import crypto from "node:crypto";
import fs from "node:fs";
import net from "node:net";
import os from "node:os";
import path from "node:path";

import { DEFAULT_AGENT_ID } from "../routing/session-key.js";

export type ExecHost = "sandbox" | "gateway" | "node";
export type ExecSecurity = "deny" | "allowlist" | "full";
export type ExecAsk = "off" | "on-miss" | "always";

export type ExecApprovalsDefaults = {
  security?: ExecSecurity;
  ask?: ExecAsk;
  askFallback?: ExecSecurity;
  autoAllowSkills?: boolean;
};

export type ExecAllowlistEntry = {
  id?: string;
  pattern: string;
  lastUsedAt?: number;
  lastUsedCommand?: string;
  lastResolvedPath?: string;
};

export type ExecApprovalsAgent = ExecApprovalsDefaults & {
  allowlist?: ExecAllowlistEntry[];
};

export type ExecApprovalsFile = {
  version: 1;
  socket?: {
    path?: string;
    token?: string;
  };
  defaults?: ExecApprovalsDefaults;
  agents?: Record<string, ExecApprovalsAgent>;
};

export type ExecApprovalsSnapshot = {
  path: string;
  exists: boolean;
  raw: string | null;
  file: ExecApprovalsFile;
  hash: string;
};

export type ExecApprovalsResolved = {
  path: string;
  socketPath: string;
  token: string;
  defaults: Required<ExecApprovalsDefaults>;
  agent: Required<ExecApprovalsDefaults>;
  allowlist: ExecAllowlistEntry[];
  file: ExecApprovalsFile;
};

const DEFAULT_SECURITY: ExecSecurity = "deny";
const DEFAULT_ASK: ExecAsk = "on-miss";
const DEFAULT_ASK_FALLBACK: ExecSecurity = "deny";
const DEFAULT_AUTO_ALLOW_SKILLS = false;
const DEFAULT_SOCKET = "~/.openclaw/exec-approvals.sock";
const DEFAULT_FILE = "~/.openclaw/exec-approvals.json";
export const DEFAULT_SAFE_BINS = ["jq", "grep", "cut", "sort", "uniq", "head", "tail", "tr", "wc"];

function hashExecApprovalsRaw(raw: string | null): string {
  return crypto
    .createHash("sha256")
    .update(raw ?? "")
    .digest("hex");
}

function expandHome(value: string): string {
  if (!value) return value;
  if (value === "~") return os.homedir();
  if (value.startsWith("~/")) return path.join(os.homedir(), value.slice(2));
  return value;
}

export function resolveExecApprovalsPath(): string {
  return expandHome(DEFAULT_FILE);
}

export function resolveExecApprovalsSocketPath(): string {
  return expandHome(DEFAULT_SOCKET);
}

function normalizeAllowlistPattern(value: string | undefined): string | null {
  const trimmed = value?.trim() ?? "";
  return trimmed ? trimmed.toLowerCase() : null;
}

function mergeLegacyAgent(
  current: ExecApprovalsAgent,
  legacy: ExecApprovalsAgent,
): ExecApprovalsAgent {
  const allowlist: ExecAllowlistEntry[] = [];
  const seen = new Set<string>();
  const pushEntry = (entry: ExecAllowlistEntry) => {
    const key = normalizeAllowlistPattern(entry.pattern);
    if (!key || seen.has(key)) return;
    seen.add(key);
    allowlist.push(entry);
  };
  for (const entry of current.allowlist ?? []) pushEntry(entry);
  for (const entry of legacy.allowlist ?? []) pushEntry(entry);

  return {
    security: current.security ?? legacy.security,
    ask: current.ask ?? legacy.ask,
    askFallback: current.askFallback ?? legacy.askFallback,
    autoAllowSkills: current.autoAllowSkills ?? legacy.autoAllowSkills,
    allowlist: allowlist.length > 0 ? allowlist : undefined,
  };
}

function ensureDir(filePath: string) {
  const dir = path.dirname(filePath);
  fs.mkdirSync(dir, { recursive: true });
}

function ensureAllowlistIds(
  allowlist: ExecAllowlistEntry[] | undefined,
): ExecAllowlistEntry[] | undefined {
  if (!Array.isArray(allowlist) || allowlist.length === 0) return allowlist;
  let changed = false;
  const next = allowlist.map((entry) => {
    if (entry.id) return entry;
    changed = true;
    return { ...entry, id: crypto.randomUUID() };
  });
  return changed ? next : allowlist;
}

export function normalizeExecApprovals(file: ExecApprovalsFile): ExecApprovalsFile {
  const socketPath = file.socket?.path?.trim();
  const token = file.socket?.token?.trim();
  const agents = { ...file.agents };
  const legacyDefault = agents.default;
  if (legacyDefault) {
    const main = agents[DEFAULT_AGENT_ID];
    agents[DEFAULT_AGENT_ID] = main ? mergeLegacyAgent(main, legacyDefault) : legacyDefault;
    delete agents.default;
  }
  for (const [key, agent] of Object.entries(agents)) {
    const allowlist = ensureAllowlistIds(agent.allowlist);
    if (allowlist !== agent.allowlist) {
      agents[key] = { ...agent, allowlist };
    }
  }
  const normalized: ExecApprovalsFile = {
    version: 1,
    socket: {
      path: socketPath && socketPath.length > 0 ? socketPath : undefined,
      token: token && token.length > 0 ? token : undefined,
    },
    defaults: {
      security: file.defaults?.security,
      ask: file.defaults?.ask,
      askFallback: file.defaults?.askFallback,
      autoAllowSkills: file.defaults?.autoAllowSkills,
    },
    agents,
  };
  return normalized;
}

