class ::StaticCms::Page
  require 'fileutils'
  require 'haml'
  require 'ruby_patch'
  extend ::RubyPatch::AutoLoad

  PARAMS_DEFAULT ={
    'visible' => true,
    'title' => '',
    'template' => 'default',
    'articles' => [],
    'statics' => [],
    'sources' => [],
    'base' => nil,
  }

  attr_accessor :site, :name, :dir, :template_file
  attr_accessor *(PARAMS_DEFAULT.keys)

  def initialize(site, name, params = {})
    @site = site
    @name = name
    @dir = File.join("root", @name)
    params = PARAMS_DEFAULT.merge(params)
    @template = params.delete('template')
    @template_file = File.join('templates', @template) + '.html.haml'
    @articles = params.delete('articles').map{|name| ::StaticCms::Article.use(self, name)}
    @statics = params.delete('statics').map{|file| File.join('statics', file)}
    @sources = params.delete('sources').map{|file| File.join('sources', file)}
    @base = params.delete('base') || @site.www
    params.each{|k, v|
      instance_variable_set("@#{k}", v)
    }
  end

  def generate
    FileUtils.mkdir_p(@dir)

    if @visible
      @statics.each{|file| cp_if_new(file)}
      @sources.each{|file| compile(file)}
      template_file = @template_file
    else
      @statics.each{|file| FileUtils.rm_rf(static_target(file))}
      @sources.each{|file| FileUtils.rm_rf(compile_target(file))}
      template_file = 'templates/moved.html.haml'
    end

    html = ::Haml::Engine.new(File.read(template_file)).render(self)
    target = File.join(@dir, 'index.html')
    open(target, 'w'){|io|
      io.write(html)
      io.flush
      io.fsync
    }
  end

  private

  def haml(text)
    ::Haml::Engine.new(text).render(self)
  end

  def nth_page_from_self(n)
    index = (@site.page_alist.to_a.index{|name, page| name == @name} + n)%@site.page_alist.size
    @site.page_alist.to_a[index][1]
  end

  def link_to_article(name)
    article = ::StaticCms::Article.alist[name]
    page = article.pages.first
    url = File.join(@site.www, page.name, "index.html\##{name}")

    "<a href='#{url}'>#{article.title}</a>"
  end

  def cp_if_new(source)
    target = static_target(source)
    if !File.file?(target) || File.mtime(source) > File.mtime(target)
      FileUtils.cp(source, target)
      FileUtils.chmod(0644, target)
    end
  end

  def compile(source)
    ext = File.extname(source)
    target = compile_target(source)

    case ext
    when /\A\.sass\z/
      system "sass #{source} > #{target}"
    else
      raise NotImplementedError, file
    end
  end

  def static_target(source)
    File.join(@dir, File.basename(source))
  end

  def compile_target(source)
    ext = File.extname(source)
    File.join(@dir, File.basename(source, ext))
  end
end