indrasaputra/url-shortener

package repository

import (
    "context"

    "github.com/indrasaputra/aptx/entity"
)

// InsertURLDatabase defines the interface to insert a new URL to the database.
type InsertURLDatabase interface {
    // Insert inserts a new URL into the database.
    // It must handle if the data already exists.
    Insert(ctx context.Context, url *entity.URL) error
}

// InsertURLCache defines the interface to insert a new URL to the cache.
type InsertURLCache interface {
    // Save saves a new URL into the cache.
    Save(ctx context.Context, url *entity.URL) error
}

// URLInserter is responsible to insert a new URL into storage.
// It uses database and cache.
type URLInserter struct {
    database InsertURLDatabase
    cache    InsertURLCache
}

// NewURLInserter creates an instance of URLInserter.
func NewURLInserter(database InsertURLDatabase, cache InsertURLCache) *URLInserter {
    return &URLInserter{
        database: database,
        cache:    cache,
    }
}

// Save saves a new URL into the storage.
// First, it inserts to database. If success, the data will be inserted to cache.
// It ignores the error from cache since it can always be generated when retrieving the data.
// But, it doesn't ignore the error from the database.
func (ui *URLInserter) Save(ctx context.Context, url *entity.URL) error {
    if url == nil {
        return entity.ErrEmptyURL()
    }

    if err := ui.database.Insert(ctx, url); err != nil {
        return err
    }
    _ = ui.cache.Save(ctx, url)
    return nil
}