import type { AgentToolResult } from "@mariozechner/pi-agent-core";
import type { ChildProcessWithoutNullStreams } from "node:child_process";
import { Type } from "@sinclair/typebox";
import path from "node:path";
import type { ExecAsk, ExecHost, ExecSecurity } from "../infra/exec-approvals.js";
import type { ProcessSession, SessionStdin } from "./bash-process-registry.js";
import type { ExecToolDetails } from "./bash-tools.exec.js";
import type { BashSandboxConfig } from "./bash-tools.shared.js";
import { requestHeartbeatNow } from "../infra/heartbeat-wake.js";
import { mergePathPrepend } from "../infra/path-prepend.js";
import { enqueueSystemEvent } from "../infra/system-events.js";
export { applyPathPrepend, normalizePathPrepend } from "../infra/path-prepend.js";
import { logWarn } from "../logger.js";
import { formatSpawnError, spawnWithFallback } from "../process/spawn-utils.js";
import {
  addSession,
  appendOutput,
  createSessionSlug,
  markExited,
  tail,
} from "./bash-process-registry.js";
import {
  buildDockerExecArgs,
  chunkString,
  clampWithDefault,
  killSession,
  readEnvInt,
} from "./bash-tools.shared.js";
import { buildCursorPositionResponse, stripDsrRequests } from "./pty-dsr.js";
import { getShellConfig, sanitizeBinaryOutput } from "./shell-utils.js";

// Security: Blocklist of environment variables that could alter execution flow
// or inject code when running on non-sandboxed hosts (Gateway/Node).
const DANGEROUS_HOST_ENV_VARS = new Set([
  "LD_PRELOAD",
  "LD_LIBRARY_PATH",
  "LD_AUDIT",
  "DYLD_INSERT_LIBRARIES",
  "DYLD_LIBRARY_PATH",
  "NODE_OPTIONS",
  "NODE_PATH",
  "PYTHONPATH",
  "PYTHONHOME",
  "RUBYLIB",
  "PERL5LIB",
  "BASH_ENV",
  "ENV",
  "GCONV_PATH",
  "IFS",
  "SSLKEYLOGFILE",
]);
const DANGEROUS_HOST_ENV_PREFIXES = ["DYLD_", "LD_"];

// Centralized sanitization helper.
// Throws an error if dangerous variables or PATH modifications are detected on the host.
export function validateHostEnv(env: Record<string, string>): void {
  for (const key of Object.keys(env)) {
    const upperKey = key.toUpperCase();

    // 1. Block known dangerous variables (Fail Closed)
    if (DANGEROUS_HOST_ENV_PREFIXES.some((prefix) => upperKey.startsWith(prefix))) {
      throw new Error(
        `Security Violation: Environment variable '${key}' is forbidden during host execution.`,
      );
    }
    if (DANGEROUS_HOST_ENV_VARS.has(upperKey)) {
      throw new Error(
        `Security Violation: Environment variable '${key}' is forbidden during host execution.`,
      );
    }

    // 2. Strictly block PATH modification on host
    // Allowing custom PATH on the gateway/node can lead to binary hijacking.
    if (upperKey === "PATH") {
      throw new Error(
        "Security Violation: Custom 'PATH' variable is forbidden during host execution.",
      );
    }
  }
}
export const DEFAULT_MAX_OUTPUT = clampWithDefault(
  readEnvInt("PI_BASH_MAX_OUTPUT_CHARS"),
  200_000,
  1_000,
  200_000,
);
export const DEFAULT_PENDING_MAX_OUTPUT = clampWithDefault(
  readEnvInt("OPENCLAW_BASH_PENDING_MAX_OUTPUT_CHARS"),
  30_000,
  1_000,
  200_000,
);
export const DEFAULT_PATH =
  process.env.PATH ?? "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin";
export const DEFAULT_NOTIFY_TAIL_CHARS = 400;
const DEFAULT_NOTIFY_SNIPPET_CHARS = 180;
export const DEFAULT_APPROVAL_TIMEOUT_MS = 120_000;
export const DEFAULT_APPROVAL_REQUEST_TIMEOUT_MS = 130_000;
const DEFAULT_APPROVAL_RUNNING_NOTICE_MS = 10_000;
const APPROVAL_SLUG_LENGTH = 8;