function generateToken(): string {
  return crypto.randomBytes(24).toString("base64url");
}

export function readExecApprovalsSnapshot(): ExecApprovalsSnapshot {
  const filePath = resolveExecApprovalsPath();
  if (!fs.existsSync(filePath)) {
    const file = normalizeExecApprovals({ version: 1, agents: {} });
    return {
      path: filePath,
      exists: false,
      raw: null,
      file,
      hash: hashExecApprovalsRaw(null),
    };
  }
  const raw = fs.readFileSync(filePath, "utf8");
  let parsed: ExecApprovalsFile | null = null;
  try {
    parsed = JSON.parse(raw) as ExecApprovalsFile;
  } catch {
    parsed = null;
  }
  const file =
    parsed?.version === 1
      ? normalizeExecApprovals(parsed)
      : normalizeExecApprovals({ version: 1, agents: {} });
  return {
    path: filePath,
    exists: true,
    raw,
    file,
    hash: hashExecApprovalsRaw(raw),
  };
}

export function loadExecApprovals(): ExecApprovalsFile {
  const filePath = resolveExecApprovalsPath();
  try {
    if (!fs.existsSync(filePath)) {
      return normalizeExecApprovals({ version: 1, agents: {} });
    }
    const raw = fs.readFileSync(filePath, "utf8");
    const parsed = JSON.parse(raw) as ExecApprovalsFile;
    if (parsed?.version !== 1) {
      return normalizeExecApprovals({ version: 1, agents: {} });
    }
    return normalizeExecApprovals(parsed);
  } catch {
    return normalizeExecApprovals({ version: 1, agents: {} });
  }
}

export function saveExecApprovals(file: ExecApprovalsFile) {
  const filePath = resolveExecApprovalsPath();
  ensureDir(filePath);
  fs.writeFileSync(filePath, `${JSON.stringify(file, null, 2)}\n`, { mode: 0o600 });
  try {
    fs.chmodSync(filePath, 0o600);
  } catch {
    // best-effort on platforms without chmod
  }
}

export function ensureExecApprovals(): ExecApprovalsFile {
  const loaded = loadExecApprovals();
  const next = normalizeExecApprovals(loaded);
  const socketPath = next.socket?.path?.trim();
  const token = next.socket?.token?.trim();
  const updated: ExecApprovalsFile = {
    ...next,
    socket: {
      path: socketPath && socketPath.length > 0 ? socketPath : resolveExecApprovalsSocketPath(),
      token: token && token.length > 0 ? token : generateToken(),
    },
  };
  saveExecApprovals(updated);
  return updated;
}

function normalizeSecurity(value: ExecSecurity | undefined, fallback: ExecSecurity): ExecSecurity {
  if (value === "allowlist" || value === "full" || value === "deny") return value;
  return fallback;
}

function normalizeAsk(value: ExecAsk | undefined, fallback: ExecAsk): ExecAsk {
  if (value === "always" || value === "off" || value === "on-miss") return value;
  return fallback;
}

export type ExecApprovalsDefaultOverrides = {
  security?: ExecSecurity;
  ask?: ExecAsk;
  askFallback?: ExecSecurity;
  autoAllowSkills?: boolean;
};

export function resolveExecApprovals(
  agentId?: string,
  overrides?: ExecApprovalsDefaultOverrides,
): ExecApprovalsResolved {
  const file = ensureExecApprovals();
  return resolveExecApprovalsFromFile({
    file,
    agentId,
    overrides,
    path: resolveExecApprovalsPath(),
    socketPath: expandHome(file.socket?.path ?? resolveExecApprovalsSocketPath()),
    token: file.socket?.token ?? "",
  });
}

export function resolveExecApprovalsFromFile(params: {
  file: ExecApprovalsFile;
  agentId?: string;
  overrides?: ExecApprovalsDefaultOverrides;
  path?: string;
  socketPath?: string;
  token?: string;
}): ExecApprovalsResolved {
  const file = normalizeExecApprovals(params.file);
  const defaults = file.defaults ?? {};
  const agentKey = params.agentId ?? DEFAULT_AGENT_ID;
  const agent = file.agents?.[agentKey] ?? {};
  const wildcard = file.agents?.["*"] ?? {};
  const fallbackSecurity = params.overrides?.security ?? DEFAULT_SECURITY;
  const fallbackAsk = params.overrides?.ask ?? DEFAULT_ASK;
  const fallbackAskFallback = params.overrides?.askFallback ?? DEFAULT_ASK_FALLBACK;
  const fallbackAutoAllowSkills = params.overrides?.autoAllowSkills ?? DEFAULT_AUTO_ALLOW_SKILLS;
  const resolvedDefaults: Required<ExecApprovalsDefaults> = {
    security: normalizeSecurity(defaults.security, fallbackSecurity),
    ask: normalizeAsk(defaults.ask, fallbackAsk),
    askFallback: normalizeSecurity(
      defaults.askFallback ?? fallbackAskFallback,
      fallbackAskFallback,
    ),
    autoAllowSkills: Boolean(defaults.autoAllowSkills ?? fallbackAutoAllowSkills),
  };
  const resolvedAgent: Required<ExecApprovalsDefaults> = {
    security: normalizeSecurity(
      agent.security ?? wildcard.security ?? resolvedDefaults.security,
      resolvedDefaults.security,
    ),
    ask: normalizeAsk(agent.ask ?? wildcard.ask ?? resolvedDefaults.ask, resolvedDefaults.ask),
    askFallback: normalizeSecurity(
      agent.askFallback ?? wildcard.askFallback ?? resolvedDefaults.askFallback,
      resolvedDefaults.askFallback,
    ),
    autoAllowSkills: Boolean(
      agent.autoAllowSkills ?? wildcard.autoAllowSkills ?? resolvedDefaults.autoAllowSkills,
    ),
  };
  const allowlist = [
    ...(Array.isArray(wildcard.allowlist) ? wildcard.allowlist : []),
    ...(Array.isArray(agent.allowlist) ? agent.allowlist : []),
  ];
  return {
    path: params.path ?? resolveExecApprovalsPath(),
    socketPath: expandHome(
      params.socketPath ?? file.socket?.path ?? resolveExecApprovalsSocketPath(),
    ),
    token: params.token ?? file.socket?.token ?? "",
    defaults: resolvedDefaults,
    agent: resolvedAgent,
    allowlist,
    file,
  };
}

