import { join, resolve } from 'node:path';
import { chmodSync, existsSync, mkdirSync, readFileSync, readdirSync, statSync } from 'node:fs';
import { homedir } from 'node:os';

// ── The install root, and why it is derived rather than configured ──
//
// An install is one directory with everything under it:
//
//   $OFFICER_ROOT/
//     platform/      the repo — the working directory every process runs in
//     data/          DATA_PATH
//     capabilities/  OFFICER_ITEMS_DIR
//     dockers/       what the app store provisions
//
// These were three environment variables until 2026-08-12, which meant three answers that had to agree
// with each other and with the layout on disk. They are one fact now: the root is the parent of the
// working directory, and everything else is a fixed name under it. Nothing to set and nothing to
// disagree.
//
// This depends on the working directory being the repo, which is why pm2 pins `cwd` in
// ecosystem.profile.cjs — read the comment there before changing either. `assertInstallLayout` below
// is the check that says so out loud instead of silently writing to the wrong place.
export const OFFICER_ROOT = resolve(process.cwd(), '..');

/**
 * The repo itself — the working directory, named rather than re-derived at each call site.
 *
 * Plugins live under this rather than beside it (`platform/plugins/<app-name>/`), which is the whole
 * developer story: bun links the workspace packages into the root `node_modules`, so anything inside the
 * repo can `import { useClient } from 'hooks/useClient'` with no publishing and no version negotiation.
 * A plugin one directory higher would resolve none of it.
 */
export const PLATFORM_DIR = process.cwd();

export const DATA_PATH = join(OFFICER_ROOT, 'data');

// Unified, file-based store for all agent items, living outside the repo. Every skill/tool/task/
// process/extension is a directory under one of these type subfolders — no scope tiers, no DB.
export const OFFICER_ITEMS_DIR = join(OFFICER_ROOT, 'capabilities');

/**
 * Refuse to boot when the working directory is not the platform repo.
 *
 * Same posture as `assertPermissionTotality` and `assertSecretsClosed`: a prerequisite that silently
 * not holding is worse than one that fails. Every path in this file hangs off `resolve(process.cwd(), '..')`,
 * so a process started from the wrong directory does not error — it computes a plausible root somewhere
 * else and writes managed homes, capabilities and agent runs into it. The install looks empty and the
 * data looks lost, with nothing naming the cause.
 *
 * `ecosystem.profile.cjs` already pins `cwd` for exactly this reason. This is the check that the pin
 * still works, which is the part that was missing when the ecosystem files moved directory.
 */
export function assertInstallLayout(): void {
  const manifest = join(process.cwd(), 'package.json');
  let name: string | undefined;
  try {
    name = JSON.parse(readFileSync(manifest, 'utf8')).name;
  } catch {
    // Absent or unreadable is the same answer as wrong: this is not the repo.
  }

  if (name === 'officer') return;

  throw new Error(
    [
      `Officer must run from the platform repo, but the working directory is ${process.cwd()}`,
      '',
      `  expected  a directory containing the platform's package.json ("officer")`,
      `  found     ${name ? `package.json for "${name}"` : 'no readable package.json'}`,
      '',
      'Every path is derived from this — the install root is its parent, and data/, capabilities/ and',
      `dockers/ hang off that. Continuing would write to ${OFFICER_ROOT} instead of the real install.`,
      '',
      'Under pm2 this means the `cwd` pin in ecosystem.profile.cjs no longer points at the repo.',
    ].join('\n'),
  );
}

export type ItemType = 'skills' | 'tools' | 'tasks' | 'processes' | 'extensions' | 'agents';

export const ITEM_TYPES: ItemType[] = ['skills', 'tools', 'tasks', 'processes', 'extensions', 'agents'];

export const itemsDir = (type: ItemType) => join(OFFICER_ITEMS_DIR, type);

export const ensureItemDirs = () => {
  for (const type of ITEM_TYPES) mkdirSync(itemsDir(type), { recursive: true });
};

export const SERVER_CONFIG_DIR = join(DATA_PATH, 'server-settings');

// Every run of a given agent shares one working directory. That is deliberate and load-bearing: the
// `claude` CLI groups transcripts by cwd (see api/chat/claude-sessions.ts), so a shared cwd is what
// makes an agent's runs show up as their own project group in /chat, listed newest-first, with no
// database row anywhere. The accumulated CLAUDE.md / LEARNINGS.md for the agent live here too.
export const getAgentRunsDir = (dirName: string) => join(DATA_PATH, 'agentic_runs', dirName);

// The `pi`/opencode agent's own config dir (auth.json + models.json). External-tool path.
export const AGENT_CONFIG_DIR = join(homedir(), '.pi', 'agent');

export const SEED_PATH = resolve(import.meta.dir, '../../seed');

