package services

import (
	"fmt"

	"github.com/google/uuid"
	"michaelthomson.dev/mthomson/go-todos-app/db"
)

type TodoService struct {
  store *db.TodosStore
}

func NewTodoService(store *db.TodosStore) *TodoService {
  return &TodoService{
    store: store,
  }
}

func (ts *TodoService) AddTodo(name string) (todo db.Todo, err error)  {
  addedTodo := db.Todo{
    Id: uuid.New(),
    Name: name,
    Done: false,
  }

  ts.store.Todos = append(ts.store.Todos, addedTodo)

  return addedTodo, nil
}

func (ts *TodoService) GetTodos() (todos []db.Todo, err error)  {
  return ts.store.Todos, nil
}

func (ts *TodoService) GetTodoById(id uuid.UUID) (todo db.Todo, err error)  {
  for _, todo := range ts.store.Todos {
    if id == todo.Id {
      return todo, nil
    }
  }

  return db.Todo{}, fmt.Errorf("Could not find todo by id %q", id)
}

func (ts *TodoService) DeleteTodoById(id uuid.UUID) (err error)  {
  index := -1
  for i, todo := range ts.store.Todos {
    if id == todo.Id {
      index = i
    }
  }

  if index == -1 {
    return fmt.Errorf("Could not find todo by id %q", id)
  }

  ts.store.Todos = append(ts.store.Todos[:index], ts.store.Todos[index + 1:]...)

  return nil
}