type CommandResolution = {
  rawExecutable: string;
  resolvedPath?: string;
  executableName: string;
};

function isExecutableFile(filePath: string): boolean {
  try {
    const stat = fs.statSync(filePath);
    if (!stat.isFile()) return false;
    if (process.platform !== "win32") {
      fs.accessSync(filePath, fs.constants.X_OK);
    }
    return true;
  } catch {
    return false;
  }
}

function parseFirstToken(command: string): string | null {
  const trimmed = command.trim();
  if (!trimmed) return null;
  const first = trimmed[0];
  if (first === '"' || first === "'") {
    const end = trimmed.indexOf(first, 1);
    if (end > 1) return trimmed.slice(1, end);
    return trimmed.slice(1);
  }
  const match = /^[^\s]+/.exec(trimmed);
  return match ? match[0] : null;
}

function resolveExecutablePath(rawExecutable: string, cwd?: string, env?: NodeJS.ProcessEnv) {
  const expanded = rawExecutable.startsWith("~") ? expandHome(rawExecutable) : rawExecutable;
  if (expanded.includes("/") || expanded.includes("\\")) {
    if (path.isAbsolute(expanded)) {
      return isExecutableFile(expanded) ? expanded : undefined;
    }
    const base = cwd && cwd.trim() ? cwd.trim() : process.cwd();
    const candidate = path.resolve(base, expanded);
    return isExecutableFile(candidate) ? candidate : undefined;
  }
  const envPath = env?.PATH ?? env?.Path ?? process.env.PATH ?? process.env.Path ?? "";
  const entries = envPath.split(path.delimiter).filter(Boolean);
  const hasExtension = process.platform === "win32" && path.extname(expanded).length > 0;
  const extensions =
    process.platform === "win32"
      ? hasExtension
        ? [""]
        : (
            env?.PATHEXT ??
            env?.Pathext ??
            process.env.PATHEXT ??
            process.env.Pathext ??
            ".EXE;.CMD;.BAT;.COM"
          )
            .split(";")
            .map((ext) => ext.toLowerCase())
      : [""];
  for (const entry of entries) {
    for (const ext of extensions) {
      const candidate = path.join(entry, expanded + ext);
      if (isExecutableFile(candidate)) return candidate;
    }
  }
  return undefined;
}

export function resolveCommandResolution(
  command: string,
  cwd?: string,
  env?: NodeJS.ProcessEnv,
): CommandResolution | null {
  const rawExecutable = parseFirstToken(command);
  if (!rawExecutable) return null;
  const resolvedPath = resolveExecutablePath(rawExecutable, cwd, env);
  const executableName = resolvedPath ? path.basename(resolvedPath) : rawExecutable;
  return { rawExecutable, resolvedPath, executableName };
}

export function resolveCommandResolutionFromArgv(
  argv: string[],
  cwd?: string,
  env?: NodeJS.ProcessEnv,
): CommandResolution | null {
  const rawExecutable = argv[0]?.trim();
  if (!rawExecutable) return null;
  const resolvedPath = resolveExecutablePath(rawExecutable, cwd, env);
  const executableName = resolvedPath ? path.basename(resolvedPath) : rawExecutable;
  return { rawExecutable, resolvedPath, executableName };
}

function normalizeMatchTarget(value: string): string {
  if (process.platform === "win32") {
    const stripped = value.replace(/^\\\\[?.]\\/, "");
    return stripped.replace(/\\/g, "/").toLowerCase();
  }
  return value.replace(/\\\\/g, "/").toLowerCase();
}

function tryRealpath(value: string): string | null {
  try {
    return fs.realpathSync(value);
  } catch {
    return null;
  }
}

function globToRegExp(pattern: string): RegExp {
  let regex = "^";
  let i = 0;
  while (i < pattern.length) {
    const ch = pattern[i];
    if (ch === "*") {
      const next = pattern[i + 1];
      if (next === "*") {
        regex += ".*";
        i += 2;
        continue;
      }
      regex += "[^/]*";
      i += 1;
      continue;
    }
    if (ch === "?") {
      regex += ".";
      i += 1;
      continue;
    }
    regex += ch.replace(/[.*+?^${}()|[\\]\\\\]/g, "\\$&");
    i += 1;
  }
  regex += "$";
  return new RegExp(regex, "i");
}

function matchesPattern(pattern: string, target: string): boolean {
  const trimmed = pattern.trim();
  if (!trimmed) return false;
  const expanded = trimmed.startsWith("~") ? expandHome(trimmed) : trimmed;
  const hasWildcard = /[*?]/.test(expanded);
  let normalizedPattern = expanded;
  let normalizedTarget = target;
  if (process.platform === "win32" && !hasWildcard) {
    normalizedPattern = tryRealpath(expanded) ?? expanded;
    normalizedTarget = tryRealpath(target) ?? target;
  }
  normalizedPattern = normalizeMatchTarget(normalizedPattern);
  normalizedTarget = normalizeMatchTarget(normalizedTarget);
  const regex = globToRegExp(normalizedPattern);
  return regex.test(normalizedTarget);
}