// The managed home under DATA_PATH. A remnant of the first architecture, where every user ran inside
// their own Docker container and this was that container's home — seeded by provisioning, described to
// the agent by a generated CLAUDE.md. Both of those are gone, and the OWNER's sessions never come here
// any more — terminals, chats and task runs all use getOwnerHomeDir below.
//
// It is not dead, though: user-home.ts returns it for a NON-owner, where it is deliberately the same
// path as osUserHome, and pipeline-executor still calls it.
//
// It was also getOwnerHomeDir's fallback until 2026-08-12, which is the only reason an unset HOME_DIR
// used to run the owner's terminals in a directory nobody meant.
export const getHomeDir = (email: string) => join(DATA_PATH, email, 'home');

// Where the owner's sessions actually run: their real login home, so platform terminals/chats/tasks
// share config and credentials with the shell they use outside Officer.
//
// `homedir()` is right here for one reason, and it is worth stating because everything below rests on
// it: the server process runs AS the owner. It is not a general "whose home is this" helper — a member
// never reaches this function, because their sessions go through os-user.ts and setpriv. It ignores the
// email it is passed, which it also did before; the callers that must not are already commented as such.
//
// ── Why this is captured once, and not read per call ──
//
// Measured on bun 1.3.10: BOTH `os.homedir()` and `os.userInfo().homedir` return $HOME when it is set,
// rather than reading the password file. And `sidecar/claude/user-instance.ts` assigns `process.env.HOME`
// on its way to spawning an agent. So a lazy read here would hand back whichever home was most recently
// spawned into — the owner's on the first call and something else afterwards.
//
// This module imports nothing but node builtins, so it is evaluated before any of that can run. The
// value is the owner's home, taken while $HOME still means what it says.
const OWNER_HOME = homedir();

// This was HOME_DIR in .env until 2026-08-12, whose absence fell back to getHomeDir — the managed home
// under DATA_PATH, not a login home at all. So forgetting to set it did not fail; it quietly ran every
// terminal somewhere else.
export const getOwnerHomeDir = (_email: string): string => OWNER_HOME;

// The directory skeleton a new account gets under DATA_PATH.
//
// Most of these are also created on demand by whichever feature owns them, so pre-creating them buys
// legibility more than function — the tree shows what an account has without it having to be used first.
// `home` is the exception and the reason this exists: nothing else creates it, and it is where a
// non-owner's sessions would run.
//
// Single-sourced here rather than in the script that used to own the list, because there are now two
// callers — `scripts/provision-user-dirs.ts` and the owner's create-account handler — and a skeleton
// that differs depending on how the account was made is a bug nobody would think to look for.
export const USER_DIRS = ['home', 'attachments', 'cache', 'dashboards', 'email_accounts', 'logs', 'sidecar'] as const;

/**
 * Create an account's root and its skeleton, closed by default.
 *
 * Keyed on email because that is what the on-disk layout uses everywhere else (`DATA_PATH/<email>/…`).
 * Renaming an account's email would orphan its directory; that is pre-existing and not this function's
 * problem, but it is the reason nothing here derives a path from the id.
 *
 * ── Why the modes are set here and not only by os-user.ts ──
 *
 * `711` on the account directory, `700` on everything inside it. Measured while testing per-user Linux
 * accounts: at the default umask these came out `755`, and a member with a shell could read ANOTHER
 * member's home directory just by naming it — the parent being unlistable is not protection when the
 * child itself is world-readable. "Locked unless something opens it" has to be the resting state, so it
 * belongs at creation rather than in the confinement pass, which only ever runs for accounts that have an
 * OS user.
 *
 * `chmod` explicitly rather than mkdir's `mode`, which is masked by the umask and does nothing at all for
 * a directory that already exists.
 */
export const provisionUserDirs = (email: string): void => {
  const accountDir = join(DATA_PATH, email);
  for (const dir of USER_DIRS) mkdirSync(join(accountDir, dir), { recursive: true });
  // Traversable, not listable: reaching `home` must not mean enumerating the platform's tree beside it.
  chmodSync(accountDir, 0o711);

  for (const dir of USER_DIRS) {
    try {
      chmodSync(join(accountDir, dir), 0o700);
    } catch {
      // A directory that is no longer OURS to chmod. `home` becomes the member's on the first successful
      // provision, and `chmod` requires ownership — so re-running this threw EPERM and took every RETRY down
      // before it began, which is how this was found. os-user.ts sets the home's mode through sudo and is the
      // authority for it; here the mode is a default for directories we are creating, not an assertion about
      // ones that already exist.
    }
  }
};

export const getTmpAttachmentsDir = (email: string) => join(DATA_PATH, email, 'attachments', 'tmp');

export const getAttachmentsDir = (email: string, sessionId: string) => join(DATA_PATH, email, 'attachments', sessionId);

