/**
 * ROLLCALC V14 - ARTICLE SELECTION & AUTO-CALCULATION
 * ====================================================
 * Handles article selection, auto-fill of dimensions, and weight calculation
 * Integrates with stddev_calculator.js for range calculations
 */

/**
 * Populate article dropdowns from ARTICLE_DATA
 */
function initializeArticleDropdowns() {
  const data = window.ARTICLE_DATA || [];
  console.log('[ArticleDropdown] Initializing with', data.length, 'articles');
  
  // Populate datalists for both tabs
  ['d-art', 'e-art'].forEach(inputId => {
    const datalist = document.getElementById(inputId + '-list');
    if (!datalist) {
      console.warn('[ArticleDropdown] Datalist not found:', inputId + '-list');
      return;
    }
    
    datalist.innerHTML = ''; // Clear existing
    data.forEach(article => {
      const option = document.createElement('option');
      option.value = `${article.nr} – ${article.name}`;
      option.dataset.articleNr = article.nr;
      option.dataset.thickness = article.thickness || 0;
      option.dataset.areaWeight = article.area_weight || 0;
      option.dataset.thicknessStddev = article.thickness_stddev || 0;
      option.dataset.areaWeightStddev = article.area_weight_stddev || 0;
      datalist.appendChild(option);
    });
  });
  
  // Setup event listeners for article selection
  setupArticleSelectionListeners();
  setupWeightCalculationListeners();
  
  console.log('[ArticleDropdown] Initialization complete');
}

/**
 * Setup listeners for when user selects an article
 */
function setupArticleSelectionListeners() {
  const dArtInput = document.getElementById('d-art');
  if (!dArtInput) return;
  
  const dArtList = document.getElementById('d-art-list');
  const data = window.ARTICLE_DATA || [];
  
  dArtInput.addEventListener('input', function() {
    const inputValue = dArtInput.value.trim();
    
    // Find matching article
    const match = data.find(a => 
      inputValue === `${a.nr} – ${a.name}` || 
      inputValue === a.nr ||
      inputValue.startsWith(a.nr + ' –')
    );
    
    if (match) {
      console.log('[ArticleSelection] Found:', match.nr, '-', match.name);
      
      // 1. Auto-fill thickness
      const thField = document.getElementById('d-th');
      if (thField) {
        thField.value = match.thickness || 0;
        thField.dataset.stddev = match.thickness_stddev || 0;
      }
      
      // 2. Auto-fill area weight
      const awField = document.getElementById('d-aw');
      if (awField && match.area_weight && match.area_weight > 0) {
        awField.value = match.area_weight;
        awField.dataset.stddev = match.area_weight_stddev || 0;
      }
      
      // 3. Extract width from article name (e.g., "5.0 x 5m" → 5.0)
      const widthMatch = match.name.match(/(\d+[,\.]\d+)\s*x\s*\d+\s*m/i);
      if (widthMatch) {
        const width = parseFloat(widthMatch[1].replace(',', '.'));
        const wiField = document.getElementById('de-wi');
        if (wiField && width > 0 && width < 100) {
          wiField.value = width;
        }
      }
      
      console.log('[ArticleSelection] Auto-filled:', {
        thickness: match.thickness,
        area_weight: match.area_weight,
        thickness_stddev: match.thickness_stddev,
        area_weight_stddev: match.area_weight_stddev
      });
      
      // Trigger auto-calculation after short delay
      setTimeout(triggerAutoWeightCalculation, 100);
    }
  });
}

/**
 * Setup listeners for weight field changes (Roll Width, Area Weight, Product Length)
 */
function setupWeightCalculationListeners() {
  const fieldIds = ['de-wi', 'd-aw', 'd-le'];
  
  fieldIds.forEach(id => {
    const el = document.getElementById(id);
    if (el) {
      el.addEventListener('change', triggerAutoWeightCalculation);
      el.addEventListener('blur', triggerAutoWeightCalculation);
      el.addEventListener('input', () => {
        // Debounce: recalculate after user stops typing
        clearTimeout(el._autoCalcTimeout);
        el._autoCalcTimeout = setTimeout(triggerAutoWeightCalculation, 300);
      });
    }
  });
}