export const execSchema = Type.Object({
  command: Type.String({ description: "Shell command to execute" }),
  workdir: Type.Optional(Type.String({ description: "Working directory (defaults to cwd)" })),
  env: Type.Optional(Type.Record(Type.String(), Type.String())),
  yieldMs: Type.Optional(
    Type.Number({
      description: "Milliseconds to wait before backgrounding (default 10000)",
    }),
  ),
  background: Type.Optional(Type.Boolean({ description: "Run in background immediately" })),
  timeout: Type.Optional(
    Type.Number({
      description: "Timeout in seconds (optional, kills process on expiry)",
    }),
  ),
  pty: Type.Optional(
    Type.Boolean({
      description:
        "Run in a pseudo-terminal (PTY) when available (TTY-required CLIs, coding agents)",
    }),
  ),
  elevated: Type.Optional(
    Type.Boolean({
      description: "Run on the host with elevated permissions (if allowed)",
    }),
  ),
  host: Type.Optional(
    Type.String({
      description: "Exec host (sandbox|gateway|node).",
    }),
  ),
  security: Type.Optional(
    Type.String({
      description: "Exec security mode (deny|allowlist|full).",
    }),
  ),
  ask: Type.Optional(
    Type.String({
      description: "Exec ask mode (off|on-miss|always).",
    }),
  ),
  node: Type.Optional(
    Type.String({
      description: "Node id/name for host=node.",
    }),
  ),
});

type PtyExitEvent = { exitCode: number; signal?: number };
type PtyListener<T> = (event: T) => void;
type PtyHandle = {
  pid: number;
  write: (data: string | Buffer) => void;
  onData: (listener: PtyListener<string>) => void;
  onExit: (listener: PtyListener<PtyExitEvent>) => void;
};
type PtySpawn = (
  file: string,
  args: string[] | string,
  options: {
    name?: string;
    cols?: number;
    rows?: number;
    cwd?: string;
    env?: Record<string, string>;
  },
) => PtyHandle;

export type ExecProcessOutcome = {
  status: "completed" | "failed";
  exitCode: number | null;
  exitSignal: NodeJS.Signals | number | null;
  durationMs: number;
  aggregated: string;
  timedOut: boolean;
  reason?: string;
};

export type ExecProcessHandle = {
  session: ProcessSession;
  startedAt: number;
  pid?: number;
  promise: Promise<ExecProcessOutcome>;
  kill: () => void;
};

export function normalizeExecHost(value?: string | null): ExecHost | null {
  const normalized = value?.trim().toLowerCase();
  if (normalized === "sandbox" || normalized === "gateway" || normalized === "node") {
    return normalized;
  }
  return null;
}

export function normalizeExecSecurity(value?: string | null): ExecSecurity | null {
  const normalized = value?.trim().toLowerCase();
  if (normalized === "deny" || normalized === "allowlist" || normalized === "full") {
    return normalized;
  }
  return null;
}

export function normalizeExecAsk(value?: string | null): ExecAsk | null {
  const normalized = value?.trim().toLowerCase();
  if (normalized === "off" || normalized === "on-miss" || normalized === "always") {
    return normalized as ExecAsk;
  }
  return null;
}

export function renderExecHostLabel(host: ExecHost) {
  return host === "sandbox" ? "sandbox" : host === "gateway" ? "gateway" : "node";
}

export function normalizeNotifyOutput(value: string) {
  return value.replace(/\s+/g, " ").trim();
}

function compactNotifyOutput(value: string, maxChars = DEFAULT_NOTIFY_SNIPPET_CHARS) {
  const normalized = normalizeNotifyOutput(value);
  if (!normalized) {
    return "";
  }
  if (normalized.length <= maxChars) {
    return normalized;
  }
  const safe = Math.max(1, maxChars - 1);
  return `${normalized.slice(0, safe)}…`;
}

export function applyShellPath(env: Record<string, string>, shellPath?: string | null) {
  if (!shellPath) {
    return;
  }
  const entries = shellPath
    .split(path.delimiter)
    .map((part) => part.trim())
    .filter(Boolean);
  if (entries.length === 0) {
    return;
  }
  const merged = mergePathPrepend(env.PATH, entries);
  if (merged) {
    env.PATH = merged;
  }
}

