#!/usr/bin/env node
// Compatibility adapter for preserved specialist modules.
// config.json is the only writable config authority. A legacy config.yaml may
// be read as a migration fallback, but this command never writes YAML.

import fs from "node:fs/promises";
import os from "node:os";
import path from "node:path";
import { createHash } from "node:crypto";
import { spawnSync } from "node:child_process";
import { fileURLToPath } from "node:url";
import {
  configGet,
  configSet,
  ensureConfig,
  loadConfig,
  parseConfigValue,
  readLegacyConfig,
} from "../runtime/config.js";
import { ensureManagedHome, withRuntimeLifecycleLock } from "../runtime/managed-home.js";

const scriptDir = path.dirname(fileURLToPath(import.meta.url));
const env = process.env.GSTACK_HOME
  ? process.env
  : process.env.GSTACK_STATE_ROOT
    ? { ...process.env, GSTACK_HOME: process.env.GSTACK_STATE_ROOT }
    : process.env.GSTACK_STATE_DIR
      ? { ...process.env, GSTACK_HOME: process.env.GSTACK_STATE_DIR }
      : process.env;
const home = path.resolve(env.GSTACK_HOME || path.join(os.homedir(), ".gstack"));
const legacyConfig = path.join(home, "config.yaml");
const defaults = Object.freeze({
  proactive: true,
  routing_declined: false,
  telemetry: "off",
  auto_upgrade: false,
  // Skill installation and update discovery belong to the Agent Skills CLI.
  // GStack never performs a passive network update check by default.
  update_check: false,
  skill_prefix: false,
  checkpoint_mode: "explicit",
  checkpoint_push: false,
  explain_level: "default",
  codex_reviews: "enabled",
  gstack_contributor: false,
  skip_eng_review: false,
  workspace_root: path.join(os.homedir(), "conductor", "workspaces"),
  cross_project_learnings: "",
  artifacts_sync_mode: "off",
  artifacts_sync_mode_prompted: false,
  plan_tune_hooks: "prompt",
  redact_repo_visibility: "",
  redact_prepush_hook: false,
  salience_allowlist: "",
});

const [command, ...args] = process.argv.slice(2);

try {
  switch (command) {
    case "get":
      await getCommand(args);
      break;
    case "set":
      await setCommand(args);
      break;
    case "list":
      await listCommand();
      break;
    case "defaults":
      printEntries(defaults);
      break;
    case "endpoint-hash":
      process.stdout.write(endpointHash());
      break;
    case "resolve-user-slug":
      await resolveUserSlug();
      break;
    case "gbrain-refresh":
      await refreshGbrainDetection();
      break;
    default:
      usage();
      process.exitCode = 1;
  }
} catch (error) {
  process.stderr.write(`gstack-config: ${error?.message ?? error}\n`);
  process.exitCode = 1;
}

async function getCommand(args) {
  if (args.length !== 1) throw new Error("Usage: gstack-config get <key>");
  const key = validateKey(args[0]);
  let value;
  if (await exists(path.join(home, "config.json"))) value = await configGet(home, key);
  if (value === undefined && await exists(legacyConfig)) value = await readLegacyValue(key);
  if (value === undefined) value = defaultFor(key);
  process.stdout.write(formatValue(value));
}

async function setCommand(args) {
  if (args.length !== 2) throw new Error("Usage: gstack-config set <key> <value>");
  const key = validateKey(args[0]);
  const raw = validateClosedValue(key, args[1]);
  await mutateConfigHome(() => configSet(home, key, parseConfigValue(raw)));
}

async function listCommand() {
  const stored = await exists(path.join(home, "config.json"))
    ? await loadConfig(home)
    : await readLegacyConfig(home);
  const flattened = { ...defaults, ...flatten(stored) };
  printEntries(flattened);
}

function defaultFor(key) {
  if (/^brain_trust_policy(?:@|$)/.test(key)) return "unset";
  return Object.hasOwn(defaults, key) ? defaults[key] : "";
}

function validateKey(key) {
  if (typeof key !== "string" || !/^[a-zA-Z0-9_]+(?:@[a-f0-9]+)?$/.test(key)) {
    throw new Error("key must contain only alphanumeric characters, underscores, and an optional @<hex-hash> suffix");
  }
  return key;
}

