class Covered::Coverage

def self.deserialize(unpacker)
	source = unpacker.read
	counts = unpacker.read
	annotations = unpacker.read
	
	self.new(source, counts, annotations)
end

def self.for(path, **options)
	self.new(Source.for(path, **options))
end

def [] line_number
	@counts[line_number]
end

def annotate(line_number, annotation)
	@annotations[line_number] ||= []
	@annotations[line_number] << annotation
end

def as_json
	{
		counts: counts,
		executable_count: executable_count,
		executed_count: executed_count,
		percentage: percentage.to_f.round(2),
	}
end

def empty
	self.class.new(@source, [nil] * @counts.size)
end

def executable_count
	executable_lines.count
end

def executable_lines
	@counts.compact
end

def executed_count
	executed_lines.count
end

def executed_lines
	executable_lines.reject(&:zero?)
end

def for_lines(line_numbers)
	counts = [nil] * @counts.size
	line_numbers.each do |line_number|
		counts[line_number] = @counts[line_number]
	end
	
	self.class.new(@source, counts, @annotations)
end

def freeze
	return self if frozen?
	
	@counts.freeze
	@annotations.freeze
	
	super
end

def fresh?
	if @source.modified_time.nil?
		# We don't know when the file was last modified, so we assume it is stale:
		return false
	end
	
	unless File.exist?(@source.path)
		# The file no longer exists, so we assume it is stale:
		return false
	end
	
	if @source.modified_time >= File.mtime(@source.path)
		# The file has not been modified since we last processed it, so we assume it is fresh:
		return true
	end
	
	return false
end

def initialize(source, counts = [], annotations = {})
	@source = source
	@counts = counts
	@annotations = annotations
end

def mark(line_number, value = 1)
	# As currently implemented, @counts is base-zero rather than base-one.
	# Line numbers generally start at line 1, so the first line, line 1, is at index 1. This means that index[0] is usually nil.
	Array(value).each_with_index do |value, index|
		offset = line_number + index
		if @counts[offset]
			@counts[offset] += value
		else
			@counts[offset] = value
		end
	end
end

def merge!(other)
	# If the counts are non-zero and don't match, that can indicate a problem.
	
	other.counts.each_with_index do |count, index|
		if count
			@counts[index] ||= 0
			@counts[index] += count
		end
	end
	
	@annotations.merge!(other.annotations) do |line_number, a, b|
		Array(a) + Array(b)
	end
end

def missing_count
	executable_count - executed_count
end

def path
	@source.path
end

def path= value
	@source.path = value
end

def print(output)
	output.puts "** #{executed_count}/#{executable_count} lines executed; #{percentage.to_f.round(2)}% covered."
end

def read(&block)
	@source.read(&block)
end

def serialize(packer)
	packer.write(@source)
	packer.write(@counts)
	packer.write(@annotations)
end

def to_a
	@counts
end

def to_s
	"\#<#{self.class} path=#{self.path} #{self.percentage.to_f.round(2)}% covered>"
end

def total
	counts.sum{|count| count || 0}
end

def zero?
	total.zero?
end