module Merb
  # A convinient way to get at Merb::Cache
  def self.inspector
    Merb::Inspector
  end

  module Inspector

    def self.root
      @root ||= File.expand_path(File.dirname(__FILE__) + "/../../")
    end

    def self.default
      Merb::Inspectors::Base
    end

    class << self
      attr_accessor :stores
      attr_accessor :caches
    end

    self.stores = Hash.new
    self.caches = Hash.new

    def self.reset
      @caches = Hash.new
    end

    def self.register(klass, inspector)
      raise "#{klass} inspector already setup" if @stores.has_key?(klass)
      @stores[klass] = inspector
      log "registered %s -> %s" % [klass, inspector]
    end

    def self.lookup(object)
      if @caches.has_key?(object.class)
        log "lookup: %s => %s (cached)" % [object.class, @caches[object.class] || 'nil']
        return @caches[object.class]
      end
      klass = object.class.ancestors.find{|klass|
        log "lookup:   %s = %s ... %s" % [object.class, klass, @stores[klass]]
        @stores.has_key?(klass)
      }
      @caches[object.class] = @stores[klass]
      if klass
        log "lookup: %s => %s (registered)" % [object.class, @caches[object.class]]
      else
        log "lookup: %s => nil (registered as negative cache)" % [object.class]
      end
      return @stores[klass]
    end

    def self.log(message)
      path = Merb.root / "log" / "inspector.log"
      message = "[Inspector] %s" % message.to_s.strip
      File.open(path, "a+") {|f| f.puts message}
    end

    ######################################################################
    ### Install

    def self.install
      mirror("public/stylesheets")
    end

    def self.mirror(dir)
      source_dir = File.join(File.dirname(__FILE__), '..', '..', 'mirror', dir)
      target_dir = File.join(Merb.root, dir)
      FileUtils.mkdir_p(target_dir) unless File.exist?(target_dir)

      Dir[source_dir + "/*"].each do |src|
        time = File.mtime(src)
        file = File.basename(src)
        dst  = File.join(target_dir, file)

        next if File.directory?(src)
        next if File.exist?(dst) and File.mtime(dst) >= time
        FileUtils.copy(src, dst)
        File.utime(time, time, dst)
        command = File.exist?(dst) ? "update" : "install"
        log "#{command}: #{dir}/#{file}"
      end
    end

  end
end