Class: HeatingSystemCalculator::ElementFinderByArea

Inherits:
BaseElementFinder show all
Defined in:
app/services/heating_system_calculator/element_finder_by_area.rb

Constant Summary collapse

MAX_SOLUTIONS =

Limit solutions to avoid explosive memory allocation

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Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from BaseElementFinder

#consolidate_elements, #find_best_solution

Methods inherited from BaseItemFinder

#get_number_of_poles_from_consolidated_elements, #get_total_from_solution

Constructor Details

#initialize(options) ⇒ ElementFinderByArea

Returns a new instance of ElementFinderByArea.



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# File 'app/services/heating_system_calculator/element_finder_by_area.rb', line 8

def initialize(options)
  @element_set = options[:element_set]
end

Instance Attribute Details

#coverage_percentage ⇒ Object (readonly)

Returns the value of attribute coverage_percentage.



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# File 'app/services/heating_system_calculator/element_finder_by_area.rb', line 3

def coverage_percentage
  @coverage_percentage
end

#elements ⇒ Object (readonly)

Returns the value of attribute elements.



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# File 'app/services/heating_system_calculator/element_finder_by_area.rb', line 3

def elements
  @elements
end

#error ⇒ Object (readonly)

Returns the value of attribute error.



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# File 'app/services/heating_system_calculator/element_finder_by_area.rb', line 3

def error
  @error
end

#target_area ⇒ Object (readonly)

Returns the value of attribute target_area.



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# File 'app/services/heating_system_calculator/element_finder_by_area.rb', line 3

def target_area
  @target_area
end

Instance Method Details

#calculate_elements_for_heated_area_sqft(heated_area_sqft, insulation_surface = nil) ⇒ Object 



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# File 'app/services/heating_system_calculator/element_finder_by_area.rb', line 12

def calculate_elements_for_heated_area_sqft(heated_area_sqft, insulation_surface = nil)
  # Priority: Find solutions that MEET OR EXCEED the heated area first
  # Only fall back to undersized solutions if nothing adequate can be found
  insulation_surface ||= heated_area_sqft

  # Phase 1: Try to find solutions that meet or exceed the target (up to insulation surface)
  # tcmin = target area, tcmax = insulation surface (allows slight overage)
  solutionset = find_elements(heated_area_sqft, insulation_surface)

  # Phase 2: If no adequate solutions, expand search to slightly over insulation surface
  if solutionset.length < MAX_SOLUTIONS
    solutionset.concat(find_elements(heated_area_sqft, 1.1 * insulation_surface))
  end

  # Phase 3: If still no solutions, allow undersized (fallback only)
  if solutionset.empty?
    # For small areas, allow down to 46-90% coverage on sliding scale
    # For larger areas, allow down to 85% coverage
    if heated_area_sqft < 120.0
      min_coverage = (0.46 + (0.44 * (heated_area_sqft / 120.0))) * heated_area_sqft
    else
      min_coverage = 0.85 * heated_area_sqft
    end
    solutionset = find_elements(min_coverage, heated_area_sqft)
  end

  foundsolution = false
  if solutionset.length > 1
    # if we get more than a single solution, find the best based on closeness to target and price
    solution = find_best_solution(solutionset, heated_area_sqft)
    foundsolution = true
  elsif solutionset.length == 1
    # if we get a single solution, we are done
    solution = solutionset[0]
    foundsolution = true
  end

  if foundsolution
    # get consolidated elements list
    @elements = consolidate_elements(solution)
    @coverage_percentage = [(100.0 * get_total_from_solution(solution, 'area').to_f / heated_area_sqft).round, 100].min
  else
    @error = { error_status: :no_solutions_found, error_message: 'No matching heating elements found.' }
  end
  @target_area = heated_area_sqft
  self
end

#find_elements(tcmin, tcmax) ⇒ Object 



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# File 'app/services/heating_system_calculator/element_finder_by_area.rb', line 60

def find_elements(tcmin, tcmax)
  # try to find a set of elements that at least covers TCMIN but does not exceed TCMAX
  # assume no set was found
  foundsolution = false
  # initialize the number of rolls to try in the solution set, guess a smaller than necessary but good starting point
  numrollstotry = [0, ((tcmin / @element_set.last['area']).floor - 1)].max
  # initialize the solution set
  solutionset = []
  # Track total solutions found across all iterations
  @total_solutions_found = 0
  # loop while no solution is found
  until foundsolution
    # increment the number of rolls to try
    numrollstotry += 1
    # test to see if smallest roll times the number of rolls to try exceeds TCMAX
    if @element_set[0]['area'] * numrollstotry > tcmax
      # yes we are done, no more solutions possible
      break
    elsif numrollstotry > 100
      # here we have a large area compared to our elements set so just set the solution to the correct set of the largest
      numrolls = ((tcmax / @element_set.last['area']).ceil - 1)
      soln = []
      numrolls.times do
        soln << @element_set.last
      end
      solutionset << soln
      foundsolution = true
    else
      # keep looking for solutions using this number of rolls
      @recurse_count = 0
      solutionset = find_solutions_for(numrollstotry, tcmin, tcmax)
      # trace("solutionset.length: "+String(solutionset.length));
      foundsolution = true if solutionset.length >= 1
    end
  end
  solutionset
end

#find_solutions_for(num, amin, amax) ⇒ Object 



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# File 'app/services/heating_system_calculator/element_finder_by_area.rb', line 98

def find_solutions_for(num, amin, amax)
  # this is a recursive function that enumerates all combinations of num rolls whose coverage
  # sums up to a value between amin and amax
  # set up an array of solutions
  solutionset = []
  # Early termination if we have enough solutions globally
  return solutionset if @total_solutions_found >= MAX_SOLUTIONS

  if @recurse_count <= 100
    if num == 1
      # we are looking for a single roll solution
      # loop over all elements in the product set
      @element_set.each do |elem|
        break if @total_solutions_found >= MAX_SOLUTIONS
        # test that area of the roll is within range
        if elem['area'] >= amin && elem['area'] <= amax
          # save this roll as a solution
          solutionset << [elem]
          @total_solutions_found += 1
        elsif elem['area'] > amax
          # we have reached a roll whose area exceeds TCMAX, we can stop looping
          # since the elements array is sorted ascending on area
          break
        end
      end
    elsif num > 1
      # we are looking for more than a single roll solution
      @recurse_count += 1
      # do a sanity check
      if @element_set[0]['area'] * num <= amax
        # loop over all elements
        @element_set.reverse_each do |elem|
          break if @total_solutions_found >= MAX_SOLUTIONS
          # Skip elements that are too large for the remaining area
          next if elem['area'] > amax

          # recursively call this function with a starting area of the current element roll
          # and num-1 rolls required
          tmpsolnset = find_solutions_for(num - 1, amin - elem['area'], amax - elem['area'])
          next if tmpsolnset.empty?

          # if the resulting solution set is non empty then add the current element roll to each solution in the set
          # Optimize: avoid creating intermediate arrays
          tmpsolnset.each do |tmpsol|
            break if @total_solutions_found >= MAX_SOLUTIONS
            solutionset << [elem, *tmpsol]
            @total_solutions_found += 1
          end
        end
      end
    end
  end
  # return the solution set
  solutionset
end