import type { Context } from 'hono';
import { createRouter, type HonoVariables } from '@@/create-router';
import { registerProxiedPrefix } from '@@/sidecar/proxied-prefixes';
import { deleteConnection, readConnection, readCredentials, recordProbe, saveConnection } from './connection';
import { readSettings, saveRootPath } from './settings';
import { readWebsiteStatus, cloneWebsite, updateWebsite } from './website';
import { readMediaStatus, createMediaDir } from './media';
import { readSync, startSync } from './sync';
import { readRuns } from './ledger';
import { reconcile } from './derive';
import { createDatabases, pushSchema, readDatabases } from './databases';
import { readBackups, restoreBackup, runBackup, saveBackups, schedule, testDestination } from './backups';
import { watchMailbox } from './messages';
import { join } from 'node:path';
import { fofosRequest, FofosError, probe, type FofosResponse } from './fofos-client';

/**
 * Mounted at `/api/fofos-admin`.
 *
 * ── Mostly a pass-through, and that is the design ──
 *
 * fofos's `/api/admin` is already the right shape for a panel: every route answers `{ data: … }`, and
 * a mutation returns the whole section it belongs to. Re-wrapping that here would add a second place
 * for the contract to be described and a second place for it to drift.
 *
 * So this holds the credential and forwards. What it does NOT do is decide what fofos's answers mean:
 * a 404 from fofos reaches the panel as a 404, because fofos's error envelope names the field and
 * nothing here could improve on that.
 *
 * The exception is `/_config`, which is this plugin's own and never leaves the machine.
 *
 * ── Permissions ──
 *
 * The platform's gate decides who gets here, and `/_config` is `ownerOnly` in the manifest. Nothing in
 * this file checks again: two places deciding the same thing is how they come to disagree.
 */
export const router = createRouter();

/**
 * The upload path forwards a body it must not have parsed. This is load-bearing.
 *
 * `bodyParser` runs across the whole protected router and calls `parseBody` on `multipart/form-data`.
 * Hono then caches the parsed FormData, so asking for the bytes afterwards RE-SERIALISES them under a
 * NEW multipart boundary — while the original `content-type` header, naming the old one, is what gets
 * forwarded. Header and body disagree and fofos rejects every upload with "Unexpected end of form".
 *
 * Registering the prefix tells `bodyParser` to leave these requests alone. Narrow on purpose — one
 * route, not the whole plugin — because everything else here is JSON that is genuinely fine to parse,
 * and claiming more than is needed turns an opt-out into a habit.
 */
registerProxiedPrefix('/api/fofos-admin/media');

/** fofos's own answer, passed through with its status and content type intact. */
const passThrough = (response: FofosResponse) =>
  new Response(response.body, {
    status: response.status,
    headers: { 'content-type': response.contentType ?? 'application/json' },
  });

/**
 * A shaped failure for the two things that can go wrong before fofos answers at all.
 *
 * `unconfigured` is the one panels branch on: it is a setup step rather than an error, and rendering
 * it as a broken list would tell somebody their site was down when they have simply not connected it
 * yet.
 */
const noConnection = (ctx: Context<{ Variables: HonoVariables }>) =>
  ctx.json({ error: 'No fofos connection is configured.', unconfigured: true }, 409);

const unreachable = (ctx: Context<{ Variables: HonoVariables }>, error: unknown) => {
  if (error instanceof FofosError) {
    return ctx.json({ error: error.message, unreachable: error.status === null }, 502);
  }
  return ctx.json({ error: error instanceof Error ? error.message : String(error) }, 500);
};

// ── Everything the panels read and write ─────────────────────────────────────────────────────────

/**
 * Uploads. Registered above so its body arrives untouched.
 *
 * Buffered rather than streamed: Bun's fetch can take a stream, but the platform is a hop in the
 * middle and a half-forwarded upload that fails mid-flight is harder to reason about than one that is
 * whole before it leaves. `arrayBuffer()` here is the ORIGINAL bytes with the ORIGINAL boundary,
 * which is exactly why the original `content-type` can be forwarded with them.
 */
router.post('/media', async (ctx) => {
  const credentials = await readCredentials();
  if (!credentials) return noConnection(ctx);

  try {
    const body = await ctx.req.arrayBuffer();
    const response = await fofosRequest(credentials, {
      method: 'POST',
      path: '/media',
      body: new Blob([body]) as unknown as FormData,
      contentType: ctx.req.header('content-type') ?? null,
    });
    return passThrough(response);
  } catch (error) {
    return unreachable(ctx, error);
  }
});

