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

public class StatusUI : MonoBehaviour
{
    public StatusIconUI iconPrefab;

    private BattleParticipant battleParticipant;

    private Dictionary<BattleStatus, StatusIconUI> icons;

    public void Init(BattleParticipant battleParticipant) {
        this.battleParticipant = battleParticipant;

        this.icons = new Dictionary<BattleStatus, StatusIconUI>();
        this.battleParticipant.OnStatusChanged += this.NotifyBattleStatusChanged;
    }

    // Start is called before the first frame update
    void Start() {
        UpdateAppearance();
    }

    public void NotifyBattleStatusChanged(BattleParticipant updatedParticipant) {
        if (updatedParticipant != this.battleParticipant) {
            throw new System.InvalidOperationException(
                "NotifyBattleStatusChanged was notified about a different participant.");
        }
        UpdateAppearance();
    }

    private void UpdateAppearance() {
        int index = 0;
        foreach (BattleStatus status in Enum.GetValues(typeof(BattleStatus)).Cast<BattleStatus>()) {
            if (status == BattleStatus.None) {
                continue;
            }

            StatusIconUI iconUI = null;
            this.icons.TryGetValue(status, out iconUI);
            if (this.battleParticipant.HasStatus(status)) {
                if (iconUI == null) {
                    iconUI = Instantiate(this.iconPrefab.gameObject, this.transform).GetComponent<StatusIconUI>();
                    iconUI.Init(status);
                    this.icons[status] = iconUI;
                }
                iconUI.SetAmount(this.battleParticipant.GetStatusAmount(status), index);
                index++;
            } else {
                if (iconUI != null) {
                    Destroy(iconUI.gameObject);
                    this.icons.Remove(status);
                }
            }
        }
    }
}