/**
 * HOALedgerIQ – Core CRUD Workflow Load Test
 * Journey: Login → Create Journal Entry → Post It → Create Invoice →
 *          Record Payment → View Accounts → Budget vs Actual → Logout
 *
 * This scenario exercises write-heavy paths gated by WriteAccessGuard
 * and the TenantMiddleware schema-switch. Run this alongside
 * auth-dashboard-flow.js to simulate a realistic mixed workload.
 *
 * Role used: treasurer (has full write access, most common power user)
 */

import http from 'k6/http';
import { check, sleep, group } from 'k6';
import { SharedArray } from 'k6/data';
import { Trend, Rate } from 'k6/metrics';
import { uuidv4 } from 'https://jslib.k6.io/k6-utils/1.4.0/index.js';

// ── Custom metrics ──────────────────────────────────────────────────────────
const journalEntryDuration  = new Trend('journal_entry_duration',   true);
const invoiceDuration       = new Trend('invoice_duration',         true);
const paymentDuration       = new Trend('payment_duration',         true);
const accountsReadDuration  = new Trend('accounts_read_duration',   true);
const budgetDuration        = new Trend('budget_vs_actual_duration',true);
const crudErrorRate         = new Rate('crud_error_rate');
const writeGuardErrorRate   = new Rate('write_guard_error_rate');

// ── User pool (treasurer + admin roles only for write access) ────────────────
const users = new SharedArray('users', function () {
  return open('../config/user-pool.csv')
    .split('\n')
    .slice(1)
    .filter(line => line.trim())
    .map(line => {
      const [email, password, orgId, role] = line.split(',');
      return { email: email.trim(), password: password.trim(), orgId: orgId.trim(), role: role.trim() };
    })
    .filter(u => ['treasurer', 'admin', 'president', 'manager'].includes(u.role));
});

// ── Environment config ───────────────────────────────────────────────────────
const ENV = __ENV.TARGET_ENV || 'staging';
const envConfig = JSON.parse(open('../config/environments.json'))[ENV];
const BASE_URL  = envConfig.baseUrl;

// ── Test options ─────────────────────────────────────────────────────────────
export const options = {
  scenarios: {
    crud_workflow: {
      executor: 'ramping-vus',
      stages: [
        { duration: '2m',  target: 10  },   // warm up (writes need more care)
        { duration: '5m',  target: 50  },   // ramp to target
        { duration: '5m',  target: 50  },   // sustained
        { duration: '3m',  target: 100 },   // peak
        { duration: '2m',  target: 0   },   // ramp down
      ],
    },
  },
  thresholds: {
    'journal_entry_duration':    [`p(95)<${envConfig.thresholds.write_p95}`],
    'invoice_duration':          [`p(95)<${envConfig.thresholds.write_p95}`],
    'payment_duration':          [`p(95)<${envConfig.thresholds.write_p95}`],
    'accounts_read_duration':    [`p(95)<${envConfig.thresholds.read_p95}`],
    'budget_vs_actual_duration': [`p(95)<${envConfig.thresholds.dashboard_p95}`],
    'crud_error_rate':           [`rate<${envConfig.thresholds.error_rate}`],
    'write_guard_error_rate':    ['rate<0.001'], // write-guard failures should be near-zero
    'http_req_failed':           [`rate<${envConfig.thresholds.error_rate}`],
    'http_req_duration':         [`p(99)<${envConfig.thresholds.global_p99}`],
  },
};

// ── Helpers ──────────────────────────────────────────────────────────────────
function jsonHeaders(token) {
  return {
    'Content-Type':  'application/json',
    'Authorization': `Bearer ${token}`,
  };
}

function currentYear() {
  return new Date().getFullYear();
}

// ── Main scenario ────────────────────────────────────────────────────────────
export default function () {
  const user = users[__VU % users.length];
  let accessToken = null;

  // ── 1. Login ────────────────────────────────────────────────────────────
  group('auth:login', () => {
    const res = http.post(
      `${BASE_URL}/api/auth/login`,
      JSON.stringify({ email: user.email, password: user.password }),
      { headers: { 'Content-Type': 'application/json' }, tags: { name: 'login' } }
    );
    const ok = check(res, {
      'login 200':        r => r.status === 200,
      'has access_token': r => r.json('access_token') !== undefined,
    });
    crudErrorRate.add(!ok);
    if (!ok) { sleep(1); return; }
    accessToken = res.json('access_token');
  });

  if (!accessToken) return;
  sleep(1);