// ── Settings — owner only, by the manifest ───────────────────────────────────────────────────────

router.get('/_config', async (ctx) => ctx.json(await readConnection()));

router.put('/_config', async (ctx) => {
  const payload = (await ctx.req.json().catch(() => null)) as { url?: string; token?: string } | null;
  if (!payload?.url?.trim()) return ctx.json({ error: 'A fofos URL is required.' }, 400);

  try {
    const saved = await saveConnection({ url: payload.url, token: payload.token?.trim() || undefined });

    // Probed immediately, so the form can say whether it works rather than only that it saved. A
    // failure here is NOT a failed save — the connection is stored either way, which is what lets
    // somebody fix a token without re-entering the URL.
    const credentials = await readCredentials();
    if (credentials) {
      const result = await probe(credentials);
      await recordProbe(result.sections ?? null, result.authenticated);
      return ctx.json({ ...(await readConnection()), probe: result });
    }

    return ctx.json(saved);
  } catch (error) {
    return ctx.json({ error: error instanceof Error ? error.message : String(error) }, 400);
  }
});

router.delete('/_config', async (ctx) => {
  await deleteConnection();
  return ctx.json(await readConnection());
});

/**
 * Check a URL and token WITHOUT storing them.
 *
 * So a wrong token never replaces a working one — the same reason proxy-manager's test route exists.
 * When the token is omitted it tests the STORED one, which is how "is my connection still good?" is
 * answered without anybody having to retype a secret.
 */
router.post('/_config/test', async (ctx) => {
  const payload = (await ctx.req.json().catch(() => null)) as { url?: string; token?: string } | null;

  const stored = await readCredentials();
  const url = payload?.url?.trim() || stored?.url;
  const token = payload?.token?.trim() || stored?.token;

  if (!url || !token) {
    return ctx.json({ reachable: false, authenticated: false, error: 'A URL and a token are needed.' }, 400);
  }

  const result = await probe({ url, token });

  // Only when testing what is actually stored. Recording a probe of some other credential would put a
  // verdict about a different server against this row.
  if (!payload?.url && !payload?.token && stored) {
    await recordProbe(result.sections ?? null, result.authenticated);
  }

  return ctx.json(result);
});

/**
 * Where the fofos site is on this machine.
 *
 * Under `/_config`, so the manifest's `ownerOnly: ['/_config']` covers it with no second rule to keep
 * in step. That is the right level: this path is what the plugin will read and write the client's
 * site through, so choosing it is an owner's decision even though editing the site is not.
 *
 * The caller's email only ever reaches `getOwnerHomeDir`, which ignores it and answers with the
 * OWNER's home. That is deliberate rather than sloppy — see `api/settings.ts`.
 */
router.get('/_config/root', async (ctx) => {
  const user = ctx.get('user');
  return ctx.json(await readSettings(user.email));
});

router.put('/_config/root', async (ctx) => {
  const user = ctx.get('user');
  const { path } = (ctx.get('body') ?? {}) as { path?: string };
  try {
    return ctx.json(await saveRootPath(path ?? '', user.email));
  } catch (error) {
    // The only failures here are the caller's own words being unusable, which is a 400 and not a fault.
    return ctx.json({ error: (error as Error).message }, 400);
  }
});

