todo.go

package todo

import (
	"encoding/json"
	"errors"
	"fmt"
	"os"
	"time"

	"github.com/alexeyco/simpletable"
)

// Declaring the structure of the Todos
type item struct {
	Task        string
	Done        bool
	CreatedAt   time.Time
	CompletedAt time.Time
}

// Slice used to store dynamic data
type Todos []item

// Controller to add task in todo
func (t *Todos) Add(task string) {

	todo := item{
		Task:        task,
		Done:        false,
		CreatedAt:   time.Now(),
		CompletedAt: time.Time{},
	}

	*t = append(*t, todo)
}

// Contorller to mark completed task
func (t *Todos) Completed(index int) error {

	ls := *t
	if index <= 0 || index > len(ls) {
		return errors.New("invalid text")
	}

	ls[index-1].CompletedAt = time.Now()
	ls[index-1].Done = true

	return nil
}

// Controller to delete a Todo
func (t *Todos) Delete(index int) error {

	ls := *t

	if index <= 0 || index > len(ls) {
		return errors.New("invalid text")
	}

	//Used slicing to remove the todo and connect it
	*t = append(ls[:index-1], ls[index:]...)

	return nil
}

// Load the file ie load  the todos
func (t *Todos) Load(filename string) error {
	file, err := os.ReadFile(filename)
	if err != nil {
		if errors.Is(err, os.ErrNotExist) {
			return nil
		}
		return err
	}
	if len(file) == 0 {
		return err
	}
	err = json.Unmarshal(file, t)
	if err != nil {
		return nil
	}
	return nil
}

// Store a todo
func (t *Todos) Store(filename string) error {
	data, err := json.Marshal(t)
	if err != nil {
		return err
	}
	return os.WriteFile(filename, data, 0644)
}

//List all todos

func (t *Todos) List() {
	table := simpletable.New()
	table.Header = &simpletable.Header{
		Cells: []*simpletable.Cell{
			{Align: simpletable.AlignCenter, Text: "#"},
			{Align: simpletable.AlignCenter, Text: "Task"},
			{Align: simpletable.AlignCenter, Text: "Done ?"},
			{Align: simpletable.AlignCenter, Text: "Created At"},
			{Align: simpletable.AlignCenter, Text: "Completed At"},
		},
	}
	var cells [][]*simpletable.Cell
	for idx, item := range *t {
		idx++
		cells = append(cells, []*simpletable.Cell{
			{Text: fmt.Sprintf("%d", idx)},
			{Text: item.Task},
			{Text: fmt.Sprintf("%t", item.Done)},
			{Text: item.CreatedAt.Format(time.RFC822)},
			{Text: item.CompletedAt.Format(time.RFC822)},
		})
	}
	table.Body = &simpletable.Body{Cells: cells}
	table.Footer = &simpletable.Footer{Cells: []*simpletable.Cell{
		{Align: simpletable.AlignCenter, Span: 5, Text: "Your Todo's Are Here"},
	}}
	table.SetStyle(simpletable.StyleUnicode)
	table.Println()
}