#!/usr/bin/lua

--require 'strict'

local Class = require 'class'

Edge = Class {
	init = function (self, s_node, e_node, label)
		self.s = s_node
		self.e = e_node
		self.label = label
		self.directed = false
	end,
}

Node = Class {
	init = function (self, label) 
		self.label = label
		self.edges = {}
	end,
}

Graph = Class {
	init = function (self, name)
		self.name = name
		self.start_node = {}
		self.end_node = {}
		self.nodes = {}
		self.edges = {}
	end,

	writeDotFile = function (self, filename)
		print ("writing file: " .. filename .. ".png")
		local outfile = io.open (filename .. ".dot", "w+")
	
		outfile:write("digraph dungeon {\n")

		for i,e in ipairs (self.edges) do
		  outfile:write (e.s.label .. " -> " .. e.e.label)
		 
			local options = {}
		
			if e.directed == false then
				table.insert (options, "dir=none")
			end

			if e.label ~= "" then
				table.insert (options, "label=" .. e.label)
			end

			local have_options = #options > 0
			if have_options then
				outfile:write (" [")
			end	

			for i,v in ipairs(options) do
				if i > 1 then
					outfile:write (", ")
				end
				outfile:write (v)
			end

			if have_options then
				outfile:write(" ]")
			end

			outfile:write ("\n")
		end
		outfile:write("}\n")
	
		outfile:close()
	
		os.execute ("dot -Tpng " .. filename .. ".dot -o " .. filename .. ".png")
	  os.execute ("eog " .. filename .. ".png")
	end,

	insertSubGraph = function (self, edge_index, subgraph)
	end
}

function create_simple() 
	local graph = Graph("simple")

	local start_node = Node("SimpleStart")
	local goal_node = Node("SimpleGoal")
	local se_edge = Edge(start_node, goal_node, "se")
	se_edge.directed = true
	local es_edge = Edge(goal_node, start_node, "es")

	graph.start_node = start_node
	graph.goal_node = goal_node
	table.insert (graph.nodes, start_node)
	table.insert (graph.nodes, goal_node)
	table.insert (graph.edges, se_edge)
	table.insert (graph.edges, es_edge)

	return graph
end

function create_lock()
	local graph = Graph("lock")

	local start_node = Node("LockStart")
	local goal_node = Node("LockGoal")
	local lock_node = Node("Lock")
	local sl_edge = Edge(start_node, lock_node, "sl")
	local ls_edge = Edge(lock_node, start_node, "ls_key")
	ls_edge.directed = true
	local lg_edge = Edge(lock_node, goal_node, "lg")

	graph.start_node = start_node
	graph.goal_node = goal_node

	table.insert (graph.nodes, start_node)
	table.insert (graph.nodes, lock_node)
	table.insert (graph.nodes, goal_node)
	table.insert (graph.edges, sl_edge)
	table.insert (graph.edges, ls_edge)
	table.insert (graph.edges, lg_edge)

	return graph
end

local simple = create_simple()
simple:writeDotFile("simple")

local lock = create_lock()
lock:writeDotFile("lock_graph")