audrenbdb/index.html

## index.html
<!DOCTYPE html>
<html>
<body>
<a
        href="http://localhost:9096/oauth/authorize?client_id=paulthebest&redirect_uri=http://localhost:8080/oauth/redirect&response_type=code">
    Login
</a>
</body>
</html>

## main.go
package main

import (
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
)

const clientID = "paulthebest"

func main() {
	fs := http.FileServer(http.Dir("public"))
	http.Handle("/", fs)

	// We will be using `httpClient` to make external HTTP requests later in our code
	httpClient := http.Client{}

	// Create a new redirect route route
	http.HandleFunc("/oauth/redirect", func(w http.ResponseWriter, r *http.Request) {
		// First, we need to get the value of the `code` query param
		err := r.ParseForm()
		if err != nil {
			fmt.Fprintf(os.Stdout, "could not parse query: %v", err)
			w.WriteHeader(http.StatusBadRequest)
		}
		code := r.Form.Get("code")

		reqURL := fmt.Sprintf("http://localhost:9096/oauth/token?client_id=%s&code=%s&grant_type=authorization_code&redirect_uri=http://localhost:8080/oauth/redirect", clientID, code)
		req, err := http.NewRequest(http.MethodPost, reqURL, nil)
		if err != nil {
			fmt.Fprintf(os.Stdout, "could not create HTTP request: %v", err)
			w.WriteHeader(http.StatusBadRequest)
		}
		// We set this header since we want the response
		// as JSON
		req.Header.Set("accept", "application/json")

		// Send out the HTTP request
		res, err := httpClient.Do(req)
		if err != nil {
			fmt.Fprintf(os.Stdout, "could not send HTTP request: %v", err)
			w.WriteHeader(http.StatusInternalServerError)
		}
		defer res.Body.Close()

		// Parse the request body into the `OAuthAccessResponse` struct
		var t OAuthAccessResponse
		b, err := io.ReadAll(res.Body)
		err = json.Unmarshal(b, &t)
		if err != nil {
			log.Printf("error decoding sakura response: %v", err)
			if e, ok := err.(*json.SyntaxError); ok {
				log.Printf("syntax error at byte offset %d", e.Offset)
			}
			log.Printf("sakura response: %q", res.Body)
		}

		// Finally, send a response to redirect the user to the "welcome" page
		// with the access token
		w.Header().Set("Location", "/welcome.html?access_token="+t.AccessToken)
		w.WriteHeader(http.StatusFound)
	})

	http.ListenAndServe(":8080", nil)

}

type OAuthAccessResponse struct {
	AccessToken string `json:"access_token"`
}

## welcome.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta http-equiv="X-UA-Compatible" content="ie=edge" />
    <title>Hello</title>
</head>

<body></body>
<script>
    // We can get the token from the "access_token" query
    // param, available in the browsers "location" global
    const query = window.location.search.substring(1);
    const token = query.split("access_token=")[1];

    // Call the user info API using the fetch browser library
    fetch("http://localhost:9096/user", {
        headers: {
            Accept: "application/json",
            Authorization: "Bearer " + token,
        },
    })
        // Parse the response as JSON
        .then((res) => res.json())
        .then((res) => {
            const nameNode = document.createTextNode(`Welcome, ${res.first_name} ${res.last_name}`)
            document.body.appendChild(nameNode);
        });
</script>
</html>
	<!DOCTYPE html>
	<html>
	<body>
	<a
	href="http://localhost:9096/oauth/authorize?client_id=paulthebest&redirect_uri=http://localhost:8080/oauth/redirect&response_type=code">
	Login
	</a>
	</body>
	</html>
	package main

	import (
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	)

	const clientID = "paulthebest"

	func main() {
	fs := http.FileServer(http.Dir("public"))
	http.Handle("/", fs)

	// We will be using `httpClient` to make external HTTP requests later in our code
	httpClient := http.Client{}

	// Create a new redirect route route
	http.HandleFunc("/oauth/redirect", func(w http.ResponseWriter, r *http.Request) {
	// First, we need to get the value of the `code` query param
	err := r.ParseForm()
	if err != nil {
	fmt.Fprintf(os.Stdout, "could not parse query: %v", err)
	w.WriteHeader(http.StatusBadRequest)
	}
	code := r.Form.Get("code")

	reqURL := fmt.Sprintf("http://localhost:9096/oauth/token?client_id=%s&code=%s&grant_type=authorization_code&redirect_uri=http://localhost:8080/oauth/redirect", clientID, code)
	req, err := http.NewRequest(http.MethodPost, reqURL, nil)
	if err != nil {
	fmt.Fprintf(os.Stdout, "could not create HTTP request: %v", err)
	w.WriteHeader(http.StatusBadRequest)
	}
	// We set this header since we want the response
	// as JSON
	req.Header.Set("accept", "application/json")

	// Send out the HTTP request
	res, err := httpClient.Do(req)
	if err != nil {
	fmt.Fprintf(os.Stdout, "could not send HTTP request: %v", err)
	w.WriteHeader(http.StatusInternalServerError)
	}
	defer res.Body.Close()

	// Parse the request body into the `OAuthAccessResponse` struct
	var t OAuthAccessResponse
	b, err := io.ReadAll(res.Body)
	err = json.Unmarshal(b, &t)
	if err != nil {
	log.Printf("error decoding sakura response: %v", err)
	if e, ok := err.(*json.SyntaxError); ok {
	log.Printf("syntax error at byte offset %d", e.Offset)
	}
	log.Printf("sakura response: %q", res.Body)
	}

	// Finally, send a response to redirect the user to the "welcome" page
	// with the access token
	w.Header().Set("Location", "/welcome.html?access_token="+t.AccessToken)
	w.WriteHeader(http.StatusFound)
	})

	http.ListenAndServe(":8080", nil)

	}

	type OAuthAccessResponse struct {
	AccessToken string `json:"access_token"`
	}
	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="UTF-8" />
	<meta name="viewport" content="width=device-width, initial-scale=1.0" />
	<meta http-equiv="X-UA-Compatible" content="ie=edge" />
	<title>Hello</title>
	</head>

	<body></body>
	<script>
	// We can get the token from the "access_token" query
	// param, available in the browsers "location" global
	const query = window.location.search.substring(1);
	const token = query.split("access_token=")[1];

	// Call the user info API using the fetch browser library
	fetch("http://localhost:9096/user", {
	headers: {
	Accept: "application/json",
	Authorization: "Bearer " + token,
	},
	})
	// Parse the response as JSON
	.then((res) => res.json())
	.then((res) => {
	const nameNode = document.createTextNode(`Welcome, ${res.first_name} ${res.last_name}`)
	document.body.appendChild(nameNode);
	});
	</script>
	</html>