using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class DialogueSystem : MonoBehaviour {
    // Allows us to get to DialogueSystem from other classes via DialogueSystem.Instance
    public static DialogueSystem Instance { get; set; } //attribute accessors

    // a list for our lines to be set via inspector
    public List<string> dialogueLines = new List<string>(); //lists are like arrays but "better", in c# you can't dynamicly size arrays

    // allows us to drag Dialog Panel into this object via inspector
    public GameObject dialoguePanel;
    public string     npcName; //will probably be set to hidden soon

    Button continueButton;         //make a button object
    Text   dialogueText, nameText; //make two text objects
    int    dialogueIndex;          //I belive this is for our dialogue array

    // When activated via NPC
    void Awake () {
        //get continue button component through dialogue panel's child 'Continue', same with text and name
        continueButton = dialoguePanel.transform.Find ("Continue").GetComponent<Button> ();
        dialogueText   = dialoguePanel.transform.Find("Text").GetComponent<Text> ();
        nameText       = dialoguePanel.transform.Find("Name").GetChild(0).GetComponent<Text>(); // 0 means get the first child (indexed by 0)

        //what happens when the button is clicked
        // Delegates are used to pass methods as arguments to other methods.
        continueButton.onClick.AddListener (delegate{ ContinueDialogue(); } );
        dialoguePanel.SetActive (false);


        // if Instance is not null and isn't this instance(?)
        if (Instance != null && Instance != this) {
            Destroy (gameObject); //Destroy self
        }
        else
        {
            Instance = this;
        }
    }

    // To be called by NPC, who will pass in their lines and name
    public void AddNewDialogue(string[] lines, string npcName)
    {
        dialogueIndex = 0;
        dialogueLines = new List<string> (lines.Length); //set the list to lines.length
        dialogueLines.AddRange (lines); //appends lines to the the list
        this.npcName = npcName; //set this instances name to the name passed
        CreateDialogue();
        Debug.Log(dialogueLines.Count);
    }

    public void CreateDialogue()
    {
        dialogueText.text = dialogueLines [dialogueIndex];
        nameText.text = npcName;
        dialoguePanel.SetActive (true);
    }

    public void ContinueDialogue()
    {
        if (dialogueIndex < dialogueLines.Count - 1)
        {
            dialogueIndex++;
            dialogueText.text = dialogueLines [dialogueIndex];
        }
        else
        {
            dialoguePanel.SetActive (false);
        }
    }
}