Initial commit

lib/api/app.rb

@@ -0,0 +1,23 @@
+require 'json'
+require 'sinatra/base'
+require_relative '../http/query'
+
+module Pruning
+  module API
+    class App < Sinatra::Base
+      before { content_type :json }
+      after  { serialise_response }
+
+      private
+
+      def serialise_response
+        return unless content_type == 'application/json'
+        response.body = [JSON(response.body)]
+      end
+
+      def query
+        Pruning::HTTP::Query.new(params)
+      end
+    end
+  end
+end

lib/api/tree.rb

@@ -0,0 +1,17 @@
+require 'rest-client'
+require_relative 'app'
+require_relative '../repos/tree'
+require_relative '../pruner'
+
+module Pruning
+  module API
+    class Tree < App
+      get '/tree/:name' do
+        tree_repo = Pruning::Repos::Tree.new(RestClient, ENV['TREE_SOURCE_API_HOSTNAME'])
+        complete_tree = tree_repo.get(query.name)
+        pruner = Pruning::Processing::Pruner.new(complete_tree)
+        pruner.prune_tree(query.indicator_ids) 
+      end
+    end
+  end 
+end

lib/http/query.rb

@@ -0,0 +1,18 @@
+module Pruning
+  module HTTP
+    class Query < Struct.new(:name, :indicator_ids)
+      def initialize(params = {})
+        values = members.map do |member|
+          value = params.fetch(member, nil)
+          next if value.nil?
+          case member
+          when :indicator_ids then value.map(&:to_i) # break on purpose if indicator_ids is not an array
+          when :name then value.to_s.gsub(/[^A-Za-z]/,'') 
+            else value
+          end
+        end
+        super(*values)
+      end
+    end
+  end
+end

lib/pruner.rb

@@ -0,0 +1,32 @@
+module Pruning
+  module Processing
+    class Pruner
+
+      def initialize(tree, indicator_ids)
+        @tree = tree
+      end
+
+      def prune_tree(nodes, indicator_ids)
+        nodes.delete_if do |node|
+          unwanted_indicator = indicator_node?(node) && !indicator_ids.include?(node['id'])  
+          has_no_wanted_indicators_in_children = prune_tree(children(node), indicator_ids)
+
+          unwanted_indicator && has_no_wanted_indicators_in_children 
+        end 
+        nodes.empty?
+      end
+
+      private
+      def children(node)
+        node.get('sub-themes', false) ||
+        node.get('categories', false) || 
+        node.get('indicators', false) ||
+        []
+      end
+      
+      def indicator_node?(node)
+        children(node).empty?
+      end
+    end
+  end
+end

lib/repos/tree.rb

@@ -0,0 +1,24 @@
+require 'rest-client'
+require 'retries'
+require 'json'
+
+module Pruning
+  module Repos
+    class Tree
+      def initialize(client=RestClient, base_url)
+        @client = client
+        @base_url = base_url
+      end
+
+      def get(name)
+        resp = @client.get(url(name))
+        JSON(resp.body)
+      end
+
+      private 
+      def url(name)
+        "#{@base_url}/tree/#{name}"
+      end
+    end
+  end
+end