function resolveAllowlistCandidatePath(
  resolution: CommandResolution | null,
  cwd?: string,
): string | undefined {
  if (!resolution) return undefined;
  if (resolution.resolvedPath) return resolution.resolvedPath;
  const raw = resolution.rawExecutable?.trim();
  if (!raw) return undefined;
  const expanded = raw.startsWith("~") ? expandHome(raw) : raw;
  if (!expanded.includes("/") && !expanded.includes("\\")) return undefined;
  if (path.isAbsolute(expanded)) return expanded;
  const base = cwd && cwd.trim() ? cwd.trim() : process.cwd();
  return path.resolve(base, expanded);
}

export function matchAllowlist(
  entries: ExecAllowlistEntry[],
  resolution: CommandResolution | null,
): ExecAllowlistEntry | null {
  if (!entries.length || !resolution?.resolvedPath) return null;
  const resolvedPath = resolution.resolvedPath;
  for (const entry of entries) {
    const pattern = entry.pattern?.trim();
    if (!pattern) continue;
    const hasPath = pattern.includes("/") || pattern.includes("\\") || pattern.includes("~");
    if (!hasPath) continue;
    if (matchesPattern(pattern, resolvedPath)) return entry;
  }
  return null;
}

export type ExecCommandSegment = {
  raw: string;
  argv: string[];
  resolution: CommandResolution | null;
};

export type ExecCommandAnalysis = {
  ok: boolean;
  reason?: string;
  segments: ExecCommandSegment[];
  chains?: ExecCommandSegment[][]; // Segments grouped by chain operator (&&, ||, ;)
};

const DISALLOWED_PIPELINE_TOKENS = new Set([">", "<", "`", "\n", "\r", "(", ")"]);
const DOUBLE_QUOTE_ESCAPES = new Set(["\\", '"', "$", "`", "\n", "\r"]);
const WINDOWS_UNSUPPORTED_TOKENS = new Set([
  "&",
  "|",
  "<",
  ">",
  "^",
  "(",
  ")",
  "%",
  "!",
  "\n",
  "\r",
]);

function isDoubleQuoteEscape(next: string | undefined): next is string {
  return Boolean(next && DOUBLE_QUOTE_ESCAPES.has(next));
}

function splitShellPipeline(command: string): { ok: boolean; reason?: string; segments: string[] } {
  type HeredocSpec = {
    delimiter: string;
    stripTabs: boolean;
  };

  const parseHeredocDelimiter = (
    source: string,
    start: number,
  ): { delimiter: string; end: number } | null => {
    let i = start;
    while (i < source.length && (source[i] === " " || source[i] === "\t")) {
      i += 1;
    }
    if (i >= source.length) {
      return null;
    }

    const first = source[i];
    if (first === "'" || first === '"') {
      const quote = first;
      i += 1;
      let delimiter = "";
      while (i < source.length) {
        const ch = source[i];
        if (ch === "\n" || ch === "\r") {
          return null;
        }
        if (quote === '"' && ch === "\\" && i + 1 < source.length) {
          delimiter += source[i + 1];
          i += 2;
          continue;
        }
        if (ch === quote) {
          return { delimiter, end: i + 1 };
        }
        delimiter += ch;
        i += 1;
      }
      return null;
    }

    let delimiter = "";
    while (i < source.length) {
      const ch = source[i];
      if (/\s/.test(ch) || ch === "|" || ch === "&" || ch === ";" || ch === "<" || ch === ">") {
        break;
      }
      delimiter += ch;
      i += 1;
    }
    if (!delimiter) {
      return null;
    }
    return { delimiter, end: i };
  };

  const segments: string[] = [];
  let buf = "";
  let inSingle = false;
  let inDouble = false;
  let escaped = false;
  let emptySegment = false;
  const pendingHeredocs: HeredocSpec[] = [];
  let inHeredocBody = false;
  let heredocLine = "";

  const pushPart = () => {
    const trimmed = buf.trim();
    if (trimmed) {
      segments.push(trimmed);
    }
    buf = "";
  };

  for (let i = 0; i < command.length; i += 1) {
    const ch = command[i];
    const next = command[i + 1];

    if (inHeredocBody) {
      if (ch === "\n" || ch === "\r") {
        const current = pendingHeredocs[0];
        if (current) {
          const line = current.stripTabs ? heredocLine.replace(/^\t+/, "") : heredocLine;
          if (line === current.delimiter) {
            pendingHeredocs.shift();
          }
        }
        heredocLine = "";
        if (pendingHeredocs.length === 0) {
          inHeredocBody = false;
        }
        if (ch === "\r" && next === "\n") {
          i += 1;
        }
      } else {
        heredocLine += ch;
      }
      continue;
    }

    if (escaped) {
      buf += ch;
      escaped = false;
      emptySegment = false;
      continue;
    }
    if (!inSingle && !inDouble && ch === "\\") {
      escaped = true;
      buf += ch;
      emptySegment = false;
      continue;
    }
    if (inSingle) {
      if (ch === "'") inSingle = false;
      buf += ch;
      emptySegment = false;
      continue;
    }
    if (inDouble) {
      if (ch === "\\" && isDoubleQuoteEscape(next)) {
        buf += ch;
        buf += next;
        i += 1;
        emptySegment = false;
        continue;
      }
      if (ch === "$" && next === "(") {
        return { ok: false, reason: "unsupported shell token: $()", segments: [] };
      }
      if (ch === "`") {
        return { ok: false, reason: "unsupported shell token: `", segments: [] };
      }
      if (ch === "\n" || ch === "\r") {
        return { ok: false, reason: "unsupported shell token: newline", segments: [] };
      }
      if (ch === '"') {
        inDouble = false;
      }
      buf += ch;
      emptySegment = false;
      continue;
    }
    if (ch === "'") {
      inSingle = true;
      buf += ch;
      emptySegment = false;
      continue;
    }
    if (ch === '"') {
      inDouble = true;
      buf += ch;
      emptySegment = false;
      continue;
    }

