go_lang

package main

import (
	"bufio"
	"fmt"
	"os"
	"os/exec"
	"strconv"
	"runtime"
	// "strings"
	// "strings"
)

type Task struct {
	ID          int
	Description string
	Completed   bool
}

type TaskManager struct {
	tasks    []Task
	nextID   int
}

func NewTaskManager() *TaskManager {
	return &TaskManager{
		tasks:    make([]Task, 0),
		nextID:   1,
	}
}

func (tm *TaskManager) addTask(description string) {
	task := Task{
		ID:          tm.nextID,
		Description: description,
		Completed:   false,
	}
	tm.tasks = append(tm.tasks, task)
	tm.nextID++
	fmt.Printf("Task added successfully with ID: %d\n", task.ID)
}

func (tm *TaskManager) listTasks() {
	if len(tm.tasks) == 0 {
		fmt.Println("No tasks found!")
		return
	}

	fmt.Println("\nTask List:")
	fmt.Println("------------------")
	for _, task := range tm.tasks {
		status := " "
		if task.Completed {
			status = "✓"
		}
		fmt.Printf("[%s] %d. %s\n", status, task.ID, task.Description)
	}
	fmt.Println("------------------")
}

func (tm *TaskManager) markComplete(id int) {
	for i := range tm.tasks {
		if tm.tasks[i].ID == id {
			tm.tasks[i].Completed = true
			fmt.Printf("Task %d marked as complete\n", id)
			return
		}
	}
	fmt.Printf("Task with ID %d not found\n", id)
}

func (tm *TaskManager) deleteTask(id int) {
	for i := range tm.tasks {
		if tm.tasks[i].ID == id {
			tm.tasks = append(tm.tasks[:i], tm.tasks[i+1:]...)
			fmt.Printf("Task %d deleted successfully\n", id)
			return
		}
	}
	fmt.Printf("Task with ID %d not found\n", id)
}

func printMenu() {
	fmt.Println("\nTask Manager Menu:")
	fmt.Println("1. Add Task")
	fmt.Println("2. List Tasks")
	fmt.Println("3. Mark Task as Complete")
	fmt.Println("4. Delete Task")
	fmt.Println("5. Exit")
	fmt.Print("Enter your choice: ")
}

func clearScreen() {
	switch runtime.GOOS {
	case "windows":
		cmd := exec.Command("cmd", "/c", "cls")
		cmd.Stdout = os.Stdout
		cmd.Run()
	default: // For linux, mac, etc.
		cmd := exec.Command("clear")
		cmd.Stdout = os.Stdout
		cmd.Run()
	}
}

func main() {
	taskManager := NewTaskManager()
	scanner := bufio.NewScanner(os.Stdin)

	for {
		clearScreen()
		printMenu()
		scanner.Scan()
		choice := scanner.Text()

		clearScreen() // Clear screen after choice

		switch choice {
		case "1":
			fmt.Print("Enter task description: ")
			scanner.Scan()
			description := scanner.Text()
			taskManager.addTask(description)
			fmt.Print("\nPress Enter to continue...")
			scanner.Scan()

		case "2":
			taskManager.listTasks()
			fmt.Print("\nPress Enter to continue...")
			scanner.Scan()

		case "3":
			fmt.Print("Enter task ID to mark as complete: ")
			scanner.Scan()
			id, err := strconv.Atoi(scanner.Text())
			if err != nil {
				fmt.Println("Invalid ID. Please enter a number.")
				fmt.Print("\nPress Enter to continue...")
				scanner.Scan()
				continue
			}
			taskManager.markComplete(id)
			fmt.Print("\nPress Enter to continue...")
			scanner.Scan()

		case "4":
			fmt.Print("Enter task ID to delete: ")
			scanner.Scan()
			id, err := strconv.Atoi(scanner.Text())
			if err != nil {
				fmt.Println("Invalid ID. Please enter a number.")
				fmt.Print("\nPress Enter to continue...")
				scanner.Scan()
				continue
			}
			taskManager.deleteTask(id)
			fmt.Print("\nPress Enter to continue...")
			scanner.Scan()

		case "5":
			clearScreen()
			fmt.Println("Goodbye!")
			return

		default:
			fmt.Println("Invalid choice. Please try again.")
			fmt.Print("\nPress Enter to continue...")
			scanner.Scan()
		}
	}
}