// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package oauth2

import (
	"context"
	"errors"
	"fmt"
	"io"
	"net/http"
	"net/http/httptest"
	"net/url"
	"testing"
	"time"
)

type mockTransport struct {
	rt func(req *http.Request) (resp *http.Response, err error)
}

func (t *mockTransport) RoundTrip(req *http.Request) (resp *http.Response, err error) {
	return t.rt(req)
}

func newConf(url string) *Config {
	return &Config{
		ClientID:     "CLIENT_ID",
		ClientSecret: "CLIENT_SECRET",
		RedirectURL:  "REDIRECT_URL",
		Scopes:       []string{"scope1", "scope2"},
		Endpoint: Endpoint{
			AuthURL:  url + "/auth",
			TokenURL: url + "/token",
		},
	}
}

func TestAuthCodeURL(t *testing.T) {
	conf := newConf("server")
	url := conf.AuthCodeURL("foo", AccessTypeOffline, ApprovalForce)
	const want = "server/auth?access_type=offline&client_id=CLIENT_ID&prompt=consent&redirect_uri=REDIRECT_URL&response_type=code&scope=scope1+scope2&state=foo"
	if got := url; got != want {
		t.Errorf("got auth code URL = %q; want %q", got, want)
	}
}

func TestAuthCodeURL_CustomParam(t *testing.T) {
	conf := newConf("server")
	param := SetAuthURLParam("foo", "bar")
	url := conf.AuthCodeURL("baz", param)
	const want = "server/auth?client_id=CLIENT_ID&foo=bar&redirect_uri=REDIRECT_URL&response_type=code&scope=scope1+scope2&state=baz"
	if got := url; got != want {
		t.Errorf("got auth code = %q; want %q", got, want)
	}
}

func TestAuthCodeURL_Optional(t *testing.T) {
	conf := &Config{
		ClientID: "CLIENT_ID",
		Endpoint: Endpoint{
			AuthURL:  "/auth-url",
			TokenURL: "/token-url",
		},
	}
	url := conf.AuthCodeURL("")
	const want = "/auth-url?client_id=CLIENT_ID&response_type=code"
	if got := url; got != want {
		t.Fatalf("got auth code = %q; want %q", got, want)
	}
}

func TestURLUnsafeClientConfig(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if got, want := r.Header.Get("Authorization"), "Basic Q0xJRU5UX0lEJTNGJTNGOkNMSUVOVF9TRUNSRVQlM0YlM0Y="; got != want {
			t.Errorf("Authorization header = %q; want %q", got, want)
		}

		w.Header().Set("Content-Type", "application/x-www-form-urlencoded")
		w.Write([]byte("access_token=90d64460d14870c08c81352a05dedd3465940a7c&scope=user&token_type=bearer"))
	}))
	defer ts.Close()
	conf := newConf(ts.URL)
	conf.ClientID = "CLIENT_ID??"
	conf.ClientSecret = "CLIENT_SECRET??"
	_, err := conf.Exchange(context.Background(), "exchange-code")
	if err != nil {
		t.Error(err)
	}
}

func TestExchangeRequest(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.String() != "/token" {
			t.Errorf("Unexpected exchange request URL %q", r.URL)
		}
		headerAuth := r.Header.Get("Authorization")
		if want := "Basic Q0xJRU5UX0lEOkNMSUVOVF9TRUNSRVQ="; headerAuth != want {
			t.Errorf("Unexpected authorization header %q, want %q", headerAuth, want)
		}
		headerContentType := r.Header.Get("Content-Type")
		if headerContentType != "application/x-www-form-urlencoded" {
			t.Errorf("Unexpected Content-Type header %q", headerContentType)
		}
		body, err := io.ReadAll(r.Body)
		if err != nil {
			t.Errorf("Failed reading request body: %s.", err)
		}
		if string(body) != "code=exchange-code&grant_type=authorization_code&redirect_uri=REDIRECT_URL" {
			t.Errorf("Unexpected exchange payload; got %q", body)
		}
		w.Header().Set("Content-Type", "application/x-www-form-urlencoded")
		w.Write([]byte("access_token=90d64460d14870c08c81352a05dedd3465940a7c&scope=user&token_type=bearer"))
	}))
	defer ts.Close()
	conf := newConf(ts.URL)
	tok, err := conf.Exchange(context.Background(), "exchange-code")
	if err != nil {
		t.Error(err)
	}
	if !tok.Valid() {
		t.Fatalf("Token invalid. Got: %#v", tok)
	}
	if tok.AccessToken != "90d64460d14870c08c81352a05dedd3465940a7c" {
		t.Errorf("Unexpected access token, %#v.", tok.AccessToken)
	}
	if tok.TokenType != "bearer" {
		t.Errorf("Unexpected token type, %#v.", tok.TokenType)
	}
	scope := tok.Extra("scope")
	if scope != "user" {
		t.Errorf("Unexpected value for scope: %v", scope)
	}
}

