from __future__ import annotations

import json
from dataclasses import dataclass, field
from pathlib import Path
from typing import Any

from pyro_mcp.vm_firecracker import build_launch_plan
from pyro_mcp.vm_network import NetworkConfig


@dataclass
class StubInstance:
    vm_id: str
    vcpu_count: int
    mem_mib: int
    workdir: Path
    metadata: dict[str, str] = field(default_factory=dict)
    network: Any = None


def test_build_launch_plan_writes_expected_files(tmp_path: Path) -> None:
    instance = StubInstance(
        vm_id="abcdef123456",
        vcpu_count=2,
        mem_mib=2048,
        workdir=tmp_path,
        metadata={
            "kernel_image": "/bundle/profiles/debian-git/vmlinux",
            "rootfs_image": "/bundle/profiles/debian-git/rootfs.ext4",
        },
        network=NetworkConfig(
            vm_id="abcdef123456",
            tap_name="pyroabcdef12",
            guest_ip="172.29.100.2",
            gateway_ip="172.29.100.1",
            subnet_cidr="172.29.100.0/24",
            mac_address="06:00:ab:cd:ef:12",
        ),
    )

    plan = build_launch_plan(instance)

    assert plan.config_path.exists()
    assert plan.guest_network_path.exists()
    assert plan.guest_exec_path.exists()
    rendered = json.loads(plan.config_path.read_text(encoding="utf-8"))
    assert rendered["machine-config"]["vcpu_count"] == 2
    assert rendered["network-interfaces"][0]["host_dev_name"] == "pyroabcdef12"
    assert "acpi=off" in rendered["boot-source"]["boot_args"]
    assert "init=/opt/pyro/bin/pyro-init" in rendered["boot-source"]["boot_args"]
    assert "pyro.guest_ip=172.29.100.2" in rendered["boot-source"]["boot_args"]
    assert "pyro.gateway_ip=172.29.100.1" in rendered["boot-source"]["boot_args"]
    guest_exec = json.loads(plan.guest_exec_path.read_text(encoding="utf-8"))
    assert guest_exec["transport"] == "vsock"