import fs from "node:fs/promises";
import { type AddressInfo, createServer } from "node:net";
import os from "node:os";
import path from "node:path";

import { afterAll, afterEach, beforeAll, beforeEach, expect, vi } from "vitest";
import { WebSocket } from "ws";

import { resolveMainSessionKeyFromConfig, type SessionEntry } from "../config/sessions.js";
import { resetAgentRunContextForTest } from "../infra/agent-events.js";
import {
  loadOrCreateDeviceIdentity,
  publicKeyRawBase64UrlFromPem,
  signDevicePayload,
} from "../infra/device-identity.js";
import { drainSystemEvents, peekSystemEvents } from "../infra/system-events.js";
import { rawDataToString } from "../infra/ws.js";
import { resetLogger, setLoggerOverride } from "../logging.js";
import { DEFAULT_AGENT_ID, toAgentStoreSessionKey } from "../routing/session-key.js";
import { getDeterministicFreePortBlock } from "../test-utils/ports.js";
import { GATEWAY_CLIENT_MODES, GATEWAY_CLIENT_NAMES } from "../utils/message-channel.js";

import { PROTOCOL_VERSION } from "./protocol/index.js";
import { buildDeviceAuthPayload } from "./device-auth.js";
import type { GatewayServerOptions } from "./server.js";
import {
  agentCommand,
  cronIsolatedRun,
  embeddedRunMock,
  piSdkMock,
  sessionStoreSaveDelayMs,
  setTestConfigRoot,
  testIsNixMode,
  testState,
  testTailnetIPv4,
} from "./test-helpers.mocks.js";

// Preload the gateway server module once per worker.
// Important: `test-helpers.mocks` must run before importing the server so vi.mock hooks apply.
const serverModulePromise = import("./server.js");

let previousHome: string | undefined;
let previousUserProfile: string | undefined;
let previousStateDir: string | undefined;
let previousConfigPath: string | undefined;
let previousSkipBrowserControl: string | undefined;
let previousSkipGmailWatcher: string | undefined;
let previousSkipCanvasHost: string | undefined;
let tempHome: string | undefined;
let tempConfigRoot: string | undefined;

export async function writeSessionStore(params: {
  entries: Record<string, Partial<SessionEntry>>;
  storePath?: string;
  agentId?: string;
  mainKey?: string;
}): Promise<void> {
  const storePath = params.storePath ?? testState.sessionStorePath;
  if (!storePath) throw new Error("writeSessionStore requires testState.sessionStorePath");
  const agentId = params.agentId ?? DEFAULT_AGENT_ID;
  const store: Record<string, Partial<SessionEntry>> = {};
  for (const [requestKey, entry] of Object.entries(params.entries)) {
    const rawKey = requestKey.trim();
    const storeKey =
      rawKey === "global" || rawKey === "unknown"
        ? rawKey
        : toAgentStoreSessionKey({
            agentId,
            requestKey,
            mainKey: params.mainKey,
          });
    store[storeKey] = entry;
  }
  await fs.mkdir(path.dirname(storePath), { recursive: true });
  await fs.writeFile(storePath, JSON.stringify(store, null, 2), "utf-8");
}

async function setupGatewayTestHome() {
  previousHome = process.env.HOME;
  previousUserProfile = process.env.USERPROFILE;
  previousStateDir = process.env.CLAWDBOT_STATE_DIR;
  previousConfigPath = process.env.CLAWDBOT_CONFIG_PATH;
  previousSkipBrowserControl = process.env.CLAWDBOT_SKIP_BROWSER_CONTROL_SERVER;
  previousSkipGmailWatcher = process.env.CLAWDBOT_SKIP_GMAIL_WATCHER;
  previousSkipCanvasHost = process.env.CLAWDBOT_SKIP_CANVAS_HOST;
  tempHome = await fs.mkdtemp(path.join(os.tmpdir(), "moltbot-gateway-home-"));
  process.env.HOME = tempHome;
  process.env.USERPROFILE = tempHome;
  process.env.CLAWDBOT_STATE_DIR = path.join(tempHome, ".clawdbot");
  delete process.env.CLAWDBOT_CONFIG_PATH;
}

function applyGatewaySkipEnv() {
  process.env.CLAWDBOT_SKIP_BROWSER_CONTROL_SERVER = "1";
  process.env.CLAWDBOT_SKIP_GMAIL_WATCHER = "1";
  process.env.CLAWDBOT_SKIP_CANVAS_HOST = "1";
}