func TestExchangeRequest_CustomParam(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.String() != "/token" {
			t.Errorf("Unexpected exchange request URL, %v is found.", r.URL)
		}
		headerAuth := r.Header.Get("Authorization")
		if headerAuth != "Basic Q0xJRU5UX0lEOkNMSUVOVF9TRUNSRVQ=" {
			t.Errorf("Unexpected authorization header, %v is found.", headerAuth)
		}
		headerContentType := r.Header.Get("Content-Type")
		if headerContentType != "application/x-www-form-urlencoded" {
			t.Errorf("Unexpected Content-Type header, %v is found.", headerContentType)
		}
		body, err := io.ReadAll(r.Body)
		if err != nil {
			t.Errorf("Failed reading request body: %s.", err)
		}
		if string(body) != "code=exchange-code&foo=bar&grant_type=authorization_code&redirect_uri=REDIRECT_URL" {
			t.Errorf("Unexpected exchange payload, %v is found.", string(body))
		}
		w.Header().Set("Content-Type", "application/x-www-form-urlencoded")
		w.Write([]byte("access_token=90d64460d14870c08c81352a05dedd3465940a7c&scope=user&token_type=bearer"))
	}))
	defer ts.Close()
	conf := newConf(ts.URL)

	param := SetAuthURLParam("foo", "bar")
	tok, err := conf.Exchange(context.Background(), "exchange-code", param)
	if err != nil {
		t.Error(err)
	}
	if !tok.Valid() {
		t.Fatalf("Token invalid. Got: %#v", tok)
	}
	if tok.AccessToken != "90d64460d14870c08c81352a05dedd3465940a7c" {
		t.Errorf("Unexpected access token, %#v.", tok.AccessToken)
	}
	if tok.TokenType != "bearer" {
		t.Errorf("Unexpected token type, %#v.", tok.TokenType)
	}
	scope := tok.Extra("scope")
	if scope != "user" {
		t.Errorf("Unexpected value for scope: %v", scope)
	}
}

func TestExchangeRequest_JSONResponse(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.String() != "/token" {
			t.Errorf("Unexpected exchange request URL, %v is found.", r.URL)
		}
		headerAuth := r.Header.Get("Authorization")
		if headerAuth != "Basic Q0xJRU5UX0lEOkNMSUVOVF9TRUNSRVQ=" {
			t.Errorf("Unexpected authorization header, %v is found.", headerAuth)
		}
		headerContentType := r.Header.Get("Content-Type")
		if headerContentType != "application/x-www-form-urlencoded" {
			t.Errorf("Unexpected Content-Type header, %v is found.", headerContentType)
		}
		body, err := io.ReadAll(r.Body)
		if err != nil {
			t.Errorf("Failed reading request body: %s.", err)
		}
		if string(body) != "code=exchange-code&grant_type=authorization_code&redirect_uri=REDIRECT_URL" {
			t.Errorf("Unexpected exchange payload, %v is found.", string(body))
		}
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"access_token": "90d64460d14870c08c81352a05dedd3465940a7c", "scope": "user", "token_type": "bearer", "expires_in": 86400}`))
	}))
	defer ts.Close()
	conf := newConf(ts.URL)
	tok, err := conf.Exchange(context.Background(), "exchange-code")
	if err != nil {
		t.Error(err)
	}
	if !tok.Valid() {
		t.Fatalf("Token invalid. Got: %#v", tok)
	}
	if tok.AccessToken != "90d64460d14870c08c81352a05dedd3465940a7c" {
		t.Errorf("Unexpected access token, %#v.", tok.AccessToken)
	}
	if tok.TokenType != "bearer" {
		t.Errorf("Unexpected token type, %#v.", tok.TokenType)
	}
	scope := tok.Extra("scope")
	if scope != "user" {
		t.Errorf("Unexpected value for scope: %v", scope)
	}
	expiresIn := tok.Extra("expires_in")
	if expiresIn != float64(86400) {
		t.Errorf("Unexpected non-numeric value for expires_in: %v", expiresIn)
	}
}

