Graph

-- Graph class
-- ModuleScript with GraphNode, GraphEdge and FloydWarshall ModuleScripts inside
-- by Ozzypig (Twitter: @Ozzypig, ozzypig.com)

local GraphNode = require(script:WaitForChild("GraphNode"))
local FloydWarshallMixin = require(script:WaitForChild("FloydWarshall"))

local Graph = {}
Graph.__index = Graph

-- Functions relating to Floyd-Warshall algorithm implementation
for k, v in pairs(FloydWarshallMixin) do Graph[k] = v end

function Graph.new()
    local self = setmetatable({
        nodeCount = 0;
        nodes = {}; -- nodes[node] = node.value (usually just true)
        nodesByIndex = {};

        edgeCount = 0;
        edges = {}; -- edge[edge] = edge.value (usually weight)
        edgesByIndex = {};
    }, Graph)

    return self
end

function Graph:newNode(...)
    local node = GraphNode.new(...)
    node.index = self.nodeCount + 1
    self.nodes[node] = node.value
    self.nodesByIndex[node.index] = node
    self.nodeCount = self.nodeCount + 1
    return node
end

function Graph:newEdge(nodeOrigin, nodeTarget, ...)
    local edge = nodeOrigin:newEdgeTo(nodeTarget, ...)
    edge.index = self.edgeCount + 1
    self.edges[edge] = edge.value
    self.edgesByIndex[edge.index] = edge
    self.edgeCount = self.edgeCount + 1
    nodeOrigin:addEdge(edge)
end

function Graph:eachNode()
    return pairs(self.nodes)
end

function Graph:eachEdge()
    return pairs(self.edges)
end

function Graph:randomNode()
    return self.nodesByIndex[math.random(1, #self.nodesByIndex)]
end

function Graph:randomEdge()
    return self.edgesByIndex[math.random(1, #self.edgesByIndex)]
end

return Graph