// engine_logic.js - Reine State- und Datenverarbeitung (Kein UI, Kein Fetch)
const EngineLogic = {
    storyData: { nodes: {} },
    state: { reboots: 1, node: "" },

    init: function(dataObj) {
        if (!dataObj || !dataObj.nodes || Object.keys(dataObj.nodes).length === 0) {
            console.warn("[System] Ungültige Graph-Daten. Fallback geladen.");
            this.storyData = {
                startNodeId: "err",
                nodes: {
                    "err": {
                        id: "err", title: "SYSTEM OFFLINE", 
                        content: "<p>Konnte <code>graph.json</code> nicht laden.</p>",
                        choices: [],
                        metadata: { status: "offline" }
                    }
                }
            };
        } else {
            this.storyData = dataObj;
        }
        
        this.state.node = this.storyData.startNodeId || Object.keys(this.storyData.nodes)[0] || "";
    },

    getNode: function(id) { return this.storyData.nodes[id]; },

    processNodeEntry: function(id) {
        const node = this.getNode(id);
        if (!node) return null;

        this.state.node = id;

        if (node.metadata) {
            Object.keys(node.metadata).forEach(key => {
                this.state[key] = node.metadata[key];
            });
        }

        if (node.isReboot) this.state.reboots++;
        return node;
    },

    parseRequirement: function(choiceText) {
        let conditionMatch = choiceText.match(/\[req:\s*([a-zA-Z0-9_]+)\s*=\s*([^\]]+)\]/i);
        let displayText = choiceText;
        let meetsCondition = true;
        let missingReq = "";

        if (conditionMatch) {
            let reqKey = conditionMatch[1].toLowerCase();
            let reqVal = conditionMatch[2];
            if (String(this.state[reqKey]) !== String(reqVal)) {
                meetsCondition = false;
                missingReq = `(Benötigt: ${reqKey}=${reqVal})`;
            }
            displayText = displayText.replace(conditionMatch[0], "").trim();
        }

        return { displayText, meetsCondition, missingReq };
    },

    triggerReboot: function() {
        const currentReboots = this.state.reboots + 1;
        this.state = { reboots: currentReboots }; 
        return this.storyData.startNodeId;
    }
};