import { AESKey } from '../src/crypto/aes-key.js';
import { StorageMemory, EncryptedStorage, type BaseStorage } from '../src/storage/index.js';

// ---------------------------------------------------------------------------
// Helpers
// ---------------------------------------------------------------------------

type Doc = {
  id: string;
  name: string;
  age: number;
  email: string;
  createdAt: Date;
};

/**
 * Generate a batch of unique documents.
 */
function generateDocs(count: number): Doc[] {
  const docs: Doc[] = [];
  for (let i = 0; i < count; i++) {
    docs.push({
      id: `id-${i}`,
      name: `user-${i}`,
      age: 20 + (i % 50),
      email: `user-${i}@test.com`,
      createdAt: new Date(Date.now() + i),
    });
  }
  return docs;
}

/**
 * Time an async operation and return elapsed milliseconds.
 */
async function time(fn: () => Promise<void>): Promise<number> {
  const start = performance.now();
  await fn();
  return performance.now() - start;
}

/**
 * Format ops/sec with thousands separators.
 */
function fmtOps(ops: number): string {
  return Math.round(ops).toLocaleString('en-US');
}

/**
 * Run a full suite of benchmarks against a given storage instance.
 */
async function benchmarkStorage(label: string, storage: BaseStorage<Doc>, docs: Doc[]) {
  const count = docs.length;
  console.log(`\n${'='.repeat(60)}`);
  console.log(` ${label}  (${count.toLocaleString()} documents)`);
  console.log('='.repeat(60));

  // --- Insert ---
  const insertMs = await time(async () => {
    await storage.insertMany(docs);
  });
  console.log(`  insertMany       ${insertMs.toFixed(2)}ms  (${fmtOps((count / insertMs) * 1000)} ops/sec)`);

  // --- Find all (no filter) ---
  const findAllMs = await time(async () => {
    await storage.find();
  });
  console.log(`  find()           ${findAllMs.toFixed(2)}ms  (${fmtOps((count / findAllMs) * 1000)} docs/sec)`);

  // --- Find by indexed field (single-key lookup, repeated) ---
  const lookupCount = Math.min(count, 1_000);
  const findIndexedMs = await time(async () => {
    for (let i = 0; i < lookupCount; i++) {
      await storage.findOne({ id: `id-${i}` } as Partial<Doc>);
    }
  });
  console.log(`  findOne indexed   ${findIndexedMs.toFixed(2)}ms  (${fmtOps((lookupCount / findIndexedMs) * 1000)} ops/sec)  [${lookupCount} lookups]`);

  // --- Find by non-indexed field (full scan, repeated) ---
  const scanCount = Math.min(count, 1_000);
  const findScanMs = await time(async () => {
    for (let i = 0; i < scanCount; i++) {
      await storage.findOne({ email: `user-${i}@test.com` } as Partial<Doc>);
    }
  });
  console.log(`  findOne scan      ${findScanMs.toFixed(2)}ms  (${fmtOps((scanCount / findScanMs) * 1000)} ops/sec)  [${scanCount} lookups]`);

  // --- Update by indexed field ---
  const updateCount = Math.min(count, 1_000);
  const updateMs = await time(async () => {
    for (let i = 0; i < updateCount; i++) {
      await storage.updateOne(
        { id: `id-${i}` } as Partial<Doc>,
        { age: 99 } as Partial<Doc>,
      );
    }
  });
  console.log(`  updateOne indexed ${updateMs.toFixed(2)}ms  (${fmtOps((updateCount / updateMs) * 1000)} ops/sec)  [${updateCount} updates]`);

  // --- Delete by indexed field ---
  const deleteCount = Math.min(count, 1_000);
  const deleteMs = await time(async () => {
    for (let i = 0; i < deleteCount; i++) {
      await storage.deleteOne({ id: `id-${i}` } as Partial<Doc>);
    }
  });
  console.log(`  deleteOne indexed ${deleteMs.toFixed(2)}ms  (${fmtOps((deleteCount / deleteMs) * 1000)} ops/sec)  [${deleteCount} deletes]`);

  // --- Verify remaining count ---
  const remaining = await storage.find();
  console.log(`  remaining docs:   ${remaining.length.toLocaleString()}`);
}

// ---------------------------------------------------------------------------
// Main
// ---------------------------------------------------------------------------

// ---------------------------------------------------------------------------
// StorageMemory — indexed vs non-indexed
// ---------------------------------------------------------------------------

const DOC_COUNTS = [1_000, 10_000, 50_000];

for (const count of DOC_COUNTS) {
  const docs = generateDocs(count);

  const indexed = StorageMemory.from<Doc>(['id', 'name']);
  await benchmarkStorage('StorageMemory (indexed: id, name)', indexed, docs);

  const noIndex = StorageMemory.from<Doc>();
  await benchmarkStorage('StorageMemory (no indexes)', noIndex, docs);
}

// ---------------------------------------------------------------------------
// EncryptedStorage — crypto overhead dominates, so use smaller counts
// ---------------------------------------------------------------------------

const ENCRYPTED_DOC_COUNTS = [100, 1_000, 10_000];
const encryptionKey = await AESKey.fromSeed('benchmark-key');

for (const count of ENCRYPTED_DOC_COUNTS) {
  const docs = generateDocs(count);

  // Encrypted + indexed backing store.
  const encBase = StorageMemory.from<Record<string, string>>(['id', 'name']);
  const encrypted = EncryptedStorage.from<Doc>(encBase, encryptionKey);
  await benchmarkStorage('EncryptedStorage (indexed backing store)', encrypted, docs);

  // Encrypted + no-index backing store.
  const encBaseNoIdx = StorageMemory.from<Record<string, string>>();
  const encryptedNoIdx = EncryptedStorage.from<Doc>(encBaseNoIdx, encryptionKey);
  await benchmarkStorage('EncryptedStorage (no indexes)', encryptedNoIdx, docs);
}

console.log('\nDone.\n');