/**
 * INTEGRATION PATCH FOR STDDEV RANGES
 * ====================================
 * 
 * This shows how to integrate the StdDev calculator into the existing
 * Direct Calculation button handler in roll_calculator.html
 * 
 * CHANGES:
 * 1. Load stddev data from article-data.json when article is selected
 * 2. Modify the d-calc button handler to use ranges
 * 3. Update Forklift checker to use worst-case weight
 * 4. Keep everything backward compatible
 */

// ===================================================================
// PATCH 1: STORE STDDEV IN HIDDEN FIELDS DURING ARTICLE SELECTION
// ===================================================================
// Add this to populateArticleDropdowns_v14() in rollcalc_improvements.js
// In the article selection handler for d-art:

/*
if (match) {
  console.log('[Article Select] Found:', match.nr, '- Thickness:', match.thickness, 'Area Weight:', match.area_weight);
  
  // 1. Auto-fill Thickness
  document.getElementById('d-th').value = match.thickness;
  
  // 2. Auto-fill Area Weight
  if (match.area_weight && match.area_weight > 0) {
    document.getElementById('d-aw').value = match.area_weight;
  }
  
  // 3. Auto-fill Roll Width
  var widthMatch = match.name.match(/(\d+[,\.]\d+)\s*x\s*\d+/);
  if (widthMatch) {
    var width = widthMatch[1].replace(',', '.');
    document.getElementById('de-wi').value = width;
  }
  
  // NEW: Store stddev values in hidden attributes
  document.getElementById('d-th').dataset.stddev = match.thickness_stddev || 0;
  document.getElementById('d-aw').dataset.stddev = match.area_weight_stddev || 0;
  
  console.log('[StdDev] Stored:', {
    thickness_stddev: match.thickness_stddev,
    area_weight_stddev: match.area_weight_stddev
  });
  
  setTimeout(function() {
    triggerAutoWeightCalculation();
  }, 50);
}
*/

// ===================================================================
// PATCH 2: MODIFY d-calc BUTTON HANDLER FOR DIAMETER MODE
// ===================================================================
// Replace the diameter calculation section in the d-calc click handler:

/*
OLD CODE (diameter mode):
  if (mode === 'diameter') {
    if (!d_mm || !t_mm || !L_m) { alert('Please enter d, t and L.'); return; }
    const D_nom = Math.sqrt(d_mm*d_mm + (4*L_m*1000*t_mm)/Math.PI);
    resLabel.textContent = 'Roll Diameter (D)';
    resVal.textContent   = D_nom.toFixed(1) + ' mm';
    if (tol) {
      const D_min = Math.sqrt(d_mm*d_mm + (4*L_m*1000*(t_mm-tol))/Math.PI);
      const D_max = Math.sqrt(d_mm*d_mm + (4*L_m*1000*(t_mm+tol))/Math.PI);
      resRange.textContent = 'Min: ' + D_min.toFixed(1) + ' mm  |  Max: ' + D_max.toFixed(1) + ' mm';
    } else { resRange.textContent = ''; }
    document.getElementById('d-di').value = D_nom.toFixed(1);
    calculatedLength = L_m;
  }

NEW CODE (with stddev):
*/

// Example replacement for diameter mode:
function calculateDiameterWithStddev(d_mm, t_mm, t_stddev, L_m, tol) {
  if (!d_mm || !t_mm || !L_m) {
    alert('Please enter d, t and L.');
    return false;
  }
  
  // Get stddev from data attribute (set during article selection)
  const thField = document.getElementById('d-th');
  const actualStddev = t_stddev || parseFloat(thField?.dataset.stddev || 0);
  
  const resBox = document.getElementById('d-result');
  const resLabel = document.getElementById('d-res-label');
  const resVal = document.getElementById('d-res-val');
  const resRange = document.getElementById('d-res-range');
  const diField = document.getElementById('d-di');
  
  // Use StdDev calculator
  const diameterRanges = window.StdDevCalculator.calculateDiameterRanges(
    d_mm, t_mm, actualStddev, L_m
  );
  
  resLabel.textContent = 'Roll Diameter (D)';
  resVal.textContent   = diameterRanges.nom.toFixed(1) + ' mm';
  
  // Show ±2σ range
  const d_low = Math.min(diameterRanges.min, diameterRanges.max);
  const d_high = Math.max(diameterRanges.min, diameterRanges.max);
  
  let rangeText = `Range (±2σ): ${d_low.toFixed(1)} – ${d_high.toFixed(1)} mm`;
  
  if (tol && tol > 0) {
    const d_tol_min = diameterRanges.nom - tol;
    const d_tol_max = diameterRanges.nom + tol;
    rangeText += ` | Tol: ${d_tol_min.toFixed(1)} – ${d_tol_max.toFixed(1)} mm`;
  }
  
  resRange.textContent = rangeText;
  diField.value = diameterRanges.nom.toFixed(1);
  resBox.style.display = 'block';
  
  console.log('[StdDev-Calc] Diameter with ranges:', diameterRanges);
  
  return {
    calculatedLength: L_m,
    diameterRanges: diameterRanges
  };
}

// ===================================================================
// PATCH 3: MODIFY WEIGHT CALCULATION FOR STDDEV RANGES
// ===================================================================
// Replace the weight calculation in calcWeight():