func TestExtraValueRetrieval(t *testing.T) {
	values := url.Values{}
	kvmap := map[string]string{
		"scope": "user", "token_type": "bearer", "expires_in": "86400.92",
		"server_time": "1443571905.5606415", "referer_ip": "10.0.0.1",
		"etag": "\"afZYj912P4alikMz_P11982\"", "request_id": "86400",
		"untrimmed": "  untrimmed  ",
	}
	for key, value := range kvmap {
		values.Set(key, value)
	}

	tok := Token{raw: values}
	scope := tok.Extra("scope")
	if got, want := scope, "user"; got != want {
		t.Errorf("got scope = %q; want %q", got, want)
	}
	serverTime := tok.Extra("server_time")
	if got, want := serverTime, 1443571905.5606415; got != want {
		t.Errorf("got server_time value = %v; want %v", got, want)
	}
	refererIP := tok.Extra("referer_ip")
	if got, want := refererIP, "10.0.0.1"; got != want {
		t.Errorf("got referer_ip value = %v, want %v", got, want)
	}
	expiresIn := tok.Extra("expires_in")
	if got, want := expiresIn, 86400.92; got != want {
		t.Errorf("got expires_in value = %v, want %v", got, want)
	}
	requestID := tok.Extra("request_id")
	if got, want := requestID, int64(86400); got != want {
		t.Errorf("got request_id value = %v, want %v", got, want)
	}
	untrimmed := tok.Extra("untrimmed")
	if got, want := untrimmed, "  untrimmed  "; got != want {
		t.Errorf("got untrimmed = %q; want %q", got, want)
	}
}

const day = 24 * time.Hour

func TestExchangeRequest_JSONResponse_Expiry(t *testing.T) {
	seconds := int32(day.Seconds())
	for _, c := range []struct {
		name        string
		expires     string
		want        bool
		nullExpires bool
	}{
		{"normal", fmt.Sprintf(`"expires_in": %d`, seconds), true, false},
		{"paypal", fmt.Sprintf(`"expires_in": "%d"`, seconds), true, false},
		{"issue_239", fmt.Sprintf(`"expires_in": null`), true, true},

		{"wrong_type", `"expires_in": false`, false, false},
		{"wrong_type2", `"expires_in": {}`, false, false},
		{"wrong_value", `"expires_in": "zzz"`, false, false},
	} {
		t.Run(c.name, func(t *testing.T) {
			testExchangeRequest_JSONResponse_expiry(t, c.expires, c.want, c.nullExpires)
		})
	}
}

func testExchangeRequest_JSONResponse_expiry(t *testing.T, exp string, want, nullExpires bool) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(fmt.Sprintf(`{"access_token": "90d", "scope": "user", "token_type": "bearer", %s}`, exp)))
	}))
	defer ts.Close()
	conf := newConf(ts.URL)
	t1 := time.Now().Add(day)
	tok, err := conf.Exchange(context.Background(), "exchange-code")
	t2 := t1.Add(day)

	if got := (err == nil); got != want {
		if want {
			t.Errorf("unexpected error: got %v", err)
		} else {
			t.Errorf("unexpected success")
		}
	}
	if !want {
		return
	}
	if !tok.Valid() {
		t.Fatalf("Token invalid. Got: %#v", tok)
	}
	expiry := tok.Expiry

	if nullExpires && expiry.IsZero() {
		return
	}
	if expiry.Before(t1) || expiry.After(t2) {
		t.Errorf("Unexpected value for Expiry: %v (should be between %v and %v)", expiry, t1, t2)
	}
}

func TestExchangeRequest_BadResponse(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"scope": "user", "token_type": "bearer"}`))
	}))
	defer ts.Close()
	conf := newConf(ts.URL)
	_, err := conf.Exchange(context.Background(), "code")
	if err == nil {
		t.Error("expected error from missing access_token")
	}
}

func TestExchangeRequest_BadResponseType(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"access_token":123,  "scope": "user", "token_type": "bearer"}`))
	}))
	defer ts.Close()
	conf := newConf(ts.URL)
	_, err := conf.Exchange(context.Background(), "exchange-code")
	if err == nil {
		t.Error("expected error from non-string access_token")
	}
}

