import "dart:convert";
import "dart:typed_data";

import "package:flutter/foundation.dart";
import "package:quotegen_client/models/gallery_item.dart";
import "package:quotegen_client/providers/form_provider.dart";
import "package:quotegen_client/services/gallery_db.dart";


class GalleryProvider extends ChangeNotifier {

  List<GalleryItem> items = [];
  bool isLoading = false;


  GalleryProvider() {
    load();
  }

  Future<void> load() async {
    isLoading = true;
    notifyListeners();

    items = await GalleryDB.getAllItems();

    isLoading = false;
    notifyListeners();
  }

  // returns false if a duplicate already exists
  Future<bool> saveCurrentForm(FormProvider form) async {
    final avatarB64 = form.avatarImage != null ? base64Encode(form.avatarImage!) : null;
    final postB64 = form.postImage != null ? base64Encode(form.postImage!) : null;
    final ts = form.combineDateTime();

    final isDuplicate = items.any((i) =>
      i.displayName == form.displayName &&
      i.handle == form.handle &&
      i.content == form.content &&
      i.verified == form.verified &&
      i.timestamp == ts &&
      i.avatarImageB64 == avatarB64 &&
      i.postImageB64 == postB64 &&
      i.replies == form.replies &&
      i.retweets == form.retweets &&
      i.likes == form.likes &&
      i.views == form.views
    );

    if (isDuplicate) return false;

    final id = DateTime.now().millisecondsSinceEpoch.toString();

    final item = GalleryItem(
      id: id,
      displayName: form.displayName,
      handle: form.handle,
      content: form.content,
      verified: form.verified,
      timestamp: ts,
      avatarImageB64: avatarB64,
      postImageB64: postB64,
      replies: form.replies,
      retweets: form.retweets,
      likes: form.likes,
      views: form.views,
      createdAt: DateTime.now().millisecondsSinceEpoch,
    );

    await GalleryDB.saveItem(item);
    items.insert(0, item);
    notifyListeners();
    return true;
  }

  Future<void> deleteItem(String id) async {
    await GalleryDB.deleteItem(id);
    items.removeWhere((i) => i.id == id);
    notifyListeners();
  }

  // decode image bytes for a gallery item - returns null if no image
  Uint8List? decodeAvatar(GalleryItem item) {
    if (item.avatarImageB64 == null) return null;
    return base64Decode(item.avatarImageB64!);
  }

  Uint8List? decodePostImage(GalleryItem item) {
    if (item.postImageB64 == null) return null;
    return base64Decode(item.postImageB64!);
  }
}