class Middleman::CoreExtensions::FileWatcher::API

def changed(matcher=nil, &block)
  @_changed << [block, matcher] if block_given?
  @_changed
end

def deleted(matcher=nil, &block)
  @_deleted << [block, matcher] if block_given?
  @_deleted
end

def did_change(path)
  return if ignored?(path)
  puts "== File Change: #{path.relative_path_from(@app.root_path)}" if @app.logging?
  @known_paths << path
  self.run_callbacks(path, :changed)
end

def did_delete(path)
  return if ignored?(path)
  puts "== File Deletion: #{path.relative_path_from(@app.root_path)}" if @app.logging?
  @known_paths.delete(path)
  self.run_callbacks(path, :deleted)
end

def find_new_files(path)
  reload_path(path, true)
end

def ignored?(path)
  path = path.relative_path_from(@app.root_path).to_s if path.is_a? Pathname
  IGNORE_LIST.any? { |r| path.to_s.match(r) }
end

def initialize(app)
  @app = app
  @known_paths = Set.new
  
  @_changed = []
  @_deleted = []
end

def reload_path(path, only_new=false)
  return unless path.exist?
  
  glob = "#{path}**/*"
  subset = @known_paths.select { |p| p.fnmatch(glob) }
  
  path.find do |filepath|
    full_path = path + filepath
    next if full_path.directory?
    
    if only_new
      next if subset.include?(full_path)
    else
      subset.delete(full_path)
    end
    
    self.did_change(full_path)
  end
  
  subset.each(&method(:did_delete)) unless only_new
end

def run_callbacks(path, callbacks_name)
  path = path.relative_path_from(@app.root_path).to_s if path.is_a? Pathname
  self.send(callbacks_name).each do |callback, matcher|
    next if path.match(%r{^#{@app.build_dir}/})
    next unless matcher.nil? || path.match(matcher)
    @app.instance_exec(path, &callback)
  end
end