Add registration tool

Cargo.toml

@@ -2,6 +2,15 @@
 name = "kensho"
 version = "0.1.0"
 edition = "2021"
+default-run = "kensho"
+
+[[bin]]
+name = "kensho"
+path = "src/main.rs"
+
+[[bin]]
+name = "register"
+path = "src/bin/register.rs"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 

src/bin/register.rs

@@ -0,0 +1,53 @@
+use megalodon::generator;
+use std::env;
+
+#[tokio::main]
+async fn main() {
+    env_logger::init();
+
+    let Ok(url) = env::var("MASTODON_URL") else {
+        println!("Specify MASTODON_URL!!");
+        return;
+    };
+    let client = generator(megalodon::SNS::Mastodon, url, None, None);
+    let options = megalodon::megalodon::AppInputOptions {
+        scopes: Some(["read".to_string()].to_vec()),
+        ..Default::default()
+    };
+
+    match client.register_app("kensho".to_string(), &options).await {
+        Ok(app_data) => {
+            let client_id = app_data.client_id;
+            let client_secret = app_data.client_secret;
+            println!("Authorization URL is generated");
+            println!("{}", app_data.url.unwrap());
+
+            println!("Enter authorization code from website: ");
+            let mut code = String::new();
+            std::io::stdin().read_line(&mut code).ok();
+
+            match client
+                .fetch_access_token(
+                    client_id,
+                    client_secret,
+                    code.trim().to_string(),
+                    megalodon::default::NO_REDIRECT.to_string(),
+                )
+                .await
+            {
+                Ok(token_data) => {
+                    println!("access_token: {}", token_data.access_token);
+                    if let Some(refresh) = token_data.refresh_token {
+                        println!("refresh_token: {}", refresh);
+                    }
+                }
+                Err(err) => {
+                    println!("{:#?}", err);
+                }
+            }
+        }
+        Err(err) => {
+            println!("{:#?}", err);
+        }
+    }
+}