  // ── 2. Read accounts (needed to pick valid account IDs for journal entry) ─
  let debitAccountId  = null;
  let creditAccountId = null;

  group('accounts:list', () => {
    const res = http.get(
      `${BASE_URL}/api/accounts`,
      { headers: jsonHeaders(accessToken), tags: { name: 'accounts_list' } }
    );
    accountsReadDuration.add(res.timings.duration);
    const ok = check(res, {
      'accounts 200':       r => r.status === 200,
      'accounts non-empty': r => Array.isArray(r.json()) && r.json().length > 0,
    });
    crudErrorRate.add(!ok);

    if (ok) {
      const accounts = res.json();
      // Pick first two distinct accounts for the journal entry
      debitAccountId  = accounts[0]?.id;
      creditAccountId = accounts[1]?.id;
    }
  });

  if (!debitAccountId || !creditAccountId) { sleep(1); return; }
  sleep(1.5);

  // ── 3. Create journal entry (draft) ────────────────────────────────────
  let journalEntryId = null;

  group('journal:create', () => {
    const payload = {
      date:        new Date().toISOString().split('T')[0],
      description: `Load test entry ${uuidv4().slice(0, 8)}`,
      lines: [
        { accountId: debitAccountId,  type: 'debit',  amount: 100.00, description: 'Load test debit'  },
        { accountId: creditAccountId, type: 'credit', amount: 100.00, description: 'Load test credit' },
      ],
    };

    const res = http.post(
      `${BASE_URL}/api/journal-entries`,
      JSON.stringify(payload),
      { headers: jsonHeaders(accessToken), tags: { name: 'journal_create' } }
    );

    journalEntryDuration.add(res.timings.duration);
    // Watch for WriteAccessGuard rejections (403)
    writeGuardErrorRate.add(res.status === 403);
    const ok = check(res, {
      'journal create 201': r => r.status === 201,
      'journal has id':     r => r.json('id') !== undefined,
    });
    crudErrorRate.add(!ok);
    if (ok) journalEntryId = res.json('id');
  });

  sleep(1);

  // ── 4. Post the journal entry ────────────────────────────────────────────
  if (journalEntryId) {
    group('journal:post', () => {
      const res = http.post(
        `${BASE_URL}/api/journal-entries/${journalEntryId}/post`,
        null,
        { headers: jsonHeaders(accessToken), tags: { name: 'journal_post' } }
      );
      journalEntryDuration.add(res.timings.duration);
      writeGuardErrorRate.add(res.status === 403);
      const ok = check(res, { 'journal post 200': r => r.status === 200 });
      crudErrorRate.add(!ok);
    });
    sleep(1.5);
  }

  // ── 5. Generate invoice preview ─────────────────────────────────────────
  let invoicePreviewOk = false;
  group('invoice:preview', () => {
    const res = http.post(
      `${BASE_URL}/api/invoices/generate-preview`,
      JSON.stringify({ period: currentYear() }),
      { headers: jsonHeaders(accessToken), tags: { name: 'invoice_preview' } }
    );
    invoiceDuration.add(res.timings.duration);
    invoicePreviewOk = check(res, { 'invoice preview 200': r => r.status === 200 });
    crudErrorRate.add(!invoicePreviewOk);
  });

  sleep(2); // user reviews invoice preview

  // ── 6. Create a payment record ───────────────────────────────────────────
  group('payment:create', () => {
    const payload = {
      amount:      150.00,
      date:        new Date().toISOString().split('T')[0],
      method:      'check',
      description: `Load test payment ${uuidv4().slice(0, 8)}`,
    };

    const res = http.post(
      `${BASE_URL}/api/payments`,
      JSON.stringify(payload),
      { headers: jsonHeaders(accessToken), tags: { name: 'payment_create' } }
    );
    paymentDuration.add(res.timings.duration);
    writeGuardErrorRate.add(res.status === 403);
    const ok = check(res, {
      'payment create 201 or 200': r => r.status === 201 || r.status === 200,
    });
    crudErrorRate.add(!ok);
  });

  sleep(1.5);

  // ── 7. Budget vs actual (typically the heaviest read query) ─────────────
  group('budget:vs-actual', () => {
    const year = currentYear();
    const res = http.get(
      `${BASE_URL}/api/budgets/${year}/vs-actual`,
      { headers: jsonHeaders(accessToken), tags: { name: 'budget_vs_actual' } }
    );
    budgetDuration.add(res.timings.duration);
    const ok = check(res, { 'budget vs-actual 200': r => r.status === 200 });
    crudErrorRate.add(!ok);
  });

  sleep(1);

  // ── 8. Trial balance read ────────────────────────────────────────────────
  group('accounts:trial-balance', () => {
    const res = http.get(
      `${BASE_URL}/api/accounts/trial-balance`,
      { headers: jsonHeaders(accessToken), tags: { name: 'trial_balance' } }
    );
    accountsReadDuration.add(res.timings.duration);
    check(res, { 'trial balance 200': r => r.status === 200 });
  });

  sleep(1);

  // ── 9. Logout ────────────────────────────────────────────────────────────
  group('auth:logout', () => {
    http.post(
      `${BASE_URL}/api/auth/logout`,
      null,
      { headers: jsonHeaders(accessToken), tags: { name: 'logout' } }
    );
  });

  sleep(1);
}