/**
 * ROLLCALC V14 - ENHANCED ARTICLE SELECTION & AUTO-WEIGHT
 * =========================================================
 * Improvements:
 * 1. Auto-fill thickness + area_weight from article-data.json
 * 2. Auto-extract roll width from product name
 * 3. Auto-calculate weight when article is selected
 * 4. Better error handling and logging
 */

// ===================================================================
// AUTO-WEIGHT CALCULATION FUNCTION
// ===================================================================
function triggerAutoWeightCalculation() {
  console.log('[AutoCalc] Attempting automatic weight calculation...');
  
  const wiEl = document.getElementById('de-wi');
  const awEl = document.getElementById('d-aw');
  const LEL = document.getElementById('d-le');
  const resultEl = document.getElementById('d-wo');
  
  if (!wiEl || !awEl || !LEL || !resultEl) {
    console.warn('[AutoCalc] Missing weight calculation elements');
    return;
  }
  
  const wi = parseFloat(wiEl.value) || 0;
  const aw = parseFloat(awEl.value) || 0;
  const L  = parseFloat(LEL.value) || 0;
  
  console.log('[AutoCalc] Values: Width=', wi, 'AreaWeight=', aw, 'Length=', L);
  
  if (wi > 0 && aw > 0 && L > 0) {
    const weight = (aw * L * wi / 1000).toFixed(1);
    resultEl.value = weight;
    console.log('[AutoCalc] ✓ Weight calculated:', weight, 'kg');
    return true;
  } else {
    console.log('[AutoCalc] Cannot calculate - missing values');
    resultEl.value = '';
    return false;
  }
}

// ===================================================================
// IMPROVED ARTICLE DROPDOWN POPULATION
// ===================================================================
function populateArticleDropdowns_v14() {
  const data = window.ARTICLE_DATA || [];
  
  if (!data || data.length === 0) {
    console.warn('[ArticleDropdown] No article data available');
    return;
  }
  
  console.log('[ArticleDropdown] Populating with', data.length, 'articles');
  
  // Populate both datalists
  ['d-art', 'e-art'].forEach(function(inputId) {
    const dl = document.getElementById(inputId + '-list');
    if (!dl) {
      console.warn('[ArticleDropdown] Datalist not found:', inputId + '-list');
      return;
    }
    
    data.forEach(function(article) {
      const displayText = article.nr + ' – ' + article.name;
      const opt = document.createElement('option');
      opt.value = displayText;
      opt.dataset.articleNr = article.nr;
      opt.dataset.thickness = article.thickness || 0;
      opt.dataset.areaWeight = article.area_weight || 0;
      opt.dataset.width = extractWidthFromName(article.name) || 0;
      opt.dataset.fullData = JSON.stringify(article);
      
      dl.appendChild(opt);
    });
  });
  
  console.log('[ArticleDropdown] ✓ Datalists populated');
  
  // ===================================================================
  // DIRECT CALCULATION TAB - Article Selection Handler
  // ===================================================================
  const dArt = document.getElementById('d-art');
  if (dArt) {
    dArt.addEventListener('input', function() {
      const inputVal = dArt.value.trim();
      
      // Try to find matching article
      const match = data.find(function(a) {
        const displayText = a.nr + ' – ' + a.name;
        return displayText === inputVal || 
               inputVal.startsWith(a.nr + ' –') || 
               inputVal === a.nr;
      });
      
      if (match) {
        console.log('[DirectCalc-Article] ✓ Article found:', match.nr);
        
        // 1. AUTO-FILL THICKNESS
        document.getElementById('d-th').value = match.thickness || 0;
        console.log('  └─ Thickness:', match.thickness);
        
        // 2. AUTO-FILL AREA WEIGHT (if available)
        if (match.area_weight && match.area_weight > 0) {
          document.getElementById('d-aw').value = match.area_weight;
          console.log('  └─ Area Weight:', match.area_weight, 'g/m²');
        } else {
          console.log('  └─ Area Weight: not available (0)');
          document.getElementById('d-aw').value = '';
        }
        
        // 3. AUTO-EXTRACT ROLL WIDTH from product name (e.g., "5,00 x 30 m" → 5.00)
        const extractedWidth = extractWidthFromName(match.name);
        if (extractedWidth > 0) {
          document.getElementById('de-wi').value = extractedWidth;
          console.log('  └─ Roll Width extracted:', extractedWidth, 'm');
        }
        
        // 4. TRIGGER automatic weight calculation (async)
        setTimeout(function() {
          triggerAutoWeightCalculation();
        }, 100);
        
      } else if (inputVal.length > 0) {
        console.log('[DirectCalc-Article] No match found for:', inputVal);
      }
    });
  }
  