async function resetGatewayTestState(options: { uniqueConfigRoot: boolean }) {
  // Some tests intentionally use fake timers; ensure they don't leak into gateway suites.
  vi.useRealTimers();
  setLoggerOverride({ level: "silent", consoleLevel: "silent" });
  if (!tempHome) {
    throw new Error("resetGatewayTestState called before temp home was initialized");
  }
  applyGatewaySkipEnv();
  tempConfigRoot = options.uniqueConfigRoot
    ? await fs.mkdtemp(path.join(tempHome, "moltbot-test-"))
    : path.join(tempHome, ".clawdbot-test");
  setTestConfigRoot(tempConfigRoot);
  sessionStoreSaveDelayMs.value = 0;
  testTailnetIPv4.value = undefined;
  testState.gatewayBind = undefined;
  testState.gatewayAuth = { mode: "token", token: "test-gateway-token-1234567890" };
  testState.gatewayControlUi = undefined;
  testState.hooksConfig = undefined;
  testState.canvasHostPort = undefined;
  testState.legacyIssues = [];
  testState.legacyParsed = {};
  testState.migrationConfig = null;
  testState.migrationChanges = [];
  testState.cronEnabled = false;
  testState.cronStorePath = undefined;
  testState.sessionConfig = undefined;
  testState.sessionStorePath = undefined;
  testState.agentConfig = undefined;
  testState.agentsConfig = undefined;
  testState.bindingsConfig = undefined;
  testState.channelsConfig = undefined;
  testState.allowFrom = undefined;
  testIsNixMode.value = false;
  cronIsolatedRun.mockClear();
  agentCommand.mockClear();
  embeddedRunMock.activeIds.clear();
  embeddedRunMock.abortCalls = [];
  embeddedRunMock.waitCalls = [];
  embeddedRunMock.waitResults.clear();
  drainSystemEvents(resolveMainSessionKeyFromConfig());
  resetAgentRunContextForTest();
  const mod = await serverModulePromise;
  mod.__resetModelCatalogCacheForTest();
  piSdkMock.enabled = false;
  piSdkMock.discoverCalls = 0;
  piSdkMock.models = [];
}

async function cleanupGatewayTestHome(options: { restoreEnv: boolean }) {
  vi.useRealTimers();
  resetLogger();
  if (options.restoreEnv) {
    if (previousHome === undefined) delete process.env.HOME;
    else process.env.HOME = previousHome;
    if (previousUserProfile === undefined) delete process.env.USERPROFILE;
    else process.env.USERPROFILE = previousUserProfile;
    if (previousStateDir === undefined) delete process.env.CLAWDBOT_STATE_DIR;
    else process.env.CLAWDBOT_STATE_DIR = previousStateDir;
    if (previousConfigPath === undefined) delete process.env.CLAWDBOT_CONFIG_PATH;
    else process.env.CLAWDBOT_CONFIG_PATH = previousConfigPath;
    if (previousSkipBrowserControl === undefined)
      delete process.env.CLAWDBOT_SKIP_BROWSER_CONTROL_SERVER;
    else process.env.CLAWDBOT_SKIP_BROWSER_CONTROL_SERVER = previousSkipBrowserControl;
    if (previousSkipGmailWatcher === undefined) delete process.env.CLAWDBOT_SKIP_GMAIL_WATCHER;
    else process.env.CLAWDBOT_SKIP_GMAIL_WATCHER = previousSkipGmailWatcher;
    if (previousSkipCanvasHost === undefined) delete process.env.CLAWDBOT_SKIP_CANVAS_HOST;
    else process.env.CLAWDBOT_SKIP_CANVAS_HOST = previousSkipCanvasHost;
  }
  if (options.restoreEnv && tempHome) {
    await fs.rm(tempHome, {
      recursive: true,
      force: true,
      maxRetries: 20,
      retryDelay: 25,
    });
    tempHome = undefined;
  }
  tempConfigRoot = undefined;
}

export function installGatewayTestHooks(options?: { scope?: "test" | "suite" }) {
  const scope = options?.scope ?? "test";
  if (scope === "suite") {
    beforeAll(async () => {
      await setupGatewayTestHome();
      await resetGatewayTestState({ uniqueConfigRoot: true });
    });
    beforeEach(async () => {
      await resetGatewayTestState({ uniqueConfigRoot: true });
    }, 60_000);
    afterEach(async () => {
      await cleanupGatewayTestHome({ restoreEnv: false });
    });
    afterAll(async () => {
      await cleanupGatewayTestHome({ restoreEnv: true });
    });
    return;
  }