function maybeNotifyOnExit(session: ProcessSession, status: "completed" | "failed") {
  if (!session.backgrounded || !session.notifyOnExit || session.exitNotified) {
    return;
  }
  const sessionKey = session.sessionKey?.trim();
  if (!sessionKey) {
    return;
  }
  session.exitNotified = true;
  const exitLabel = session.exitSignal
    ? `signal ${session.exitSignal}`
    : `code ${session.exitCode ?? 0}`;
  const output = compactNotifyOutput(
    tail(session.tail || session.aggregated || "", DEFAULT_NOTIFY_TAIL_CHARS),
  );
  if (status === "completed" && !output && session.notifyOnExitEmptySuccess !== true) {
    return;
  }
  const summary = output
    ? `Exec ${status} (${session.id.slice(0, 8)}, ${exitLabel}) :: ${output}`
    : `Exec ${status} (${session.id.slice(0, 8)}, ${exitLabel})`;
  enqueueSystemEvent(summary, { sessionKey });
  requestHeartbeatNow({ reason: `exec:${session.id}:exit` });
}

export function createApprovalSlug(id: string) {
  return id.slice(0, APPROVAL_SLUG_LENGTH);
}

export function resolveApprovalRunningNoticeMs(value?: number) {
  if (typeof value !== "number" || !Number.isFinite(value)) {
    return DEFAULT_APPROVAL_RUNNING_NOTICE_MS;
  }
  if (value <= 0) {
    return 0;
  }
  return Math.floor(value);
}

export function emitExecSystemEvent(
  text: string,
  opts: { sessionKey?: string; contextKey?: string },
) {
  const sessionKey = opts.sessionKey?.trim();
  if (!sessionKey) {
    return;
  }
  enqueueSystemEvent(text, { sessionKey, contextKey: opts.contextKey });
  requestHeartbeatNow({ reason: "exec-event" });
}

export async function runExecProcess(opts: {
  command: string;
  // Execute this instead of `command` (which is kept for display/session/logging).
  // Used to sanitize safeBins execution while preserving the original user input.
  execCommand?: string;
  workdir: string;
  env: Record<string, string>;
  sandbox?: BashSandboxConfig;
  containerWorkdir?: string | null;
  usePty: boolean;
  warnings: string[];
  maxOutput: number;
  pendingMaxOutput: number;
  notifyOnExit: boolean;
  notifyOnExitEmptySuccess?: boolean;
  scopeKey?: string;
  sessionKey?: string;
  timeoutSec: number;
  onUpdate?: (partialResult: AgentToolResult<ExecToolDetails>) => void;
}): Promise<ExecProcessHandle> {
  const startedAt = Date.now();
  const sessionId = createSessionSlug();
  let child: ChildProcessWithoutNullStreams | null = null;
  let pty: PtyHandle | null = null;
  let stdin: SessionStdin | undefined;
  const execCommand = opts.execCommand ?? opts.command;

  const spawnFallbacks = [
    {
      label: "no-detach",
      options: { detached: false },
    },
  ];

  const handleSpawnFallback = (err: unknown, fallback: { label: string }) => {
    const errText = formatSpawnError(err);
    const warning = `Warning: spawn failed (${errText}); retrying with ${fallback.label}.`;
    logWarn(`exec: spawn failed (${errText}); retrying with ${fallback.label}.`);
    opts.warnings.push(warning);
  };

  const spawnShellChild = async (
    shell: string,
    shellArgs: string[],
  ): Promise<ChildProcessWithoutNullStreams> => {
    const { child: spawned } = await spawnWithFallback({
      argv: [shell, ...shellArgs, execCommand],
      options: {
        cwd: opts.workdir,
        env: opts.env,
        detached: process.platform !== "win32",
        stdio: ["pipe", "pipe", "pipe"],
        windowsHide: true,
      },
      fallbacks: spawnFallbacks,
      onFallback: handleSpawnFallback,
    });
    return spawned as ChildProcessWithoutNullStreams;
  };

  // `exec` does not currently accept tool-provided stdin content. For non-PTY runs,
  // keeping stdin open can cause commands like `wc -l` (or safeBins-hardened segments)
  // to block forever waiting for input, leading to accidental backgrounding.
  // For interactive flows, callers should use `pty: true` (stdin kept open).
  const maybeCloseNonPtyStdin = () => {
    if (opts.usePty) {
      return;
    }
    try {
      // Signal EOF immediately so stdin-only commands can terminate.
      child?.stdin?.end();
    } catch {
      // ignore stdin close errors
    }
  };

