siftlode/backend/app/routes/admin.py

"""Admin-only onboarding: review access requests (Invites), approve/deny, manual add.
Also the demo-account admin surface: the demo email whitelist + a manual state reset."""
import re
from datetime import datetime, timezone

from fastapi import APIRouter, BackgroundTasks, Depends, HTTPException
from sqlalchemy import delete, func, select
from sqlalchemy.orm import Session

from app import email as email_mod
from app.auth import current_user, get_or_create_demo_user
from app.db import get_db
from app.models import (
    DemoWhitelist,
    Invite,
    Playlist,
    PlaylistItem,
    User,
    Video,
    VideoState,
)

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

_EMAIL_RE = re.compile(r"^[^@\s]+@[^@\s]+\.[^@\s]+$")


def admin_user(user: User = Depends(current_user)) -> User:
    if user.role != "admin":
        raise HTTPException(status_code=403, detail="Admin only")
    return user


def _serialize(inv: Invite) -> dict:
    return {
        "id": inv.id,
        "email": inv.email,
        "status": inv.status,
        "note": inv.note,
        "requested_at": inv.requested_at.isoformat() if inv.requested_at else None,
        "decided_at": inv.decided_at.isoformat() if inv.decided_at else None,
        "decided_by": inv.decided_by,
    }


@router.get("/invites")
def list_invites(
    status: str | None = None,
    _: User = Depends(admin_user),
    db: Session = Depends(get_db),
) -> list[dict]:
    stmt = select(Invite)
    if status:
        stmt = stmt.where(Invite.status == status)
    # Pending first, then most-recently requested.
    rows = db.execute(stmt.order_by(Invite.requested_at.desc())).scalars().all()
    order = {"pending": 0, "approved": 1, "denied": 2}
    rows.sort(key=lambda i: order.get(i.status, 9))
    return [_serialize(i) for i in rows]


def _activate_user_by_email(db: Session, email: str) -> None:
    """Approving access activates a matching (e.g. pending password-registration) account so
    it can sign in. No-op if no such user exists yet (a Google user is created at first login)."""
    user = db.execute(select(User).where(User.email == email.lower())).scalar_one_or_none()
    if user is not None and not user.is_active:
        user.is_active = True
        db.commit()


def _decide(db: Session, invite_id: int, admin: User, approved: bool) -> Invite:
    inv = db.get(Invite, invite_id)
    if inv is None:
        raise HTTPException(status_code=404, detail="No such invite")
    inv.status = "approved" if approved else "denied"
    inv.decided_at = datetime.now(timezone.utc)
    inv.decided_by = admin.email
    db.commit()
    return inv


@router.post("/invites/{invite_id}/approve")
def approve_invite(
    invite_id: int,
    background: BackgroundTasks,
    admin: User = Depends(admin_user),
    db: Session = Depends(get_db),
) -> dict:
    inv = _decide(db, invite_id, admin, approved=True)
    _activate_user_by_email(db, inv.email)
    background.add_task(email_mod.send_access_approved, inv.email)
    return _serialize(inv)


@router.post("/invites/{invite_id}/deny")
def deny_invite(
    invite_id: int,
    admin: User = Depends(admin_user),
    db: Session = Depends(get_db),
) -> dict:
    return _serialize(_decide(db, invite_id, admin, approved=False))


@router.post("/invites")
def add_invite(
    payload: dict,
    admin: User = Depends(admin_user),
    db: Session = Depends(get_db),
) -> dict:
    """Manually whitelist an email (approved straight away). Convenience for the admin."""
    email = (payload.get("email") or "").strip().lower()
    if "@" not in email:
        raise HTTPException(status_code=400, detail="Enter a valid email address.")
    inv = db.execute(select(Invite).where(Invite.email == email)).scalar_one_or_none()
    if inv is None:
        inv = Invite(email=email)
        db.add(inv)
    inv.status = "approved"
    inv.decided_at = datetime.now(timezone.utc)
    inv.decided_by = admin.email
    db.commit()
    _activate_user_by_email(db, email)
    return _serialize(inv)


# --- Users & roles --------------------------------------------------------------------

def _serialize_user(u: User) -> dict:
    return {
        "id": u.id,
        "email": u.email,
        "display_name": u.display_name,
        "role": u.role,
        "is_active": u.is_active,
        "email_verified": u.email_verified,
        "is_demo": u.is_demo,
        "has_password": u.password_hash is not None,
        "has_google": u.google_sub is not None,
        "created_at": u.created_at.isoformat() if u.created_at else None,
    }


@router.get("/users")
def list_users(_: User = Depends(admin_user), db: Session = Depends(get_db)) -> list[dict]:
    rows = db.execute(select(User).order_by(User.created_at.desc())).scalars().all()
    return [_serialize_user(u) for u in rows]