/**
 * The website checkout under the root location — is it there, and put it there.
 *
 * Under `/_config` so the manifest's `ownerOnly` covers it, and it has to be: these write to the
 * filesystem and reach the network with the owner's SSH key. Reading the state is owner-only for the
 * same reason rather than a separate rule — it names a path on the machine.
 *
 * Clone and update return git's own output on failure. It is more use than anything this could write
 * in its place: "Permission denied (publickey)" says exactly what is wrong, and a friendlier sentence
 * would be a guess at which of a dozen causes it was.
 */
router.get('/_config/website', async (ctx) => {
  const user = ctx.get('user');
  return ctx.json(await readWebsiteStatus(user.email));
});

router.post('/_config/website/clone', async (ctx) => {
  const user = ctx.get('user');
  const result = await cloneWebsite(user.email);
  // The status is re-read either way, so a partial failure shows what actually ended up on disk rather
  // than what was asked for.
  return ctx.json({ ...result, status: await readWebsiteStatus(user.email) }, result.ok ? 200 : 400);
});

router.post('/_config/website/update', async (ctx) => {
  const user = ctx.get('user');
  const result = await updateWebsite(user.email);
  return ctx.json({ ...result, status: await readWebsiteStatus(user.email) }, result.ok ? 200 : 400);
});

/**
 * The media directory beside the checkout. Same `/_config` prefix, so the same owner-only rule.
 */
router.get('/_config/media', async (ctx) => {
  const user = ctx.get('user');
  return ctx.json(await readMediaStatus(user.email));
});

router.post('/_config/media/create', async (ctx) => {
  const user = ctx.get('user');
  const result = await createMediaDir(user.email);
  // The status is re-read either way, so what the panel shows is what is on disk rather than what was
  // asked for.
  return ctx.json({ ...result, status: await readMediaStatus(user.email) }, result.ok ? 200 : 400);
});

/**
 * Building `derived/` from `originals/`.
 *
 * Two routes and no more: start one, and ask how it is going. The work is asynchronous because a
 * folder of photographs takes minutes, and the panel polls the second route rather than holding a
 * request open — a connection that has to survive an eight-minute encode is a connection that will
 * not.
 *
 * `POST` answers 200 whether it started a run or found one already going, and says which in `started`.
 * "Already running" is not a failure to report to somebody who pressed Sync; the honest answer is the
 * run that is in progress, which is what comes back.
 */
router.post('/_config/media/sync', async (ctx) => {
  const user = ctx.get('user');
  // A folder inside `originals/`, or nothing for all of it. Named `path` because that is what the file
  // browser calls it, and this is the value it will hand over when a folder is synced from there.
  const { path } = (ctx.get('body') ?? {}) as { path?: string };
  try {
    return ctx.json(startSync(user.email, { scope: path }));
  } catch (error) {
    return ctx.json({ error: (error as Error).message }, 400);
  }
});

router.get('/_config/media/sync', async (ctx) => {
  const user = ctx.get('user');
  return ctx.json(readSync(user.email));
});

/**
 * What has been done, and what is left.
 *
 * Separate from the live job state on purpose: that one is polled every second while a run is in
 * flight, and this one walks the whole tree reading manifests. Answering both from one route would
 * make every tick of a progress bar re-read the library.
 */
/**
 * The three bits Root location needs BEFORE it paints: is it set up?
 *
 * ── Why this is not assembled from the children ──
 *
 * Each part of that block fetches its own status, which is right — but it means the block cannot know
 * whether it is finished until its children have mounted and answered, so it must render open and then
 * fold itself away. That flicker is on every page load, and it is not a rendering problem to be tuned
 * away: the information genuinely was not there yet.
 *
 * One request that answers it first removes the cause. The children still own their own detail and
 * still report changes upward while the block is open — this only seeds the opening state so the first
 * paint is already correct.
 *
 * It walks the media tree, which is the expensive part, and is therefore deliberately NOT polled.
 */
/**
 * The two databases the site reads. Owner-only, like everything else under `/_config`.
 *
 * ONE write route, not two. There was a `PUT` that only stored the names, on the reasoning that naming
 * and creating are separate decisions — but the panel has one button, so nothing called it, and a
 * second way to write the same two columns is a second thing that can drift from the first.
 */
router.get('/_config/databases', async (ctx) => ctx.json(await readDatabases()));

router.post('/_config/databases/:target/push-schema', async (ctx) => {
  const user = ctx.get('user');
  const target = ctx.req.param('target');
  if (target !== 'production' && target !== 'development') {
    return ctx.json({ error: 'Target must be production or development.' }, 400);
  }
  try {
    const settings = await readSettings(user.email);
    const result = await pushSchema(target, join(settings.rootPath, 'website'));
    return ctx.json({ ...result, status: await readDatabases() }, result.ok ? 200 : 400);
  } catch (error) {
    return ctx.json({ error: (error as Error).message }, 400);
  }
});

