TopologicalData.swift

//
//  TopologicalData.swift
//
//
//  Created by Elliot Boschwitz on 6/4/24.
//

import Foundation

// TODO: topological data should be recalculated only when the node schema count and/or connections dict changes
// TODO: move wirelessBroadcastChoices outside of topological data
public struct GraphTopologicalData<Node: NodeCalculatable> {
    public typealias InputRowId = Node.InputRow.RowID
    public typealias OutputRowId = Node.OutputRow.RowID
    public typealias ShallowDownstreamNodesDict = [Node.ID: Set<Node.ID>]
    typealias CachedDownstreamNodes = [OutputRowId: Set<Node.ID>]
    typealias UpstreamNodesCache = [Node.ID: Set<Node.ID>]
    public typealias Connections = [OutputRowId: Set<InputRowId>]
    typealias NodeCycles = Set<Set<Node.ID>>
    typealias GraphDependencies = [Node.ID: [Node.ID]]
    typealias NodeId = Node.ID
    typealias NodeIdSet = Set<NodeId>
    
    public init() { }
    
    var nodesForNextGraphStep = Set<Node.ID>()
    
    // Maps NodeID to set of connected input coordinates
    var shallowDownstreamNodes = ShallowDownstreamNodesDict()
    
    // Maps output coordinate to set of connected input coordinates
    var cachedDownstreamIds = CachedDownstreamNodes()
    
    // Tracks which nodes are in cycles
    var nodeCycles = NodeCycles()
    
    // Tracks preferred node starting points, which persist with documents
    var preferredRootCycleNodes = NodeIdSet()
    
    // Tracks all posible candidates for root cycles, resets whenever
    // topological data is updated
    var allCandidateRootCycleNodes = NodeIdSet()
    
    var upstreamNodesCache = UpstreamNodesCache()
    
    var connections = Connections()
    
    var _allMustRunNodes = Set<Node.ID>()
    
    // Memoizes a sorted list of nodes to eval given some set of node IDs
    var memoizedQueues = [Set<Node.ID>: Node.ID]()
    
    // Nodes that scheduled themselves via their node eval,
    // e.g. Classic Animation node
    var nodesScheduledToRun = Set<Node.ID>() {
        didSet {
            self._allMustRunNodes = self.getMustRunNodes()
        }
    }
    
    // Nodes that need to run every graph step,
    // e.g. Time node
    // memoized: changes when patch node count changes.
    var nodesToAlwaysRun = Set<Node.ID>() {
        didSet {
            self._allMustRunNodes = self.getMustRunNodes()
        }
    }
    
    var keyboardNodes = Set<Node.ID>() {
        didSet {
            self._allMustRunNodes = self.getMustRunNodes()
        }
    }
}

extension GraphTopologicalData {
    // fka `allMustRunNodes`
    var nodesToRunOnGraphStep: Set<Node.ID> {
        self._allMustRunNodes.union(self.nodesForNextGraphStep)
    }

    func getMustRunNodes() -> Set<Node.ID> {
        self.nodesToAlwaysRun
            .union(self.nodesScheduledToRun)
            .union(self.keyboardNodes)
    }
}