module Jekyll

  class Page
    include Convertible

    attr_accessor :site, :pager
    attr_accessor :name, :ext, :basename, :dir
    attr_accessor :data, :content, :output

    # Initialize a new Page.
    #   +site+ is the Site
    #   +base+ is the String path to the <source>
    #   +dir+ is the String path between <source> and the file
    #   +name+ is the String filename of the file
    #
    # Returns <Page>
    def initialize(site, base, dir, name)
      @site = site
      @base = base
      @dir  = dir
      @name = name

      self.process(name)
      self.read_yaml(File.join(base, dir), name)
    end

    # The generated directory into which the page will be placed
    # upon generation. This is derived from the permalink or, if
    # permalink is absent, set to '/'
    #
    # Returns <String>
    def dir
      url[-1, 1] == '/' ? url : File.dirname(url)
    end

    # The full path and filename of the post.
    # Defined in the YAML of the post body
    # (Optional)
    #
    # Returns <String>
    def permalink
      self.data && self.data['permalink']
    end

    def template
      if self.site.permalink_style == :pretty && !index? && html?
        "/:basename/"
      else
        "/:basename:output_ext"
      end
    end

    # The generated relative url of this page
    # e.g. /about.html
    #
    # Returns <String>
    def url
      return permalink if permalink

      @url ||= {
        "basename"   => self.basename,
        "output_ext" => self.output_ext,
      }.inject(template) { |result, token|
        result.gsub(/:#{token.first}/, token.last)
      }.gsub(/\/\//, "/")
    end

    # Extract information from the page filename
    #   +name+ is the String filename of the page file
    #
    # Returns nothing
    def process(name)
      self.ext = File.extname(name)
      self.basename = name[0 .. -self.ext.length-1]
    end

    # Add any necessary layouts to this post
    #   +layouts+ is a Hash of {"name" => "layout"}
    #   +site_payload+ is the site payload hash
    #
    # Returns nothing
    def render(layouts, site_payload)
      payload = {
        "page" => self.to_liquid,
        'paginator' => pager.to_liquid
      }.deep_merge(site_payload)

      do_layout(payload, layouts)
    end

    def to_liquid
      self.data.deep_merge({
        "url"        => File.join(@dir, self.url),
        "content"    => self.content })
    end
    
    # Obtain destination path.
    #   +dest+ is the String path to the destination dir
    #
    # Returns destination file path.
    def destination(dest)
      # The url needs to be unescaped in order to preserve the correct filename
      path = File.join(dest, @dir, CGI.unescape(self.url))
      path = File.join(path, "index.html") if self.url =~ /\/$/
      path
    end

    # Write the generated page file to the destination directory.
    #   +dest+ is the String path to the destination dir
    #
    # Returns nothing
    def write(dest)
      path = destination(dest)
      FileUtils.mkdir_p(File.dirname(path))
      File.open(path, 'w') do |f|
        f.write(self.output)
      end
    end

    def inspect
      "#<Jekyll:Page @name=#{self.name.inspect}>"
    end

    def html?
      output_ext == '.html'
    end

    def index?
      basename == 'index'
    end

  end

end