  // ===================================================================
  // EXTRAPOLATION TAB - Article Selection Handler
  // ===================================================================
  const eArt = document.getElementById('e-art');
  if (eArt) {
    eArt.addEventListener('input', function() {
      const inputVal = eArt.value.trim();
      
      const match = data.find(function(a) {
        const displayText = a.nr + ' – ' + a.name;
        return displayText === inputVal || 
               inputVal.startsWith(a.nr + ' –') || 
               inputVal === a.nr;
      });
      
      if (match) {
        console.log('[Extrap-Article] ✓ Article found:', match.nr);
        
        // Set core diameter (default 150 if not specified)
        const coreVal = match.core_type && match.core_type > 0 ? match.core_type : 150;
        document.getElementById('e-co').value = coreVal;
        console.log('  └─ Core Diameter:', coreVal, 'mm');
      }
    });
  }
  
  // ===================================================================
  // CORE PRESET BUTTONS
  // ===================================================================
  document.querySelectorAll('.core-preset-btn').forEach(function(btn) {
    btn.addEventListener('click', function(e) {
      e.preventDefault();
      const coreVal = btn.dataset.core;
      const pane = btn.closest('.tab-pane');
      
      if (pane) {
        const inp = pane.querySelector('input[id$="-co"]');
        if (inp) {
          inp.value = coreVal;
          
          // Visual feedback
          pane.querySelectorAll('.core-preset-btn').forEach(function(b) {
            b.classList.remove('active');
          });
          btn.classList.add('active');
          
          console.log('[CorePreset] Set to:', coreVal, 'mm');
        }
      }
    });
  });
  
  console.log('[ArticleDropdown] ✓ All event listeners attached');
}

// ===================================================================
// HELPER: Extract width from product name
// ===================================================================
function extractWidthFromName(productName) {
  if (!productName) return 0;
  
  // Regex: Match patterns like "5,00 x 30 m" or "5.00 x 30 m" or "4,85 x 40 m"
  const match = productName.match(/(\d+[,\.]\d+)\s*x\s*\d+\s*m/i);
  
  if (match && match[1]) {
    // Convert German decimal (comma) to English decimal (dot)
    const widthStr = match[1].replace(',', '.');
    const width = parseFloat(widthStr);
    
    if (width > 0 && width < 100) {  // Sanity check
      return width;
    }
  }
  
  return 0;
}

// ===================================================================
// ENHANCED WEIGHT CALCULATION - Listen to all relevant inputs
// ===================================================================
function setupWeightCalculationListeners() {
  console.log('[WeightCalc] Setting up automatic calculation listeners...');
  
  const inputIds = ['de-wi', 'd-aw', 'd-le'];
  
  inputIds.forEach(function(id) {
    const el = document.getElementById(id);
    if (el) {
      el.addEventListener('change', function() {
        console.log('[WeightCalc] Input changed:', id);
        triggerAutoWeightCalculation();
      });
      
      // Also trigger on blur for better UX
      el.addEventListener('blur', function() {
        triggerAutoWeightCalculation();
      });
    }
  });
  
  console.log('[WeightCalc] ✓ Listeners attached to:', inputIds.join(', '));
}

// ===================================================================
// INITIALIZATION HOOK
// ===================================================================
function initRollCalcV14() {
  console.log('[RollCalcV14] Initializing enhanced features...');
  
  // Wait for article data to be loaded
  const checkDataInterval = setInterval(function() {
    if (window.ARTICLE_DATA && window.ARTICLE_DATA.length > 0) {
      clearInterval(checkDataInterval);
      console.log('[RollCalcV14] ✓ Article data ready, populating dropdowns...');
      
      // Use improved version
      populateArticleDropdowns_v14();
      setupWeightCalculationListeners();
      
      console.log('[RollCalcV14] ✓ Initialization complete');
    }
  }, 100);
  
  // Failsafe: timeout after 5 seconds
  setTimeout(function() {
    if (window.ARTICLE_DATA && window.ARTICLE_DATA.length > 0) {
      clearInterval(checkDataInterval);
    } else {
      console.warn('[RollCalcV14] Article data not loaded within 5s - using fallback');
      clearInterval(checkDataInterval);
    }
  }, 5000);
}

// ===================================================================
// EXPORT & ATTACH TO WINDOW
// ===================================================================
window.RollCalcV14 = {
  initRollCalcV14: initRollCalcV14,
  triggerAutoWeightCalculation: triggerAutoWeightCalculation,
  populateArticleDropdowns_v14: populateArticleDropdowns_v14,
  extractWidthFromName: extractWidthFromName,
  setupWeightCalculationListeners: setupWeightCalculationListeners
};

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

// Auto-init when DOM is ready
document.addEventListener('DOMContentLoaded', function() {
  console.log('[RollCalcV14] DOM ready - starting initialization');
  window.RollCalcV14.initRollCalcV14();
});