session.go

package fitbit

import (
	"encoding/json"
	"errors"
	"time"

	"github.com/markbates/goth"
	"golang.org/x/oauth2"
)

// Session stores data during the auth process with Fitbit.
type Session struct {
	AuthURL      string
	AccessToken  string
	RefreshToken string
	ExpiresAt    time.Time
	UserID       string
}

// GetAuthURL will return the URL set by calling the `BeginAuth` function on the
// Fitbit provider.
func (s Session) GetAuthURL() (string, error) {
	if s.AuthURL == "" {
		return "", errors.New(goth.NoAuthUrlErrorMessage)
	}
	return s.AuthURL, nil
}

// Authorize completes the authorization with Fitbit and returns the access
// token to be stored for future use.
func (s *Session) Authorize(provider goth.Provider, params goth.Params) (string, error) {
	p := provider.(*Provider)
	token, err := p.config.Exchange(oauth2.NoContext, params.Get("code"), oauth2.SetAuthURLParam("code_verifier", params.Get("code_verifier")))
	if err != nil {
		return "", err
	}
	s.AccessToken = token.AccessToken
	s.RefreshToken = token.RefreshToken
	s.ExpiresAt = token.Expiry
	s.UserID = token.Extra("user_id").(string)
	return token.AccessToken, err
}

// Marshal marshals a session into a JSON string.
func (s Session) Marshal() string {
	j, _ := json.Marshal(s)
	return string(j)
}

// String is equivalent to Marshal.  It returns a JSON representation of the session.
func (s Session) String() string {
	return s.Marshal()
}

// UnmarshalSession will unmarshal a JSON string into a session.
func (p *Provider) UnmarshalSession(data string) (goth.Session, error) {
	s := Session{}
	err := json.Unmarshal([]byte(data), &s)
	return &s, err
}