export interface GridfinitySpec {
  gridSize: number; // e.g., 42mm
  heightUnit: number; // e.g., 7mm
  baseThickness: number; // Height of baseplate above drawer surface
}

export const DEFAULT_SPEC: GridfinitySpec = {
  gridSize: 42,
  heightUnit: 7,
  baseThickness: 4.8, // Standard baseplate height is 5mm, but usually 4.8mm-5mm
};

export interface CalculatorInputs {
  width: number;
  length: number;
  height: number;
  unit: 'mm' | 'in';
  spec: GridfinitySpec;
}

export interface CalculatorResults {
  widthGrids: number;
  lengthGrids: number;
  fullGridsX: number;
  fullGridsY: number;
  maxBinUnits: number;
  remainingWidth: number;
  remainingLength: number;
  remainingHeight: number;
}

const INCH_TO_MM = 25.4;

export function calculateGridfinity(inputs: CalculatorInputs): CalculatorResults {
  const { width, length, height, unit, spec } = inputs;
  
  // Convert all to mm for internal calculation
  const w = unit === 'in' ? width * INCH_TO_MM : width;
  const l = unit === 'in' ? length * INCH_TO_MM : length;
  const h = unit === 'in' ? height * INCH_TO_MM : height;

  const widthGrids = w / spec.gridSize;
  const lengthGrids = l / spec.gridSize;
  
  const fullGridsX = Math.floor(widthGrids);
  const fullGridsY = Math.floor(lengthGrids);
  
  // Height calculation: (Available Height - Baseplate Thickness) / 7mm
  // We floor this because bins come in whole unit increments
  const maxBinUnits = Math.max(0, Math.floor((h - spec.baseThickness) / spec.heightUnit));
  
  const remainingWidth = w % spec.gridSize;
  const remainingLength = l % spec.gridSize;
  const remainingHeight = (h - spec.baseThickness) % spec.heightUnit;

  return {
    widthGrids,
    lengthGrids,
    fullGridsX,
    fullGridsY,
    maxBinUnits,
    remainingWidth,
    remainingLength,
    remainingHeight
  };
}