# frozen_string_literal: true

require "much-result"

class MuchResult; end

class MuchResult::Aggregate
  def self.call(values)
    new(values).call
  end

  def initialize(values)
    @values = values
  end

  def call
    combine_values(@values)
  end

  private

  def combine_values(values)
    combine_in_a_collection(array_wrap(values))
  end

  def combine_in_a_collection(values)
    if all_hash_values?(values)
      values
        .reduce{ |acc, value| combine_in_a_hash(acc, value) }
        .transform_values{ |nested_values| combine_values(nested_values) }
    else
      array_wrap(
        values.reduce([]){ |acc, value| combine_in_an_array(acc, value) },
      )
    end
  end

  def combine_in_a_hash(hash1, hash2)
    ((h1 = hash1 || {}).keys + (h2 = hash2 || {}).keys)
      .uniq
      .reduce({}) do |hash, key|
        hash[key] = combine_in_an_array(h1[key], h2[key])
        hash
      end
  end

  def combine_in_an_array(acc, other)
    array_wrap(acc) + array_wrap(other)
  end

  def array_wrap(value)
    value.is_a?(Array) ? value : [value]
  end

  def all_hash_values?(values)
    (compacted = values.compact).reduce(compacted.any?) do |acc, value|
      acc && value.is_a?(::Hash)
    end
  end
end