/**
 * The whole backup chain, against real data.
 *
 * Talks to a running `scaffoldd` over its unix socket, asks what the backup
 * set is, reads those files off disk, pushes them through the vault, and pulls
 * them back — then compares byte-for-byte.
 *
 * This is the test that would catch the things unit tests cannot: a path that
 * survives the round trip wrong, a 600 KB log that trips a size ceiling, a
 * workspace whose file count makes the manifest too large to commit. It is
 * skipped when no daemon is listening, so it never blocks an ordinary run.
 *
 *   scaffoldd --socket /tmp/scaffoldd-e2e.sock &
 *   SCAFFOLDD_SOCKET=/tmp/scaffoldd-e2e.sock bun test scaffoldd-e2e
 */
import { describe, test, expect } from 'bun:test';
import { connect } from 'node:net';
import { readFile } from 'node:fs/promises';
import { SubtleCryptoProvider } from '@shade/crypto-web';
import { createVaultRoutes } from '../src/server.js';
import { MemoryVaultStore } from '../src/store.js';
import { HttpVaultTransport } from '../src/http-transport.js';
import { VaultClient, deriveVaultKeys } from '../src/client.js';
import type { VaultFile } from '../src/client.js';

const SOCKET = process.env.SCAFFOLDD_SOCKET;
const crypto = new SubtleCryptoProvider();

interface BackupFile {
  path: string;
  source: string;
  size: number;
}

function ask(socketPath: string, request: object): Promise<any> {
  return new Promise((resolve, reject) => {
    const sock = connect(socketPath);
    let buf = '';
    const timer = setTimeout(() => {
      sock.destroy();
      reject(new Error('scaffoldd svarte ikke innen 20 s'));
    }, 20_000);
    // Deliberately no `end()` after writing: Bun's socket closes both
    // directions, so the daemon's reply is discarded before it arrives. The
    // protocol is line-delimited, so read until the first complete line and
    // close from here instead.
    sock.on('connect', () => {
      sock.write(`${JSON.stringify(request)}\n`);
    });
    sock.on('data', (c) => {
      buf += c.toString();
      const nl = buf.indexOf('\n');
      if (nl === -1) return;
      clearTimeout(timer);
      sock.destroy();
      const res = JSON.parse(buf.slice(0, nl));
      res.ok ? resolve(res.result) : reject(new Error(`${res.code}: ${res.error}`));
    });
    sock.on('end', () => {
      clearTimeout(timer);
      if (!buf.includes('\n')) reject(new Error('tomt svar'));
    });
    sock.on('error', (e) => {
      clearTimeout(timer);
      reject(e);
    });
  });
}

async function harness() {
  const store = new MemoryVaultStore();
  const routes = createVaultRoutes(store, crypto);
  const transport = new HttpVaultTransport('http://vault.test', (i, init) =>
    routes.fetch(new Request(i, init)),
  );
  const keys = await deriveVaultKeys(new Uint8Array(32).fill(42), 'scaffold-e2e');
  return { store, client: new VaultClient(crypto, keys, transport) };
}

describe.skipIf(!SOCKET)('scaffoldd → vault, real workspace', () => {
  test('the whole backup set round-trips byte-for-byte', async () => {
    const set = (await ask(SOCKET!, { op: 'backupSet' })) as {
      files: BackupFile[];
      count: number;
      bytes: number;
    };
    expect(set.count).toBeGreaterThan(50);

    const files: VaultFile[] = [];
    for (const f of set.files) {
      try {
        files.push({ path: f.path, bytes: new Uint8Array(await readFile(f.source)) });
      } catch {
        // Matches the bridge: one unreadable file is skipped, not fatal.
      }
    }

    const { client } = await harness();
    const push = await client.push(files, 1_786_600_000_000, 'e2e');
    expect(push.seq).toBe(1);
    expect(push.uploaded).toBe(files.length);

    const { files: back } = await client.pull();
    expect(back.size).toBe(files.length);

    // Every single file, not a sample: a backup that restores 99% of a
    // workspace is not a backup.
    for (const f of files) {
      const restored = back.get(f.path);
      expect(restored).toBeDefined();
      expect(restored!.length).toBe(f.bytes.length);
      expect(Buffer.from(restored!).equals(Buffer.from(f.bytes))).toBe(true);
    }
  }, 120_000);

  test('a second push after one edit sends almost nothing', async () => {
    // The property that decides whether hourly backup is affordable.
    const set = (await ask(SOCKET!, { op: 'backupSet' })) as { files: BackupFile[] };
    const files: VaultFile[] = [];
    for (const f of set.files.slice(0, 120)) {
      try {
        files.push({ path: f.path, bytes: new Uint8Array(await readFile(f.source)) });
      } catch {
        /* skipped */
      }
    }

    const { client } = await harness();
    const first = await client.push(files, 1_786_600_000_000);

    const edited = files.map((f, i) =>
      i === 0 ? { path: f.path, bytes: new TextEncoder().encode('endret én linje') } : f,
    );
    const second = await client.push(edited, 1_786_600_001_000);

    expect(first.uploaded).toBe(files.length);
    expect(second.uploaded).toBe(1);
    expect(second.reused).toBe(files.length - 1);
  }, 120_000);

  test('the largest file in the workspace survives the round trip', async () => {
    // Terra's log.md is ~617 KB. Nothing in the chain may quietly cap it.
    const set = (await ask(SOCKET!, { op: 'backupSet' })) as { files: BackupFile[] };
    const biggest = set.files.reduce((a, b) => (a.size > b.size ? a : b));
    expect(biggest.size).toBeGreaterThan(100_000);

    const bytes = new Uint8Array(await readFile(biggest.source));
    const { client } = await harness();
    await client.push([{ path: biggest.path, bytes }], 1_786_600_000_000);
    const { files } = await client.pull();
    expect(files.get(biggest.path)!.length).toBe(bytes.length);
  }, 120_000);
});