class Samovar::Table

def self.nested(klass, parent = nil)
	if klass.superclass.respond_to?(:table)
		parent = klass.superclass.table
	end
	
	self.new(parent, name: klass.name)
end

def << row
	if existing_row = @rows[row.key] and existing_row.respond_to?(:merge!)
		existing_row.merge!(row)
	else
		# In the above case where there is an existing row, but it doensn't support being merged, we overwrite it. This preserves order.
		@rows[row.key] = row.dup
	end
end

def [] key
	@rows[key]
end

def each(&block)
	@rows.each_value(&block)
end

def empty?
	@rows.empty? && @parent&.empty?
end

def freeze
	return self if frozen?
	
	@rows.freeze
	
	super
end

def initialize(parent = nil, name: nil)
	@parent = parent
	@name = name
	@rows = {}
end

def merge_into(table)
	@parent&.merge_into(table)
	
	@rows.each_value do |row|
		table << row
	end
	
	return table
end

def merged
	if @parent.nil? or @parent.empty?
		return self
	else
		merge_into(self.class.new)
	end
end

def parse(input, parent)
	@rows.each do |key, row|
		next unless row.respond_to?(:parse)
		
		current = parent.send(key)
		
		if result = row.parse(input, parent, current)
			parent.send("#{row.key}=", result)
		end
	end
end

def usage
	@rows.each_value.collect(&:to_s).reject(&:empty?).join(' ')
end