    if ((ch === "\n" || ch === "\r") && pendingHeredocs.length > 0) {
      inHeredocBody = true;
      heredocLine = "";
      if (ch === "\r" && next === "\n") {
        i += 1;
      }
      continue;
    }

    if (ch === "|" && next === "|") {
      return { ok: false, reason: "unsupported shell token: ||", segments: [] };
    }
    if (ch === "|" && next === "&") {
      return { ok: false, reason: "unsupported shell token: |&", segments: [] };
    }
    if (ch === "|") {
      emptySegment = true;
      pushPart();
      continue;
    }
    if (ch === "&" || ch === ";") {
      return { ok: false, reason: `unsupported shell token: ${ch}`, segments: [] };
    }
    if (ch === "<" && next === "<") {
      buf += "<<";
      emptySegment = false;
      i += 1;

      let scanIndex = i + 1;
      let stripTabs = false;
      if (command[scanIndex] === "-") {
        stripTabs = true;
        buf += "-";
        scanIndex += 1;
      }

      const parsed = parseHeredocDelimiter(command, scanIndex);
      if (parsed) {
        pendingHeredocs.push({ delimiter: parsed.delimiter, stripTabs });
        buf += command.slice(scanIndex, parsed.end);
        i = parsed.end - 1;
      }
      continue;
    }
    if (DISALLOWED_PIPELINE_TOKENS.has(ch)) {
      return { ok: false, reason: `unsupported shell token: ${ch}`, segments: [] };
    }
    if (ch === "$" && next === "(") {
      return { ok: false, reason: "unsupported shell token: $()", segments: [] };
    }
    buf += ch;
    emptySegment = false;
  }

  if (inHeredocBody && pendingHeredocs.length > 0) {
    const current = pendingHeredocs[0];
    const line = current.stripTabs ? heredocLine.replace(/^\t+/, "") : heredocLine;
    if (line === current.delimiter) {
      pendingHeredocs.shift();
    }
  }

  if (escaped || inSingle || inDouble) {
    return { ok: false, reason: "unterminated shell quote/escape", segments: [] };
  }

  pushPart();
  if (emptySegment || segments.length === 0) {
    return {
      ok: false,
      reason: segments.length === 0 ? "empty command" : "empty pipeline segment",
      segments: [],
    };
  }
  return { ok: true, segments };
}

function findWindowsUnsupportedToken(command: string): string | null {
  for (const ch of command) {
    if (WINDOWS_UNSUPPORTED_TOKENS.has(ch)) {
      if (ch === "\n" || ch === "\r") {
        return "newline";
      }
      return ch;
    }
  }
  return null;
}

function tokenizeWindowsSegment(segment: string): string[] | null {
  const tokens: string[] = [];
  let buf = "";
  let inDouble = false;

  const pushToken = () => {
    if (buf.length > 0) {
      tokens.push(buf);
      buf = "";
    }
  };

  for (let i = 0; i < segment.length; i += 1) {
    const ch = segment[i];
    if (ch === '"') {
      inDouble = !inDouble;
      continue;
    }
    if (!inDouble && /\s/.test(ch)) {
      pushToken();
      continue;
    }
    buf += ch;
  }

  if (inDouble) {
    return null;
  }
  pushToken();
  return tokens.length > 0 ? tokens : null;
}

function analyzeWindowsShellCommand(params: {
  command: string;
  cwd?: string;
  env?: NodeJS.ProcessEnv;
}): ExecCommandAnalysis {
  const unsupported = findWindowsUnsupportedToken(params.command);
  if (unsupported) {
    return {
      ok: false,
      reason: `unsupported windows shell token: ${unsupported}`,
      segments: [],
    };
  }
  const argv = tokenizeWindowsSegment(params.command);
  if (!argv || argv.length === 0) {
    return { ok: false, reason: "unable to parse windows command", segments: [] };
  }
  return {
    ok: true,
    segments: [
      {
        raw: params.command,
        argv,
        resolution: resolveCommandResolutionFromArgv(argv, params.cwd, params.env),
      },
    ],
  };
}

function isWindowsPlatform(platform?: string | null): boolean {
  const normalized = String(platform ?? "")
    .trim()
    .toLowerCase();
  return normalized.startsWith("win");
}

function tokenizeShellSegment(segment: string): string[] | null {
  const tokens: string[] = [];
  let buf = "";
  let inSingle = false;
  let inDouble = false;
  let escaped = false;

  const pushToken = () => {
    if (buf.length > 0) {
      tokens.push(buf);
      buf = "";
    }
  };

  for (let i = 0; i < segment.length; i += 1) {
    const ch = segment[i];
    if (escaped) {
      buf += ch;
      escaped = false;
      continue;
    }
    if (!inSingle && !inDouble && ch === "\\") {
      escaped = true;
      continue;
    }
    if (inSingle) {
      if (ch === "'") {
        inSingle = false;
      } else {
        buf += ch;
      }
      continue;
    }
    if (inDouble) {
      const next = segment[i + 1];
      if (ch === "\\" && isDoubleQuoteEscape(next)) {
        buf += next;
        i += 1;
        continue;
      }
      if (ch === '"') {
        inDouble = false;
      } else {
        buf += ch;
      }
      continue;
    }
    if (ch === "'") {
      inSingle = true;
      continue;
    }
    if (ch === '"') {
      inDouble = true;
      continue;
    }
    if (/\s/.test(ch)) {
      pushToken();
      continue;
    }
    buf += ch;
  }