router.post('/_config/databases/create', async (ctx) => {
  // The names come with the request, so what gets created is what is on screen rather than what was
  // stored at some earlier point. They are saved first, by the same validation as the PUT above.
  const { production, development } = (ctx.get('body') ?? {}) as { production?: string; development?: string };
  try {
    return ctx.json(await createDatabases({ production, development }));
  } catch (error) {
    return ctx.json({ error: (error as Error).message }, 400);
  }
});

/**
 * Backups — the schedule, the location, and one on demand.
 *
 * `POST /run` exists so somebody can prove the location and the credentials work without waiting until
 * three in the morning to find out they do not.
 */
router.get('/_config/backups', async (ctx) => ctx.json(await readBackups()));

router.put('/_config/backups', async (ctx) => {
  const body = (ctx.get('body') ?? {}) as {
    cron?: string;
    dir?: string;
    sshHost?: string;
    sshPath?: string;
    keep?: number | null;
  };
  try {
    return ctx.json(
      await saveBackups({
        cron: body.cron ?? '',
        dir: body.dir ?? '',
        sshHost: body.sshHost ?? '',
        sshPath: body.sshPath ?? '',
        keep: body.keep ?? null,
      }),
    );
  } catch (error) {
    return ctx.json({ error: (error as Error).message }, 400);
  }
});

/**
 * Prove the destination before anything is trusted to it.
 *
 * Takes the values from the FORM rather than from storage, so it tests what is on screen — testing a
 * saved destination while somebody looks at a different one is worse than not testing at all.
 */
router.post('/_config/backups/test', async (ctx) => {
  const { sshHost, sshPath } = (ctx.get('body') ?? {}) as { sshHost?: string; sshPath?: string };
  try {
    const result = await testDestination(sshHost ?? '', sshPath ?? '');
    return ctx.json(result, result.ok ? 200 : 400);
  } catch (error) {
    return ctx.json({ error: (error as Error).message }, 400);
  }
});

/**
 * Load a dump back into one of the databases.
 *
 * `confirm` is required by the function behind this, not merely by the panel. A restore empties the
 * target first — a pg_dump carries CREATE TABLE and cannot be layered onto a database that already has
 * the schema — and that is not something any code path should be able to reach by accident.
 */
router.post('/_config/backups/restore', async (ctx) => {
  const { file, target, confirm } = (ctx.get('body') ?? {}) as {
    file?: string;
    target?: string;
    confirm?: boolean;
  };
  if (target !== 'production' && target !== 'development') {
    return ctx.json({ error: 'Target must be production or development.' }, 400);
  }
  try {
    const result = await restoreBackup({ file: file ?? '', target, confirm: confirm === true });
    return ctx.json({ ...result, status: await readDatabases() }, result.ok ? 200 : 400);
  } catch (error) {
    return ctx.json({ error: (error as Error).message }, 400);
  }
});

router.post('/_config/backups/run', async (ctx) => {
  try {
    const result = await runBackup();
    return ctx.json({ ...result, settings: await readBackups() }, result.ok ? 200 : 400);
  } catch (error) {
    return ctx.json({ error: (error as Error).message }, 400);
  }
});

router.get('/_config/summary', async (ctx) => {
  const user = ctx.get('user');
  const settings = await readSettings(user.email);

  const [website, media] = await Promise.all([
    readWebsiteStatus(user.email),
    readMediaStatus(user.email),
  ]);

  // Only walked when there is somewhere to walk. Reconciling against a media folder that does not
  // exist is a guaranteed empty answer bought at the price of a tree walk.
  const outstanding = media.complete
    ? await reconcile(user.email).then((state) => state.missing.length + state.stale.length)
    : null;

  /*
    The Database block folds away on the same terms as Root location, so its answer comes from here too
    — for the same reason: a block that cannot know it is finished until its children report must paint
    open and then shut, on every load.

