lolibrary/lolibrary

package dao

import (
    "context"

    "cloud.google.com/go/firestore"
    "github.com/lolibrary/lolibrary/libraries/database"
    "github.com/lolibrary/lolibrary/service.category/domain"
    "github.com/monzo/terrors"
    "google.golang.org/api/iterator"
)

func ReadCategory(ctx context.Context, id string) (*domain.Category, error) {
    snap, err := categoriesByID.Doc(id).Get(ctx)
    if err != nil {
        if database.NotFound(err) {
            return nil, database.ErrNotFound("category", "id", id)
        }

        return nil, terrors.Wrap(err, nil)
    }

    category := &domain.Category{}
    if err := snap.DataTo(&category); err != nil {
        return nil, terrors.Wrap(err, nil)
    }

    return category, nil
}

func ReadCategoryBySlug(ctx context.Context, slug string) (*domain.Category, error) {
    snap, err := categoriesBySlug.Doc(slug).Get(ctx)
    if err != nil {
        if database.NotFound(err) {
            return nil, database.ErrNotFound("category", "slug", slug)
        }

        return nil, terrors.Wrap(err, nil)
    }

    category := &domain.Category{}
    if err := snap.DataTo(&category); err != nil {
        return nil, terrors.Wrap(err, nil)
    }

    return category, nil
}

func CreateCategory(ctx context.Context, category *domain.Category) error {
    if err := Firestore.RunTransaction(ctx, func(ctx context.Context, tx *firestore.Transaction) error {
        if err := tx.Create(categoriesByID.Doc(category.ID), category); err != nil {
            if database.AlreadyExists(err) {
                return database.ErrAlreadyExists("category", "id", category.ID)
            }

            return err
        }

        if err := tx.Create(categoriesBySlug.Doc(category.Slug), category); err != nil {
            if database.AlreadyExists(err) {
                return database.ErrAlreadyExists("category", "slug", category.Slug)
            }

            return err
        }

        return nil
    }); err != nil {
        return terrors.Wrap(err, nil)
    }

    return nil
}

func UpdateCategory(ctx context.Context, category *domain.Category) error {
    if err := Firestore.RunTransaction(ctx, func(ctx context.Context, tx *firestore.Transaction) error {
        if err := tx.Set(categoriesByID.Doc(category.ID), category); err != nil {
            return err
        }

        if err := tx.Set(categoriesBySlug.Doc(category.Slug), category); err != nil {
            return err
        }

        return nil
    }); err != nil {
        return terrors.Wrap(err, nil)
    }

    return nil
}

func DeleteCategory(ctx context.Context, category *domain.Category) error {
    if err := Firestore.RunTransaction(ctx, func(ctx context.Context, tx *firestore.Transaction) error {
        if err := tx.Delete(categoriesByID.Doc(category.ID)); err != nil {
            return err
        }

        if err := tx.Delete(categoriesBySlug.Doc(category.Slug)); err != nil {
            return err
        }

        return nil
    }); err != nil {
        return terrors.Wrap(err, nil)
    }

    return nil
}

func ListCategories(ctx context.Context) ([]*domain.Category, error) {
    documents := categoriesByID.Documents(ctx)
    defer documents.Stop()

    categories := make([]*domain.Category, 0, 32)
    for {
        doc, err := documents.Next()
        if err == iterator.Done {
            break
        }
        if err != nil {
            return nil, terrors.Wrap(err, nil)
        }

        category := &domain.Category{}
        if err := doc.DataTo(&category); err != nil {
            return nil, terrors.Wrap(err, nil)
        }

        categories = append(categories, category)
    }

    return categories, nil
}