import assert from "node:assert/strict";
import { EventEmitter } from "node:events";
import test from "node:test";

import { AppRuntimeConfig } from "../main/config/runtime-config";
import { createNodecgProcessManager } from "../main/nodecg/process-manager";

class MockChildProcess extends EventEmitter {
  pid: number | undefined;
  killed = false;
  exitCode: number | null = null;
  signalCode: NodeJS.Signals | null = null;

  constructor(pid: number) {
    super();
    this.pid = pid;
  }
}

function getBaseConfig(): AppRuntimeConfig {
  return {
    title: "Scoreko",
    userModelId: "com.scoreko.desktop",
    userDataDirectoryName: "scoreko",
    nodecgPort: "9090",
    bundleName: "scoreko-dev",
    mainDashboardRoute: "dashboard/scoreko-dev/main.html?standalone=true",
    loadingDashboardRoute: "dashboard/loading/main.html?standalone=true",
    loadDelayMs: 10000,
    startupTimeoutMs: 100,
    nodecgKillTimeoutMs: 10,
  };
}

test("startNodeCG validates NodeCG installation before starting", async () => {
  const manager = createNodecgProcessManager({
    isDev: true,
    nodecgRootPath: "/fake/scoreko-dev",
    nodecgBaseUrl: "http://127.0.0.1:9090",
    appConfig: getBaseConfig(),
    log: () => undefined,
    deps: {
      pathExists: () => false,
      spawnProcess: () => {
        throw new Error("it must not try to start if validation fails");
      },
    },
  });

  await assert.rejects(async () => {
    await manager.startNodecgProcess();
  }, /Scoreko app folder does not exist/);
});

test("startNodeCG fails when there are no read/write permissions", async () => {
  const manager = createNodecgProcessManager({
    isDev: true,
    nodecgRootPath: "/fake/scoreko-dev",
    nodecgBaseUrl: "http://127.0.0.1:9090",
    appConfig: getBaseConfig(),
    log: () => undefined,
    deps: {
      pathExists: () => true,
      hasReadWriteAccess: () => false,
    },
  });

  await assert.rejects(async () => {
    await manager.startNodecgProcess();
  }, /No read\/write permissions on scoreko app folder/);
});

test("waitForNodeCGReady resolves when endpoint returns 404", async () => {
  const child = new MockChildProcess(4321);
  const manager = createNodecgProcessManager({
    isDev: true,
    nodecgRootPath: "/fake/scoreko-dev",
    nodecgBaseUrl: "http://127.0.0.1:9090",
    appConfig: getBaseConfig(),
    log: () => undefined,
    deps: {
      platform: "linux",
      pathExists: () => true,
      spawnProcess: () => child as unknown as import("node:child_process").ChildProcess,
      fetchUrl: async () => ({ ok: false, status: 404 }) as Response,
      setTimer: (handler: (...args: unknown[]) => void, _timeoutMs: number) => {
        handler();
        return 0 as never;
      },
      stdoutWrite: () => undefined,
      stderrWrite: () => undefined,
      probePortAvailable: async () => true,
      hasReadWriteAccess: () => true,
    },
  });

  await manager.startNodecgProcess();
  await assert.doesNotReject(async () => {
    await manager.waitForNodecgReady(Date.now());
  });
});

test("stopNodeCG sends SIGTERM and then SIGKILL if the process does not exit", async () => {
  const child = new MockChildProcess(9999);
  const timers: Array<() => void> = [];
  const killSignals: Array<{ pid: number; signal: NodeJS.Signals }> = [];

  const manager = createNodecgProcessManager({
    isDev: true,
    nodecgRootPath: "/fake/scoreko-dev",
    nodecgBaseUrl: "http://127.0.0.1:9090",
    appConfig: getBaseConfig(),
    log: () => undefined,
    deps: {
      platform: "linux",
      pathExists: () => true,
      spawnProcess: () => child as unknown as import("node:child_process").ChildProcess,
      fetchUrl: async () => ({ ok: false, status: 404 }) as Response,
      killProcess: (pid, signal) => {
        killSignals.push({ pid, signal });
      },
      setTimer: (handler: (...args: unknown[]) => void, _timeoutMs: number) => {
        timers.push(() => handler());
        return 0 as never;
      },
      stdoutWrite: () => undefined,
      stderrWrite: () => undefined,
      probePortAvailable: async () => true,
      hasReadWriteAccess: () => true,
    },
  });

  await manager.startNodecgProcess();
  const stopPromise = manager.stopNodecgProcessGracefully();