    "Finished" is both databases existing WITH a schema in them, and backups configured. Not backups
    having run: a site that has just been set up has taken none, and telling somebody their setup is
    incomplete because nothing has happened yet is telling them to fix something that is not broken.
  */
  const databases = await readDatabases();
  const backups = await readBackups();

  return ctx.json({
    rootSet: settings.isSet,
    websiteReady: website.isRepo,
    mediaReady: media.complete && outstanding === 0,
    databasesReady:
      Boolean(databases.production.exists && databases.development.exists) &&
      (databases.production.tables ?? 0) > 0 &&
      (databases.development.tables ?? 0) > 0 &&
      Boolean(backups.cron && backups.sshHost && backups.sshPath),
  });
});

router.get('/_config/media/ledger', async (ctx) => {
  const user = ctx.get('user');
  const scope = ctx.req.query('path') ?? '';
  try {
    const [runs, state] = await Promise.all([readRuns(user.email), reconcile(user.email, scope)]);
    return ctx.json({ runs, reconciliation: state });
  } catch (error) {
    return ctx.json({ error: (error as Error).message }, 400);
  }
});

/**
 * Is this plugin usable? Asked once by the detail panel rather than by all nine sections.
 *
 * Not owner-only, and not under `/_config` for that reason: a member needs to know whether to render a
 * section or a "not connected yet" message, and that answer contains no credential.
 */
router.get('/status', async (ctx) => {
  const user = ctx.get('user');
  const connection = await readConnection();
  const settings = await readSettings(user.email);

  /*
    `rootSet` is a BOOLEAN and this route is deliberately not owner-only.

    The nav has to know whether Media can be opened, and every account that can see the section needs
    that answer. The path itself stays behind `/_config`, which is owner-only — this says only whether
    one has been chosen, which reveals nothing about the machine.
  */
  return ctx.json({
    configured: connection.configured,
    lastProbeOk: connection.lastProbeOk,
    rootSet: settings.isSet,
  });
});

/**
 * Everything else, forwarded verbatim.
 *
 * A catch-all rather than a route per section, because the sections are fofos's to define — see its
 * `docs/SURFACES.md`. Enumerating them here would mean this plugin needs a release every time fofos
 * adds one, which is a coupling with nothing to show for it.
 *
 * ── LAST in the file, and that is load-bearing ──
 *
 * Hono runs every matching handler in REGISTRATION order, so `/*` declared above `/_config` would
 * swallow it — the settings routes would forward themselves to fofos, which has no such endpoint, and
 * the settings form would 404 against a plugin that was working perfectly. Everything this plugin
 * serves itself is registered before this point.
 */
router.all('/*', async (ctx) => {
  const credentials = await readCredentials();
  if (!credentials) return noConnection(ctx);

  const url = new URL(ctx.req.url);
  // Everything after the mount, so `/gallery/3/media` reaches fofos as `/api/admin/gallery/3/media`.
  const path = url.pathname.slice(url.pathname.indexOf('/fofos-admin') + '/fofos-admin'.length) || '';

  const method = ctx.req.method;
  // Read as TEXT and forwarded as text, so what fofos parses is what the panel sent. Safe after
  // bodyParser because Hono caches the body — and correct because these are all JSON.
  const body = method === 'GET' || method === 'HEAD' ? null : await ctx.req.text();

  try {
    const response = await fofosRequest(credentials, {
      method,
      path,
      search: url.search,
      body,
      contentType: body ? 'application/json' : null,
    });
    return passThrough(response);
  } catch (error) {
    return unreachable(ctx, error);
  }
});

/*
  Start the backup timer when this router is imported, which is once, at boot.

  Not awaited: the server must not wait on a database read to finish mounting a router, and a schedule
  that starts a moment late costs nothing. Failures are swallowed for the same reason the timer swallows
  them — a bad expression in one column must not stop the plugin from loading, because the panel is
  where somebody would go to fix it.
*/
void schedule().catch(() => {});

/*
  Watch the contact inbox and copy it whenever it changes.

  Separate from the backup schedule on purpose: messages arrive between publishes, so they are the one
  thing a publish-triggered backup would never contain. Not awaited, and failures swallowed, for the
  same reason as above.
*/
void watchMailbox().catch(() => {});