import { createRouter } from '../../create-router';
import { rebuildFrontend } from '../../plugins/generate';
import { isKnownToPm2, restartProcess } from '../../app-store/pm2';
import { fixEnvFile } from '../../env-prefix';
import { PLATFORM_DIR } from '../../data-path';
import { readdirSync, existsSync } from 'node:fs';
import { join } from 'node:path';
import { readServerSettings, writeServerSettings } from 'officerdb';
import { chatProvidersRouter } from './chat-providers';
import { smtpRouter } from './smtp';
import { ttsRouter } from './tts';
import { ocrRouter } from './ocr';

export const serverSettingsRouter = createRouter();

serverSettingsRouter.route('/chat-providers', chatProvidersRouter);
serverSettingsRouter.route('/smtp', smtpRouter);
serverSettingsRouter.route('/tts', ttsRouter);
serverSettingsRouter.route('/ocr', ocrRouter);

export { readServerSettings as readSettings };

/**
 * Rebuild the SPA from source, without restarting anything.
 *
 * This is the same `rebuildFrontend` a plugin install runs, exposed as a button. It works — and it is
 * worth being precise about WHY, because its neighbour below does not:
 *
 * `Bun.build` reads the source from disk on every call and writes `build/`, and the server serves that
 * directory by reading each file per request. So a rebuild is visible on the next page load with no
 * process restart, no dropped websocket, and no chat session lost.
 *
 * Frontend changes only. Nothing here can pick up an edit to server code — see `/restart`.
 */
serverSettingsRouter.post('/rebuild-frontend', async (ctx) => {
  const result = await rebuildFrontend();
  if (!result.ok) return ctx.json({ ok: false, error: result.error }, 500);
  return ctx.json({ ok: true, ms: result.ms, outputs: result.outputs });
});

/**
 * Pull the platform's own repository.
 *
 * The button that was missing between the two below: `/rebuild-frontend` compiles what is on disk and
 * `/restart` reloads it, but neither CHANGES what is on disk. Doing that meant a terminal, on every
 * server, every time.
 *
 * ── What it refuses, and why ──
 *
 * A dirty tree, and a non-fast-forward. Same two refusals as `pullPlugin`, for the same reason: this
 * checkout is somebody's working copy on at least one machine, and a button that discards uncommitted
 * work is worse than a button that does not exist. `--ff-only` so a divergence is reported rather than
 * merged by a machine.
 *
 * ── What it does NOT do ──
 *
 * It does not rebuild, restart, install dependencies or push the schema. Those are separate buttons and
 * separate decisions — `bun install` after a lockfile change is a supply-chain moment the frozen-lockfile
 * rule exists to make deliberate, and `db:push` alters a live database. So this REPORTS when the pull
 * touched `package.json`, `bun.lock` or a schema file, and leaves the choice with whoever pressed it.
 */
serverSettingsRouter.post('/pull', async (ctx) => {
  const git = async (args: string[]) => {
    const proc = Bun.spawn(['git', ...args], { cwd: PLATFORM_DIR, stdout: 'pipe', stderr: 'pipe' });
    const [out, err] = await Promise.all([new Response(proc.stdout).text(), new Response(proc.stderr).text()]);
    return { code: await proc.exited, out: out.trim(), err: err.trim() };
  };

  const dirty = await git(['status', '--porcelain']);
  if (dirty.out) {
    const files = dirty.out.split('\n').length;
    return ctx.json(
      {
        ok: false,
        error: `${files} uncommitted change(s) — commit or discard them first, refusing to overwrite local work`,
      },
      400,
    );
  }

  const before = (await git(['rev-parse', 'HEAD'])).out;

  // `origin HEAD`, not a branch name: a checkout made before the default branch was renamed is on one
  // the remote no longer has, and `git pull origin <local-name>` fails on exactly the installs that most
  // need updating. Learned in `plugins/update.ts`; the same trap applies here.
  const fetched = await git(['fetch', 'origin', 'HEAD']);
  if (fetched.code !== 0) return ctx.json({ ok: false, error: fetched.err || 'git fetch failed' }, 500);

  const merged = await git(['merge', '--ff-only', 'FETCH_HEAD']);
  if (merged.code !== 0) {
    return ctx.json(
      { ok: false, error: merged.err || merged.out || 'not a fast-forward — this checkout has diverged' },
      409,
    );
  }

  const after = (await git(['rev-parse', 'HEAD'])).out;
  if (before === after) return ctx.json({ ok: true, updated: false, commits: [], needs: [] });

  const log = await git(['log', '--oneline', '--no-decorate', `${before}..${after}`]);
  const changed = (await git(['diff', '--name-only', `${before}..${after}`])).out.split('\n');

