// k6 load test pour les endpoints d'upload de veza-backend-api
// Installation: https://k6.io/docs/get-started/installation/
// Usage: k6 run scripts/loadtest/k6_upload_load_test.js
//
// Variables d'environnement:
//   BASE_URL: URL de base de l'API (défaut: http://localhost:8080)
//   AUTH_TOKEN: Token JWT pour authentification (requis pour uploads)
//   CHUNK_SIZE: Taille des chunks en bytes (défaut: 1024 * 1024 = 1MB)
//   TOTAL_CHUNKS: Nombre de chunks par upload (défaut: 5)

import http from 'k6/http';
import { check, sleep } from 'k6';
import { Rate, Trend, Counter } from 'k6/metrics';

// Métriques custom
const errorRate = new Rate('errors');
const uploadDuration = new Trend('upload_duration');
const chunkedUploadDuration = new Trend('chunked_upload_duration');
const concurrentUploads = new Counter('concurrent_uploads');
const chunkedUploads = new Counter('chunked_uploads');
const uploadFailures = new Counter('upload_failures');

// Configuration
export const options = {
  stages: [
    { duration: '30s', target: 5 },   // Ramp-up: 0 à 5 VUs en 30s
    { duration: '2m', target: 10 },     // Augmentation: 5 à 10 VUs en 2m
    { duration: '2m', target: 10 },     // Stabilité: 10 VUs pendant 2m
    { duration: '30s', target: 0 },     // Ramp-down: 10 à 0 VUs en 30s
  ],
  thresholds: {
    'http_req_duration': ['p(95)<5000', 'p(99)<10000'], // Uploads peuvent être plus lents
    'errors': ['rate<0.10'],                            // < 10% d'erreurs (uploads plus fragiles)
    'upload_duration': ['p(95)<3000'],                  // Upload simple < 3s
    'chunked_upload_duration': ['p(95)<8000'],         // Upload chunked < 8s
  },
};

// Base URL (configurable via env)
const BASE_URL = __ENV.BASE_URL || 'http://localhost:8080';
const AUTH_TOKEN = __ENV.AUTH_TOKEN || '';
const CHUNK_SIZE = parseInt(__ENV.CHUNK_SIZE || '1048576'); // 1MB par défaut
const TOTAL_CHUNKS = parseInt(__ENV.TOTAL_CHUNKS || '5');

// Générer un fichier de test (simulation)
// k6 utilise des Uint8Array pour les données binaires
function generateTestFile(size) {
  const buffer = new Uint8Array(size);
  // Remplir avec des données pseudo-aléatoires
  for (let i = 0; i < size; i++) {
    buffer[i] = Math.floor(Math.random() * 256);
  }
  return buffer;
}

// Créer un multipart form data manuellement pour k6
function createMultipartBody(fields, fileField, fileData, filename, contentType) {
  const boundary = `----WebKitFormBoundary${Date.now()}${Math.random().toString(36)}`;
  let body = '';
  
  // Ajouter les champs de formulaire
  for (const [key, value] of Object.entries(fields)) {
    body += `--${boundary}\r\n`;
    body += `Content-Disposition: form-data; name="${key}"\r\n\r\n`;
    body += `${value}\r\n`;
  }
  
  // Ajouter le fichier
  body += `--${boundary}\r\n`;
  body += `Content-Disposition: form-data; name="${fileField}"; filename="${filename}"\r\n`;
  body += `Content-Type: ${contentType}\r\n\r\n`;
  
  // Convertir Uint8Array en string binaire (approximation)
  // Note: Pour un vrai test, on devrait utiliser une approche plus robuste
  const fileString = String.fromCharCode.apply(null, fileData);
  body += fileString;
  body += `\r\n--${boundary}--\r\n`;
  
  return {
    body: body,
    contentType: `multipart/form-data; boundary=${boundary}`,
  };
}

// Test upload simple
function testSimpleUpload() {
  const filename = `test_${Date.now()}_${Math.random().toString(36).substring(7)}.mp3`;
  const fileSize = Math.min(CHUNK_SIZE * 2, 1024 * 1024); // Max 1MB pour éviter problèmes mémoire
  const fileData = generateTestFile(fileSize);
  
  const startTime = Date.now();
  
