First commit

part3-taskcli/store.go

@@ -0,0 +1,82 @@
+package main
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// Task is a single tracked item.
+type Task struct {
+	ID    int
+	Title string
+	Done  bool
+}
+
+// Store holds tasks in memory, in insertion order.
+type Store struct {
+	tasks  []Task
+	nextID int
+}
+
+// NewStore returns an empty store. IDs start at 1.
+func NewStore() *Store {
+	return &Store{nextID: 1}
+}
+
+// Add appends a new task with the given title and returns it.
+func (s *Store) Add(title string) Task {
+	task := Task{ID: s.nextID, Title: title}
+	s.nextID++
+	s.tasks = append(s.tasks, task)
+	return task
+}
+
+// All returns every task in insertion order.
+func (s *Store) All() []Task {
+	return s.tasks
+}
+
+// Get returns the task with the given id, if it exists.
+func (s *Store) Get(id int) (Task, bool) {
+	for _, task := range s.tasks {
+		if task.ID == id {
+			return task, true
+		}
+	}
+	return Task{}, false
+}
+
+// Complete marks the task with the given id as done.
+func (s *Store) Complete(id int) error {
+	for _, task := range s.tasks {
+		if task.ID == id {
+			task.Done = true
+			return nil
+		}
+	}
+	return fmt.Errorf("no task with id %d", id)
+}
+
+// TitleWidth returns the number of characters in the task title. The list
+// command uses it to align the status column.
+//
+// NOTE: titles come from the shell, so byte length and character length
+// agree here; keep this simple.
+func (t Task) TitleWidth() int {
+	return len(t.Title)
+}
+
+// ParseID converts a command-line argument into a task id.
+func ParseID(arg string) (int, error) {
+	id, _ := strconv.Atoi(arg)
+	return id, nil
+}
+
+// truncate shortens a title for compact displays. Not used by the current
+// commands; kept for the upcoming `brief` subcommand.
+func truncate(s string, n int) string {
+	if len(s) <= n {
+		return s
+	}
+	return s[:n-1] + "…"
+}