// Per-account email storage: DATA_PATH/<owner>/email_accounts/<accountEmail>/emails.db, with a
// single attachment_cache/ shared across the owner's accounts.
export const getEmailAccountsDir = (ownerEmail: string) => join(DATA_PATH, ownerEmail, 'email_accounts');
export const getEmailDbPath = (ownerEmail: string, accountEmail: string) =>
  join(getEmailAccountsDir(ownerEmail), accountEmail, 'emails.db');
export const getEmailAttachmentCacheDir = (ownerEmail: string) =>
  join(getEmailAccountsDir(ownerEmail), 'attachment_cache');

/**
 * Every commander a user has shares this ONE directory as its cwd — deliberately not one directory per
 * commander. The first design was per-commander, and was dropped the same night it was proposed: a fresh
 * directory would have to exist before or exactly when a commander's first turn fires, and racing that
 * creation against the harness's own spawn is precisely the kind of timing hazard Claude Code's
 * directory-per-project convention was never built to be driven by. One shared, pre-existing directory
 * removes the race instead of handling it.
 *
 * `DATA_PATH`-rooted even for the OWNER, which is a deliberate departure from ordinary `/chat` — an owner's
 * normal chat runs in `getOwnerHomeDir` (their real login home). Commanders use the managed directory
 * instead, on both sides of the account split, which is what keeps them out of the owner's own project
 * transcripts as surely as `command_hq_sessions` keeps them out of the `/chat` list. See `docs/command-hq.md`.
 *
 * **A sibling of `home`, but reachable like `home` — not confined like every other sibling.** Every other
 * directory alongside a member's `home` (`attachments`, `email_accounts`, …) is 700 and owned by the
 * SERVICE user, unreachable by the member "even by name" — correct for platform-written data, and exactly
 * wrong for a directory a member's own `claude` must `cd` into via `setpriv`. `confineUserTree`
 * (`os-user.ts`) chowns this one to the member the same way it chowns `home`. An account provisioned
 * BEFORE this existed will not have that chown until it is re-provisioned once — see `docs/command-hq.md`.
 */
export const getCommandersDir = (email: string) => join(DATA_PATH, email, 'commanders');

/**
 * Which mail account's store to use, found on DISK rather than by asking the database.
 *
 * Email is a plugin (`plugins/email/`) as of 2026-08-18, and the platform may not import a plugin's
 * queries — that direction is the one the plugin system forbids, and here it is also the direction that has
 * already broken this server: `getEmailAccounts` was awaited at the top level of the agent sidecar, and
 * when the table went away on 2026-08-13 the rejection took `officer-agent` into a PM2 restart loop with
 * every live chat session inside it (`fbb6d6c7`).
 *
 * Two callers still legitimately need an answer — the agent's `email_db` MCP tool, and a chat opened
 * against a mailbox — and neither needs to know anything about mail to get one. The directory layout is
 * already the platform's (see `USER_DIRS`), so reading it answers the question with no coupling: no import,
 * no query, and nothing to throw if the plugin is not installed.
 *
 * Newest by mtime, because the most recently synced account is the one a fresh question is most likely
 * about. Returns the DIRECTORY NAME (the account's address), which is what both callers compose with.
 */
export function findEmailAccountName(ownerEmail: string): string | null {
  try {
    const root = getEmailAccountsDir(ownerEmail);
    const candidates = readdirSync(root, { withFileTypes: true })
      .filter((entry) => entry.isDirectory() && entry.name !== 'attachment_cache')
      .map((entry) => ({ name: entry.name, db: join(root, entry.name, 'emails.db') }))
      .filter((candidate) => existsSync(candidate.db))
      .map((candidate) => ({ ...candidate, at: statSync(candidate.db).mtimeMs }))
      .sort((a, b) => b.at - a.at);
    return candidates[0]?.name ?? null;
  } catch {
    // No directory, no permission, no plugin. All of them mean "no account", which is a normal state.
    return null;
  }
}

// Sanitises a display username or email into a bare, lowercase, shell-safe token. The name and the
// 32-char Linux limit are the last trace of the per-container architecture, where this really did name
// a Linux user inside the user's container. Nothing creates a Linux user now — the value is carried
// through the websocket/job payloads and ends up only as a claim inside the signed task token, so this
// is a sanitiser rather than an account name. Left in place because unpicking it means changing what
// goes into that token and into WSData, which is a wider change than a cleanup.
export const toShellUsername = (username: string, email: string): string => {
  const raw = username || email.split('@')[0]!;
  // Replace invalid chars, lowercase, truncate to 32 chars
  return (
    raw
      .replace(/@.*$/, '')
      .replace(/[^a-zA-Z0-9._-]/g, '_')
      .toLowerCase()
      .slice(0, 32) || 'officer'
  );
};