class ComplexConfig::Tree

def self.convert(name, value)
  case value
  when ComplexConfig::Settings
    convert(name, value.to_h)
  when Hash
    obj = new(name.to_s)
    value.each do |name, value|
      obj << convert(name, value)
    end
    obj
  when Array
    obj = new(name.to_s)
    value.each_with_index do |value, i|
      obj << convert(i, value)
    end
    obj
  else
    if name.is_a?(Integer)
      new value.inspect
    else
      new "#{name} = #{value.inspect}"
    end
  end
end

def <<(child)
  @children << child
end

def default_utf8
  !!(ENV['LANG'] =~ /utf-8\z/i)
end

def initialize(name, utf8: default_utf8)
  @name     = name
  @utf8     = utf8
  @children = []
end

def inner_child_prefix(i)
  if @utf8
    i.zero? ? "├─ " : "│  "
  else
    i.zero? ? "+- " : "|  "
  end
end

def last_child_prefix(i)
  if @utf8
    i.zero? ? "└─ " : "   "
  else
    i.zero? ? "`- " : "   "
  end
end

def to_ary
  to_enum.to_a
end

def to_enum
  Enumerator.new do |y|
    y.yield @name
    @children.each_with_index do |child, child_index|
      children_enum = child.to_enum
      if child_index < @children.size - 1
        children_enum.each_with_index do |setting, i|
          y.yield "#{inner_child_prefix(i)}#{setting}"
        end
      else
        children_enum.each_with_index do |setting, i|
          y.yield "#{last_child_prefix(i)}#{setting}"
        end
      end
    end
  end
end

def to_str
  to_ary * ?\n
end