class Bismas::Mapping

# File lib/bismas/mapping.rb, line 37
def self.[](mapping)
  mapping ? new(mapping) : NULL
end

# File lib/bismas/mapping.rb, line 41
def initialize(mapping)
  @mapping = default_hash.update(default: Array(DEFAULT_MAPPING))

  mapping.each { |key, value|
    value = Array(value.is_a?(String) ? range(value) : value)

    !key.is_a?(String) ? @mapping[key] = value :
      range(key) { |m| @mapping[m].concat(value) }
  }

  @mapping.each_value(&:uniq!)
end

# File lib/bismas/mapping.rb, line 62
def [](key)
  map(key).to_a
end

# File lib/bismas/mapping.rb, line 54
def apply(hash, new_hash = default_hash)
  hash.each { |key, value| map(key) { |new_key|
    new_hash[new_key].concat(Array(value))
  } }

  new_hash
end

# File lib/bismas/mapping.rb, line 68
def default_hash
  Hash.new { |h, k| h[k] = [] }
end

# File lib/bismas/mapping.rb, line 83
def fetch(key)
  @mapping.key?(key) ? @mapping[key] : @mapping[:default]
end

# File lib/bismas/mapping.rb, line 87
def map(key)
  return enum_for(__method__, key) unless block_given?

  fetch(key).each { |new_key|
    yield new_key == true ? key : new_key if new_key }
end

# File lib/bismas/mapping.rb, line 72
def range(list, &block)
  return enum_for(__method__, list) unless block

  list.split(/\s*,\s*/).each { |part|
    LITERALS.key?(part) ? block[LITERALS[part]] : begin
      from, to = part.split('-')
      from.upto(to || from, &block)
    end
  }
end