  // Créer un multipart form manuellement
  const fields = {
    title: `Test Track ${Date.now()}`,
    artist: 'Test Artist',
    file_type: 'audio',
  };
  
  const multipart = createMultipartBody(fields, 'file', fileData, filename, 'audio/mpeg');
  
  const params = {
    headers: {
      'Authorization': `Bearer ${AUTH_TOKEN}`,
      'Content-Type': multipart.contentType,
    },
  };
  
  // POST /api/v1/tracks (upload simple)
  const res = http.post(`${BASE_URL}/api/v1/tracks`, multipart.body, params);
  
  const duration = Date.now() - startTime;
  uploadDuration.add(duration);
  concurrentUploads.add(1);
  
  const success = check(res, {
    'simple upload status is 201 or 200': (r) => r.status === 201 || r.status === 200,
    'simple upload has response data': (r) => {
      try {
        const body = JSON.parse(r.body);
        return body.success !== false && body.data !== undefined;
      } catch (e) {
        return false;
      }
    },
  });
  
  errorRate.add(!success);
  if (!success) {
    uploadFailures.add(1);
  }
  
  return success;
}

// Test upload par chunks
function testChunkedUpload() {
  const filename = `test_chunked_${Date.now()}_${Math.random().toString(36).substring(7)}.mp3`;
  const totalSize = CHUNK_SIZE * TOTAL_CHUNKS;
  
  const startTime = Date.now();
  
  // Step 1: Initiate chunked upload
  const initiatePayload = JSON.stringify({
    total_chunks: TOTAL_CHUNKS,
    total_size: totalSize,
    filename: filename,
  });
  
  const initiateRes = http.post(
    `${BASE_URL}/api/v1/tracks/initiate`,
    initiatePayload,
    {
      headers: {
        'Content-Type': 'application/json',
        'Authorization': `Bearer ${AUTH_TOKEN}`,
      },
    }
  );
  
  const initiateCheck = check(initiateRes, {
    'initiate returns 200': (r) => r.status === 200,
    'initiate returns upload_id': (r) => {
      try {
        const body = JSON.parse(r.body);
        return body.success === true && body.data && body.data.upload_id;
      } catch (e) {
        return false;
      }
    },
  });
  
  if (!initiateCheck) {
    errorRate.add(true);
    uploadFailures.add(1);
    return false;
  }
  
  const initiateBody = JSON.parse(initiateRes.body);
  const uploadID = initiateBody.data.upload_id;
  
  // Step 2: Upload chunks
  for (let chunkNum = 1; chunkNum <= TOTAL_CHUNKS; chunkNum++) {
    const chunkData = generateTestFile(Math.min(CHUNK_SIZE, 1024 * 1024)); // Max 1MB par chunk
    
    // Créer multipart form manuellement
    const fields = {
      upload_id: uploadID,
      chunk_number: chunkNum.toString(),
      total_chunks: TOTAL_CHUNKS.toString(),
      total_size: totalSize.toString(),
      filename: filename,
    };
    
    const multipart = createMultipartBody(fields, 'chunk', chunkData, `chunk${chunkNum}.bin`, 'application/octet-stream');
    
    const chunkRes = http.post(
      `${BASE_URL}/api/v1/tracks/chunk`,
      multipart.body,
      {
        headers: {
          'Authorization': `Bearer ${AUTH_TOKEN}`,
          'Content-Type': multipart.contentType,
        },
      }
    );
    
    const chunkCheck = check(chunkRes, {
      [`chunk ${chunkNum} returns 200`]: (r) => r.status === 200,
      [`chunk ${chunkNum} has progress`]: (r) => {
        try {
          const body = JSON.parse(r.body);
          return body.success === true && body.data && body.data.progress !== undefined;
        } catch (e) {
          return false;
        }
      },
    });
    
    if (!chunkCheck) {
      errorRate.add(true);
      uploadFailures.add(1);
      return false;
    }
    
    // Petit délai entre chunks pour simuler un comportement réaliste
    sleep(0.1);
  }
  