function validateClosedValue(key, value) {
  const domains = [
    [/^brain_trust_policy(?:@|$)/, ["personal", "shared", "unset"], "unset"],
    [/^explain_level$/, ["default", "terse"], "default"],
    [/^artifacts_sync_mode$/, ["off", "artifacts-only", "full"], "off"],
    [/^redact_repo_visibility$/, ["public", "private", "unknown"], "unknown"],
    [/^redact_prepush_hook$/, ["true", "false"], "false"],
    [/^plan_tune_hooks$/, ["prompt", "yes", "no"], "prompt"],
  ];
  if (key === "codex_reviews" && !["enabled", "disabled"].includes(value)) {
    throw new Error(`codex_reviews '${value}' not recognized. Valid values: enabled, disabled. Existing value left unchanged.`);
  }
  for (const [pattern, allowed, fallback] of domains) {
    if (pattern.test(key) && !allowed.includes(value)) {
      process.stderr.write(`Warning: ${key} '${value}' not recognized. Valid values: ${allowed.join(", ")}. Using ${fallback}.\n`);
      return fallback;
    }
  }
  return value;
}

async function readLegacyValue(key) {
  const content = await fs.readFile(legacyConfig, "utf8");
  let found;
  for (const line of content.split(/\r?\n/)) {
    const match = line.match(/^([A-Za-z0-9_]+(?:@[a-f0-9]+)?):\s*(.*?)\s*(?:#.*)?$/);
    if (match?.[1] === key) found = parseConfigValue(unquote(match[2]));
  }
  return found;
}

function unquote(value) {
  if (value.length >= 2 && ((value.startsWith('"') && value.endsWith('"')) ||
      (value.startsWith("'") && value.endsWith("'")))) return value.slice(1, -1);
  return value;
}

function endpointHash() {
  const endpoint = env.GSTACK_GBRAIN_ENDPOINT || env.GBRAIN_URL || "";
  return endpoint ? createHash("sha256").update(endpoint).digest("hex").slice(0, 8) : "local";
}

async function resolveUserSlug() {
  const key = `user_slug_at_${endpointHash()}`;
  if (await exists(path.join(home, "config.json"))) {
    const stored = await configGet(home, key);
    if (typeof stored === "string" && stored) {
      process.stdout.write(stored);
      return;
    }
  }
  const user = sanitizeSlug(env.USER || "");
  const email = spawnSync("git", ["config", "user.email"], { encoding: "utf8" }).stdout?.trim();
  const fallback = email
    ? `email-${sha8(email)}`
    : `anonymous-${sha8(os.hostname() || "unknown")}`;
  const slug = user || fallback;
  await mutateConfigHome(() => configSet(home, key, slug));
  process.stdout.write(slug);
}

async function refreshGbrainDetection() {
  await mutateConfigHome(async () => {
    const detector = path.join(scriptDir, "gstack-gbrain-detect");
    const result = spawnSync(detector, [], { encoding: "utf8", env });
    const payload = result.status === 0 && result.stdout.trim()
      ? result.stdout.trim()
      : '{"gbrain_on_path":false,"gbrain_local_status":"no-cli"}';
    JSON.parse(payload);
    const target = path.join(home, "gbrain-detection.json");
    const temporary = `${target}.tmp-${process.pid}`;
    await fs.writeFile(temporary, `${payload}\n`, { mode: 0o600 });
    await fs.rename(temporary, target);
  });
  process.stdout.write("GBrain detection refreshed. Re-run the standard Agent Skills installer if skill content must change.\n");
}

async function mutateConfigHome(callback) {
  return withRuntimeLifecycleLock(home, async () => {
    await ensureManagedHome(home);
    await ensureConfig(home);
    return callback();
  });
}

function sanitizeSlug(value) {
  return value.toLowerCase().replace(/\s+/g, "-").replace(/[^a-z0-9-]/g, "");
}

function sha8(value) {
  return createHash("sha256").update(value).digest("hex").slice(0, 8);
}

function flatten(value, prefix = "", output = {}) {
  for (const [key, child] of Object.entries(value ?? {})) {
    const name = prefix ? `${prefix}.${key}` : key;
    if (child && typeof child === "object" && !Array.isArray(child)) flatten(child, name, output);
    else output[name] = child;
  }
  return output;
}

function printEntries(entries) {
  for (const key of Object.keys(entries).sort()) {
    process.stdout.write(`${key}: ${formatValue(entries[key])}\n`);
  }
}

function formatValue(value) {
  if (value === undefined || value === null) return "";
  return typeof value === "string" ? value : JSON.stringify(value);
}

async function exists(target) {
  return fs.lstat(target).then(() => true, (error) => {
    if (error?.code === "ENOENT") return false;
    throw error;
  });
}

function usage() {
  process.stderr.write("Usage: gstack-config {get|set|list|defaults|endpoint-hash|resolve-user-slug|gbrain-refresh} [key] [value]\n");
}