  if (escaped || inSingle || inDouble) {
    return null;
  }
  pushToken();
  return tokens;
}

function parseSegmentsFromParts(
  parts: string[],
  cwd?: string,
  env?: NodeJS.ProcessEnv,
): ExecCommandSegment[] | null {
  const segments: ExecCommandSegment[] = [];
  for (const raw of parts) {
    const argv = tokenizeShellSegment(raw);
    if (!argv || argv.length === 0) {
      return null;
    }
    segments.push({
      raw,
      argv,
      resolution: resolveCommandResolutionFromArgv(argv, cwd, env),
    });
  }
  return segments;
}

export function analyzeShellCommand(params: {
  command: string;
  cwd?: string;
  env?: NodeJS.ProcessEnv;
  platform?: string | null;
}): ExecCommandAnalysis {
  if (isWindowsPlatform(params.platform)) {
    return analyzeWindowsShellCommand(params);
  }
  // First try splitting by chain operators (&&, ||, ;)
  const chainParts = splitCommandChain(params.command);
  if (chainParts) {
    const chains: ExecCommandSegment[][] = [];
    const allSegments: ExecCommandSegment[] = [];

    for (const part of chainParts) {
      const pipelineSplit = splitShellPipeline(part);
      if (!pipelineSplit.ok) {
        return { ok: false, reason: pipelineSplit.reason, segments: [] };
      }
      const segments = parseSegmentsFromParts(pipelineSplit.segments, params.cwd, params.env);
      if (!segments) {
        return { ok: false, reason: "unable to parse shell segment", segments: [] };
      }
      chains.push(segments);
      allSegments.push(...segments);
    }

    return { ok: true, segments: allSegments, chains };
  }

  // No chain operators, parse as simple pipeline
  const split = splitShellPipeline(params.command);
  if (!split.ok) {
    return { ok: false, reason: split.reason, segments: [] };
  }
  const segments = parseSegmentsFromParts(split.segments, params.cwd, params.env);
  if (!segments) {
    return { ok: false, reason: "unable to parse shell segment", segments: [] };
  }
  return { ok: true, segments };
}

export function analyzeArgvCommand(params: {
  argv: string[];
  cwd?: string;
  env?: NodeJS.ProcessEnv;
}): ExecCommandAnalysis {
  const argv = params.argv.filter((entry) => entry.trim().length > 0);
  if (argv.length === 0) {
    return { ok: false, reason: "empty argv", segments: [] };
  }
  return {
    ok: true,
    segments: [
      {
        raw: argv.join(" "),
        argv,
        resolution: resolveCommandResolutionFromArgv(argv, params.cwd, params.env),
      },
    ],
  };
}

function isPathLikeToken(value: string): boolean {
  const trimmed = value.trim();
  if (!trimmed) return false;
  if (trimmed === "-") return false;
  if (trimmed.startsWith("./") || trimmed.startsWith("../") || trimmed.startsWith("~")) return true;
  if (trimmed.startsWith("/")) return true;
  return /^[A-Za-z]:[\\/]/.test(trimmed);
}

function defaultFileExists(filePath: string): boolean {
  try {
    return fs.existsSync(filePath);
  } catch {
    return false;
  }
}

export function normalizeSafeBins(entries?: string[]): Set<string> {
  if (!Array.isArray(entries)) return new Set();
  const normalized = entries
    .map((entry) => entry.trim().toLowerCase())
    .filter((entry) => entry.length > 0);
  return new Set(normalized);
}

export function resolveSafeBins(entries?: string[] | null): Set<string> {
  if (entries === undefined) return normalizeSafeBins(DEFAULT_SAFE_BINS);
  return normalizeSafeBins(entries ?? []);
}

export function isSafeBinUsage(params: {
  argv: string[];
  resolution: CommandResolution | null;
  safeBins: Set<string>;
  cwd?: string;
  fileExists?: (filePath: string) => boolean;
}): boolean {
  if (params.safeBins.size === 0) return false;
  const resolution = params.resolution;
  const execName = resolution?.executableName?.toLowerCase();
  if (!execName) return false;
  const matchesSafeBin =
    params.safeBins.has(execName) ||
    (process.platform === "win32" && params.safeBins.has(path.parse(execName).name));
  if (!matchesSafeBin) return false;
  if (!resolution?.resolvedPath) return false;
  const cwd = params.cwd ?? process.cwd();
  const exists = params.fileExists ?? defaultFileExists;
  const argv = params.argv.slice(1);
  for (let i = 0; i < argv.length; i += 1) {
    const token = argv[i];
    if (!token) continue;
    if (token === "-") continue;
    if (token.startsWith("-")) {
      const eqIndex = token.indexOf("=");
      if (eqIndex > 0) {
        const value = token.slice(eqIndex + 1);
        if (value && (isPathLikeToken(value) || exists(path.resolve(cwd, value)))) {
          return false;
        }
      }
      continue;
    }
    if (isPathLikeToken(token)) return false;
    if (exists(path.resolve(cwd, token))) return false;
  }
  return true;
}

export type ExecAllowlistEvaluation = {
  allowlistSatisfied: boolean;
  allowlistMatches: ExecAllowlistEntry[];
};

function evaluateSegments(
  segments: ExecCommandSegment[],
  params: {
    allowlist: ExecAllowlistEntry[];
    safeBins: Set<string>;
    cwd?: string;
    skillBins?: Set<string>;
    autoAllowSkills?: boolean;
  },
): { satisfied: boolean; matches: ExecAllowlistEntry[] } {
  const matches: ExecAllowlistEntry[] = [];
  const allowSkills = params.autoAllowSkills === true && (params.skillBins?.size ?? 0) > 0;

