module Config

def default_paths
  paths = {}
  # configuration files to look for
  EXTENSIONS.each do |ext|
    paths[ext] = [] unless paths[ext]
    ###############################
    # system level configuration
    ###############################
    paths[ext] << File.join(%(/etc), %(pangea), %(pangea.#{ext}))
    paths[ext].concat(
      Dir.glob(
        File.join(%(/etc/), %(pangea), %(conf.d), %(*.#{ext}))
      )
    )
    # end system level configuration
    ###############################
    # home configuration
    ###############################
    paths[ext] << File.join(xdg_config_home, %(pangea), %(pangea.#{ext}))
    paths[ext].concat(
      Dir.glob(
        File.join(xdg_config_home, %(pangea), %(conf.d), %(*.#{ext}))
      )
    )
    # end home configuration
    ###############################
    # local configuration
    ###############################
    paths[ext] << %(pangea.#{ext})
    paths[ext] << Dir.glob(
      File.join(
        %(pangea),
        %(conf.d),
        %(*.#{ext})
      )
    )
    # end local configuration
  end
  # only return existing files
  res = []
  EXTENSIONS.each do |ext|
    files = paths[ext]
    files.each do |file|
      res << file if File.exist?(file.to_s)
    end
  end
  res
end

def resolve_configurations(ignore_default_paths: false, extra_paths: [])
  paths = if ignore_default_paths
            extra_paths
          else
            default_paths.concat(extra_paths)
          end
  paths.each do |path|
    parted  = path.split(%(.))
    ext     = parted[-1]
    _base   = parted[0]
    synthesizer.synthesize(File.read(path), ext)
  end
  synthesizer.synthesis
end

def synthesizer
  @synthesizer ||= ConfigSynthesizer.new
end

def xdg_config_home
  ENV.fetch(
    %(XDG_CONFIG_HOME),
    %(#{ENV.fetch('HOME', nil)}/.config)
  )
end