import { assertEquals, assertExists } from 'jsr:@std/assert@^1.0.0';
import { CLUSTER, PATHS } from '../ts/constants.ts';
import { ClusterManager } from '../ts/cluster/cluster-manager.ts';
import type { IClusterNodeHeartbeat } from '../ts/interfaces/cluster.ts';

function createNode(nodeName: string, lastSeenAt: number): IClusterNodeHeartbeat {
  return {
    nodeName,
    role: nodeName === 'control' ? 'control-plane' : 'worker',
    endpoint: `http://${nodeName}:8080`,
    healthy: true,
    resources: {
      gpuCount: 1,
      totalVramGb: 24,
      availableVramGb: 24,
      maxSingleGpuVramGb: 24,
      largestGpuGroupCount: 1,
      largestGpuGroupVramGb: 24,
      deploymentCount: 0,
      topologyGroups: [
        {
          id: 'nvidia-0',
          vendor: 'nvidia',
          gpuIds: ['gpu-0'],
          gpuCount: 1,
          totalVramGb: 24,
          maxSingleGpuVramGb: 24,
          busNumbers: [1],
        },
      ],
    },
    deployments: [],
    lastSeenAt,
  };
}

async function waitForPersistence(): Promise<void> {
  await new Promise((resolve) => setTimeout(resolve, 25));
}

Deno.test('ClusterManager initialize loads persisted state and prunes stale nodes', async () => {
  const originalDataDir = PATHS.DATA_DIR;
  const tempDir = await Deno.makeTempDir();
  (PATHS as { DATA_DIR: string }).DATA_DIR = tempDir;

  try {
    const now = Date.now();
    await Deno.writeTextFile(
      `${tempDir}/cluster-state.json`,
      JSON.stringify({
        nodes: [
          createNode('control', now),
          createNode('worker-fresh', now),
          createNode('worker-stale', now - CLUSTER.NODE_STALE_AFTER_MS - 1000),
        ],
      }),
    );
    await Deno.writeTextFile(
      `${tempDir}/cluster-control-state.json`,
      JSON.stringify({
        desiredDeployments: [
          { modelId: 'meta-llama/Llama-3.1-8B-Instruct', desiredReplicas: 2, updatedAt: now },
        ],
        nodeSchedulerStates: {
          'worker-fresh': 'cordoned',
        },
      }),
    );

    const clusterManager = new ClusterManager();
    clusterManager.configure({
      enabled: true,
      nodeName: 'control',
      role: 'control-plane',
      bindHost: '0.0.0.0',
      gossipPort: 7946,
      heartbeatIntervalMs: 5000,
      seedNodes: [],
    });

    await clusterManager.initialize();

    assertEquals(clusterManager.getAllNodes().map((node) => node.nodeName), ['control', 'worker-fresh']);
    assertExists(clusterManager.getLocalNode());
    assertEquals(clusterManager.getDesiredDeployments().length, 1);
    assertEquals(clusterManager.getNodeSchedulerState('worker-fresh'), 'cordoned');
  } finally {
    (PATHS as { DATA_DIR: string }).DATA_DIR = originalDataDir;
    await Deno.remove(tempDir, { recursive: true });
  }
});

Deno.test('ClusterManager persists state only after initialization completes', async () => {
  const originalDataDir = PATHS.DATA_DIR;
  const tempDir = await Deno.makeTempDir();
  (PATHS as { DATA_DIR: string }).DATA_DIR = tempDir;

  try {
    const clusterManager = new ClusterManager();
    clusterManager.configure({
      enabled: true,
      nodeName: 'control',
      role: 'control-plane',
      bindHost: '0.0.0.0',
      gossipPort: 7946,
      heartbeatIntervalMs: 5000,
      seedNodes: [],
    });

    clusterManager.updateLocalNode(createNode('control', Date.now()));
    clusterManager.upsertDesiredDeployment('meta-llama/Llama-3.1-8B-Instruct', 1);
    await waitForPersistence();

    assertEquals(await Deno.stat(`${tempDir}/cluster-state.json`).catch(() => null), null);
    assertEquals(await Deno.stat(`${tempDir}/cluster-control-state.json`).catch(() => null), null);

    await clusterManager.initialize();
    clusterManager.updateLocalNode(createNode('control', Date.now()));
    clusterManager.setNodeSchedulerState('control', 'active');
    clusterManager.upsertDesiredDeployment('meta-llama/Llama-3.1-8B-Instruct', 3);
    await waitForPersistence();

    const stateFile = JSON.parse(await Deno.readTextFile(`${tempDir}/cluster-state.json`));
    const controlFile = JSON.parse(await Deno.readTextFile(`${tempDir}/cluster-control-state.json`));

    assertEquals(stateFile.nodes.length, 1);
    assertEquals(stateFile.nodes[0].nodeName, 'control');
    assertEquals(controlFile.desiredDeployments[0].desiredReplicas, 3);
    assertEquals(controlFile.nodeSchedulerStates.control, 'active');
  } finally {
    (PATHS as { DATA_DIR: string }).DATA_DIR = originalDataDir;
    await Deno.remove(tempDir, { recursive: true });
  }
});