class Hashiform

# File lib/hashiform.rb, line 2
def initialize(original_hash, catalysts = {})
  @original_hash = original_hash
  @catalysts = catalysts
end

# File lib/hashiform.rb, line 34
def apply_mod(modifier, value)
  return :_reject if modifier =~ /^if/ && value.nil?

  mod, arg_list = modifier.split('+')

  args = if arg_list
    arg_list =~ /^,/ ?
      arg_list :
      arg_list.split(/, ?/)
  end

  case mod
  when sendable(value)
    args ? value.public_send(mod, *args) : value.public_send(mod)
  when catalyst_target?
    @catalysts[mod][value]
  else
    value
  end
end

# File lib/hashiform.rb, line 7
def transform(mapping)
  new_hash = {}

  mapping.each do |new_key, transformation|
    *modifiers, path = transformation.split(':')
    path_segments    = path.split('.')

    value = @original_hash.dig(*path_segments)

    if modifiers.empty?
      new_hash[new_key] = value
    else
      value = modifiers.reduce(value) do |new_value, mod|
        new_value = apply_mod(mod, new_value)

        break new_value if new_value == :_reject

        new_value
      end

      new_hash[new_key] = value unless value == :_reject
    end
  end

  new_hash
end

# File lib/hashiform.rb, line 57
def catalyst_target?
  -> mod { @catalysts.key?(mod) }
end

# File lib/hashiform.rb, line 61
def sendable(value)
  -> meth { value.respond_to?(meth) }
end