class Supertramp

# File lib/supertramp.rb, line 22
def self.configure
  yield @@config
end

# File lib/supertramp.rb, line 9
def initialize(initials: nil, name: nil, background: nil, shape: nil)
  @initials = initials
  @name = name
  @background = background
  @shape = shape

  validate_arguments
end

# File lib/supertramp.rb, line 18
def to_s
  Avatar.new(initials: initials, background: background, shape: shape).to_s
end

# File lib/supertramp.rb, line 51
def background
  @background ||= background_for_initials
end

# File lib/supertramp.rb, line 55
def background_for_initials
  Random.srand(initials_seed)
  index = (rand * config.colours.length).floor
  config.colours[index]
end

# File lib/supertramp.rb, line 35
def config
  @@config
end

# File lib/supertramp.rb, line 39
def initials
  @initials ||= initials_from_name

  return @initials.upcase if config.uppercase

  @initials
end

# File lib/supertramp.rb, line 47
def initials_from_name
  name.split.map { |n| n[0] }.join
end

# File lib/supertramp.rb, line 61
def initials_seed
  initials.downcase.chars.map(&:ord).sum
end

# File lib/supertramp.rb, line 65
def shape
  @shape ||= config.shape
end

# File lib/supertramp.rb, line 30
def validate_arguments
  raise ArgumentError, 'either `initials:` or `name:` must be specified' unless @name || @initials
  raise ArgumentError, "`shape:` must be one of #{Avatar::SHAPES}" unless Avatar::SHAPES.include?(shape)
end