/**
 * Auto-calculate weight when width, area_weight, or length changes
 */
function triggerAutoWeightCalculation() {
  const wiEl = document.getElementById('de-wi');
  const awEl = document.getElementById('d-aw');
  const leEl = document.getElementById('d-le');
  const woEl = document.getElementById('d-wo');
  
  if (!wiEl || !awEl || !leEl || !woEl) return;
  
  const wi = parseFloat(wiEl.value) || 0;
  const aw = parseFloat(awEl.value) || 0;
  const le = parseFloat(leEl.value) || 0;
  
  if (wi > 0 && aw > 0 && le > 0) {
    // Calculate with stddev if available
    const aw_stddev = parseFloat(awEl.dataset.stddev) || 0;
    
    if (window.StdDevCalculator && aw_stddev > 0) {
      // Calculate weight ranges
      const ranges = window.StdDevCalculator.calculateWeightRanges(aw, aw_stddev, le, wi);
      woEl.value = ranges.nom.toFixed(1);
      woEl.dataset.weight_nom = ranges.nom.toFixed(1);
      woEl.dataset.weight_min = ranges.min.toFixed(1);
      woEl.dataset.weight_max = ranges.max.toFixed(1);
      
      console.log('[AutoCalc] Weight with stddev:', {
        nom: ranges.nom.toFixed(1),
        min: ranges.min.toFixed(1),
        max: ranges.max.toFixed(1)
      });
    } else {
      // Simple calculation without stddev
      const weight = (aw * le * wi / 1000).toFixed(1);
      woEl.value = weight;
      woEl.dataset.weight_nom = weight;
      woEl.dataset.weight_max = weight;
      
      console.log('[AutoCalc] Weight (no stddev):', weight, 'kg');
    }
    
    return true;
  }
  
  woEl.value = '';
  delete woEl.dataset.weight_nom;
  delete woEl.dataset.weight_max;
  return false;
}

/**
 * Setup core preset buttons
 */
function setupCorePresetButtons() {
  document.querySelectorAll('.core-preset-btn').forEach(btn => {
    btn.addEventListener('click', function(e) {
      e.preventDefault();
      const coreValue = btn.dataset.core;
      const tabPane = btn.closest('.tab-pane');
      
      if (tabPane) {
        const coreInput = tabPane.querySelector('input[id$="-co"]');
        if (coreInput) {
          coreInput.value = coreValue;
          
          // Update active state
          tabPane.querySelectorAll('.core-preset-btn').forEach(b => b.classList.remove('active'));
          btn.classList.add('active');
          
          console.log('[CorePreset] Set core diameter:', coreValue, 'mm');
        }
      }
    });
  });
}

/**
 * Initialize everything when DOM is ready
 */
document.addEventListener('DOMContentLoaded', function() {
  console.log('[RollCalcV14] Initializing...');
  
  // Wait for article data to be loaded
  const maxRetries = 50;
  let retries = 0;
  
  const waitForData = setInterval(function() {
    if (window.ARTICLE_DATA && window.ARTICLE_DATA.length > 0) {
      clearInterval(waitForData);
      initializeArticleDropdowns();
      setupCorePresetButtons();
      console.log('[RollCalcV14] Ready');
    } else if (retries++ > maxRetries) {
      clearInterval(waitForData);
      console.warn('[RollCalcV14] Article data not loaded after', maxRetries, 'retries');
    }
  }, 100);
});

// Export functions
window.RollCalcV14 = {
  initializeArticleDropdowns,
  setupArticleSelectionListeners,
  setupWeightCalculationListeners,
  triggerAutoWeightCalculation,
  setupCorePresetButtons
};

console.log('[RollCalcV14] Module loaded');