import json

from flask import Blueprint, Response, jsonify, request
from sqlalchemy import delete, func, select

from l4d2web.auth import current_user, require_login
from l4d2web.db import session_scope
from l4d2web.models import Blueprint as BlueprintModel
from l4d2web.models import BlueprintOverlay, Server


bp = Blueprint("blueprint", __name__)


@bp.post("/blueprints")
@require_login
def create_blueprint() -> Response:
    payload = request.get_json(silent=True) or {}
    user = current_user()
    assert user is not None

    name = str(payload.get("name", "")).strip()
    if not name:
        return Response("name is required", status=400)

    with session_scope() as db:
        blueprint = BlueprintModel(
            user_id=user.id,
            name=name,
            arguments=json.dumps(payload.get("arguments", [])),
            config=json.dumps(payload.get("config", [])),
        )
        db.add(blueprint)
        db.flush()

        for position, overlay_id in enumerate(payload.get("overlay_ids", [])):
            db.add(
                BlueprintOverlay(
                    blueprint_id=blueprint.id,
                    overlay_id=int(overlay_id),
                    position=position,
                )
            )

        blueprint_id = blueprint.id

    return jsonify({"id": blueprint_id}), 201


@bp.delete("/blueprints/<int:blueprint_id>")
@require_login
def delete_blueprint(blueprint_id: int) -> Response:
    user = current_user()
    assert user is not None

    with session_scope() as db:
        blueprint = db.scalar(
            select(BlueprintModel).where(
                BlueprintModel.id == blueprint_id,
                BlueprintModel.user_id == user.id,
            )
        )
        if blueprint is None:
            return Response(status=404)

        linked_count = db.scalar(
            select(func.count(Server.id)).where(Server.blueprint_id == blueprint.id)
        ) or 0
        if linked_count > 0:
            return Response("blueprint is in use", status=409)

        db.execute(delete(BlueprintOverlay).where(BlueprintOverlay.blueprint_id == blueprint.id))
        db.delete(blueprint)

    return Response(status=204)