  const satisfied = segments.every((segment) => {
    const candidatePath = resolveAllowlistCandidatePath(segment.resolution, params.cwd);
    const candidateResolution =
      candidatePath && segment.resolution
        ? { ...segment.resolution, resolvedPath: candidatePath }
        : segment.resolution;
    const match = matchAllowlist(params.allowlist, candidateResolution);
    if (match) matches.push(match);
    const safe = isSafeBinUsage({
      argv: segment.argv,
      resolution: segment.resolution,
      safeBins: params.safeBins,
      cwd: params.cwd,
    });
    const skillAllow =
      allowSkills && segment.resolution?.executableName
        ? params.skillBins?.has(segment.resolution.executableName)
        : false;
    return Boolean(match || safe || skillAllow);
  });

  return { satisfied, matches };
}

export function evaluateExecAllowlist(params: {
  analysis: ExecCommandAnalysis;
  allowlist: ExecAllowlistEntry[];
  safeBins: Set<string>;
  cwd?: string;
  skillBins?: Set<string>;
  autoAllowSkills?: boolean;
}): ExecAllowlistEvaluation {
  const allowlistMatches: ExecAllowlistEntry[] = [];
  if (!params.analysis.ok || params.analysis.segments.length === 0) {
    return { allowlistSatisfied: false, allowlistMatches };
  }

  // If the analysis contains chains, evaluate each chain part separately
  if (params.analysis.chains) {
    for (const chainSegments of params.analysis.chains) {
      const result = evaluateSegments(chainSegments, {
        allowlist: params.allowlist,
        safeBins: params.safeBins,
        cwd: params.cwd,
        skillBins: params.skillBins,
        autoAllowSkills: params.autoAllowSkills,
      });
      if (!result.satisfied) {
        return { allowlistSatisfied: false, allowlistMatches: [] };
      }
      allowlistMatches.push(...result.matches);
    }
    return { allowlistSatisfied: true, allowlistMatches };
  }

  // No chains, evaluate all segments together
  const result = evaluateSegments(params.analysis.segments, {
    allowlist: params.allowlist,
    safeBins: params.safeBins,
    cwd: params.cwd,
    skillBins: params.skillBins,
    autoAllowSkills: params.autoAllowSkills,
  });
  return { allowlistSatisfied: result.satisfied, allowlistMatches: result.matches };
}

/**
 * Splits a command string by chain operators (&&, ||, ;) while respecting quotes.
 * Returns null when no chain is present or when the chain is malformed.
 */
function splitCommandChain(command: string): string[] | null {
  const parts: string[] = [];
  let buf = "";
  let inSingle = false;
  let inDouble = false;
  let escaped = false;
  let foundChain = false;
  let invalidChain = false;

  const pushPart = () => {
    const trimmed = buf.trim();
    if (trimmed) {
      parts.push(trimmed);
      buf = "";
      return true;
    }
    buf = "";
    return false;
  };

  for (let i = 0; i < command.length; i += 1) {
    const ch = command[i];
    const next = command[i + 1];
    if (escaped) {
      buf += ch;
      escaped = false;
      continue;
    }
    if (!inSingle && !inDouble && ch === "\\") {
      escaped = true;
      buf += ch;
      continue;
    }
    if (inSingle) {
      if (ch === "'") inSingle = false;
      buf += ch;
      continue;
    }
    if (inDouble) {
      if (ch === "\\" && isDoubleQuoteEscape(next)) {
        buf += ch;
        buf += next;
        i += 1;
        continue;
      }
      if (ch === '"') {
        inDouble = false;
      }
      buf += ch;
      continue;
    }
    if (ch === "'") {
      inSingle = true;
      buf += ch;
      continue;
    }
    if (ch === '"') {
      inDouble = true;
      buf += ch;
      continue;
    }

    if (ch === "&" && command[i + 1] === "&") {
      if (!pushPart()) invalidChain = true;
      i += 1;
      foundChain = true;
      continue;
    }
    if (ch === "|" && command[i + 1] === "|") {
      if (!pushPart()) invalidChain = true;
      i += 1;
      foundChain = true;
      continue;
    }
    if (ch === ";") {
      if (!pushPart()) invalidChain = true;
      foundChain = true;
      continue;
    }

    buf += ch;
  }

  const pushedFinal = pushPart();
  if (!foundChain) return null;
  if (invalidChain || !pushedFinal) return null;
  return parts.length > 0 ? parts : null;
}

export type ExecAllowlistAnalysis = {
  analysisOk: boolean;
  allowlistSatisfied: boolean;
  allowlistMatches: ExecAllowlistEntry[];
  segments: ExecCommandSegment[];
};

/**
 * Evaluates allowlist for shell commands (including &&, ||, ;) and returns analysis metadata.
 */
export function evaluateShellAllowlist(params: {
  command: string;
  allowlist: ExecAllowlistEntry[];
  safeBins: Set<string>;
  cwd?: string;
  env?: NodeJS.ProcessEnv;
  skillBins?: Set<string>;
  autoAllowSkills?: boolean;
  platform?: string | null;
}): ExecAllowlistAnalysis {
  const chainParts = isWindowsPlatform(params.platform) ? null : splitCommandChain(params.command);
  if (!chainParts) {
    const analysis = analyzeShellCommand({
      command: params.command,
      cwd: params.cwd,
      env: params.env,
      platform: params.platform,
    });
    if (!analysis.ok) {
      return {
        analysisOk: false,
        allowlistSatisfied: false,
        allowlistMatches: [],
        segments: [],
      };
    }
    const evaluation = evaluateExecAllowlist({
      analysis,
      allowlist: params.allowlist,
      safeBins: params.safeBins,
      cwd: params.cwd,
      skillBins: params.skillBins,
      autoAllowSkills: params.autoAllowSkills,
    });
    return {
      analysisOk: true,
      allowlistSatisfied: evaluation.allowlistSatisfied,
      allowlistMatches: evaluation.allowlistMatches,
      segments: analysis.segments,
    };
  }

