# Methods for finding records on the filesystem.

module ActiveCopy
  module Finders
    extend ActiveSupport::Concern

    # Test if the query matches this particular model.
    def matches? query
      query.reduce(true) do |matches, (key, value)|
        matches = if key == 'tag'
          return false unless tags.present?
          tags.include? value
        else
          attributes[key] == value
        end
      end
    end

    module ClassMethods
      # Return the folder where all documents are stored for this model.
      def collection_path
        @collection_path ||= "#{ActiveCopy.content_path}/#{name.tableize}/content"
      end

      # Find this model by its filename.
      def find by_filename
        if File.exists? "#{Rails.root}/#{collection_path}/#{by_filename}.md"
          new id: by_filename
        else
          nil
        end
      end

      # Read all files from the +collection_path+, then instantiate them
      # as members of this model. Return as an +Array+.
      def all
        Dir["#{absolute_collection_path}/*.md"].reduce([]) do |articles, md_path|
          unless md_path == "#{Rails.root}/#{collection_path}"
            file_name = File.basename(md_path).gsub('.md', '')
            articles << self.new(id: file_name)
          end
        end
      end

      # Look for all of the matching key/value pairs in the YAML front
      # matter, and return an array of models that match them.
      def where query={}
        all.reject { |a| a.nil? }.reduce([]) do |results, article|
          results << article if article.matches? query
          results
        end
      end

      private
      def absolute_collection_path
        "#{Rails.root}/#{collection_path}"
      end
    end
  end
end