  beforeEach(async () => {
    await setupGatewayTestHome();
    await resetGatewayTestState({ uniqueConfigRoot: false });
  }, 60_000);

  afterEach(async () => {
    await cleanupGatewayTestHome({ restoreEnv: true });
  });
}

export async function getFreePort(): Promise<number> {
  return await getDeterministicFreePortBlock({ offsets: [0, 1, 2, 3, 4] });
}

export async function occupyPort(): Promise<{
  server: ReturnType<typeof createServer>;
  port: number;
}> {
  return await new Promise((resolve, reject) => {
    const server = createServer();
    server.once("error", reject);
    server.listen(0, "127.0.0.1", () => {
      const port = (server.address() as AddressInfo).port;
      resolve({ server, port });
    });
  });
}

export function onceMessage<T = unknown>(
  ws: WebSocket,
  filter: (obj: unknown) => boolean,
  // Full-suite runs can saturate the event loop (581+ files). Keep this high
  // enough to avoid flaky RPC timeouts, but still fail fast when a response
  // never arrives.
  timeoutMs = 10_000,
): Promise<T> {
  return new Promise<T>((resolve, reject) => {
    const timer = setTimeout(() => reject(new Error("timeout")), timeoutMs);
    const closeHandler = (code: number, reason: Buffer) => {
      clearTimeout(timer);
      ws.off("message", handler);
      reject(new Error(`closed ${code}: ${reason.toString()}`));
    };
    const handler = (data: WebSocket.RawData) => {
      const obj = JSON.parse(rawDataToString(data));
      if (filter(obj)) {
        clearTimeout(timer);
        ws.off("message", handler);
        ws.off("close", closeHandler);
        resolve(obj as T);
      }
    };
    ws.on("message", handler);
    ws.once("close", closeHandler);
  });
}

export async function startGatewayServer(port: number, opts?: GatewayServerOptions) {
  const mod = await serverModulePromise;
  return await mod.startGatewayServer(port, opts);
}

export async function startServerWithClient(token?: string, opts?: GatewayServerOptions) {
  let port = await getFreePort();
  const prev = process.env.CLAWDBOT_GATEWAY_TOKEN;
  if (typeof token === "string") {
    testState.gatewayAuth = { mode: "token", token };
  }
  const fallbackToken =
    token ??
    (typeof (testState.gatewayAuth as { token?: unknown } | undefined)?.token === "string"
      ? (testState.gatewayAuth as { token?: string }).token
      : undefined);
  if (fallbackToken === undefined) {
    delete process.env.CLAWDBOT_GATEWAY_TOKEN;
  } else {
    process.env.CLAWDBOT_GATEWAY_TOKEN = fallbackToken;
  }

  let server: Awaited<ReturnType<typeof startGatewayServer>> | null = null;
  for (let attempt = 0; attempt < 10; attempt++) {
    try {
      server = await startGatewayServer(port, opts);
      break;
    } catch (err) {
      const code = (err as { cause?: { code?: string } }).cause?.code;
      if (code !== "EADDRINUSE") throw err;
      port = await getFreePort();
    }
  }
  if (!server) {
    throw new Error("failed to start gateway server after retries");
  }

  const ws = new WebSocket(`ws://127.0.0.1:${port}`);
  await new Promise<void>((resolve) => ws.once("open", resolve));
  return { server, ws, port, prevToken: prev };
}

type ConnectResponse = {
  type: "res";
  id: string;
  ok: boolean;
  payload?: unknown;
  error?: { message?: string };
};

