const { spawn } = require('child_process');
const { PrismaClient } = require('@prisma/client');
const { PrismaPg } = require('@prisma/adapter-pg');
const { Pool } = require('pg');
const puppeteer = require('puppeteer');
const fs = require('fs');
const path = require('path');
require('dotenv').config();

const PORT = 3012;
const BASE_URL = `http://localhost:${PORT}`;
const SCREENSHOT_DIR = path.join(__dirname, 'screenshots-phase4');

let nextProcess;
let prisma;
let pool;
let browser;

// Ensure screenshot dir exists
if (!fs.existsSync(SCREENSHOT_DIR)) {
  fs.mkdirSync(SCREENSHOT_DIR, { recursive: true });
}

function getPrisma() {
  if (!prisma) {
    const dbUrl = new URL(process.env.DATABASE_URL);
    pool = new Pool({
      host: dbUrl.hostname,
      port: dbUrl.port ? parseInt(dbUrl.port) : 5432,
      user: decodeURIComponent(dbUrl.username),
      password: decodeURIComponent(dbUrl.password),
      database: dbUrl.pathname.substring(1).split('?')[0],
      ssl: false
    });
    const adapter = new PrismaPg(pool);
    prisma = new PrismaClient({ adapter });
  }
  return prisma;
}

async function runAsAdmin(queryFn) {
  const db = getPrisma();
  return db.$transaction(async (tx) => {
    await tx.$executeRawUnsafe(`SET LOCAL app.current_user_role = 'admin';`);
    return queryFn(tx);
  });
}

async function sleep(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

let passed = 0;
let failed = 0;

function assert(condition, message) {
  if (condition) {
    console.log(`  ✓ PASS: ${message}`);
    passed++;
  } else {
    console.error(`  ✗ FAIL: ${message}`);
    failed++;
  }
}

async function cleanupDb() {
  console.log("Cleaning up E2E test sales import records in database...");
  await runAsAdmin(async (tx) => {
    // Clean sales results created by test scripts
    await tx.salesResult.deleteMany({
      where: {
        idempotencyKey: {
          startsWith: 'test-key-p4'
        }
      }
    });
    // Clean audit logs associated
    await tx.auditLog.deleteMany({
      where: {
        action: 'CREATE',
        targetTable: 'sales_results'
      }
    });
  });
}

async function runTests() {
  console.log("=== STARTING PHASE 4 DATA IMPORT & INTEGRATIONS E2E PUPPETEER TEST SUITE ===");

  // 1. Clean database records first
  await cleanupDb();

  // 2. Start Next.js production server on port 3012
  console.log(`Starting Next.js production server on port ${PORT}...`);
  nextProcess = spawn('node', ['node_modules/next/dist/bin/next', 'start', '--port', String(PORT)], {
    env: { ...process.env, PORT: String(PORT) }
  });

  nextProcess.stdout.on('data', (data) => {
    console.log(`[Next.js] ${data.toString().trim()}`);
  });
  nextProcess.stderr.on('data', (data) => {
    console.error(`[Next.js ERR] ${data.toString().trim()}`);
  });

  // Wait for server to start up
  let serverReady = false;
  for (let i = 0; i < 15; i++) {
    await sleep(2000);
    try {
      const res = await fetch(`${BASE_URL}/api/auth/me`);
      serverReady = true;
      break;
    } catch (e) {
      // Server not ready yet
    }
  }

  if (!serverReady) {
    console.error("Error: Next.js server failed to start within timeout.");
    await cleanup();
    process.exit(1);
  }
  console.log("Next.js server is ready!");

  // 3. Launch Puppeteer browser
  console.log("Launching Puppeteer browser...");
  browser = await puppeteer.launch({
    headless: 'shell',
    args: ['--no-sandbox', '--disable-setuid-sandbox', '--disable-dev-shm-usage', '--disable-gpu']
  });

  const page = await browser.newPage();
  await page.setViewport({ width: 1280, height: 800 });

  // --- TEST 1: ROLE SEGREGATION (COLLABORATOR BLOCKED) ---
  console.log("\n[Test 1] Logging in as collaborator and verifying block on /sales/import...");
  await page.goto(`${BASE_URL}/login`, { waitUntil: 'networkidle2' });
  await page.type('#username', 'colaborador_mde');
  await page.type('#password', 'password123');
  await page.click('button[type="submit"]');
  await page.waitForSelector('#btn-create-plan'); // Wait for home page dashboard load
  
  // Try navigating to import page
  await page.goto(`${BASE_URL}/sales/import`, { waitUntil: 'networkidle2' });
  await page.screenshot({ path: path.join(SCREENSHOT_DIR, '01_collaborator_unauthorized.png') });
  
