wavelength_app/app/(tabs)/messages.tsx

import React, { useCallback, useReducer } from 'react';
import { ThemedText, ThemedView } from '@/components/theme/Theme';
import { Alert, Linking, Platform, StyleSheet } from 'react-native';
import { MaterialIcons } from '@expo/vector-icons';
import {
  GiftedChat,
  IMessage,
  Send,
  SendProps,
  SystemMessage,
} from 'react-native-gifted-chat';
import { SafeAreaProvider, SafeAreaView } from 'react-native-safe-area-context';
import AccessoryBar from '@/components/chat/AccessoryBar';
import CustomActions from '@/components/chat/CustomActions';
import CustomView from '@/components/chat/CustomView';
import NavBar from '@/components/chat/NavBar';
import earlierMessages from '@/components/chat/data/earlierMessages';
import messages from '@/components/chat/data/messages';
import * as Clipboard from 'expo-clipboard';
import {
  GCUser,
  GCState,
  GCStateAction,
  ActionKind,
  GCMessage
} from '@/constants/Types';

const tempUser: GCUser = {
  _id: 1,
  name: 'Developer',
};

const reducer = (state: GCState, action: GCStateAction) => {
  switch (action.type) {
    case ActionKind.SEND_MESSAGE: {
      return {
        ...state,
        step: state.step + 1,
        messages: action.payload,
      };
    }
    case ActionKind.LOAD_EARLIER_MESSAGES: {
      return {
        ...state,
        loadEarlier: true,
        isLoadingEarlier: false,
        messages: action.payload,
      };
    }
    case ActionKind.LOAD_EARLIER_START: {
      return {
        ...state,
        isLoadingEarlier: true,
      }
    }
    case ActionKind.SET_IS_TYPING: {
      return {
        ...state,
        isTyping: action.payload,
      }
    }
  }
};

const MessagesScreen = () => {
  const [state, dispatch] = useReducer(reducer, {
    messages: messages,
    step: 0,
    loadEarlier: true,
    isLoadingEarlier: false,
    isTyping: false,
  })

  const onSend = useCallback((messages: GCMessage[]) => {
    const sentMessages = [{ ...messages[0], sent: true, received: true }]

};
export default MessagesScreen;