const assert = require('node:assert/strict');
const test = require('node:test');

const { closeDbPool, getDb } = require('../src/config/db');
const {
  chargeBalance,
  creditBalance,
  createDepositRequest,
  reviewDeposit,
  runReconciliation
} = require('../src/services/wallet.service');

const createdUserIds = [];

function unique(prefix) {
  return `${prefix}_${Date.now()}_${Math.random().toString(36).slice(2)}`;
}

async function createUser(overrides = {}) {
  const db = getDb();
  const username = unique('wallet_user');
  const [id] = await db('users').insert({
    username,
    email: `${username}@example.com`,
    password_hash: 'test_hash',
    balance: '0.0000',
    role: 'user',
    status: 'active',
    ...overrides
  });

  createdUserIds.push(id);
  return id;
}

async function readUser(userId) {
  return getDb()('users').where({ id: userId }).first();
}

async function cleanup() {
  if (createdUserIds.length === 0) {
    return;
  }

  const db = getDb();

  await db('password_reset_tokens').whereIn('user_id', createdUserIds).del();
  await db('refresh_tokens').whereIn('user_id', createdUserIds).del();
  await db('idempotency_keys').whereIn('user_id', createdUserIds).del();
  await db('deposits').whereIn('user_id', createdUserIds).orWhereIn('reviewed_by', createdUserIds).del();
  await db('transactions').whereIn('user_id', createdUserIds).del();
  await db('users').whereIn('id', createdUserIds).del();
}

test.after(async () => {
  await cleanup();
  await closeDbPool();
});

test('charge bigger than balance is rejected and leaves balance unchanged', async () => {
  const userId = await createUser();

  await assert.rejects(
    () => chargeBalance(userId, '1.0000', unique('order_ref'), 'too expensive'),
    (error) => error.code === 'INSUFFICIENT_BALANCE'
  );

  const user = await readUser(userId);
  const transactions = await getDb()('transactions').where({ user_id: userId });

  assert.equal(user.balance, '0.0000');
  assert.equal(transactions.length, 0);
});

test('parallel charges on same balance allow only one spend when funds cover one order', async () => {
  const userId = await createUser();
  await creditBalance(userId, '10.0000', unique('seed_ref'), 'seed balance');

  const results = await Promise.allSettled([
    chargeBalance(userId, '6.0000', unique('order_ref_a'), 'parallel A'),
    chargeBalance(userId, '6.0000', unique('order_ref_b'), 'parallel B')
  ]);

  const fulfilled = results.filter((result) => result.status === 'fulfilled');
  const rejected = results.filter((result) => result.status === 'rejected');
  const user = await readUser(userId);
  const orderTransactions = await getDb()('transactions').where({ user_id: userId, type: 'order' });

  assert.equal(fulfilled.length, 1);
  assert.equal(rejected.length, 1);
  assert.equal(rejected[0].reason.code, 'INSUFFICIENT_BALANCE');
  assert.equal(user.balance, '4.0000');
  assert.equal(orderTransactions.length, 1);
});

test('parallel approval of one deposit credits balance only once', async () => {
  const adminId = await createUser({ role: 'admin' });
  const userId = await createUser();
  const deposit = await createDepositRequest(userId, {
    amount: '15.0000',
    method: 'paypal',
    tx_ref: unique('tx_ref')
  });

  const results = await Promise.allSettled([
    reviewDeposit(deposit.id, adminId, 'approve', 'approved once'),
    reviewDeposit(deposit.id, adminId, 'approve', 'approved twice')
  ]);

  const fulfilled = results.filter((result) => result.status === 'fulfilled');
  const rejected = results.filter((result) => result.status === 'rejected');
  const user = await readUser(userId);
  const depositTransactions = await getDb()('transactions').where({
    user_id: userId,
    type: 'deposit',
    reference: `deposit:${deposit.id}`
  });

  assert.equal(fulfilled.length, 1);
  assert.equal(rejected.length, 1);
  assert.equal(rejected[0].reason.code, 'DEPOSIT_ALREADY_REVIEWED');
  assert.equal(user.balance, '15.0000');
  assert.equal(depositTransactions.length, 1);
});

test('duplicate tx_ref is rejected without touching balance', async () => {
  const userId = await createUser();
  const txRef = unique('duplicate_tx_ref');

  await createDepositRequest(userId, {
    amount: '5.0000',
    method: 'paypal',
    tx_ref: txRef
  });

  await assert.rejects(
    () => createDepositRequest(userId, {
      amount: '9.0000',
      method: 'paypal',
      tx_ref: txRef
    }),
    (error) => error.code === 'DUPLICATE_TX_REF'
  );

  const user = await readUser(userId);
  const deposits = await getDb()('deposits').where({ user_id: userId, tx_ref: txRef });

  assert.equal(user.balance, '0.0000');
  assert.equal(deposits.length, 1);
});

test('deposit with unavailable payment method is rejected before creating a request', async () => {
  const userId = await createUser();
  const txRef = unique('missing_method_tx_ref');

  await assert.rejects(
    () => createDepositRequest(userId, {
      amount: '5.0000',
      method: 'missing_method',
      tx_ref: txRef
    }),
    (error) => error.code === 'PAYMENT_METHOD_UNAVAILABLE'
  );

  const deposits = await getDb()('deposits').where({ user_id: userId, tx_ref: txRef });
  const user = await readUser(userId);

  assert.equal(deposits.length, 0);
  assert.equal(user.balance, '0.0000');
});

test('transaction sum remains equal to user balance after a mixed sequence', async () => {
  const userId = await createUser();

  await creditBalance(userId, '20.0000', unique('credit_ref'), 'first credit');
  await chargeBalance(userId, '7.2500', unique('order_ref'), 'order charge');
  await creditBalance(userId, '2.1250', unique('refund_ref'), 'partial refund', 'refund');
  await chargeBalance(userId, '4.8750', unique('order_ref'), 'second order');

  const mismatches = await runReconciliation();
  const ownMismatch = mismatches.find((row) => Number(row.userId) === Number(userId));
  const [sumRow] = await getDb()('transactions').where({ user_id: userId }).sum({ total: 'amount' });
  const user = await readUser(userId);

  assert.equal(ownMismatch, undefined);
  assert.equal(sumRow.total, user.balance);
  assert.equal(user.balance, '10.0000');
});