@router.patch("/users/{user_id}/role")
def set_user_role(
    user_id: int,
    payload: dict,
    admin: User = Depends(admin_user),
    db: Session = Depends(get_db),
) -> dict:
    """Promote/demote a user. Guards: can't change your own role, can't touch the demo
    account, and can't remove the last remaining admin."""
    role = payload.get("role")
    if role not in ("user", "admin"):
        raise HTTPException(status_code=400, detail="role must be 'user' or 'admin'")
    target = db.get(User, user_id)
    if target is None:
        raise HTTPException(status_code=404, detail="No such user")
    if target.is_demo:
        raise HTTPException(status_code=400, detail="The demo account's role can't be changed.")
    if target.id == admin.id:
        raise HTTPException(status_code=400, detail="You can't change your own role.")
    if target.role == "admin" and role == "user":
        admin_count = db.scalar(select(func.count()).select_from(User).where(User.role == "admin"))
        if (admin_count or 0) <= 1:
            raise HTTPException(status_code=400, detail="Can't remove the last admin.")
    target.role = role
    db.commit()
    return _serialize_user(target)


# --- Demo account: email whitelist + state reset -------------------------------------

def _serialize_demo(row: DemoWhitelist) -> dict:
    return {
        "id": row.id,
        "email": row.email,
        "note": row.note,
        "added_by": row.added_by,
        "created_at": row.created_at.isoformat() if row.created_at else None,
    }


@router.get("/demo/whitelist")
def list_demo_whitelist(
    _: User = Depends(admin_user), db: Session = Depends(get_db)
) -> list[dict]:
    rows = (
        db.execute(select(DemoWhitelist).order_by(DemoWhitelist.created_at.desc()))
        .scalars()
        .all()
    )
    return [_serialize_demo(r) for r in rows]


@router.post("/demo/whitelist")
def add_demo_whitelist(
    payload: dict,
    admin: User = Depends(admin_user),
    db: Session = Depends(get_db),
) -> dict:
    """Add an email that may enter the shared demo account from the login page (no Google
    sign-in). Idempotent — re-adding an existing email just returns it."""
    email = (payload.get("email") or "").strip().lower()
    if not _EMAIL_RE.match(email):
        raise HTTPException(status_code=400, detail="Enter a valid email address.")
    row = db.execute(
        select(DemoWhitelist).where(DemoWhitelist.email == email)
    ).scalar_one_or_none()
    if row is None:
        row = DemoWhitelist(
            email=email,
            note=(payload.get("note") or "").strip() or None,
            added_by=admin.email,
        )
        db.add(row)
        db.commit()
    return _serialize_demo(row)


@router.delete("/demo/whitelist/{entry_id}")
def remove_demo_whitelist(
    entry_id: int,
    _: User = Depends(admin_user),
    db: Session = Depends(get_db),
) -> dict:
    row = db.get(DemoWhitelist, entry_id)
    if row is not None:
        db.delete(row)
        db.commit()
    return {"deleted": entry_id}


def _seed_demo_playlists(db: Session, demo: User) -> int:
    """Seed a few sample playlists from the shared catalog so a freshly-reset demo isn't
    empty — gives visitors something to play with. Best-effort: skips silently if the
    catalog is too small."""
    recent = (
        db.execute(
            select(Video.id)
            .where(Video.is_short.is_(False), Video.live_status == "none")
            .order_by(Video.published_at.desc().nullslast())
            .limit(60)
        )
        .scalars()
        .all()
    )
    if not recent:
        return 0
    samples = [
        ("Fresh picks", recent[0:10]),
        ("Quick watch", recent[10:18]),
        ("Saved for later", recent[18:26]),
    ]
    created = 0
    for pos, (name, vids) in enumerate(samples):
        if not vids:
            continue
        pl = Playlist(user_id=demo.id, name=name, position=pos)
        db.add(pl)
        db.flush()
        for ipos, vid in enumerate(vids):
            db.add(PlaylistItem(playlist_id=pl.id, video_id=vid, position=ipos))
        created += 1
    return created


def reset_demo_state(db: Session, demo: User) -> int:
    """Wipe the demo account's per-user state (watch/save/hide states, playlists, preferences)
    back to a clean baseline and re-seed a few sample playlists. Returns the seeded count.
    Shared by the admin's manual reset button and the scheduled demo reset (see scheduler)."""
    db.execute(delete(VideoState).where(VideoState.user_id == demo.id))
    # Playlist items cascade on playlist delete (ondelete="CASCADE").
    db.execute(delete(Playlist).where(Playlist.user_id == demo.id))
    demo.preferences = {"language": "en"}
    db.commit()
    seeded = _seed_demo_playlists(db, demo)
    db.commit()
    return seeded


@router.post("/demo/reset")
def reset_demo(
    _: User = Depends(admin_user), db: Session = Depends(get_db)
) -> dict:
    """Manually clean up the shared demo sandbox back to a baseline. A scheduled job does the
    same automatically (admin-tunable interval); this is the admin's on-demand button."""
    demo = get_or_create_demo_user(db)
    return {"reset": True, "playlists_seeded": reset_demo_state(db, demo)}