1 files changed, 101 insertions, 0 deletions
diff --git a/db.go b/db.go
new file mode 100644
index 0000000..ccee504
--- /dev/null
+++ b/db.go
@@ -0,0 +1,101 @@
+package main
+
+import (
+	"errors"
+	"time"
+)
+
+type Database interface {
+	GetTracking() (*Task, error)
+	GetTasks() ([]*Task, error)
+	QueryTask(id *int) (*Task, error)
+	StartNewEntry(now time.Time, task *Task) (*Task, error)
+	StopEntry(now time.Time) error
+	SaveEntry(task *Task) (*Task, error)
+}
+
+type InMemDb struct {
+	tasks   []*Task
+	current *Task
+}
+
+var (
+	ErrNotFound = errors.New("Not found")
+	ErrNotRunning = errors.New("Not running")
+)
+
+func NewInMemDb() Database {
+	return &InMemDb {
+		tasks: []*Task{},
+		current: nil,
+	}
+}
+
+func (db *InMemDb) GetTracking() (*Task, error) {
+	return db.current, nil
+}
+
+func (db *InMemDb) GetTasks() ([]*Task, error) {
+	res := make([]*Task, 0, len(db.tasks))
+	for _, task := range db.tasks {
+		res = append(res, task)
+	}
+
+	return res, nil
+}
+
+func (db *InMemDb) QueryTask(id *int) (*Task, error) {
+	for _, task := range db.tasks {
+		if id != nil && task.Id == *id {
+			return task, nil
+		}
+	}
+
+	return nil, ErrNotFound
+}
+
+func (db *InMemDb) StartNewEntry(now time.Time, task *Task) (*Task, error) {
+	newTask := &Task {
+		Id: len(db.tasks),
+		From: task.From,
+		To: nil,
+		Tag: task.Tag,
+		Comment: task.Comment,
+	}
+
+	if newTask.From == nil {
+		newTask.From = &now
+	}
+
+	db.tasks = append(db.tasks, newTask)
+	db.StopEntry(now)
+	db.current = newTask
+	return newTask, nil
+}
+
+func (db *InMemDb) StopEntry(now time.Time) error {
+	if db.current != nil {
+		db.current.To = &now
+		db.current = nil
+	} else {
+		return ErrNotRunning
+	}
+	return nil
+}
+
+func (db *InMemDb) SaveEntry(task *Task) (*Task, error) {
+	if task.Id < 0 || task.Id >= len(db.tasks) {
+		copyTask := *task
+		copyTask.Id = len(db.tasks)
+		db.tasks = append(db.tasks, &copyTask)
+
+		return &copyTask, nil
+	}
+	
+	existent := db.tasks[task.Id]
+	existent.Comment = task.Comment
+	existent.Tag = task.Tag
+	existent.From = task.From
+	existent.To = task.To
+	return existent, nil
+}