import { describe, expect, test } from "bun:test";
import {
  createSshStdoutForwarder,
  formatSshStdoutTruncationHint,
  parseSshInvocation,
  sshStdoutStreamMaxBytes,
  sshStdoutTruncationHint,
  windowsPowerShellScriptPrelude,
} from "./ssh";

describe("ssh windows PowerShell safety prelude", () => {
  test("shadows ConvertTo-Json and strips filesystem ETS metadata", () => {
    const prelude = windowsPowerShellScriptPrelude("C:\\test");

    expect(prelude).toContain("function ConvertTo-UniDeskPlainJsonValue");
    expect(prelude).toContain("function ConvertTo-Json");
    expect(prelude).toContain("'PSPath','PSParentPath','PSChildName','PSDrive','PSProvider','ReadCount'");
    expect(prelude).toContain("Microsoft.PowerShell.Utility\\ConvertTo-Json");
    expect(prelude).toContain("Set-Location -LiteralPath 'C:\\test'");
  });
});

describe("ssh stdout bounded streaming", () => {
  test("uses bounded defaults and clamps env override", () => {
    expect(sshStdoutStreamMaxBytes({} as NodeJS.ProcessEnv)).toBe(256 * 1024);
    expect(sshStdoutStreamMaxBytes({ UNIDESK_SSH_STDOUT_STREAM_MAX_BYTES: "8192" } as NodeJS.ProcessEnv)).toBe(8192);
    expect(sshStdoutStreamMaxBytes({ UNIDESK_SSH_STDOUT_STREAM_MAX_BYTES: "1" } as NodeJS.ProcessEnv)).toBe(4096);
    expect(sshStdoutStreamMaxBytes({ UNIDESK_SSH_STDOUT_STREAM_MAX_BYTES: String(64 * 1024 * 1024) } as NodeJS.ProcessEnv)).toBe(16 * 1024 * 1024);
  });

  test("formats truncation hint without echoing remote command", () => {
    const invocation = parseSshInvocation("D601:win", ["ps"]);
    expect(invocation.parsed.remoteCommand).not.toBeNull();
    const hint = sshStdoutTruncationHint({
      invocation,
      transport: "backend-core-broker",
      thresholdBytes: 4096,
      observedBytesAtTruncation: 5000,
      dumpPath: "/tmp/unidesk-cli-output/sample.stdout.bin",
    });
    const formatted = formatSshStdoutTruncationHint(hint);

    expect(formatted.startsWith("UNIDESK_SSH_STDOUT_TRUNCATED ")).toBe(true);
    const payload = JSON.parse(formatted.slice("UNIDESK_SSH_STDOUT_TRUNCATED ".length)) as Record<string, unknown>;
    expect(payload.code).toBe("ssh-stdout-truncated");
    expect(payload.providerId).toBe("D601");
    expect(payload.route).toBe("D601:win");
    expect(payload.thresholdBytes).toBe(4096);
    expect(formatted).not.toContain("Get-Content");
  });

  test("forwarder bounds stdout and emits one truncation hint", () => {
    const invocation = parseSshInvocation("D601:win", ["ps"]);
    const forwarded: Buffer[] = [];
    const stdout = {
      write(chunk: string | Buffer): boolean {
        forwarded.push(Buffer.isBuffer(chunk) ? chunk : Buffer.from(chunk));
        return true;
      },
    } as NodeJS.WritableStream;
    const forwarder = createSshStdoutForwarder({
      invocation,
      transport: "frontend-websocket",
      maxBytes: 5,
      stdout,
    });

    expect(forwarder.write(Buffer.from("abc"))).toBeNull();
    const hint = forwarder.write(Buffer.from("defgh"));
    expect(hint).not.toBeNull();
    expect(forwarder.write(Buffer.from("ijkl"))).toBeNull();
    expect(Buffer.concat(forwarded).toString("utf8")).toBe("abcde");
    expect(hint).toContain("UNIDESK_SSH_STDOUT_TRUNCATED");
    expect(hint).toContain("\"transport\":\"frontend-websocket\"");
  });
});

describe("ssh removed shell aliases", () => {
  test("reports route-aware replacement examples for trans script", () => {
    const previousEntrypoint = process.env.UNIDESK_SSH_ENTRYPOINT;
    process.env.UNIDESK_SSH_ENTRYPOINT = "trans";
    try {
      parseSshInvocation("D601:/tmp", ["script", "--", "pwd"]);
      throw new Error("expected script alias to fail");
    } catch (error) {
      expect(error).toBeInstanceOf(Error);
      const payload = error as Error & {
        code?: string;
        entrypoint?: string;
        route?: string;
        operation?: string;
        replacementExamples?: {
          posixSh?: string;
          bash?: string;
        };
      };
      expect(payload.code).toBe("ssh-removed-shell-alias");
      expect(payload.entrypoint).toBe("trans");
      expect(payload.route).toBe("D601:/tmp");
      expect(payload.operation).toBe("script");
      expect(payload.replacementExamples?.posixSh).toBe("trans D601:/tmp sh -- 'pwd'");
      expect(payload.replacementExamples?.bash).toBe("trans D601:/tmp bash -- 'pwd'");
    } finally {
      if (previousEntrypoint === undefined) {
        delete process.env.UNIDESK_SSH_ENTRYPOINT;
      } else {
        process.env.UNIDESK_SSH_ENTRYPOINT = previousEntrypoint;
      }
    }
  });
});