import { spawn } from "node:child_process";
import fs from "node:fs/promises";
import os from "node:os";
import path from "node:path";
import { parseSshTarget } from "../../infra/ssh-tunnel.js";
import { resolvePreferredOpenClawTmpDir } from "../../infra/tmp-openclaw-dir.js";
import { resolveUserPath } from "../../utils.js";
import type { SandboxBackendCommandResult } from "./backend.js";

export type SshSandboxSettings = {
  command: string;
  target: string;
  strictHostKeyChecking: boolean;
  updateHostKeys: boolean;
  identityFile?: string;
  certificateFile?: string;
  knownHostsFile?: string;
  identityData?: string;
  certificateData?: string;
  knownHostsData?: string;
};

export type SshSandboxSession = {
  command: string;
  configPath: string;
  host: string;
};

export type RunSshSandboxCommandParams = {
  session: SshSandboxSession;
  remoteCommand: string;
  stdin?: Buffer | string;
  allowFailure?: boolean;
  signal?: AbortSignal;
  tty?: boolean;
};

function normalizeInlineSshMaterial(contents: string, filename: string): string {
  const withoutBom = contents.replace(/^\uFEFF/, "");
  const normalizedNewlines = withoutBom.replace(/\r\n?/g, "\n");
  const normalizedEscapedNewlines = normalizedNewlines
    .replace(/\\r\\n/g, "\\n")
    .replace(/\\r/g, "\\n");
  const expanded =
    filename === "identity" || filename === "certificate.pub"
      ? normalizedEscapedNewlines.replace(/\\n/g, "\n")
      : normalizedEscapedNewlines;
  return expanded.endsWith("\n") ? expanded : `${expanded}\n`;
}

function buildSshFailureMessage(stderr: string, exitCode?: number): string {
  const trimmed = stderr.trim();
  if (
    trimmed.includes("error in libcrypto") &&
    (trimmed.includes('Load key "') || trimmed.includes("Permission denied (publickey)"))
  ) {
    return `${trimmed}\nSSH sandbox failed to load the configured identity. The private key contents may be malformed (for example CRLF or escaped newlines). Prefer identityFile when possible.`;
  }
  return (
    trimmed ||
    (exitCode !== undefined
      ? `ssh exited with code ${exitCode}`
      : "ssh exited with a non-zero status")
  );
}

export function shellEscape(value: string): string {
  return `'${value.replaceAll("'", `'"'"'`)}'`;
}

export function buildRemoteCommand(argv: string[]): string {
  return argv.map((entry) => shellEscape(entry)).join(" ");
}

export function buildExecRemoteCommand(params: {
  command: string;
  workdir?: string;
  env: Record<string, string>;
}): string {
  const body = params.workdir
    ? `cd ${shellEscape(params.workdir)} && ${params.command}`
    : params.command;
  const argv =
    Object.keys(params.env).length > 0
      ? [
          "env",
          ...Object.entries(params.env).map(([key, value]) => `${key}=${value}`),
          "/bin/sh",
          "-c",
          body,
        ]
      : ["/bin/sh", "-c", body];
  return buildRemoteCommand(argv);
}

export function buildSshSandboxArgv(params: {
  session: SshSandboxSession;
  remoteCommand: string;
  tty?: boolean;
}): string[] {
  return [
    params.session.command,
    "-F",
    params.session.configPath,
    ...(params.tty
      ? ["-tt", "-o", "RequestTTY=force", "-o", "SetEnv=TERM=xterm-256color"]
      : ["-T", "-o", "RequestTTY=no"]),
    params.session.host,
    params.remoteCommand,
  ];
}

export async function createSshSandboxSessionFromConfigText(params: {
  configText: string;
  host?: string;
  command?: string;
}): Promise<SshSandboxSession> {
  const host = params.host?.trim() || parseSshConfigHost(params.configText);
  if (!host) {
    throw new Error("Failed to parse SSH config output.");
  }
  const configDir = await fs.mkdtemp(path.join(resolveSshTmpRoot(), "openclaw-sandbox-ssh-"));
  const configPath = path.join(configDir, "config");
  await fs.writeFile(configPath, params.configText, { encoding: "utf8", mode: 0o600 });
  await fs.chmod(configPath, 0o600);
  return {
    command: params.command?.trim() || "ssh",
    configPath,
    host,
  };
}

