from flask import Blueprint, Response, jsonify, redirect, request
from sqlalchemy import select
from sqlalchemy.exc import IntegrityError

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 Job, Server


bp = Blueprint("server", __name__)


@bp.post("/servers")
@require_login
def create_server() -> Response:
    user = current_user()
    assert user is not None
    json_response = request.is_json
    payload = request.get_json(silent=True) if json_response else request.form

    with session_scope() as db:
        blueprint = db.scalar(
            select(BlueprintModel).where(
                BlueprintModel.id == int(payload["blueprint_id"]),
                BlueprintModel.user_id == user.id,
            )
        )
        if blueprint is None:
            return Response("blueprint not found", status=404)

        server = Server(
            user_id=user.id,
            blueprint_id=blueprint.id,
            name=str(payload["name"]),
            port=int(payload["port"]),
            desired_state="stopped",
            actual_state="unknown",
            last_error="",
        )
        db.add(server)
        
        try:
            db.flush()
        except IntegrityError:
            db.rollback()
            return Response("port already in use", status=409)
            
        server_id = server.id

    if json_response:
        return jsonify({"id": server_id}), 201
    return redirect(f"/servers/{server_id}")


@bp.patch("/servers/<int:server_id>")
@require_login
def update_server(server_id: int) -> Response:
    user = current_user()
    assert user is not None
    payload = request.get_json(silent=True) or {}

    with session_scope() as db:
        server = db.scalar(select(Server).where(Server.id == server_id, Server.user_id == user.id))
        if server is None:
            return Response(status=404)

        blueprint = db.scalar(
            select(BlueprintModel).where(
                BlueprintModel.id == int(payload["blueprint_id"]),
                BlueprintModel.user_id == user.id,
            )
        )
        if blueprint is None:
            return Response("blueprint not found", status=404)

        server.blueprint_id = blueprint.id

    return jsonify({"id": server_id}), 200


LIFECYCLE_OPERATIONS = {"initialize", "start", "stop", "delete"}


@bp.post("/servers/<int:server_id>/<operation>")
@require_login
def enqueue_server_operation(server_id: int, operation: str) -> Response:
    user = current_user()
    assert user is not None
    if operation not in LIFECYCLE_OPERATIONS:
        return Response(status=404)

    with session_scope() as db:
        server = db.scalar(select(Server).where(Server.id == server_id, Server.user_id == user.id))
        if server is None:
            return Response(status=404)
        db.add(Job(user_id=user.id, server_id=server.id, operation=operation, state="queued"))
        if operation == "start":
            server.desired_state = "running"
        if operation in {"stop", "delete"}:
            server.desired_state = "stopped"

    return redirect(f"/servers/{server_id}")