import { existsSync } from 'node:fs';
import { PLATFORM_DIR } from './data-path';
import { readEcosystemApps, addCoreProcess, type Pm2App } from './plugins/ecosystem';
import { detectPackageManager, installCommand, manualInstallHint, sudoAvailable } from './plugins/os-deps';

// Bringing an EXISTING server up to the 2026-08-19 layout, where calendar and contacts are core.
//
// A fresh install needs none of this: `officer-setup` writes officer-caldav into the ecosystem from
// CORE_PROCESSES, and machine-setup installs `radicale` with the other packages. But a server set up
// before today has neither, and `git pull` changes no state outside the repository — so without this a
// pull would leave `/calendar` mounted, working, and talking to nothing, which is precisely the silent
// half-working failure this codebase keeps being bitten by.
//
// ── Why it does not block the boot ──
//
// Everything here is best-effort and runs AFTER `serve()`. A package manager holding a lock, an
// unreachable mirror or a machine with no passwordless sudo must not stop Officer from starting. The
// worst outcome is that calendar does not work and the log says why, which is the same outcome as doing
// nothing — only louder.

const RADICALE_ENTRY: Pm2App = {
  name: 'officer-caldav',
  script: 'bun',
  args: 'run src/servers/sidecar/caldav/index.ts',
  cwd: PLATFORM_DIR,
  watch: false,
};

/** Is Radicale on PATH? The sidecar spawns it by bare name, so this is the same question it will ask. */
export function radicaleInstalled(): boolean {
  return Bun.which('radicale') !== null;
}

/**
 * Add `officer-caldav` to the ecosystem file if a pre-2026-08-19 install lacks it.
 *
 * Returns true when it wrote. PM2 still has to be told — `pm2 start ecosystem.config.cjs
 * --only officer-caldav` — because this process cannot restart its own supervisor's view of the file.
 */
export function ensureCaldavProcess(): boolean {
  const apps = readEcosystemApps();
  if (apps.some((a) => a.name === RADICALE_ENTRY.name)) return false;
  addCoreProcess(RADICALE_ENTRY);
  return true;
}

/**
 * Install Radicale when it is missing and the platform is allowed to.
 *
 * `sudo -n` only, never a prompt: this runs unattended under PM2, where a password prompt is not a slow
 * path but a hang. When it cannot, it prints the exact command for a person to run rather than failing
 * silently — the whole point is that the operator finds out from the log rather than from a phone that
 * stopped syncing.
 */
export async function ensureRadicale(): Promise<'present' | 'installed' | 'blocked' | 'failed'> {
  if (radicaleInstalled()) return 'present';

  const manager = detectPackageManager();
  if (!manager || (manager !== 'brew' && !sudoAvailable())) {
    const hint = manualInstallHint(manager, ['radicale']);
    console.warn(
      `[caldav] radicale is not installed and the platform cannot install it` +
        `${manager ? '' : ' (no supported package manager found)'}.` +
        `${hint ? ` Run: ${hint}` : ''}`,
    );
    return 'blocked';
  }

  console.log('[caldav] radicale missing — installing');
  const argv = installCommand(manager, ['radicale']);
  try {
    const proc = Bun.spawn(argv, { stdout: 'pipe', stderr: 'pipe' });
    const code = await proc.exited;
    if (code !== 0 || !radicaleInstalled()) {
      const err = await new Response(proc.stderr).text();
      console.error(`[caldav] radicale install failed (exit ${code}): ${err.trim().split('\n').slice(-3).join(' ')}`);
      return 'failed';
    }
  } catch (err) {
    console.error(`[caldav] radicale install failed: ${err instanceof Error ? err.message : err}`);
    return 'failed';
  }
  console.log('[caldav] radicale installed');
  return 'installed';
}

/** Both halves, in the order that makes the log read sensibly. Never throws. */
export async function bootstrapCaldav(): Promise<void> {
  try {
    if (ensureCaldavProcess()) {
      console.log('[caldav] added officer-caldav to the ecosystem — run `pm2 start ecosystem.config.cjs`');
    }
    await ensureRadicale();
  } catch (err) {
    console.error('[caldav] bootstrap skipped —', err instanceof Error ? err.message : err);
  }
}

/** Exported for the test, which must not depend on this machine having an ecosystem file. */
export const _ecosystemPathExists = (): boolean => existsSync(`${PLATFORM_DIR}/ecosystem.config.cjs`);