module Plate
  require 'tilt'
  
  # This class contains everything you'll want to know about a site. It contains all data
  # about the site, including blog posts, content pages, static files, assets and anything else.
  class Site
    include Callbacks
    
    attr_accessor :assets, :build_destination, :cache_location, :destination, 
                  :layouts, :logger, :options, :pages, :posts, :source
    
    def initialize(source, destination, options = {})
      # Setup source and destination for the site files
      self.source = source
      self.destination = destination
      
      # By default, the build goes into the destination folder.
      # Override this to output to a different folder by default
      self.build_destination = destination
      
      # Sanitize options
      self.options = Hash === options ? options.clone : {}
      self.options.symbolize_keys!
            
      clear
    end
    
    %w( assets layouts pages posts ).each do |group|
      class_eval "def #{group}; load!; @#{group}; end"
    end
    
    def all_files
      @all_files ||= self.assets + self.layouts + self.pages + self.posts.to_a
    end
    
    # All extensions that are registered, as strings.
    def asset_engine_extensions
      @asset_engine_extensions ||= self.registered_asset_engines.keys.collect { |e| ".#{e}" }
    end
    
    # Alphabetical list of all blog post categories used.
    def categories
      @categories ||= self.posts.collect(&:category).uniq.sort
    end
    
    # Clear out all data related to this site. Prepare for a reload, or first time load.
    def clear
      @loaded = false
      @tags_counts = nil
      @default_layout = nil
      
      self.assets = []
      self.layouts = []
      self.pages = []
      self.posts = PostCollection.new
    end
    
    # The default blog post category
    def default_category
      options[:default_category] || 'Posts'
    end
    
    # The default layout for all pages that do not specifically name their own
    def default_layout
      return nil if self.layouts.size == 0
      return @default_layout if @default_layout
      
      layout ||= self.layouts.reject { |l| !l.default?  }
      layout = self.layouts if layout.size == 0
      
      if Array === layout and layout.size > 0
        layout = layout[0]
      end
      
      @default_layout = layout
    end
    
    # Find a page, asset or layout by source relative file path
    def find(search_path)
      self.all_files.find { |file| file == search_path }
    end
    
    # Find all pages and posts with this layout
    def find_by_layout(layout_name)
      result = []
      
      result += self.pages.find_all { |page| page.layout == layout_name }
      result += self.posts.find_all { |post| post.layout == layout_name }
      
      result
    end
    
    # Find a specific layout by its file name. Any extensions are removed. 
    def find_layout(layout_name)
      search_name = layout_name.to_s.downcase.strip.split('.')[0]
      matches = self.layouts.reject { |l| l.name != search_name }
      matches.empty? ? self.default_layout : matches[0]
    end
    
    def inspect
      "#<#{self.class}:0x#{object_id.to_s(16)} source=#{source.to_s.inspect}>"
    end
    
    # Load all data from the various source directories.
    def load!
      return if @loaded
      
      log("Loading site from source [#{source}]")
      
      run_callback :before_load
      
      self.load_pages!
      self.load_layouts!
      self.load_posts!
      
      run_callback :after_load
      
      @loaded = true
    end
    
    # Returns true if the site has been loaded from the source directories.
    def loaded?
      !!@loaded
    end
    
    # Write to the log if enable_logging is enabled
    def log(message, style = :indent)
      logger.send(:log, message, style) if logger and logger.respond_to?(:log)
    end
    
    def page_engine_extensions
      @page_engine_extensions ||= self.registered_page_engines.keys.collect { |e| ".#{e}" }
    end
    
    def relative_path(file_or_directory)
      file_or_directory.to_s.gsub(/^#{Regexp.quote(source)}(.*)$/, '\1')
    end
    
    def reload!
      clear
      load!
    end
    
    # Returns the asset engines that are available for use.
    def registered_asset_engines
      Plate.asset_engines
    end
    
    # Returns the engines available for use in page and layout formatting.
    def registered_page_engines
      Plate.template_engines     
    end
    
    # All tags used on this site
    def tags
      @tags ||= self.posts.tag_list
    end
    
    def to_url(str)
      result = str.to_s.strip.downcase
      result = result.gsub(/[^-a-z0-9~\s\.:;+=_]/, '')
      result = result.gsub(/[\.:;=+-]+/, '')
      result = result.gsub(/[\s]/, '-')
      result
    end
    alias_method :sanitize_slug, :to_url
    
    # The base URL for this site. The url can be set using the config option named `:base_url`.
    #
    # The base URL will not have any trailing slashes.
    def url
      return '' unless self.options[:base_url]
      @url ||= self.options[:base_url].to_s.gsub(/(.*?)\/?$/, '\1')
    end
    
    protected
      # Load all layouts from layouts/
      def load_layouts!(log = true)
        @layouts = []
        
        Dir.glob(File.join(source, "layouts/**/*")).each do |file|
          # If this 'file' is a directory, just skip it. We only care about files.
          unless File.directory?(file)          
            @layouts << Layout.new(self, file)
          end
        end

        log("#{@layouts.size} layouts loaded") if log
        
        @layouts
      end
      
      def load_pages!(log = true)
        @assets = []
        @pages = []
        
        # Load all pages, static pages and assets from content/
        Dir.glob(File.join(source, "content/**/*")).each do |file|
          # If this 'file' is a directory, just skip it. We only care about files.
          unless File.directory?(file)
            # Check for assets that need to be compiled. Currently only looks to see if the file
            # ends in .coffee, .scss or .sass.
            #
            # Assets that start with _ are assumed to be partials and are not loaded.
            if asset_engine_extensions.include?(File.extname(file))
              unless File.basename(file).start_with?('_')
                @assets << Asset.new(self, file)
              end
            else
              # Check for YAML meta header. If it starts with ---, then process it as a page
              intro = File.open(file) { |f| f.read(3) }

              # If file contents start with ---, then it is something we should process as a page.
              if intro == "---"
                @pages << Page.new(self, file)
              else
                @pages << StaticPage.new(self, file)
              end
            end
          end
        end

        log("#{@assets.size} assets loaded") if log
        log("#{@pages.size} pages and other files loaded") if log
        
        @pages
      end
      
      # Load blog posts from posts/
      def load_posts!(log = true)
        @posts = PostCollection.new
        
        Dir.glob(File.join(source, "posts/**/*")).each do |file|
          # If this 'file' is a directory, just skip it. We only care about files.
          unless File.directory?(file)
            # Check for YAML meta header. If it starts with ---, then process it as a page
            intro = File.open(file) { |f| f.read(3) }

            # If file contents start with ---, then it is something we should process as a page.
            if intro == "---"
              @posts.add(Post.new(self, file))
            end
          end          
        end
        
        @posts.sort!
        
        log("#{@posts.size} posts loaded") if log     
        
        @posts
      end
  end
end