export async function connectReq(
  ws: WebSocket,
  opts?: {
    token?: string;
    password?: string;
    skipDefaultAuth?: boolean;
    minProtocol?: number;
    maxProtocol?: number;
    client?: {
      id: string;
      displayName?: string;
      version: string;
      platform: string;
      mode: string;
      deviceFamily?: string;
      modelIdentifier?: string;
      instanceId?: string;
    };
    role?: string;
    scopes?: string[];
    caps?: string[];
    commands?: string[];
    permissions?: Record<string, boolean>;
    device?: {
      id: string;
      publicKey: string;
      signature: string;
      signedAt: number;
      nonce?: string;
    } | null;
  },
): Promise<ConnectResponse> {
  const { randomUUID } = await import("node:crypto");
  const id = randomUUID();
  const client = opts?.client ?? {
    id: GATEWAY_CLIENT_NAMES.TEST,
    version: "1.0.0",
    platform: "test",
    mode: GATEWAY_CLIENT_MODES.TEST,
  };
  const role = opts?.role ?? "operator";
  const defaultToken =
    opts?.skipDefaultAuth === true
      ? undefined
      : typeof (testState.gatewayAuth as { token?: unknown } | undefined)?.token === "string"
        ? ((testState.gatewayAuth as { token?: string }).token ?? undefined)
        : process.env.CLAWDBOT_GATEWAY_TOKEN;
  const defaultPassword =
    opts?.skipDefaultAuth === true
      ? undefined
      : typeof (testState.gatewayAuth as { password?: unknown } | undefined)?.password === "string"
        ? ((testState.gatewayAuth as { password?: string }).password ?? undefined)
        : process.env.CLAWDBOT_GATEWAY_PASSWORD;
  const token = opts?.token ?? defaultToken;
  const password = opts?.password ?? defaultPassword;
  const requestedScopes = Array.isArray(opts?.scopes) ? opts?.scopes : [];
  const device = (() => {
    if (opts?.device === null) return undefined;
    if (opts?.device) return opts.device;
    const identity = loadOrCreateDeviceIdentity();
    const signedAtMs = Date.now();
    const payload = buildDeviceAuthPayload({
      deviceId: identity.deviceId,
      clientId: client.id,
      clientMode: client.mode,
      role,
      scopes: requestedScopes,
      signedAtMs,
      token: token ?? null,
    });
    return {
      id: identity.deviceId,
      publicKey: publicKeyRawBase64UrlFromPem(identity.publicKeyPem),
      signature: signDevicePayload(identity.privateKeyPem, payload),
      signedAt: signedAtMs,
      nonce: opts?.device?.nonce,
    };
  })();
  ws.send(
    JSON.stringify({
      type: "req",
      id,
      method: "connect",
      params: {
        minProtocol: opts?.minProtocol ?? PROTOCOL_VERSION,
        maxProtocol: opts?.maxProtocol ?? PROTOCOL_VERSION,
        client,
        caps: opts?.caps ?? [],
        commands: opts?.commands ?? [],
        permissions: opts?.permissions ?? undefined,
        role,
        scopes: opts?.scopes,
        auth:
          token || password
            ? {
                token,
                password,
              }
            : undefined,
        device,
      },
    }),
  );
  const isResponseForId = (o: unknown): boolean => {
    if (!o || typeof o !== "object" || Array.isArray(o)) return false;
    const rec = o as Record<string, unknown>;
    return rec.type === "res" && rec.id === id;
  };
  return await onceMessage<ConnectResponse>(ws, isResponseForId);
}

export async function connectOk(ws: WebSocket, opts?: Parameters<typeof connectReq>[1]) {
  const res = await connectReq(ws, opts);
  expect(res.ok).toBe(true);
  expect((res.payload as { type?: unknown } | undefined)?.type).toBe("hello-ok");
  return res.payload as { type: "hello-ok" };
}

export async function rpcReq<T = unknown>(
  ws: WebSocket,
  method: string,
  params?: unknown,
  timeoutMs?: number,
) {
  const { randomUUID } = await import("node:crypto");
  const id = randomUUID();
  ws.send(JSON.stringify({ type: "req", id, method, params }));
  return await onceMessage<{
    type: "res";
    id: string;
    ok: boolean;
    payload?: T;
    error?: { message?: string; code?: string };
  }>(
    ws,
    (o) => {
      if (!o || typeof o !== "object" || Array.isArray(o)) return false;
      const rec = o as Record<string, unknown>;
      return rec.type === "res" && rec.id === id;
    },
    timeoutMs,
  );
}

export async function waitForSystemEvent(timeoutMs = 2000) {
  const sessionKey = resolveMainSessionKeyFromConfig();
  const deadline = Date.now() + timeoutMs;
  while (Date.now() < deadline) {
    const events = peekSystemEvents(sessionKey);
    if (events.length > 0) return events;
    await new Promise((resolve) => setTimeout(resolve, 10));
  }
  throw new Error("timeout waiting for system event");
}