  if (opts.sandbox) {
    const { child: spawned } = await spawnWithFallback({
      argv: [
        "docker",
        ...buildDockerExecArgs({
          containerName: opts.sandbox.containerName,
          command: execCommand,
          workdir: opts.containerWorkdir ?? opts.sandbox.containerWorkdir,
          env: opts.env,
          tty: opts.usePty,
        }),
      ],
      options: {
        cwd: opts.workdir,
        env: process.env,
        detached: process.platform !== "win32",
        stdio: ["pipe", "pipe", "pipe"],
        windowsHide: true,
      },
      fallbacks: spawnFallbacks,
      onFallback: handleSpawnFallback,
    });
    child = spawned as ChildProcessWithoutNullStreams;
    stdin = child.stdin;
    maybeCloseNonPtyStdin();
  } else if (opts.usePty) {
    const { shell, args: shellArgs } = getShellConfig();
    try {
      const ptyModule = (await import("@lydell/node-pty")) as unknown as {
        spawn?: PtySpawn;
        default?: { spawn?: PtySpawn };
      };
      const spawnPty = ptyModule.spawn ?? ptyModule.default?.spawn;
      if (!spawnPty) {
        throw new Error("PTY support is unavailable (node-pty spawn not found).");
      }
      pty = spawnPty(shell, [...shellArgs, execCommand], {
        cwd: opts.workdir,
        env: opts.env,
        name: process.env.TERM ?? "xterm-256color",
        cols: 120,
        rows: 30,
      });
      stdin = {
        destroyed: false,
        write: (data, cb) => {
          try {
            pty?.write(data);
            cb?.(null);
          } catch (err) {
            cb?.(err as Error);
          }
        },
        end: () => {
          try {
            const eof = process.platform === "win32" ? "\x1a" : "\x04";
            pty?.write(eof);
          } catch {
            // ignore EOF errors
          }
        },
      };
    } catch (err) {
      const errText = String(err);
      const warning = `Warning: PTY spawn failed (${errText}); retrying without PTY for \`${opts.command}\`.`;
      logWarn(`exec: PTY spawn failed (${errText}); retrying without PTY for "${opts.command}".`);
      opts.warnings.push(warning);
      child = await spawnShellChild(shell, shellArgs);
      stdin = child.stdin;
    }
  } else {
    const { shell, args: shellArgs } = getShellConfig();
    child = await spawnShellChild(shell, shellArgs);
    stdin = child.stdin;
    maybeCloseNonPtyStdin();
  }

  const session = {
    id: sessionId,
    command: opts.command,
    scopeKey: opts.scopeKey,
    sessionKey: opts.sessionKey,
    notifyOnExit: opts.notifyOnExit,
    notifyOnExitEmptySuccess: opts.notifyOnExitEmptySuccess === true,
    exitNotified: false,
    child: child ?? undefined,
    stdin,
    pid: child?.pid ?? pty?.pid,
    startedAt,
    cwd: opts.workdir,
    maxOutputChars: opts.maxOutput,
    pendingMaxOutputChars: opts.pendingMaxOutput,
    totalOutputChars: 0,
    pendingStdout: [],
    pendingStderr: [],
    pendingStdoutChars: 0,
    pendingStderrChars: 0,
    aggregated: "",
    tail: "",
    exited: false,
    exitCode: undefined as number | null | undefined,
    exitSignal: undefined as NodeJS.Signals | number | null | undefined,
    truncated: false,
    backgrounded: false,
  } satisfies ProcessSession;
  addSession(session);

  let settled = false;
  let timeoutTimer: NodeJS.Timeout | null = null;
  let timeoutFinalizeTimer: NodeJS.Timeout | null = null;
  let timedOut = false;
  const timeoutFinalizeMs = 1000;
  let resolveFn: ((outcome: ExecProcessOutcome) => void) | null = null;

  const settle = (outcome: ExecProcessOutcome) => {
    if (settled) {
      return;
    }
    settled = true;
    resolveFn?.(outcome);
  };

  const finalizeTimeout = () => {
    if (session.exited) {
      return;
    }
    markExited(session, null, "SIGKILL", "failed");
    maybeNotifyOnExit(session, "failed");
    const aggregated = session.aggregated.trim();
    const reason = `Command timed out after ${opts.timeoutSec} seconds`;
    settle({
      status: "failed",
      exitCode: null,
      exitSignal: "SIGKILL",
      durationMs: Date.now() - startedAt,
      aggregated,
      timedOut: true,
      reason: aggregated ? `${aggregated}\n\n${reason}` : reason,
    });
  };

  const onTimeout = () => {
    timedOut = true;
    killSession(session);
    if (!timeoutFinalizeTimer) {
      timeoutFinalizeTimer = setTimeout(() => {
        finalizeTimeout();
      }, timeoutFinalizeMs);
    }
  };

