articles-api/service/shortener/shortener.go

package shortener

import (
	"database/sql"
	"log"
	"net/http"

	"git.xdrm.io/example/aicra/service/auth"
	"git.xdrm.io/example/aicra/storage"
	"git.xdrm.io/go/aicra"
	"git.xdrm.io/go/aicra/api"
)

// Service manages the url shortener
type Service struct {
	storage     *sql.DB
	authService *auth.Service
	repo        *repository
}

// New returns a bare service
func New(storage *sql.DB, auth *auth.Service) *Service {
	log.Printf("[service.shortener] creating")

	service := &Service{
		storage:     storage,
		authService: auth,
	}

	// init repo
	repo, err := newRepo(db)
	if err != nil {
		log.Printf("[service.shortener] cannot create repo")
		return service
	}

	log.Printf("[service.shortener] creating")
	return service
}

// Wire to the aicra server
func (svc *Service) Wire(server *aicra.Server) {
	log.Printf("[service.shortener] wired")
	server.HandleFunc("GET", "/", svc.redirect)
	server.HandleFunc("POST", "/", svc.authService.CheckToken(svc.register))
	server.HandleFunc("PUT", "/", svc.authService.CheckToken(svc.update))
	server.HandleFunc("DELETE", "/", svc.authService.CheckToken(svc.delete))
}

// redirect from a tiny url to the long url
func (svc *Service) redirect(req api.Request, res *api.Response) {

	// 1. extract input
	tinyURL, err := req.Param.GetString("url")
	if err != nil {
		res.SetError(api.ErrorInvalidParam(), "url", err.Error())
		return
	}

	// 2. check in db if exists
	longURL := svc.storage.Get(storage.DATA, tinyURL)
	if longURL == nil {
		res.SetError(api.ErrorNoMatchFound())
		return
	}

	// 3. redirect
	res.Status = http.StatusPermanentRedirect
	res.Headers.Set("Location", string(longURL))
	res.SetError(api.ErrorSuccess())

}

// register registers a new tiny url to a long one
func (svc *Service) register(req api.Request, res *api.Response) {

	// 1. extract arguments
	longURL, err := req.Param.GetString("target")
	if err != nil {
		res.SetError(api.ErrorInvalidParam(), "target", err.Error())
		return
	}
	tinyURL, err := req.Param.GetString("url")
	if err != nil {
		res.SetError(api.ErrorInvalidParam(), "url", err.Error())
		return
	}

	// 2. fail if already used
	if svc.storage.Get(storage.DATA, tinyURL) != nil {
		res.SetError(api.ErrorAlreadyExists(), "url")
		return
	}

	// 3. store association
	if !svc.storage.Set(storage.DATA, tinyURL, longURL) {
		res.SetError(api.ErrorFailure())
		return
	}

	res.SetError(api.ErrorSuccess())
}

// update updates an existing tiny url to a new long one
func (svc *Service) update(req api.Request, res *api.Response) {

	// 1. extract arguments
	longURL, err := req.Param.GetString("target")
	if err != nil {
		res.SetError(api.ErrorInvalidParam(), "target", err.Error())
		return
	}
	tinyURL, err := req.Param.GetString("url")
	if err != nil {
		res.SetError(api.ErrorInvalidParam(), "url", err.Error())
		return
	}

	// 2. fail if not already existing
	if svc.storage.Get(storage.DATA, tinyURL) == nil {
		res.SetError(api.ErrorNoMatchFound())
		return
	}

	// 3. update association
	if !svc.storage.Set(storage.DATA, tinyURL, longURL) {
		res.SetError(api.ErrorFailure())
		return
	}

	res.SetError(api.ErrorSuccess())
}

// delete removes a new tiny url
func (svc *Service) delete(req api.Request, res *api.Response) {

	// 1. extract arguments
	tinyURL, err := req.Param.GetString("url")
	if err != nil {
		res.SetError(api.ErrorInvalidParam(), "url", err.Error())
		return
	}

	// 2. fail if not already existing
	if svc.storage.Get(storage.DATA, tinyURL) == nil {
		res.SetError(api.ErrorNoMatchFound())
		return
	}

	// 3. update association
	if !svc.storage.Del(storage.DATA, tinyURL) {
		res.SetError(api.ErrorFailure())
		return
	}

	res.SetError(api.ErrorSuccess())
}