func TestExchangeRequest_NonBasicAuth(t *testing.T) {
	tr := &mockTransport{
		rt: func(r *http.Request) (w *http.Response, err error) {
			headerAuth := r.Header.Get("Authorization")
			if headerAuth != "" {
				t.Errorf("Unexpected authorization header %q", headerAuth)
			}
			return nil, errors.New("no response")
		},
	}
	c := &http.Client{Transport: tr}
	conf := &Config{
		ClientID: "CLIENT_ID",
		Endpoint: Endpoint{
			AuthURL:   "https://accounts.google.com/auth",
			TokenURL:  "https://accounts.google.com/token",
			AuthStyle: AuthStyleInParams,
		},
	}

	ctx := context.WithValue(context.Background(), HTTPClient, c)
	conf.Exchange(ctx, "code")
}

func TestPasswordCredentialsTokenRequest(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		defer r.Body.Close()
		expected := "/token"
		if r.URL.String() != expected {
			t.Errorf("URL = %q; want %q", r.URL, expected)
		}
		headerAuth := r.Header.Get("Authorization")
		expected = "Basic Q0xJRU5UX0lEOkNMSUVOVF9TRUNSRVQ="
		if headerAuth != expected {
			t.Errorf("Authorization header = %q; want %q", headerAuth, expected)
		}
		headerContentType := r.Header.Get("Content-Type")
		expected = "application/x-www-form-urlencoded"
		if headerContentType != expected {
			t.Errorf("Content-Type header = %q; want %q", headerContentType, expected)
		}
		body, err := io.ReadAll(r.Body)
		if err != nil {
			t.Errorf("Failed reading request body: %s.", err)
		}
		expected = "grant_type=password&password=password1&scope=scope1+scope2&username=user1"
		if string(body) != expected {
			t.Errorf("res.Body = %q; want %q", string(body), expected)
		}
		w.Header().Set("Content-Type", "application/x-www-form-urlencoded")
		w.Write([]byte("access_token=90d64460d14870c08c81352a05dedd3465940a7c&scope=user&token_type=bearer"))
	}))
	defer ts.Close()
	conf := newConf(ts.URL)
	tok, err := conf.PasswordCredentialsToken(context.Background(), "user1", "password1")
	if err != nil {
		t.Error(err)
	}
	if !tok.Valid() {
		t.Fatalf("Token invalid. Got: %#v", tok)
	}
	expected := "90d64460d14870c08c81352a05dedd3465940a7c"
	if tok.AccessToken != expected {
		t.Errorf("AccessToken = %q; want %q", tok.AccessToken, expected)
	}
	expected = "bearer"
	if tok.TokenType != expected {
		t.Errorf("TokenType = %q; want %q", tok.TokenType, expected)
	}
}

func TestTokenRefreshRequest(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.String() == "/somethingelse" {
			return
		}
		if r.URL.String() != "/token" {
			t.Errorf("Unexpected token refresh request URL %q", r.URL)
		}
		headerContentType := r.Header.Get("Content-Type")
		if headerContentType != "application/x-www-form-urlencoded" {
			t.Errorf("Unexpected Content-Type header %q", headerContentType)
		}
		body, _ := io.ReadAll(r.Body)
		if string(body) != "grant_type=refresh_token&refresh_token=REFRESH_TOKEN" {
			t.Errorf("Unexpected refresh token payload %q", body)
		}
		w.Header().Set("Content-Type", "application/json")
		io.WriteString(w, `{"access_token": "foo", "refresh_token": "bar"}`)
	}))
	defer ts.Close()
	conf := newConf(ts.URL)
	c := conf.Client(context.Background(), &Token{RefreshToken: "REFRESH_TOKEN"})
	c.Get(ts.URL + "/somethingelse")
}

func TestFetchWithNoRefreshToken(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.String() == "/somethingelse" {
			return
		}
		if r.URL.String() != "/token" {
			t.Errorf("Unexpected token refresh request URL, %v is found.", r.URL)
		}
		headerContentType := r.Header.Get("Content-Type")
		if headerContentType != "application/x-www-form-urlencoded" {
			t.Errorf("Unexpected Content-Type header, %v is found.", headerContentType)
		}
		body, _ := io.ReadAll(r.Body)
		if string(body) != "client_id=CLIENT_ID&grant_type=refresh_token&refresh_token=REFRESH_TOKEN" {
			t.Errorf("Unexpected refresh token payload, %v is found.", string(body))
		}
	}))
	defer ts.Close()
	conf := newConf(ts.URL)
	c := conf.Client(context.Background(), nil)
	_, err := c.Get(ts.URL + "/somethingelse")
	if err == nil {
		t.Errorf("Fetch should return an error if no refresh token is set")
	}
}

