/**
 * NarrativeManager.js
 * Manages the flow of story events, dialogue, and tutorials.
 * Extends EventTarget to broadcast UI updates.
 */
export class NarrativeManager extends EventTarget {
  constructor() {
    super();
    this.currentSequence = null;
    this.currentNode = null;
    this.history = new Set(); // Track played sequences IDs
  }

  /**
   * Loads and starts a narrative sequence.
   * @param {Object} sequenceData - The JSON object of the conversation.
   */
  startSequence(sequenceData) {
    if (!sequenceData || !sequenceData.nodes) {
      console.error("Invalid sequence data");
      return;
    }

    console.log(`Starting Narrative: ${sequenceData.id}`);
    this.currentSequence = sequenceData;
    this.history.add(sequenceData.id);

    // Find first node (usually index 0 or id '1')
    this.currentNode = sequenceData.nodes[0];
    this.broadcastUpdate();
  }

  /**
   * Advances to the next node in the sequence.
   */
  next() {
    if (!this.currentNode) return;

    // 1. Handle Triggers (Side Effects)
    if (this.currentNode.trigger) {
      this.dispatchEvent(
        new CustomEvent("narrative-trigger", {
          detail: { action: this.currentNode.trigger },
        })
      );
    }

    // 2. Find Next Node
    const nextId = this.currentNode.next;

    if (nextId === "END" || !nextId) {
      this.endSequence();
    } else {
      this.currentNode = this.currentSequence.nodes.find(
        (n) => n.id === nextId
      );
      this.broadcastUpdate();
    }
  }

  /**
   * Handles player choice selection.
   */
  makeChoice(choiceIndex) {
    if (!this.currentNode.choices) return;

    const choice = this.currentNode.choices[choiceIndex];
    const nextId = choice.next;

    if (choice.trigger) {
      this.dispatchEvent(
        new CustomEvent("narrative-trigger", {
          detail: { action: choice.trigger },
        })
      );
    }

    this.currentNode = this.currentSequence.nodes.find((n) => n.id === nextId);
    this.broadcastUpdate();
  }

  endSequence() {
    console.log("Narrative Ended");
    this.currentSequence = null;
    this.currentNode = null;
    this.dispatchEvent(new CustomEvent("narrative-end"));
  }

  broadcastUpdate() {
    this.dispatchEvent(
      new CustomEvent("narrative-update", {
        detail: {
          node: this.currentNode,
          active: !!this.currentNode,
        },
      })
    );
  }
}

// Export singleton for global access
export const narrativeManager = new NarrativeManager();