# encoding: utf-8

class Object
  # An object is blank if it's false, empty, or a whitespace string.
  # For example, '', '   ', +nil+, [], and {} are all blank.
  #
  # This simplifies
  #
  #   address.nil? || address.empty?
  #
  # to
  #
  #   address.blank?
  #
  # @return [true, false]
  def blank?
    respond_to?(:empty?) ? empty? : !self
  end

  # An object is present if it's not blank.
  #
  # @return [true, false]
  def present?
    !blank?
  end

  # Returns the receiver if it's present otherwise returns +nil+.
  # <tt>object.presence</tt> is equivalent to
  #
  #    object.present? ? object : nil
  #
  # For example, something like
  #
  #   state   = params[:state]   if params[:state].present?
  #   country = params[:country] if params[:country].present?
  #   region  = state || country || 'US'
  #
  # becomes
  #
  #   region = params[:state].presence || params[:country].presence || 'US'
  #
  # @return [Object]
  def presence
    self if present?
  end
end

class NilClass
  # +nil+ is blank:
  #
  #   nil.blank? # => true
  #
  # @return [true]
  def blank?
    true
  end
end

class FalseClass
  # +false+ is blank:
  #
  #   false.blank? # => true
  #
  # @return [true]
  def blank?
    true
  end
end

class TrueClass
  # +true+ is not blank:
  #
  #   true.blank? # => false
  #
  # @return [false]
  def blank?
    false
  end
end

class Array
  # An array is blank if it's empty:
  #
  #   [].blank?      # => true
  #   [1,2,3].blank? # => false
  #
  # @return [true, false]
  alias_method :blank?, :empty?
end

class Hash
  # A hash is blank if it's empty:
  #
  #   {}.blank?                # => true
  #   { key: 'value' }.blank?  # => false
  #
  # @return [true, false]
  alias_method :blank?, :empty?
end

class String
  BLANK_RE = /\A[[:space:]]*\z/

  # A string is blank if it's empty or contains whitespaces only:
  #
  #   ''.blank?       # => true
  #   '   '.blank?    # => true
  #   "\t\n\r".blank? # => true
  #   ' blah '.blank? # => false
  #
  # Unicode whitespace is supported:
  #
  #   "\u00a0".blank? # => true
  #
  # @return [true, false]
  def blank?
    BLANK_RE === self
  end
end

class Numeric #:nodoc:
  # No number is blank:
  #
  #   1.blank? # => false
  #   0.blank? # => false
  #
  # @return [false]
  def blank?
    false
  end
end

class Hash
  # Returns a new hash with all keys converted using the block operation.
  #
  #  hash = { name: 'Rob', age: '28' }
  #
  #  hash.transform_keys{ |key| key.to_s.upcase }
  #  # => {"NAME"=>"Rob", "AGE"=>"28"}
  def transform_keys
    return enum_for(:transform_keys) unless block_given?
    result = self.class.new
    each_key do |key|
      result[yield(key)] = self[key]
    end
    result
  end

  # Returns a new hash with all keys converted to symbols, as long as
  # they respond to +to_sym+.
  #
  #   hash = { 'name' => 'Rob', 'age' => '28' }
  #
  #   hash.symbolize_keys
  #   # => {:name=>"Rob", :age=>"28"}
  def symbolize_keys
    transform_keys { |key| key.to_sym rescue key }
  end

  # Returns a new hash with all keys converted by the block operation.
  # This includes the keys from the root hash and from all
  # nested hashes and arrays.
  #
  #  hash = { person: { name: 'Rob', age: '28' } }
  #
  #  hash.deep_transform_keys{ |key| key.to_s.upcase }
  #  # => {"PERSON"=>{"NAME"=>"Rob", "AGE"=>"28"}}
  def deep_transform_keys(&block)
    _deep_transform_keys_in_object(self, &block)
  end

  # Returns a new hash with all keys converted to symbols, as long as
  # they respond to +to_sym+. This includes the keys from the root hash
  # and from all nested hashes and arrays.
  #
  #   hash = { 'person' => { 'name' => 'Rob', 'age' => '28' } }
  #
  #   hash.deep_symbolize_keys
  #   # => {:person=>{:name=>"Rob", :age=>"28"}}
  def deep_symbolize_keys
    deep_transform_keys { |key| key.to_sym rescue key }
  end

  private

    # support methods for deep transforming nested hashes and arrays
    def _deep_transform_keys_in_object(object, &block)
      case object
      when Hash
        object.each_with_object({}) do |(key, value), result|
          result[yield(key)] = _deep_transform_keys_in_object(value, &block)
        end
      when Array
        object.map { |e| _deep_transform_keys_in_object(e, &block) }
      else
        object
      end
    end
end

class File
  class << self
    # A binary file is Mach-O dSYM
    #
    # @return [true, false]
    def dsym?(file_path)
      !(`file -b #{file_path}` =~ /dSYM/).nil?
    end

    # A file is ASCII text
    #
    # @return [true, false]
    def text?(file_path)
      !(`file -b #{file_path}` =~ /text/).nil?
    end
  end
end

class String
  # Convert String encoding to UTF-8
  #
  # @return string
  def to_utf8
    encode(Encoding.find('UTF-8'), invalid: :replace, undef: :replace, replace: '')
  end
end