  if (opts.timeoutSec > 0) {
    timeoutTimer = setTimeout(() => {
      onTimeout();
    }, opts.timeoutSec * 1000);
  }

  const emitUpdate = () => {
    if (!opts.onUpdate) {
      return;
    }
    const tailText = session.tail || session.aggregated;
    const warningText = opts.warnings.length ? `${opts.warnings.join("\n")}\n\n` : "";
    opts.onUpdate({
      content: [{ type: "text", text: warningText + (tailText || "") }],
      details: {
        status: "running",
        sessionId,
        pid: session.pid ?? undefined,
        startedAt,
        cwd: session.cwd,
        tail: session.tail,
      },
    });
  };

  const handleStdout = (data: string) => {
    const str = sanitizeBinaryOutput(data.toString());
    for (const chunk of chunkString(str)) {
      appendOutput(session, "stdout", chunk);
      emitUpdate();
    }
  };

  const handleStderr = (data: string) => {
    const str = sanitizeBinaryOutput(data.toString());
    for (const chunk of chunkString(str)) {
      appendOutput(session, "stderr", chunk);
      emitUpdate();
    }
  };

  if (pty) {
    const cursorResponse = buildCursorPositionResponse();
    pty.onData((data) => {
      const raw = data.toString();
      const { cleaned, requests } = stripDsrRequests(raw);
      if (requests > 0) {
        for (let i = 0; i < requests; i += 1) {
          pty.write(cursorResponse);
        }
      }
      handleStdout(cleaned);
    });
  } else if (child) {
    child.stdout.on("data", handleStdout);
    child.stderr.on("data", handleStderr);
  }

  const promise = new Promise<ExecProcessOutcome>((resolve) => {
    resolveFn = resolve;
    const handleExit = (code: number | null, exitSignal: NodeJS.Signals | number | null) => {
      if (timeoutTimer) {
        clearTimeout(timeoutTimer);
      }
      if (timeoutFinalizeTimer) {
        clearTimeout(timeoutFinalizeTimer);
      }
      const durationMs = Date.now() - startedAt;
      const wasSignal = exitSignal != null;
      const isSuccess = code === 0 && !wasSignal && !timedOut;
      const status: "completed" | "failed" = isSuccess ? "completed" : "failed";
      markExited(session, code, exitSignal, status);
      maybeNotifyOnExit(session, status);
      if (!session.child && session.stdin) {
        session.stdin.destroyed = true;
      }

      if (settled) {
        return;
      }
      const aggregated = session.aggregated.trim();
      if (!isSuccess) {
        const reason = timedOut
          ? `Command timed out after ${opts.timeoutSec} seconds`
          : wasSignal && exitSignal
            ? `Command aborted by signal ${exitSignal}`
            : code === null
              ? "Command aborted before exit code was captured"
              : `Command exited with code ${code}`;
        const message = aggregated ? `${aggregated}\n\n${reason}` : reason;
        settle({
          status: "failed",
          exitCode: code ?? null,
          exitSignal: exitSignal ?? null,
          durationMs,
          aggregated,
          timedOut,
          reason: message,
        });
        return;
      }
      settle({
        status: "completed",
        exitCode: code ?? 0,
        exitSignal: exitSignal ?? null,
        durationMs,
        aggregated,
        timedOut: false,
      });
    };

    if (pty) {
      pty.onExit((event) => {
        const rawSignal = event.signal ?? null;
        const normalizedSignal = rawSignal === 0 ? null : rawSignal;
        handleExit(event.exitCode ?? null, normalizedSignal);
      });
    } else if (child) {
      child.once("close", (code, exitSignal) => {
        handleExit(code, exitSignal);
      });

      child.once("error", (err) => {
        if (timeoutTimer) {
          clearTimeout(timeoutTimer);
        }
        if (timeoutFinalizeTimer) {
          clearTimeout(timeoutFinalizeTimer);
        }
        markExited(session, null, null, "failed");
        maybeNotifyOnExit(session, "failed");
        const aggregated = session.aggregated.trim();
        const message = aggregated ? `${aggregated}\n\n${String(err)}` : String(err);
        settle({
          status: "failed",
          exitCode: null,
          exitSignal: null,
          durationMs: Date.now() - startedAt,
          aggregated,
          timedOut,
          reason: message,
        });
      });
    }
  });

  return {
    session,
    startedAt,
    pid: session.pid ?? undefined,
    promise,
    kill: () => killSession(session),
  };
}