taskeep-app/app/(tabs)/index.tsx

import { Pressable, ScrollView, StyleSheet, View } from 'react-native';

import Ionicons from '@expo/vector-icons/Ionicons';
import { useFocusEffect } from 'expo-router';
import { navigate } from 'expo-router/build/global-state/routing';
import React, { useEffect, useState } from 'react';
import { useTranslation } from 'react-i18next';
import { PermissionsAndroid, Platform } from 'react-native';
import { TaskItem } from '../../components/taskItem';
import { ThemedText } from '../../components/ThemedText';
import { ThemedView } from '../../components/ThemedView';
import { Category, CategoryQuery } from '../../models/category';
import { Task, TaskQuery } from '../../models/task';
import { CategoryRepository } from '../../repositories/CategoryRepository';
import { TaskRepository } from '../../repositories/TaskRepository';
import { SQLiteDataService } from '../../services/data/sqliteDataService';

export const checkApplicationPermission = async () => {
  if (Platform.OS === 'android') {
    try {
      await PermissionsAndroid.request(
        PermissionsAndroid.PERMISSIONS.POST_NOTIFICATIONS,
      );
    } catch (error) {
    }
  }
}

const categoryRepository = new CategoryRepository(new SQLiteDataService<Category>(CategoryQuery));
const taskRepository = new TaskRepository(new SQLiteDataService<Task>(TaskQuery));

export default function HomeScreen() {

  const [tasks, setTasks] = useState<Task[]>([]);
  const [categories, setCategories] = useState<Category[]>([]);
  const [ready, setReady] = useState(false);
  const { t } = useTranslation();

  useEffect(() => { // Initial data fetch
    (async () => {
      console.log("Fetching categories...");
      try {
        const fetchedCategories = await categoryRepository.findAll();
        if (fetchedCategories.length === 0) {
          // If no categories, create a default one
          const defaultCategory = new Category("Uncategorized", "🤷‍♂️");
          const createdCat = await categoryRepository.create(defaultCategory);
          setCategories([createdCat]);
        } else {
          setCategories(fetchedCategories);
        }
      } catch (error) {
        console.error("Error fetching categories:", error);
      }
      try {
        console.log("Fetching tasks...");
        RefreshTasks();
      } catch (error) {
        console.error("Error fetching categories or tasks:", error);
      }
      setReady(true);
    })();
  }, []);

  useEffect(() => { // NOTIFICATION HANDLER
    if (Platform.OS !== 'web') {
      if (Platform.OS === 'android') {
        checkApplicationPermission();
      }
    }
  }, []);


  const RefreshTasks = async () => {
    try {
      const fetchedTasks = await taskRepository.findAll();
      fetchedTasks.sort((a, b) => {
        return (a.daysToRedo! * 24 * 3600 * 1000 - (Date.now() - a.lastDone!)) - ((b.daysToRedo! * 24 * 3600 * 1000) - (Date.now() - b.lastDone!));
      })
      console.log("Tasks fetched:", fetchedTasks);


      setTasks(fetchedTasks);
    } catch (error) {
      console.error("Error refreshing tasks:", error);
    }
  }

  const RefreshCategories = async () => {
    try {
      const fetchedCategories = await categoryRepository.findAll();
      setCategories(fetchedCategories);
    } catch (error) {
      console.error("Error refreshing categories:", error);
    }
  }

  useEffect(() => {
    if (ready) {
      (async () => {
        await RefreshTasks();
        await RefreshCategories();
      })();
    }
  }, [ready]);

  //On layout focus to refresh tasks
  useFocusEffect(React.useCallback(() => {
    console.log("focus");
    (async () => {
      await RefreshTasks();
      await RefreshCategories();
    })();
  }, []));

  return (
    <ThemedView style={styles.mainContainer}>
      <ThemedView style={styles.headerContainer}>
        <ThemedText type="title" style={
          {
            color: '#fff',
          }
        }>Taskeep!</ThemedText>
        <Pressable onPress={() => {
          navigate('./taskForm', {})
        }}>
          <Ionicons name='add-circle-sharp' size={32} color="#fff" />
        </Pressable>
      </ThemedView>
      <ThemedText style={{ padding: 24 }} type="subtitle">Your Tasks</ThemedText>
      <ScrollView style={styles.scrollView}>
        {tasks.map((task, index) => (
          <TaskItem categories={categories} key={Date.now() + "-" + task.id} task={task} onUpdate={() => {
            RefreshTasks();
          }} />
        ))}
        {tasks.length === 0 && (<>
          <ThemedText type="defaultSemiBold" style={{ textAlign: 'center', marginTop: 20 }}>
            No tasks available.
          </ThemedText>
          <ThemedText type="default" style={{ textAlign: 'center', marginTop: 20 }}>
            Add a task to get started!
          </ThemedText>
        </>)}
        <View style={{ height: 50 }} />
      </ScrollView>
    </ThemedView>
  );
}

const styles = StyleSheet.create({
  mainContainer: {
    flex: 1,
  },
  headerContainer: {
    flexDirection: 'row',
    alignItems: 'center',
    justifyContent: 'space-between',
    gap: 8,
    paddingHorizontal: 24,
    paddingTop: 50,
    paddingBottom: 18,
    backgroundColor: '#6a254fff',
  },
  scrollView: {
    paddingHorizontal: 24,
    flex: 1,
  },
  stepContainer: {
    gap: 8,
    marginBottom: 8,
  },
  reactLogo: {
    height: 178,
    width: 290,
    bottom: 0,
    left: 0,
    position: 'absolute',
  },
  addButton: {
    backgroundColor: '#b91f7eff',
    height: 50,
    color: '#fff',
    borderRadius: 8,
    padding: 10,
    lineHeight: 30,
    alignItems: 'center',
    justifyContent: 'center',
  }
});