  // Step 3: Complete chunked upload
  const completePayload = JSON.stringify({
    upload_id: uploadID,
  });
  
  const completeRes = http.post(
    `${BASE_URL}/api/v1/tracks/complete`,
    completePayload,
    {
      headers: {
        'Content-Type': 'application/json',
        'Authorization': `Bearer ${AUTH_TOKEN}`,
      },
    }
  );
  
  const duration = Date.now() - startTime;
  chunkedUploadDuration.add(duration);
  chunkedUploads.add(1);
  
  const completeCheck = check(completeRes, {
    'complete returns 201 or 200': (r) => r.status === 201 || r.status === 200,
    'complete has track data': (r) => {
      try {
        const body = JSON.parse(r.body);
        return body.success === true && body.data && body.data.track;
      } catch (e) {
        return false;
      }
    },
  });
  
  errorRate.add(!completeCheck);
  if (!completeCheck) {
    uploadFailures.add(1);
  }
  
  return completeCheck;
}

// Test upload batch
function testBatchUpload() {
  // Note: Batch upload peut nécessiter plusieurs fichiers
  // Pour simplifier, on teste juste l'endpoint avec un fichier
  const filename = `test_batch_${Date.now()}_${Math.random().toString(36).substring(7)}.mp3`;
  const fileSize = Math.min(CHUNK_SIZE, 1024 * 1024); // Max 1MB
  const fileData = generateTestFile(fileSize);
  
  // Créer multipart form manuellement
  const fields = {};
  const multipart = createMultipartBody(fields, 'files', fileData, filename, 'audio/mpeg');
  
  const params = {
    headers: {
      'Authorization': `Bearer ${AUTH_TOKEN}`,
      'Content-Type': multipart.contentType,
    },
  };
  
  const res = http.post(`${BASE_URL}/api/v1/uploads/batch`, multipart.body, params);
  
  const success = check(res, {
    'batch upload status is 200 or 201': (r) => r.status === 200 || r.status === 201,
  });
  
  errorRate.add(!success);
  if (!success) {
    uploadFailures.add(1);
  }
  
  return success;
}

// Fonction principale exécutée par chaque VU
export default function () {
  if (!AUTH_TOKEN) {
    console.error('AUTH_TOKEN is required for upload tests');
    return;
  }
  
  // Distribuer les tests: 50% upload simple, 40% chunked, 10% batch
  const rand = Math.random();
  
  if (rand < 0.5) {
    // 50% upload simple
    testSimpleUpload();
  } else if (rand < 0.9) {
    // 40% upload chunked
    testChunkedUpload();
  } else {
    // 10% batch upload
    testBatchUpload();
  }
  
  // Délai entre requêtes pour simuler un comportement utilisateur
  sleep(2);
}

// Résumé des résultats
export function handleSummary(data) {
  return {
    'stdout': textSummary(data, { indent: ' ', enableColors: true }),
    'scripts/loadtest/k6_upload_summary.json': JSON.stringify(data),
  };
}

function textSummary(data, options) {
  const indent = options.indent || '';
  const enableColors = options.enableColors || false;
  
  let summary = '\n';
  summary += `${indent}Upload Load Test Summary\n`;
  summary += `${indent}========================\n\n`;
  
  // HTTP Requests
  summary += `${indent}HTTP Requests:\n`;
  summary += `${indent}  Total: ${data.metrics.http_reqs.values.count}\n`;
  summary += `${indent}  Failed: ${(data.metrics.http_req_failed.values.rate * 100).toFixed(2)}%\n\n`;
  
  // Durations
  summary += `${indent}Durations:\n`;
  summary += `${indent}  P95: ${data.metrics.http_req_duration.values['p(95)']}ms\n`;
  summary += `${indent}  P99: ${data.metrics.http_req_duration.values['p(99)']}ms\n\n`;
  
  // Upload metrics
  if (data.metrics.upload_duration) {
    summary += `${indent}Simple Upload Duration:\n`;
    summary += `${indent}  P95: ${data.metrics.upload_duration.values['p(95)']}ms\n`;
    summary += `${indent}  P99: ${data.metrics.upload_duration.values['p(99)']}ms\n`;
  }
  
  if (data.metrics.chunked_upload_duration) {
    summary += `${indent}Chunked Upload Duration:\n`;
    summary += `${indent}  P95: ${data.metrics.chunked_upload_duration.values['p(95)']}ms\n`;
    summary += `${indent}  P99: ${data.metrics.chunked_upload_duration.values['p(99)']}ms\n`;
  }
  
  if (data.metrics.concurrent_uploads) {
    summary += `${indent}Concurrent Uploads: ${data.metrics.concurrent_uploads.values.count}\n`;
  }
  
  if (data.metrics.chunked_uploads) {
    summary += `${indent}Chunked Uploads: ${data.metrics.chunked_uploads.values.count}\n`;
  }
  
  if (data.metrics.upload_failures) {
    summary += `${indent}Upload Failures: ${data.metrics.upload_failures.values.count}\n`;
  }
  
  return summary;
}