articles-api/service/shortener/shortener.go

package shortener

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

	"git.xdrm.io/example/aicra/service/auth"
	"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, error) {
	log.Printf("[shortener] creating service")

	log.Printf("[shortener] creating repo")
	repo, err := newRepo(storage)
	if err != nil {
		return nil, err
	}
	log.Printf("[shortener] repo created")

	log.Printf("[shortener] service created")
	return &Service{
		repo:        repo,
		authService: auth,
	}, nil
}

// Wire to the aicra server
func (svc *Service) Wire(server *aicra.Server) {
	log.Printf("[shortener] service 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
	model := svc.repo.NewModel(tinyURL, "")
	if model.Search() != nil {
		res.SetError(api.ErrorNoMatchFound())
		return
	}

	// 3. redirect
	res.Status = http.StatusPermanentRedirect
	res.Headers.Set("Location", model.long)
	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
	model := svc.repo.NewModel(tinyURL, "")
	if model.Search() == nil {
		res.SetError(api.ErrorAlreadyExists(), "url")
		return
	}

	// 3. store association
	model.long = longURL
	if model.Create() != nil {
		res.SetError(api.ErrorFailure())
		return
	}
	log.Printf("[shortener] new %q -> %q", model.tiny, model.long)

	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
	model := svc.repo.NewModel(tinyURL, "")
	if model.Search() != nil {
		res.SetError(api.ErrorNoMatchFound())
		return
	}

	// 3. update association
	model.long = longURL
	if model.Update() != nil {
		res.SetError(api.ErrorFailure())
		return
	}
	log.Printf("[shortener] upd %q -> %q", model.tiny, model.long)

	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
	model := svc.repo.NewModel(tinyURL, "")
	if model.Search() != nil {
		res.SetError(api.ErrorNoMatchFound())
		return
	}

	// 3. delete association
	if model.Delete() != nil {
		res.SetError(api.ErrorFailure())
		return
	}
	log.Printf("[shortener] del %q", model.tiny)

	res.SetError(api.ErrorSuccess())
}