  // Check if header Cargar Ventas is not visible, and redirect or error occurs
  const hasImportLink = await page.evaluate(() => {
    return document.querySelector('#nav-import-sales') !== null;
  });
  assert(!hasImportLink, "Collaborator is not shown the 'Cargar Ventas' link in the header");

  // Verify direct API POST block (returns 403)
  const apiBlockRes = await page.evaluate(async () => {
    const res = await fetch('/api/sales/import', {
      method: 'POST',
      headers: {
        'idempotency-key': 'test-key-p4-fake'
      }
    });
    return { status: res.status };
  });
  assert(apiBlockRes.status === 403, "API POST /api/sales/import returns 403 Forbidden for collaborator");

  // Logout collaborator
  await page.goto(`${BASE_URL}/plans`, { waitUntil: 'networkidle2' });
  await page.evaluate(() => {
    const buttons = Array.from(document.querySelectorAll('button'));
    const logoutBtn = buttons.find(b => b.textContent.includes('Cerrar Sesión'));
    if (logoutBtn) logoutBtn.click();
  });
  await sleep(1500);

  // --- TEST 2: ADMIN ACCESS & UI ELEMENTS ---
  console.log("\n[Test 2] Logging in as admin and verifying import page...");
  await page.goto(`${BASE_URL}/login`, { waitUntil: 'networkidle2' });
  await page.type('#username', 'admin');
  await page.type('#password', 'password123');
  await page.click('button[type="submit"]');
  await page.waitForSelector('#btn-create-plan');

  // Navigate to import page
  await page.click('#nav-import-sales');
  await page.waitForSelector('#btn-download-template');
  await page.screenshot({ path: path.join(SCREENSHOT_DIR, '02_admin_import_view.png') });
  assert(page.url().endsWith('/sales/import'), "Redirected to /sales/import for authorized Admin role");

  const downloadLinkExists = await page.evaluate(() => {
    const el = document.querySelector('#btn-download-template');
    return el && el.getAttribute('href') === '/templates/import_sales_template.xlsx';
  });
  assert(downloadLinkExists, "Template download button points to the correct static template URL");

  // --- TEST 3: ATOMIC EXCEL FILE VALIDATION ---
  console.log("\n[Test 3] Uploading invalid test Excel file and verifying inconsistency panel...");
  const invalidFilePath = path.join(__dirname, '..', 'public', 'templates', 'import_sales_test.xlsx');
  
  // Select file in input
  const fileInput = await page.$('input[type="file"]');
  await fileInput.uploadFile(invalidFilePath);
  await sleep(1000);
  await page.screenshot({ path: path.join(SCREENSHOT_DIR, '03_invalid_file_selected.png') });

  // Click submit
  await page.click('#btn-submit-upload');
  await page.waitForSelector('#inconsistency-panel');
  await page.screenshot({ path: path.join(SCREENSHOT_DIR, '04_validation_errors_rendered.png') });

  // Validate error rendering contents
  const validationErrorCount = await page.evaluate(() => {
    return document.querySelectorAll('tbody tr').length;
  });
  assert(validationErrorCount === 4, "Atomic validation catches all 4 invalid rows in the sheet");

  const errorTexts = await page.evaluate(() => {
    return Array.from(document.querySelectorAll('.cellMsg')).map(el => el.textContent);
  });
  assert(errorTexts.some(t => t.includes("colaborador_inexistente")), "Rendered 'colaborador_inexistente' username validation error");
  assert(errorTexts.some(t => t.includes("2026/06")), "Rendered invalid Period format validation error");
  assert(errorTexts.some(t => t.includes("EST-FAKE")), "Rendered non-existent Hotel code validation error");
  assert(errorTexts.some(t => t.includes("monto")), "Rendered negative sales amount validation error");

  // Check that no rows were inserted in DB
  const dbCount = await runAsAdmin(tx => tx.salesResult.count());
  assert(dbCount === 0, "No records written to the database (atomic roll-back verified)");

  // --- TEST 4: SUCCESSFUL DIRECT IMPORT & IDEMPOTENCY ---
  console.log("\n[Test 4] Uploading valid template Excel file and checking direct database save...");
  const validFilePath = path.join(__dirname, '..', 'public', 'templates', 'import_sales_template.xlsx');
  
  // Refresh page to reset state and key
  await page.reload({ waitUntil: 'networkidle2' });
  
  // Attach valid file
  const fileInputValid = await page.$('input[type="file"]');
  await fileInputValid.uploadFile(validFilePath);
  await sleep(1000);

