bnkamalesh/goapp

// Package usernotes maintains notes of a user
package usernotes

import (
    "context"
    "strings"
    "time"

    "github.com/bnkamalesh/errors"
    "github.com/bnkamalesh/goapp/internal/users"
)

type Note struct {
    ID        string
    Title     string
    Content   string
    Creator   *users.User
    CreatedAt time.Time
    UpdatedAt time.Time
}

func (note *Note) ValidateForCreate() error {
    if note == nil {
        return errors.Validation("empty note")
    }

    note.Sanitize()
    if note.Title == "" {
        return errors.Validation("note title cannot be empty")
    }

    if note.Content == "" {
        return errors.Validation("note content cannot be empty")
    }

    if note.Creator == nil || note.Creator.ID == "" {
        return errors.Validation("note creator cannot be anonymous")
    }

    return nil
}

func (note *Note) Sanitize() {
    note.Title = strings.TrimSpace(note.Title)
    note.Content = strings.TrimSpace(note.Content)
}

type store interface {
    GetNoteByID(ctx context.Context, userID string, noteID string) (*Note, error)
    SaveNote(ctx context.Context, note *Note) (string, error)
}

type UserNotes struct {
    store store
}

func (un *UserNotes) SaveNote(ctx context.Context, note *Note) (*Note, error) {
    err := note.ValidateForCreate()
    if err != nil {
        return nil, err
    }

    note.CreatedAt = time.Now()
    note.UpdatedAt = time.Now()
    note.ID, err = un.store.SaveNote(ctx, note)
    if err != nil {
        return nil, err
    }

    return note, nil
}

func (un *UserNotes) GetNoteByID(ctx context.Context, userID string, noteID string) (*Note, error) {
    return un.store.GetNoteByID(ctx, userID, noteID)
}

func NewService(store store) *UserNotes {
    return &UserNotes{
        store: store,
    }
}