export async function createSshSandboxSessionFromSettings(
  settings: SshSandboxSettings,
): Promise<SshSandboxSession> {
  const parsed = parseSshTarget(settings.target);
  if (!parsed) {
    throw new Error(`Invalid sandbox SSH target: ${settings.target}`);
  }

  const configDir = await fs.mkdtemp(path.join(resolveSshTmpRoot(), "openclaw-sandbox-ssh-"));
  try {
    const materializedIdentity = settings.identityData
      ? await writeSecretMaterial(configDir, "identity", settings.identityData)
      : undefined;
    const materializedCertificate = settings.certificateData
      ? await writeSecretMaterial(configDir, "certificate.pub", settings.certificateData)
      : undefined;
    const materializedKnownHosts = settings.knownHostsData
      ? await writeSecretMaterial(configDir, "known_hosts", settings.knownHostsData)
      : undefined;
    const identityFile = materializedIdentity ?? resolveOptionalLocalPath(settings.identityFile);
    const certificateFile =
      materializedCertificate ?? resolveOptionalLocalPath(settings.certificateFile);
    const knownHostsFile =
      materializedKnownHosts ?? resolveOptionalLocalPath(settings.knownHostsFile);
    const hostAlias = "openclaw-sandbox";
    const configPath = path.join(configDir, "config");
    const lines = [
      `Host ${hostAlias}`,
      `  HostName ${parsed.host}`,
      `  Port ${parsed.port}`,
      "  BatchMode yes",
      "  ConnectTimeout 5",
      "  ServerAliveInterval 15",
      "  ServerAliveCountMax 3",
      `  StrictHostKeyChecking ${settings.strictHostKeyChecking ? "yes" : "no"}`,
      `  UpdateHostKeys ${settings.updateHostKeys ? "yes" : "no"}`,
    ];
    if (parsed.user) {
      lines.push(`  User ${parsed.user}`);
    }
    if (knownHostsFile) {
      lines.push(`  UserKnownHostsFile ${knownHostsFile}`);
    } else if (!settings.strictHostKeyChecking) {
      lines.push("  UserKnownHostsFile /dev/null");
    }
    if (identityFile) {
      lines.push(`  IdentityFile ${identityFile}`);
    }
    if (certificateFile) {
      lines.push(`  CertificateFile ${certificateFile}`);
    }
    if (identityFile || certificateFile) {
      lines.push("  IdentitiesOnly yes");
    }
    await fs.writeFile(configPath, `${lines.join("\n")}\n`, {
      encoding: "utf8",
      mode: 0o600,
    });
    await fs.chmod(configPath, 0o600);
    return {
      command: settings.command.trim() || "ssh",
      configPath,
      host: hostAlias,
    };
  } catch (error) {
    await fs.rm(configDir, { recursive: true, force: true });
    throw error;
  }
}

export async function disposeSshSandboxSession(session: SshSandboxSession): Promise<void> {
  await fs.rm(path.dirname(session.configPath), { recursive: true, force: true });
}

export async function runSshSandboxCommand(
  params: RunSshSandboxCommandParams,
): Promise<SandboxBackendCommandResult> {
  const argv = buildSshSandboxArgv({
    session: params.session,
    remoteCommand: params.remoteCommand,
    tty: params.tty,
  });
  return await new Promise<SandboxBackendCommandResult>((resolve, reject) => {
    const child = spawn(argv[0], argv.slice(1), {
      stdio: ["pipe", "pipe", "pipe"],
      env: process.env,
      signal: params.signal,
    });
    const stdoutChunks: Buffer[] = [];
    const stderrChunks: Buffer[] = [];