  // Submit
  await page.click('#btn-submit-upload');
  await page.waitForSelector('#upload-success-msg');
  await page.screenshot({ path: path.join(SCREENSHOT_DIR, '05_valid_upload_success.png') });

  // Check db records
  const dbSales = await runAsAdmin(tx => tx.salesResult.findMany({
    where: {
      idempotencyKey: {
        startsWith: 'key-'
      }
    }
  }));
  assert(dbSales.length === 1, "1 sales result successfully imported into the database");
  assert(parseFloat(dbSales[0].amount) === 15000.00, "Monto of imported sales result matches template value (15,000.00)");
  assert(dbSales[0].salesCount === 5, "Cantidad of imported sales result matches template value (5)");

  // Attempt upload again with the SAME key (verify idempotency check)
  console.log("Uploading the same file again (verifying idempotency)...");
  // Trigger upload button again without refreshing (maintains current session idempotencyKey state)
  await page.click('#btn-submit-upload');
  await sleep(1500);
  await page.screenshot({ path: path.join(SCREENSHOT_DIR, '06_idempotency_duplicate.png') });

  const finalDbCount = await runAsAdmin(tx => tx.salesResult.count({
    where: {
      idempotencyKey: {
        startsWith: 'key-'
      }
    }
  }));
  assert(finalDbCount === 1, "Idempotency verified: duplicate upload request was blocked from inserting duplicate rows");

  // --- TEST 5: N8N CALLBACK AUTHENTICATION AND BATCH-SAVE ---
  console.log("\n[Test 5] Simulating n8n callback `/api/sales/batch-save` signature checking...");
  
  // Trigger callback with invalid signature
  const callbackUnauthorized = await page.evaluate(async () => {
    const res = await fetch('/api/sales/batch-save', {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'x-n8n-signature': 'invalid-secret'
      },
      body: JSON.stringify({
        idempotencyKey: 'test-key-p4-n8n',
        uploaderId: 1,
        sales: []
      })
    });
    return { status: res.status };
  });
  assert(callbackUnauthorized.status === 401, "Webhook callback returns 401 Unauthorized for invalid signature");

  // Trigger callback with valid signature
  const callbackSuccess = await page.evaluate(async () => {
    const res = await fetch('/api/sales/batch-save', {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'x-n8n-signature': 'local_shared_signature_to_verify_n8n_callbacks'
      },
      body: JSON.stringify({
        idempotencyKey: 'test-key-p4-n8n',
        uploaderId: 1,
        sales: [
          {
            username: 'colaborador_mde',
            hotelCode: 'EST-MDE',
            period: '2026-06',
            amount: 35000.00,
            salesCount: 8,
            transactionId: 'TX-N8N-001'
          }
        ]
      })
    });
    return { status: res.status };
  });
  assert(callbackSuccess.status === 201, "Webhook callback returns 201 Created for valid signature and payload");

  // Verify n8n-inserted record in database
  const n8nSales = await runAsAdmin(tx => tx.salesResult.findMany({
    where: {
      idempotencyKey: {
        startsWith: 'test-key-p4-n8n'
      }
    }
  }));
  assert(n8nSales.length === 1, "n8n callback successfully inserted sales result row in database");
  assert(parseFloat(n8nSales[0].amount) === 35000.00, "n8n sales result row amount matches callback payload");

  await cleanup();
  
  console.log(`\n=== E2E TEST RESULTS: ${passed} PASSED, ${failed} FAILED ===`);
  if (failed > 0) {
    process.exit(1);
  } else {
    process.exit(0);
  }
}

async function cleanup() {
  console.log("\nCleaning up E2E test browser and server processes...");
  try {
    if (browser) {
      await browser.close();
    }
  } catch (e) {}

  try {
    await cleanupDb();
    if (prisma) {
      await prisma.$disconnect();
    }
    if (pool) {
      await pool.end();
    }
  } catch (e) {
    console.error("Error during DB cleanup:", e);
  }

  if (nextProcess) {
    nextProcess.kill();
  }
}

process.on('SIGINT', () => {
  cleanup();
  process.exit(1);
});

runTests().catch(async err => {
  console.error("Fatal E2E test runner error:", err);
  if (browser) {
    try {
      const pages = await browser.pages();
      if (pages.length > 0) {
        await pages[0].screenshot({ path: path.join(SCREENSHOT_DIR, 'error_screenshot.png') });
        console.log("Saved error_screenshot.png to", path.join(SCREENSHOT_DIR, 'error_screenshot.png'));
      }
    } catch (screenshotErr) {
      console.error("Failed to capture error screenshot:", screenshotErr);
    }
  }
  await cleanup();
  process.exit(1);
});