package gondole

import (

	"encoding/json"

	"github.com/sendgrid/rest"

	"log"

	"strings"

)

var (

	ourScopes = []string{

		"read",

		"write",

		"follow",

	}

)

type registerApp struct {

	ID           int64  `json:"id"`

	ClientSecret string `json:"client_secret"`

}

func registerApplication(name string, scopes []string, redirectURI string) (g *Gondole, err error) {

	g = &Gondole{

		Name: name,

	}

	req := g.prepareRequest("apps")

	if redirectURI != "" {

		req.QueryParams["redirect_uris"] = redirectURI

	} else {

		req.QueryParams["redirect_uris"] = NoRedirect

	}

	req.QueryParams["client_name"] = name

	req.QueryParams["scopes"] = strings.Join(scopes, " ")

	req.Method = rest.Post

	r, err := rest.API(req)

	if err != nil {

		log.Fatalf("error can not register app: %v", err)

	}

	var resp registerApp

	err = json.Unmarshal([]byte(r.Body), &resp)

	if err != nil {

		log.Fatalf("error can not register app: %v", err)

	}

	g.ID = resp.ClientID

	g.Secret = resp.ClientSecret

	server := &Server{

		ID:          g.ID,

		Name:        name,

		BearerToken: g.Secret,

	}

	err = server.WriteToken(name)

	if err != nil {

		log.Fatalf("error: can not write token for %s", name)

	}

	return

}

// NewApp registers a new instance

func NewApp(name string, scopes []string, redirectURI string) (g *Gondole, err error) {

	// Load configuration, will register if none is found

	cnf, err := LoadConfig(name)

	if err != nil {

		// Nothing exist yet

		cnf := Config{

			Default: name,

		}

		err = cnf.Write()

		if err != nil {

			log.Fatalf("error: can not write config for %s", name)

		}

		// Now register this through OAuth

		if scopes == nil {

			scopes = ourScopes

		}

		g, err = registerApplication(name, scopes, redirectURI)

	} else {

		g = &Gondole{

			Name:   cnf.Name,

			ID:     cnf.ID,

			Secret: cnf.BearerToken,

		}

	}

	return

}