  // What the pull implies but must not do on its own.
  const needs: string[] = [];
  if (changed.some((f) => f === 'package.json' || f === 'bun.lock')) needs.push('bun install');
  if (changed.some((f) => f.includes('/schema.ts') || f.endsWith('drizzle-schema.ts'))) needs.push('bun db:push');
  if (changed.some((f) => f.startsWith('src/servers/') || f.startsWith('src/databases/'))) needs.push('restart');
  else if (changed.some((f) => f.startsWith('src/'))) needs.push('rebuild-frontend');

  return ctx.json({
    ok: true,
    updated: true,
    from: before.slice(0, 7),
    to: after.slice(0, 7),
    commits: log.out ? log.out.split('\n') : [],
    files: changed.length,
    needs,
  });
});

/**
 * Restart the platform process. The only way to load changed SERVER code.
 *
 * ── Why there is no gentler option ──
 *
 * Bun caches modules for the life of the process. Measured rather than assumed: editing a file and
 * re-importing it returns the ORIGINAL export, and a cache-busting query picks up only that one
 * specifier while everything it imports stays cached. Rebuilding the Hono app — which install already
 * does — therefore re-wires the same module instances into a new router tree and cannot see an edit.
 *
 * Busting the whole graph would not be a fix either: singletons would be duplicated, giving two database
 * clients and two in-memory session maps in one process.
 *
 * So this is honest about what it costs. Websockets drop, in-memory chat sessions are lost, and the
 * browser must reconnect. It saves a terminal, not a reconnection.
 *
 * The response is sent BEFORE the restart is scheduled, or the caller would never learn it worked: the
 * process serving this request is the one about to be replaced.
 */
serverSettingsRouter.post('/restart', async (ctx) => {
  // Refuse when PM2 does not know this process, rather than reporting a restart that cannot happen. In
  // development the platform runs under `bun --watch`, where `pm2 restart officer` would exit non-zero
  // into a promise nobody awaits — and the button would say it worked.
  if (!(await isKnownToPm2('officer', PLATFORM_DIR))) {
    return ctx.json({ ok: false, error: 'not running under PM2 — restart it the way you started it' }, 400);
  }

  // Convert `.env` to the `OFFICERDEV_` prefix on the way past.
  //
  // Here rather than at boot, because a restart is the one moment the file can be rewritten and the
  // change take effect in the same breath — the process about to start is the one that reads it. Doing
  // it at boot would rewrite a file the running process had already loaded.
  //
  // Idempotent and non-fatal: an already-converted file is not even written, and a failure must not stop
  // a restart the owner asked for. Every consumer still reads the unprefixed name as a fallback, so the
  // worst case is that nothing changed.
  let envFixed: string[] = [];
  try {
    envFixed = fixEnvFile(join(PLATFORM_DIR, '.env')).changed;
    if (envFixed.length) console.log(`[env] prefixed on restart: ${envFixed.join(', ')}`);
  } catch (err) {
    console.error('[env] could not prefix .env —', err instanceof Error ? err.message : err);
  }

  setTimeout(() => {
    void restartProcess('officer', PLATFORM_DIR);
  }, 250);
  return ctx.json({ ok: true, restartingIn: 250, envFixed });
});

serverSettingsRouter.get('/settings', async (ctx) => {
  return ctx.json(await readServerSettings());
});

serverSettingsRouter.put('/', async (ctx) => {
  const body = await ctx.req.json();
  const settings = await readServerSettings();
  const updated = { ...settings, ...body };
  await writeServerSettings(updated);
  return ctx.json(updated);
});

serverSettingsRouter.get('/plugins', async (ctx) => {
  const pluginsDir = join(import.meta.dir, '../../../workspaces/plugins');
  const settings = await readServerSettings();
  const pluginSettings: Record<string, boolean> = (settings.plugins as Record<string, boolean>) ?? {};

  const plugins: { id: string; name: string; description: string; enabled: boolean }[] = [];

  if (!existsSync(pluginsDir)) return ctx.json(plugins);

  const dirs = readdirSync(pluginsDir, { withFileTypes: true }).filter((d) => d.isDirectory());

  for (const dir of dirs) {
    const hasServer = existsSync(join(pluginsDir, dir.name, 'server', 'index.ts'));
    const hasClient = existsSync(join(pluginsDir, dir.name, 'client', 'index.ts'));
    if (!hasServer && !hasClient) continue;

    const mainIndex = join(pluginsDir, dir.name, 'index.ts');
    if (!existsSync(mainIndex)) continue;

    const mod = await import(mainIndex);
    const meta = mod.plugin ?? { id: dir.name, name: dir.name, description: '' };
    plugins.push({
      id: meta.id,
      name: meta.name,
      description: meta.description,
      enabled: pluginSettings[meta.id] !== false,
    });
  }

  return ctx.json(plugins);
});