ioquatix/graphviz

# Copyright, 2014, by Samuel G. D. Williams. <http://www.codeotaku.com>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

require 'stringio'

require_relative 'node'

module Graphviz
    # Contains a set of nodes, edges and subgraphs.
    class Graph < Node
        # Initialize the graph with the specified unique name.
        def initialize(name = 'G', parent = nil, **attributes)
            super
            
            @edges = []
            @nodes = {}
        end
        
        # All edges in the graph
        attr :edges
        
        # @return [Array<Node>] All nodes in the graph.
        attr :nodes
        
        # @return [Hash] Any associated graphviz attributes.
        attr_accessor :attributes
        
        # @return [Node] Add a node to this graph.
        def add_node(name = nil, **attributes)
            name ||= "#{@name}N#{@nodes.count}"
            
            Node.new(name, self, **attributes)
        end
        
        # Add a subgraph with a given name and attributes.
        # @return [Graph] the new graph.
        def add_subgraph(name = nil, **attributes)
            name ||= "#{@name}S#{@nodes.count}"
            
            subgraph = Graph.new(name, self, attributes)
            
            self << subgraph
            
            return subgraph
        end
        
        # Finds all nodes with a given name
        #
        # @param [String] node_name the name to look for
        # @return [Array<Graphviz::Node>, nil] list of all found nodes or nil
        def get_node(node_name)
            @nodes.select{ |k, v| v.name == node_name}.values
        end

        # Determines if a node with a given name exists in the graph
        #
        # @param [String] node_name the name to look for
        # @return [Boolean] if node exists in graph
        def node_exists?(node_name)
            @nodes.select{ |k, v| v.name == node_name}.any?
        end


        def << node
            @nodes[node.name] = node
            
            node.attach(self)
        end
        
        # @return [String] Output the graph using the dot format.
        def to_dot(**options)
            buffer = StringIO.new
            
            dump_graph(buffer, **options)
            
            return buffer.string
        end
        
        def graph_format(options)
            if @graph
                'subgraph'
            else
                options[:format] || 'digraph'
            end
        end
        
        def identifier
            if @attributes[:cluster]
                "cluster_#{@name}"
            else
                super
            end
        end
        
        def dump_edges(buffer, indent, **options)
            @edges.each do |edge|
                edge_attributes_text = dump_attributes(edge.attributes)
                
                buffer.puts "#{indent}#{edge}#{edge_attributes_text};"
            end
        end
        
        # Dump the entire graph and all subgraphs to dot text format.
        def dump_graph(buffer, indent = "", **options)
            format = graph_format(options)
            
            buffer.puts "#{indent}#{format} #{dump_value(self.identifier)} {"
            
            @attributes.each do |name, value|
                buffer.puts "#{indent}\t#{name}=#{dump_value(value)};"
            end
            
            @nodes.each do |_name, node|
                node.dump_graph(buffer, indent + "\t", **options)
            end
            
            dump_edges(buffer, indent + "\t", **options)
            
            buffer.puts "#{indent}}"
        end
    end
end