didvan-app/lib/views/ai/ai_chat_state.dart

import 'dart:convert';
import 'dart:io';

import 'package:didvan/models/ai/bots_model.dart';
import 'package:didvan/models/ai/chats_model.dart';
import 'package:didvan/models/ai/messages_model.dart';
import 'package:didvan/models/enums.dart';
import 'package:didvan/models/view/alert_data.dart';
import 'package:didvan/providers/core.dart';
import 'package:didvan/services/ai/ai_api_service.dart';
import 'package:didvan/services/network/request.dart';
import 'package:didvan/services/network/request_helper.dart';
import 'package:didvan/utils/action_sheet.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:persian_number_utility/persian_number_utility.dart';

class AiChatState extends CoreProvier {
  Stream<String> messageOnstream = const Stream.empty();
  List<MessageModel> messages = [];
  bool onResponsing = false;
  bool loading = false;
  final ScrollController scrollController = ScrollController();
  int? chatId;
  File? file;

  Future<void> _scrolledEnd() async {
    WidgetsBinding.instance.addPostFrameCallback((_) async {
      await scrollController.animateTo(
        scrollController.position.minScrollExtent,
        duration: const Duration(milliseconds: 600),
        curve: Curves.easeInOut,
      );
    });
  }

  Future<void> _onError(e) async {
    onResponsing = false;
    messages.last.prompts.removeLast();
    messages.last.prompts.removeLast();
    messageOnstream = const Stream.empty();

    await ActionSheetUtils.showAlert(AlertData(
        message: 'خطا در برقراری ارتباط', aLertType: ALertType.error));

    update();
  }

  Future<RequestService> getChatId() async {
    final service = RequestService(
      RequestHelper.aiChatId(),
    );
    await service.httpGet();
    if (service.isSuccess) {
      final id = service.result['id'];
      chatId = id;
    }
    return service;
  }

  Future<void> getAllMessages(int chatId) async {
    loading = true;
    onResponsing = true;
    final service = RequestService(
      RequestHelper.aiAChat(chatId),
    );
    await service.httpGet();
    if (service.isSuccess) {
      messages.clear();
      final ChatsModel allMessages =
          ChatsModel.fromJson(service.result['chat']);
      for (var i = 0; i < allMessages.prompts!.length; i++) {
        final prompt = allMessages.prompts![i];
        if (messages.isNotEmpty &&
            DateTime.parse(messages.last.prompts.last.createdAt.toString())
                .toPersianDateStr()
                .contains(DateTime.parse(prompt.createdAt.toString())
                    .toPersianDateStr())) {
          messages.last.prompts.add(prompt);
        } else {
          messages.add(MessageModel(
              dateTime: prompt.createdAt.toString(), prompts: [prompt]));
        }
        // chats.add("chats: $chats");
      }
      appState = AppState.idle;
      loading = false;
      onResponsing = false;

      // Add this code to scroll to maxScrollExtent after the ListView is built
      update();

      return;
    }
    appState = AppState.failed;
    loading = false;
    onResponsing = false;

    update();
  }

  Future<void> postMessage(BotsModel bot) async {
    onResponsing = true;

    update();
    String message = messages.last.prompts.last.text!;

    messages.last.prompts.add(Prompts(
        finished: false,
        text: '...',
        role: 'bot',
        createdAt: DateTime.now()
            .subtract(const Duration(minutes: 210))
            .toIso8601String()));
    update();
    await _scrolledEnd();
    final req = await AiApiService.initial(
        url: '/${bot.id}/${bot.name}'.toLowerCase(),
        message: message,
        chatId: chatId,
        file: file);
    final res = await AiApiService.getResponse(req).catchError((e) {
      _onError(e);
      throw e;
    });
    String responseMessgae = '';
    var r = res.listen((value) async {
      var str = utf8.decode(value);
      responseMessgae += str;
      messageOnstream = Stream.value(responseMessgae);

      update();
    });

    r.onDone(() async {
      if (chatId == null) {
        final service = await getChatId();
        if (!service.isSuccess) {
          _onError(null);
          return;
        }
      }
      onResponsing = false;
      messages.last.prompts.last = messages.last.prompts.last.copyWith(
        finished: true,
        text: responseMessgae,
      );
      messageOnstream = const Stream.empty();

      update();
      _scrolledEnd();
    });

    r.onError(_onError);
  }
}