    child.stdout.on("data", (chunk) => stdoutChunks.push(Buffer.from(chunk)));
    child.stderr.on("data", (chunk) => stderrChunks.push(Buffer.from(chunk)));
    child.on("error", reject);
    child.on("close", (code) => {
      const stdout = Buffer.concat(stdoutChunks);
      const stderr = Buffer.concat(stderrChunks);
      const exitCode = code ?? 0;
      if (exitCode !== 0 && !params.allowFailure) {
        reject(
          Object.assign(new Error(buildSshFailureMessage(stderr.toString("utf8"), exitCode)), {
            code: exitCode,
            stdout,
            stderr,
          }),
        );
        return;
      }
      resolve({ stdout, stderr, code: exitCode });
    });

    if (params.stdin !== undefined) {
      child.stdin.end(params.stdin);
      return;
    }
    child.stdin.end();
  });
}

export async function uploadDirectoryToSshTarget(params: {
  session: SshSandboxSession;
  localDir: string;
  remoteDir: string;
  signal?: AbortSignal;
}): Promise<void> {
  const remoteCommand = buildRemoteCommand([
    "/bin/sh",
    "-c",
    'mkdir -p -- "$1" && tar -xf - -C "$1"',
    "openclaw-sandbox-upload",
    params.remoteDir,
  ]);
  const sshArgv = buildSshSandboxArgv({
    session: params.session,
    remoteCommand,
  });
  await new Promise<void>((resolve, reject) => {
    const tar = spawn("tar", ["-C", params.localDir, "-cf", "-", "."], {
      stdio: ["ignore", "pipe", "pipe"],
      signal: params.signal,
    });
    const ssh = spawn(sshArgv[0], sshArgv.slice(1), {
      stdio: ["pipe", "pipe", "pipe"],
      env: process.env,
      signal: params.signal,
    });
    const tarStderr: Buffer[] = [];
    const sshStdout: Buffer[] = [];
    const sshStderr: Buffer[] = [];
    let tarClosed = false;
    let sshClosed = false;
    let tarCode = 0;
    let sshCode = 0;

    tar.stderr.on("data", (chunk) => tarStderr.push(Buffer.from(chunk)));
    ssh.stdout.on("data", (chunk) => sshStdout.push(Buffer.from(chunk)));
    ssh.stderr.on("data", (chunk) => sshStderr.push(Buffer.from(chunk)));

    const fail = (error: unknown) => {
      tar.kill("SIGKILL");
      ssh.kill("SIGKILL");
      reject(error);
    };

    tar.on("error", fail);
    ssh.on("error", fail);
    tar.stdout.pipe(ssh.stdin);

    tar.on("close", (code) => {
      tarClosed = true;
      tarCode = code ?? 0;
      maybeResolve();
    });
    ssh.on("close", (code) => {
      sshClosed = true;
      sshCode = code ?? 0;
      maybeResolve();
    });

    function maybeResolve() {
      if (!tarClosed || !sshClosed) {
        return;
      }
      if (tarCode !== 0) {
        reject(
          new Error(
            Buffer.concat(tarStderr).toString("utf8").trim() || `tar exited with code ${tarCode}`,
          ),
        );
        return;
      }
      if (sshCode !== 0) {
        reject(
          new Error(
            Buffer.concat(sshStderr).toString("utf8").trim() || `ssh exited with code ${sshCode}`,
          ),
        );
        return;
      }
      resolve();
    }
  });
}

function parseSshConfigHost(configText: string): string | null {
  const hostMatch = configText.match(/^\s*Host\s+(\S+)/m);
  return hostMatch?.[1]?.trim() || null;
}

function resolveSshTmpRoot(): string {
  return path.resolve(resolvePreferredOpenClawTmpDir() ?? os.tmpdir());
}

function resolveOptionalLocalPath(value: string | undefined): string | undefined {
  const trimmed = value?.trim();
  return trimmed ? resolveUserPath(trimmed) : undefined;
}

async function writeSecretMaterial(
  dir: string,
  filename: string,
  contents: string,
): Promise<string> {
  const pathname = path.join(dir, filename);
  await fs.writeFile(pathname, normalizeInlineSshMaterial(contents, filename), {
    encoding: "utf8",
    mode: 0o600,
  });
  await fs.chmod(pathname, 0o600);
  return pathname;
}