
        spent_at=invite.spent_at,
        revoked_at=invite.revoked_at,
    )


@router.get("/{identifier}/check", response_model=InviteCheckResponse)
async def check_invite(
    identifier: str,
    db: AsyncSession = Depends(get_db),
) -> InviteCheckResponse:
    """Check if an invite is valid and can be used for signup."""
    normalized = normalize_identifier(identifier)

    # Validate format before querying database
    if not is_valid_identifier_format(normalized):
        return InviteCheckResponse(valid=False, error="Invalid invite code format")

    result = await db.execute(select(Invite).where(Invite.identifier == normalized))
    invite = result.scalar_one_or_none()

    # Return same error for not found, spent, and revoked to avoid information leakage
    if not invite or invite.status in (InviteStatus.SPENT, InviteStatus.REVOKED):
        return InviteCheckResponse(valid=False, error="Invite not found")

    return InviteCheckResponse(valid=True, status=invite.status.value)


@router.get("", response_model=list[UserInviteResponse])
async def get_my_invites(
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(require_permission(Permission.VIEW_OWN_INVITES)),
) -> list[UserInviteResponse]:
    """Get all invites owned by the current user."""
    result = await db.execute(
        select(Invite)
        .where(Invite.godfather_id == current_user.id)
        .order_by(desc(Invite.created_at))
    )
    invites = result.scalars().all()

    # Use preloaded used_by relationship (selectin loading)
    return [
        UserInviteResponse(
            id=invite.id,
            identifier=invite.identifier,
            status=invite.status.value,
            used_by_email=invite.used_by.email if invite.used_by else None,
            created_at=invite.created_at,
            spent_at=invite.spent_at,
        )
        for invite in invites
    ]


@admin_router.get("/users", response_model=list[AdminUserResponse])
async def list_users_for_admin(
    db: AsyncSession = Depends(get_db),
    _current_user: User = Depends(require_permission(Permission.MANAGE_INVITES)),
) -> list[AdminUserResponse]:
    """List all users for admin dropdowns (invite creation, etc.)."""
    result = await db.execute(select(User.id, User.email).order_by(User.email))
    users = result.all()
    return [AdminUserResponse(id=u.id, email=u.email) for u in users]


@admin_router.post("/invites", response_model=InviteResponse)
async def create_invite(
    data: InviteCreate,
    db: AsyncSession = Depends(get_db),
    _current_user: User = Depends(require_permission(Permission.MANAGE_INVITES)),
) -> InviteResponse:
    """Create a new invite for a specified godfather user."""
    # Validate godfather exists
    result = await db.execute(select(User.id).where(User.id == data.godfather_id))
    godfather_id = result.scalar_one_or_none()
    if not godfather_id:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Godfather user not found",
        )

    # Try to create invite with retry on collision
    invite: Invite | None = None
    for attempt in range(MAX_INVITE_COLLISION_RETRIES):
        identifier = generate_invite_identifier()
        invite = Invite(
            identifier=identifier,
            godfather_id=godfather_id,
            status=InviteStatus.READY,
        )
        db.add(invite)
        try:
            await db.commit()
            await db.refresh(invite, ["godfather"])
            break
        except IntegrityError:
            await db.rollback()
            if attempt == MAX_INVITE_COLLISION_RETRIES - 1:
                raise HTTPException(
                    status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
                    detail="Failed to generate unique invite code. Try again.",
                ) from None

    if invite is None:
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Failed to create invite",
        )
    return build_invite_response(invite)


@admin_router.get("/invites", response_model=PaginatedInviteRecords)
async def list_all_invites(
    page: int = Query(1, ge=1),
    per_page: int = Query(10, ge=1, le=100),
    status_filter: str | None = Query(
        None, alias="status", description="Filter by status: ready, spent, revoked"
    ),
    godfather_id: int | None = Query(None, description="Filter by godfather user ID"),
    db: AsyncSession = Depends(get_db),
    _current_user: User = Depends(require_permission(Permission.MANAGE_INVITES)),
) -> PaginatedInviteRecords:
    """List all invites with optional filtering and pagination."""
    # Build query
    query = select(Invite)
    count_query = select(func.count(Invite.id))

    # Apply filters
    if status_filter:
        try:
            status_enum = InviteStatus(status_filter)
            query = query.where(Invite.status == status_enum)
            count_query = count_query.where(Invite.status == status_enum)
        except ValueError:
            raise HTTPException(
                status_code=400,
                detail=f"Invalid status: {status_filter}. "
                "Must be ready, spent, or revoked",
            ) from None

    if godfather_id:
        query = query.where(Invite.godfather_id == godfather_id)
        count_query = count_query.where(Invite.godfather_id == godfather_id)

    # Get total count
    count_result = await db.execute(count_query)
    total = count_result.scalar() or 0

    # Get paginated invites (relationships loaded via selectin)
    offset = calculate_offset(page, per_page)
    query = query.order_by(desc(Invite.created_at)).offset(offset).limit(per_page)
    result = await db.execute(query)
    invites = result.scalars().all()

    # Build responses using preloaded relationships
    records = [build_invite_response(invite) for invite in invites]

    return create_paginated_response(records, total, page, per_page)


@admin_router.post("/invites/{invite_id}/revoke", response_model=InviteResponse)
async def revoke_invite(
    invite_id: int,
    db: AsyncSession = Depends(get_db),
    _current_user: User = Depends(require_permission(Permission.MANAGE_INVITES)),
) -> InviteResponse:
    """Revoke an invite. Only READY invites can be revoked."""
    result = await db.execute(select(Invite).where(Invite.id == invite_id))
    invite = result.scalar_one_or_none()

    if not invite:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Invite not found",
        )

    if invite.status != InviteStatus.READY:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=f"Cannot revoke invite with status '{invite.status.value}'. "
            "Only READY invites can be revoked.",
        )

    invite.status = InviteStatus.REVOKED
    invite.revoked_at = datetime.now(UTC)
    await db.commit()
    await db.refresh(invite)

    return build_invite_response(invite)