  assert.deepEqual(killSignals, [{ pid: -9999, signal: "SIGTERM" }]);

  timers.forEach((runTimer) => {
    runTimer();
  });

  assert.deepEqual(killSignals, [
    { pid: -9999, signal: "SIGTERM" },
    { pid: -9999, signal: "SIGKILL" },
  ]);

  child.emit("exit", 0, null);
  await stopPromise;
});

test("stopNodeCG reuses the same promise when invoked in parallel", async () => {
  const child = new MockChildProcess(5555);

  const manager = createNodecgProcessManager({
    isDev: true,
    nodecgRootPath: "/fake/scoreko-dev",
    nodecgBaseUrl: "http://127.0.0.1:9090",
    appConfig: getBaseConfig(),
    log: () => undefined,
    deps: {
      pathExists: () => true,
      spawnProcess: () => child as unknown as import("node:child_process").ChildProcess,
      fetchUrl: async () => ({ ok: false, status: 404 }) as Response,
      killProcess: () => undefined,
      setTimer: () => 0,
      stdoutWrite: () => undefined,
      stderrWrite: () => undefined,
      probePortAvailable: async () => true,
      hasReadWriteAccess: () => true,
    },
  });

  await manager.startNodecgProcess();
  const firstStop = manager.stopNodecgProcessGracefully();
  const secondStop = manager.stopNodecgProcessGracefully();

  assert.equal(firstStop, secondStop);

  child.emit("exit", 0, null);
  await firstStop;
});

test("stopNodeCG normalizes negative timeout to zero", async () => {
  const child = new MockChildProcess(7777);
  const timeouts: number[] = [];

  const manager = createNodecgProcessManager({
    isDev: true,
    nodecgRootPath: "/fake/scoreko-dev",
    nodecgBaseUrl: "http://127.0.0.1:9090",
    appConfig: {
      ...getBaseConfig(),
      nodecgKillTimeoutMs: -10,
    },
    log: () => undefined,
    deps: {
      pathExists: () => true,
      spawnProcess: () => child as unknown as import("node:child_process").ChildProcess,
      fetchUrl: async () => ({ ok: false, status: 404 }) as Response,
      killProcess: () => undefined,
      setTimer: (handler, timeoutMs) => {
        timeouts.push(timeoutMs);
        handler();
        return 0;
      },
      stdoutWrite: () => undefined,
      stderrWrite: () => undefined,
      probePortAvailable: async () => true,
      hasReadWriteAccess: () => true,
    },
  });

  await manager.startNodecgProcess();
  const stopPromise = manager.stopNodecgProcessGracefully();

  assert.ok(timeouts.includes(0));

  child.emit("exit", 0, null);
  await stopPromise;
});

test("startNodeCG fails if the port is already in use", async () => {
  const manager = createNodecgProcessManager({
    isDev: true,
    nodecgRootPath: "/fake/scoreko-dev",
    nodecgBaseUrl: "http://127.0.0.1:9090",
    appConfig: getBaseConfig(),
    log: () => undefined,
    deps: {
      pathExists: () => true,
      hasReadWriteAccess: () => true,
      probePortAvailable: async () => false,
    },
  });

  await assert.rejects(async () => {
    await manager.startNodecgProcess();
  }, /is already in use/);
});

test("waitForNodeCGReady exposes diagnostics when NodeCG exits before readiness", async () => {
  const child = new MockChildProcess(4242);
  const manager = createNodecgProcessManager({
    isDev: true,
    nodecgRootPath: "/fake/scoreko-dev",
    nodecgBaseUrl: "http://127.0.0.1:9090",
    appConfig: getBaseConfig(),
    log: () => undefined,
    deps: {
      pathExists: () => true,
      platform: "linux",
      spawnProcess: () => child as unknown as import("node:child_process").ChildProcess,
      fetchUrl: async () => {
        child.emit("exit", 1, null);
        throw new Error("still starting");
      },
      setTimer: (handler) => {
        handler();
        return 0;
      },
      stdoutWrite: () => undefined,
      stderrWrite: () => undefined,
      probePortAvailable: async () => true,
      hasReadWriteAccess: () => true,
    },
  });

  await manager.startNodecgProcess();

  await assert.rejects(
    async () => {
      await manager.waitForNodecgReady(Date.now());
    },
    (error: unknown) => {
      assert.ok(error instanceof Error);
      assert.match(error.message, /NodeCG exited before becoming ready/);
      assert.match(error.message, /Last recorded exit/);
      assert.match(error.message, /NodeCG path: \/fake\/scoreko-dev/);
      return true;
    },
  );
});