/*
OLD:
  function calcWeight(length) {
    const wi = parseFloat(document.getElementById('de-wi').value) || 0;
    const aw = parseFloat(document.getElementById('d-aw').value) || 0;
    if (wi > 0 && aw > 0 && length > 0) {
      const w = (aw * length * wi / 1000).toFixed(1);
      document.getElementById('d-wo').value = w;
      return parseFloat(w);
    }
    document.getElementById('d-wo').value = '';
    return null;
  }

NEW:
*/

function calcWeightWithStddev(length) {
  const wi = parseFloat(document.getElementById('de-wi').value) || 0;
  const aw = parseFloat(document.getElementById('d-aw').value) || 0;
  const awField = document.getElementById('d-aw');
  const awStddev = parseFloat(awField?.dataset.stddev || 0);
  
  if (wi > 0 && aw > 0 && length > 0) {
    // Calculate weight ranges
    const weightRanges = window.StdDevCalculator.calculateWeightRanges(
      aw, awStddev, length, wi
    );
    
    // Store in field and data attributes
    const woField = document.getElementById('d-wo');
    woField.value = weightRanges.nom.toFixed(1);
    woField.dataset.weight_nom = weightRanges.nom.toFixed(1);
    woField.dataset.weight_min = weightRanges.min.toFixed(1);
    woField.dataset.weight_max = weightRanges.max.toFixed(1);
    
    console.log('[StdDev-Weight] Calculated ranges:', {
      nom: weightRanges.nom.toFixed(1),
      min: weightRanges.min.toFixed(1),
      max: weightRanges.max.toFixed(1)
    });
    
    return weightRanges;
  }
  
  document.getElementById('d-wo').value = '';
  return null;
}

// ===================================================================
// PATCH 4: UPDATE FORKLIFT CHECKER TO USE WORST-CASE
// ===================================================================
// In ForkliftChecker.evaluate(), use worst-case weight:

/*
OLD:
  evaluate(weightKg, coreMm, category) {
    const box = document.getElementById('forkliftCheck');
    // ... check if weightKg > limit
  }

NEW:
*/

function evaluateForkliftWithWorstCase(coreMm, category) {
  const woField = document.getElementById('d-wo');
  if (!woField) return true;
  
  // Get worst-case weight
  const weight_nom = parseFloat(woField.value) || 0;
  const weight_max = parseFloat(woField.dataset.weight_max) || weight_nom;
  
  // Use maximum for safety
  const weightToCheck = Math.max(weight_nom, weight_max);
  
  console.log('[Forklift-StdDev] Using worst-case weight:', {
    nominal: weight_nom.toFixed(1),
    worst_case: weight_max.toFixed(1),
    checking: weightToCheck.toFixed(1)
  });
  
  if (window.ForkliftChecker) {
    return window.ForkliftChecker.evaluate(weightToCheck, coreMm, category);
  }
  
  return true;
}

// ===================================================================
// COMPLETE EXAMPLE: NEW d-calc HANDLER WITH STDDEV
// ===================================================================
/*
document.getElementById('d-calc').addEventListener('click', () => {
  const mode     = document.querySelector('.mode-btn.active')?.dataset.mode || 'diameter';
  const d_mm     = parseFloat(document.getElementById('d-co').value)  || 0;
  const t_mm     = parseFloat(document.getElementById('d-th').value)  || 0;
  const tol      = parseFloat(document.getElementById('d-tol').value) || 0;
  const L_m      = parseFloat(document.getElementById('d-le').value)  || 0;
  const D_mm     = parseFloat(document.getElementById('d-di').value)  || 0;
  const category = (document.getElementById('d-cat')?.value || '').toLowerCase();

  if (mode === 'diameter') {
    // Use new function with stddev
    const result = calculateDiameterWithStddev(d_mm, t_mm, null, L_m, tol);
    if (!result) return;
    
    const calculatedLength = result.calculatedLength;
    const diameterRanges = result.diameterRanges;
    
    // Calculate weight with stddev
    const weightRanges = calcWeightWithStddev(calculatedLength);
    
    // Evaluate forklift with worst-case weight
    evaluateForkliftWithWorstCase(d_mm, category);
    
    // Store for Load Optimizer (use nominal)
    if (weightRanges) {
      window.loadOptimizerUI.optimizer.setRollData({
        rollDiameter: diameterRanges.nom,
        coreDiameter: d_mm,
        rollWidth: parseFloat(document.getElementById('de-wi').value) || 0,
        rollWeight: weightRanges.nom,  // Nominal for optimizer
        m2PerRoll: calculatedLength * (parseFloat(document.getElementById('de-wi').value) || 0),
        productLength: calculatedLength
      });
    }
  }
  
  // ... handle other modes ...
});
*/

// ===================================================================
// EXPORT FUNCTIONS
// ===================================================================
window.StdDevIntegration = {
  calculateDiameterWithStddev: calculateDiameterWithStddev,
  calcWeightWithStddev: calcWeightWithStddev,
  evaluateForkliftWithWorstCase: evaluateForkliftWithWorstCase
};

console.log('[StdDevIntegration] Integration functions ready');