"""Discord's legacy /discord/* auth routes, plus the DM opt-in toggle.

The OAuth flow itself moved to ``accounts/oauth.py`` when Google was added — this
module holds no auth logic, only the paths that have to keep answering:

* **/discord/link/callback is registered in Discord's developer portal.** Changing
  it would need an operator to edit the portal before any Discord login worked, so
  it stays exactly where it is and forwards to the shared handler.
* The other /discord/* routes are what the currently-deployed frontend calls.
  Frontend and backend deploy independently (see the root CLAUDE.md), so a newer
  backend must keep serving an older frontend. They can go once no deployed
  frontend predates /oauth/*.

``POST /discord/dm`` is not legacy and is not moving: it toggles alert delivery,
which is a notifications concern, not an authentication one.
"""
from __future__ import annotations

from fastapi import APIRouter, Depends, Request
from pydantic import BaseModel
from sqlalchemy import update
from sqlalchemy.ext.asyncio import AsyncSession

from accounts import oauth
from accounts.db import get_async_session
from accounts.models import User
from accounts.users import (
    current_active_user,
    current_user_optional,
    get_access_token_db,
    get_user_manager,
)

router = APIRouter(tags=["discord"])


@router.get("/discord/config")
async def discord_config():
    """Superseded by /oauth/config, which reports every provider. Kept because the
    deployed frontend asks this one."""
    return {"enabled": oauth.enabled("discord")}


@router.get("/discord/link/start")
async def link_start(request: Request, user=Depends(current_active_user)):
    return await oauth.link_start("discord", request, user)


@router.get("/discord/login/start")
async def login_start(request: Request, user=Depends(current_user_optional)):
    return await oauth.login_start("discord", request, user)


@router.get("/discord/link/callback")
async def link_callback(
    request: Request,
    user=Depends(current_user_optional),
    session: AsyncSession = Depends(get_async_session),
    user_manager=Depends(get_user_manager),
    access_token_db=Depends(get_access_token_db),
):
    """The URL registered in Discord's portal. Both Discord flows land here."""
    return await oauth._callback("discord", request, user, session, user_manager,
                                 access_token_db)


@router.post("/discord/unlink", status_code=204)
async def unlink(
    user=Depends(current_active_user),
    session: AsyncSession = Depends(get_async_session),
):
    await oauth._unlink("discord", user, session)


class DmToggle(BaseModel):
    enabled: bool


@router.post("/discord/dm", status_code=204)
async def set_dm(
    payload: DmToggle,
    user=Depends(current_active_user),
    session: AsyncSession = Depends(get_async_session),
):
    """Turn Discord DM alerts on or off without unlinking. A no-op unless a Discord
    account is actually linked."""
    await session.execute(
        update(User).where(User.id == user.id, User.discord_id.is_not(None))
        .values(discord_dm=payload.enabled)
    )
    await session.commit()