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

public class mailSlotPrefab : MonoBehaviour
{
    private static readonly Dictionary<string, Sprite> RewardPreviewCache = new Dictionary<string, Sprite>(System.StringComparer.Ordinal);
    private static readonly HashSet<string> RewardPreviewLoadsInFlight = new HashSet<string>(System.StringComparer.Ordinal);

    [Header("buttons")]
    public Button openButton;
    public Button receivedButton;
    [Header("basic infomations")]
    public Image mailImage;
    public Text mailTitle;
    public Text mailSender;
    public Text mailTime;
    [Header("dots")]
    public Image isRead_redDot;
    public Image hasGift_icon;
    [Header("select")]
    public Image selectedImage;
    [Header("gifts")]
    public Text rewards_with_mail_text;
    [Header("reward previews")]
    public Transform rewardPreviewRoot;
    public GameObject rewardPreviewPrefab;
    public Sprite fallbackRewardPreviewSprite;

    public void RefreshRewardsWithMailText(mail_so mailData)
    {
        if (rewards_with_mail_text == null)
        {
            return;
        }

        int rewardCount = GetRewardCount(mailData);
        rewards_with_mail_text.text = rewardCount <= 0
            ? "\u4e0d\u5305\u542b\u9644\u4ef6"
            : $"\u5305\u542b{rewardCount}\u4e2a\u9644\u4ef6";
    }

    public void RefreshRewardPreviews(mail_so mailData)
    {
        if (rewardPreviewRoot == null)
        {
            return;
        }

        for (int i = rewardPreviewRoot.childCount - 1; i >= 0; i--)
        {
            Destroy(rewardPreviewRoot.GetChild(i).gameObject);
        }

        if (mailData == null || mailData.rewardList == null || mailData.rewardList.Count == 0 || rewardPreviewPrefab == null)
        {
            return;
        }

        for (int i = 0; i < mailData.rewardList.Count; i++)
        {
            mail_so.rewardItem reward = mailData.rewardList[i];
            if (reward == null)
            {
                continue;
            }

            GameObject go = Instantiate(rewardPreviewPrefab, rewardPreviewRoot);
            Image icon = go.GetComponent<Image>();
            if (icon == null)
            {
                icon = go.GetComponentInChildren<Image>(true);
            }

            BindRewardPreviewIcon(icon, reward);
        }
    }

    private void BindRewardPreviewIcon(Image icon, mail_so.rewardItem reward)
    {
        if (icon == null)
        {
            return;
        }

        if (reward != null && reward.reward_image != null)
        {
            icon.sprite = reward.reward_image;
            icon.enabled = true;
            return;
        }

        string url = reward != null ? (reward.reward_icon_url ?? string.Empty).Trim() : string.Empty;
        if (string.IsNullOrWhiteSpace(url))
        {
            icon.sprite = fallbackRewardPreviewSprite;
            icon.enabled = fallbackRewardPreviewSprite != null;
            return;
        }

        if (RewardPreviewCache.TryGetValue(url, out Sprite cachedSprite) && cachedSprite != null)
        {
            icon.sprite = cachedSprite;
            icon.enabled = true;
            return;
        }

        icon.sprite = fallbackRewardPreviewSprite;
        icon.enabled = icon.sprite != null;

        if (!RewardPreviewLoadsInFlight.Add(url))
        {
            return;
        }

        StartCoroutine(LoadRewardPreviewSpriteRoutine(url, icon));
    }

    private IEnumerator LoadRewardPreviewSpriteRoutine(string imageUrl, Image icon)
    {
        using (UnityWebRequest request = UnityWebRequestTexture.GetTexture(imageUrl))
        {
            yield return request.SendWebRequest();
            try
            {
                if (request.result != UnityWebRequest.Result.Success)
                {
                    yield break;
                }

                Texture2D texture = DownloadHandlerTexture.GetContent(request);
                if (texture == null)
                {
                    yield break;
                }

                Sprite sprite = Sprite.Create(
                    texture,
                    new Rect(0f, 0f, texture.width, texture.height),
                    new Vector2(0.5f, 0.5f));
                RewardPreviewCache[imageUrl] = sprite;
                if (icon != null)
                {
                    icon.sprite = sprite;
                    icon.enabled = true;
                }
            }
            finally
            {
                RewardPreviewLoadsInFlight.Remove(imageUrl);
            }
        }
    }

    private static int GetRewardCount(mail_so mailData)
    {
        if (mailData == null || mailData.rewardList == null)
        {
            return 0;
        }

        int count = 0;
        for (int i = 0; i < mailData.rewardList.Count; i++)
        {
            mail_so.rewardItem reward = mailData.rewardList[i];
            if (reward == null)
            {
                continue;
            }

            count += Mathf.Max(0, reward.reward_ammount);
        }

        return count;
    }
}