"""AI access: personal API tokens for MCP clients.

Every logged-in user manages their own tokens here, whatever their role — a
token acts as its user, capped at the role it was given. These routes are
session-only: a share-link viewer has no user to mint tokens for, and no token
can reach them (MCP tools never mint or revoke tokens).
"""
from __future__ import annotations
from datetime import datetime, timezone

from quart import Blueprint, abort, current_app, redirect, render_template, request
from sqlalchemy import select

from steward.auth.middleware import current_user_id, require_role
from steward.core import api_tokens
from steward.core.audit import log_audit
from steward.core.settings import public_base_url
from steward.mcp.server import MCP_PATH
from steward.models.users import User, UserRole

ai_access_bp = Blueprint("ai_access", __name__, url_prefix="/ai-access")

_EXPIRY_CHOICES = [("", "Never"), ("30", "30 days"), ("90", "90 days"), ("365", "1 year")]


def _mcp_url() -> str:
    """The /mcp endpoint as a client outside this request reaches it."""
    return public_base_url(request) + MCP_PATH


async def _session_user(db) -> User:
    user_id = current_user_id()
    if not user_id:
        abort(403)
    user = (await db.execute(select(User).where(User.id == user_id))).scalar_one_or_none()
    if user is None or not user.is_active:
        abort(403)
    return user


async def _render_index(db, user: User, *, error: str | None = None, status: int = 200):
    tokens = await api_tokens.list_tokens(db, user.id)
    now = datetime.now(timezone.utc)
    rows = [{"token": t, "state": api_tokens.token_state(t, now)} for t in tokens]
    body = await render_template(
        "ai_access/index.html",
        rows=rows,
        user_role=user.role,
        grantable=api_tokens.grantable_roles(user.role),
        expiry_choices=_EXPIRY_CHOICES,
        error=error,
        mcp_url=_mcp_url(),
    )
    return body, status


@ai_access_bp.get("/")
@require_role(UserRole.viewer)
async def index():
    async with current_app.db_sessionmaker() as db:
        user = await _session_user(db)
        return await _render_index(db, user)


@ai_access_bp.post("/tokens")
@require_role(UserRole.viewer)
async def create():
    form = await request.form
    name = form.get("name", "")
    expires = form.get("expires_in_days", "")
    try:
        role = UserRole(form.get("role", UserRole.viewer.value))
    except ValueError:
        role = None

    async with current_app.db_sessionmaker() as db:
        user = await _session_user(db)
        if role is None:
            return await _render_index(db, user, error="Pick a role for the token.", status=400)
        try:
            raw, token = await api_tokens.create_token(
                db, user_id=user.id, user_role=user.role, name=name, role=role,
                expires_in_days=int(expires) if expires.isdigit() and int(expires) > 0 else None,
            )
        except ValueError as exc:
            return await _render_index(db, user, error=str(exc), status=400)
        await db.commit()

    await log_audit(current_app, user.id, user.username, "api_token.create",
                    entity_type="api_token", entity_id=str(token.id),
                    detail={"name": token.name, "role": token.role.value})
    return await render_template("ai_access/created.html", raw_token=raw, token=token,
                                 mcp_url=_mcp_url())


@ai_access_bp.post("/tokens/<int:token_id>/revoke")
@require_role(UserRole.viewer)
async def revoke(token_id: int):
    async with current_app.db_sessionmaker() as db:
        user = await _session_user(db)
        token = await api_tokens.revoke_token(db, user_id=user.id, token_id=token_id)
        await db.commit()
    if token is None:
        abort(404)
    await log_audit(current_app, user.id, user.username, "api_token.revoke",
                    entity_type="api_token", entity_id=str(token_id),
                    detail={"name": token.name})
    return redirect("/ai-access/")