1package goth
2
3import (
4	"context"
5	"fmt"
6	"net/http"
7
8	"golang.org/x/oauth2"
9)
10
11// Provider needs to be implemented for each 3rd party authentication provider
12// e.g. Facebook, Twitter, etc...
13type Provider interface {
14	Name() string
15	SetName(name string)
16	BeginAuth(state string) (Session, error)
17	UnmarshalSession(string) (Session, error)
18	FetchUser(Session) (User, error)
19	Debug(bool)
20	RefreshToken(refreshToken string) (*oauth2.Token, error) //Get new access token based on the refresh token
21	RefreshTokenAvailable() bool                             //Refresh token is provided by auth provider or not
22}
23
24const NoAuthUrlErrorMessage = "an AuthURL has not been set"
25
26// Providers is list of known/available providers.
27type Providers map[string]Provider
28
29var providers = Providers{}
30
31// UseProviders adds a list of available providers for use with Goth.
32// Can be called multiple times. If you pass the same provider more
33// than once, the last will be used.
34func UseProviders(viders ...Provider) {
35	for _, provider := range viders {
36		providers[provider.Name()] = provider
37	}
38}
39
40// GetProviders returns a list of all the providers currently in use.
41func GetProviders() Providers {
42	return providers
43}
44
45// GetProvider returns a previously created provider. If Goth has not
46// been told to use the named provider it will return an error.
47func GetProvider(name string) (Provider, error) {
48	provider := providers[name]
49	if provider == nil {
50		return nil, fmt.Errorf("no provider for %s exists", name)
51	}
52	return provider, nil
53}
54
55// ClearProviders will remove all providers currently in use.
56// This is useful, mostly, for testing purposes.
57func ClearProviders() {
58	providers = Providers{}
59}
60
61// ContextForClient provides a context for use with oauth2.
62func ContextForClient(h *http.Client) context.Context {
63	if h == nil {
64		return oauth2.NoContext
65	}
66	return context.WithValue(oauth2.NoContext, oauth2.HTTPClient, h)
67}
68
69// HTTPClientWithFallBack to be used in all fetch operations.
70func HTTPClientWithFallBack(h *http.Client) *http.Client {
71	if h != nil {
72		return h
73	}
74	return http.DefaultClient
75}
76