  const allowlistMatches: ExecAllowlistEntry[] = [];
  const segments: ExecCommandSegment[] = [];

  for (const part of chainParts) {
    const analysis = analyzeShellCommand({
      command: part,
      cwd: params.cwd,
      env: params.env,
      platform: params.platform,
    });
    if (!analysis.ok) {
      return {
        analysisOk: false,
        allowlistSatisfied: false,
        allowlistMatches: [],
        segments: [],
      };
    }

    segments.push(...analysis.segments);
    const evaluation = evaluateExecAllowlist({
      analysis,
      allowlist: params.allowlist,
      safeBins: params.safeBins,
      cwd: params.cwd,
      skillBins: params.skillBins,
      autoAllowSkills: params.autoAllowSkills,
    });
    allowlistMatches.push(...evaluation.allowlistMatches);
    if (!evaluation.allowlistSatisfied) {
      return {
        analysisOk: true,
        allowlistSatisfied: false,
        allowlistMatches,
        segments,
      };
    }
  }

  return {
    analysisOk: true,
    allowlistSatisfied: true,
    allowlistMatches,
    segments,
  };
}

export function requiresExecApproval(params: {
  ask: ExecAsk;
  security: ExecSecurity;
  analysisOk: boolean;
  allowlistSatisfied: boolean;
}): boolean {
  return (
    params.ask === "always" ||
    (params.ask === "on-miss" &&
      params.security === "allowlist" &&
      (!params.analysisOk || !params.allowlistSatisfied))
  );
}

export function recordAllowlistUse(
  approvals: ExecApprovalsFile,
  agentId: string | undefined,
  entry: ExecAllowlistEntry,
  command: string,
  resolvedPath?: string,
) {
  const target = agentId ?? DEFAULT_AGENT_ID;
  const agents = approvals.agents ?? {};
  const existing = agents[target] ?? {};
  const allowlist = Array.isArray(existing.allowlist) ? existing.allowlist : [];
  const nextAllowlist = allowlist.map((item) =>
    item.pattern === entry.pattern
      ? {
          ...item,
          id: item.id ?? crypto.randomUUID(),
          lastUsedAt: Date.now(),
          lastUsedCommand: command,
          lastResolvedPath: resolvedPath,
        }
      : item,
  );
  agents[target] = { ...existing, allowlist: nextAllowlist };
  approvals.agents = agents;
  saveExecApprovals(approvals);
}

export function addAllowlistEntry(
  approvals: ExecApprovalsFile,
  agentId: string | undefined,
  pattern: string,
) {
  const target = agentId ?? DEFAULT_AGENT_ID;
  const agents = approvals.agents ?? {};
  const existing = agents[target] ?? {};
  const allowlist = Array.isArray(existing.allowlist) ? existing.allowlist : [];
  const trimmed = pattern.trim();
  if (!trimmed) return;
  if (allowlist.some((entry) => entry.pattern === trimmed)) return;
  allowlist.push({ id: crypto.randomUUID(), pattern: trimmed, lastUsedAt: Date.now() });
  agents[target] = { ...existing, allowlist };
  approvals.agents = agents;
  saveExecApprovals(approvals);
}

export function minSecurity(a: ExecSecurity, b: ExecSecurity): ExecSecurity {
  const order: Record<ExecSecurity, number> = { deny: 0, allowlist: 1, full: 2 };
  return order[a] <= order[b] ? a : b;
}

export function maxAsk(a: ExecAsk, b: ExecAsk): ExecAsk {
  const order: Record<ExecAsk, number> = { off: 0, "on-miss": 1, always: 2 };
  return order[a] >= order[b] ? a : b;
}

export type ExecApprovalDecision = "allow-once" | "allow-always" | "deny";

export async function requestExecApprovalViaSocket(params: {
  socketPath: string;
  token: string;
  request: Record<string, unknown>;
  timeoutMs?: number;
}): Promise<ExecApprovalDecision | null> {
  const { socketPath, token, request } = params;
  if (!socketPath || !token) return null;
  const timeoutMs = params.timeoutMs ?? 15_000;
  return await new Promise((resolve) => {
    const client = new net.Socket();
    let settled = false;
    let buffer = "";
    const finish = (value: ExecApprovalDecision | null) => {
      if (settled) return;
      settled = true;
      try {
        client.destroy();
      } catch {
        // ignore
      }
      resolve(value);
    };

    const timer = setTimeout(() => finish(null), timeoutMs);
    const payload = JSON.stringify({
      type: "request",
      token,
      id: crypto.randomUUID(),
      request,
    });

    client.on("error", () => finish(null));
    client.connect(socketPath, () => {
      client.write(`${payload}\n`);
    });
    client.on("data", (data) => {
      buffer += data.toString("utf8");
      let idx = buffer.indexOf("\n");
      while (idx !== -1) {
        const line = buffer.slice(0, idx).trim();
        buffer = buffer.slice(idx + 1);
        idx = buffer.indexOf("\n");
        if (!line) continue;
        try {
          const msg = JSON.parse(line) as { type?: string; decision?: ExecApprovalDecision };
          if (msg?.type === "decision" && msg.decision) {
            clearTimeout(timer);
            finish(msg.decision);
            return;
          }
        } catch {
          // ignore
        }
      }
    });
  });
}

export * from "./exec-approvals-analysis.js";
export * from "./exec-approvals-allowlist.js";
