#!/usr/bin/env node
/**
 * audit-scope.mjs — compare workspace changes against the .swarm ownership map.
 *
 * Usage:
 *   node scripts/audit-scope.mjs --init [--root <dir>]
 *   node scripts/audit-scope.mjs [--root <dir>] [--json]
 *
 * --init writes .swarm/baseline.json (run before the first worker starts).
 * The audit lists every changed path with its owning task(s) and fails when a
 * path is unowned or owned by more than one task.
 *
 * Exit codes: 0 clean, 1 violations, 2 usage or I/O error.
 */

import { createHash } from "node:crypto";
import {
  existsSync,
  mkdirSync,
  readFileSync,
  readdirSync,
  statSync,
  writeFileSync
} from "node:fs";
import { join, relative, resolve, sep } from "node:path";

const IGNORED_DIRS = new Set([
  ".git",
  ".swarm",
  "node_modules",
  "dist",
  "build",
  ".next",
  ".nuxt",
  ".venv",
  "venv",
  "__pycache__",
  ".cache",
  "target",
  "coverage",
  ".idea",
  ".vscode"
]);

const HASH_LIMIT = 512 * 1024;

function parseArgs(argv) {
  const opts = { init: false, json: false, root: process.cwd() };
  for (let i = 0; i < argv.length; i++) {
    const arg = argv[i];
    if (arg === "--init") opts.init = true;
    else if (arg === "--json") opts.json = true;
    else if (arg === "--root") {
      const value = argv[++i];
      if (!value) throw new Error("--root requires a directory");
      opts.root = resolve(value);
    } else if (arg === "-h" || arg === "--help") {
      console.log("Usage: node audit-scope.mjs [--init] [--root <dir>] [--json]");
      process.exit(0);
    } else {
      throw new Error(`unknown argument: ${arg}`);
    }
  }
  if (!existsSync(opts.root) || !statSync(opts.root).isDirectory()) {
    throw new Error(`root is not a directory: ${opts.root}`);
  }
  return opts;
}

function walk(dir, base, out) {
  for (const entry of readdirSync(dir, { withFileTypes: true })) {
    if (entry.isDirectory()) {
      if (IGNORED_DIRS.has(entry.name)) continue;
      walk(join(dir, entry.name), base, out);
    } else if (entry.isFile()) {
      const full = join(dir, entry.name);
      const st = statSync(full);
      const path = relative(base, full).split(sep).join("/");
      const record = { size: st.size, mtime: Math.round(st.mtimeMs) };
      if (st.size <= HASH_LIMIT) {
        record.hash = createHash("sha1").update(readFileSync(full)).digest("hex").slice(0, 16);
      }
      out[path] = record;
    }
  }
}

function snapshot(root) {
  const files = {};
  walk(root, root, files);
  return { version: 1, createdAt: new Date().toISOString(), files };
}

function same(a, b) {
  if (!a || !b) return false;
  if (a.hash && b.hash) return a.hash === b.hash && a.size === b.size;
  return a.size === b.size && a.mtime === b.mtime;
}

function globToRegExp(glob) {
  let out = "^";
  for (let i = 0; i < glob.length; i++) {
    const c = glob[i];
    if (c === "*") {
      if (glob[i + 1] === "*") {
        i++;
        if (glob[i + 1] === "/") {
          i++;
          out += "(?:[^/]+/)*";
        } else {
          out += ".*";
        }
      } else {
        out += "[^/]*";
      }
    } else if (c === "?") {
      out += "[^/]";
    } else {
      out += c.replace(/[.+^${}()|[\]\\]/g, "\\$&");
    }
  }
  return new RegExp(out + "$");
}

function normalizeGlobs(task, root) {
  const globs = Array.isArray(task.write) ? task.write : [];
  return globs
    .map((raw) => {
      let glob = String(raw).trim().replace(/^\.\//, "");
      if (!glob) return null;
      const abs = resolve(root, glob);
      const isDir = !/[*?[]/.test(glob) && existsSync(abs) && statSync(abs).isDirectory();
      if (isDir) glob = glob.replace(/\/+$/, "") + "/**";
      return { raw, re: globToRegExp(glob) };
    })
    .filter(Boolean);
}

function main() {
  const opts = parseArgs(process.argv.slice(2));
  const root = opts.root;
  const swarmDir = join(root, ".swarm");
  const baselinePath = join(swarmDir, "baseline.json");
  const planPath = join(swarmDir, "plan.json");

  if (opts.init) {
    mkdirSync(swarmDir, { recursive: true });
    const snap = snapshot(root);
    writeFileSync(baselinePath, JSON.stringify(snap, null, 2) + "\n");
    console.log(
      `baseline: ${Object.keys(snap.files).length} files -> ${relative(root, baselinePath) || baselinePath}`
    );
    return 0;
  }

  if (!existsSync(baselinePath)) {
    throw new Error(`missing ${baselinePath}; run with --init before the swarm starts`);
  }
  if (!existsSync(planPath)) {
    throw new Error(`missing ${planPath}; the plan gate must pass before auditing`);
  }

  const baseline = JSON.parse(readFileSync(baselinePath, "utf8"));
  const plan = JSON.parse(readFileSync(planPath, "utf8"));
  const current = snapshot(root);
  const tasks = (plan.tasks || []).map((task) => ({
    id: task.id,
    globs: normalizeGlobs(task, root)
  }));

  const changed = [];
  for (const [path, record] of Object.entries(current.files)) {
    if (!same(record, baseline.files[path])) changed.push({ path, deleted: false });
  }
  for (const path of Object.keys(baseline.files)) {
    if (!(path in current.files)) changed.push({ path, deleted: true });
  }
  changed.sort((a, b) => a.path.localeCompare(b.path));

  const rows = changed.map(({ path, deleted }) => {
    const owners = tasks
      .filter((task) => task.globs.some((glob) => glob.re.test(path)))
      .map((task) => task.id);
    const status = owners.length === 0 ? "unowned" : owners.length > 1 ? "conflict" : "ok";
    return { path, deleted, owners, status };
  });

  const summary = {
    changed: rows.length,
    ok: rows.filter((row) => row.status === "ok").length,
    unowned: rows.filter((row) => row.status === "unowned").length,
    conflict: rows.filter((row) => row.status === "conflict").length
  };

  if (opts.json) {
    console.log(JSON.stringify({ summary, changes: rows }, null, 2));
  } else {
    console.log(
      `changed: ${summary.changed} | ok: ${summary.ok} | unowned: ${summary.unowned} | conflict: ${summary.conflict}`
    );
    for (const row of rows) {
      const mark = row.status === "ok" ? "ok  " : row.status === "unowned" ? "BAD " : "CONF";
      const owners = row.owners.length ? row.owners.join(", ") : "-";
      console.log(`  ${mark} ${row.path}${row.deleted ? " [deleted]" : ""}  ${owners}`);
    }
  }

  return summary.unowned + summary.conflict > 0 ? 1 : 0;
}

try {
  process.exitCode = main();
} catch (error) {
  console.error(`audit-scope: ${error instanceof Error ? error.message : String(error)}`);
  process.exitCode = 2;
}