func TestTokenRetrieveError(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.String() != "/token" {
			t.Errorf("Unexpected token refresh request URL, %v is found.", r.URL)
		}
		w.Header().Set("Content-type", "application/json")
		// "The authorization server responds with an HTTP 400 (Bad Request)" https://www.rfc-editor.org/rfc/rfc6749#section-5.2
		w.WriteHeader(http.StatusBadRequest)
		w.Write([]byte(`{"error": "invalid_grant"}`))
	}))
	defer ts.Close()
	conf := newConf(ts.URL)
	_, err := conf.Exchange(context.Background(), "exchange-code")
	if err == nil {
		t.Fatalf("got no error, expected one")
	}
	re, ok := err.(*RetrieveError)
	if !ok {
		t.Fatalf("got %T error, expected *RetrieveError; error was: %v", err, err)
	}
	expected := `oauth2: "invalid_grant"`
	if errStr := err.Error(); errStr != expected {
		t.Fatalf("got %#v, expected %#v", errStr, expected)
	}
	expected = "invalid_grant"
	if re.ErrorCode != expected {
		t.Fatalf("got %#v, expected %#v", re.ErrorCode, expected)
	}
}

// TestTokenRetrieveError200 tests handling of unorthodox server that returns 200 in error case
func TestTokenRetrieveError200(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.String() != "/token" {
			t.Errorf("Unexpected token refresh request URL, %v is found.", r.URL)
		}
		w.Header().Set("Content-type", "application/json")
		w.Write([]byte(`{"error": "invalid_grant"}`))
	}))
	defer ts.Close()
	conf := newConf(ts.URL)
	_, err := conf.Exchange(context.Background(), "exchange-code")
	if err == nil {
		t.Fatalf("got no error, expected one")
	}
	re, ok := err.(*RetrieveError)
	if !ok {
		t.Fatalf("got %T error, expected *RetrieveError; error was: %v", err, err)
	}
	expected := `oauth2: "invalid_grant"`
	if errStr := err.Error(); errStr != expected {
		t.Fatalf("got %#v, expected %#v", errStr, expected)
	}
	expected = "invalid_grant"
	if re.ErrorCode != expected {
		t.Fatalf("got %#v, expected %#v", re.ErrorCode, expected)
	}
}

func TestRefreshToken_RefreshTokenReplacement(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"access_token":"ACCESS_TOKEN",  "scope": "user", "token_type": "bearer", "refresh_token": "NEW_REFRESH_TOKEN"}`))
		return
	}))
	defer ts.Close()
	conf := newConf(ts.URL)
	tkr := conf.TokenSource(context.Background(), &Token{RefreshToken: "OLD_REFRESH_TOKEN"})
	tk, err := tkr.Token()
	if err != nil {
		t.Errorf("got err = %v; want none", err)
		return
	}
	if want := "NEW_REFRESH_TOKEN"; tk.RefreshToken != want {
		t.Errorf("RefreshToken = %q; want %q", tk.RefreshToken, want)
	}
}

func TestRefreshToken_RefreshTokenPreservation(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"access_token":"ACCESS_TOKEN",  "scope": "user", "token_type": "bearer"}`))
		return
	}))
	defer ts.Close()
	conf := newConf(ts.URL)
	const oldRefreshToken = "OLD_REFRESH_TOKEN"
	tkr := conf.TokenSource(context.Background(), &Token{RefreshToken: oldRefreshToken})
	tk, err := tkr.Token()
	if err != nil {
		t.Fatalf("got err = %v; want none", err)
	}
	if tk.RefreshToken != oldRefreshToken {
		t.Errorf("RefreshToken = %q; want %q", tk.RefreshToken, oldRefreshToken)
	}
}

func TestConfigClientWithToken(t *testing.T) {
	tok := &Token{
		AccessToken: "abc123",
	}
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if got, want := r.Header.Get("Authorization"), fmt.Sprintf("Bearer %s", tok.AccessToken); got != want {
			t.Errorf("Authorization header = %q; want %q", got, want)
		}
		return
	}))
	defer ts.Close()
	conf := newConf(ts.URL)

	c := conf.Client(context.Background(), tok)
	req, err := http.NewRequest("GET", ts.URL, nil)
	if err != nil {
		t.Error(err)
	}
	_, err = c.Do(req)
	if err != nil {
		t.Error(err)
	}
}