use std::error::Error;
use std::fs::read_to_string;

use oauth2::basic::BasicClient;
use oauth2::reqwest::http_client;
use oauth2::AccessToken;
use oauth2::AuthUrl;
use oauth2::ClientId;
use oauth2::ClientSecret;
use oauth2::TokenResponse;
use oauth2::TokenUrl;

mod types;
use types::ClientAuth;

pub fn run() -> Result<(), Box<dyn Error>> {
    let client_auth = read_client_auth()?;

    println!("Client ID: {}", client_auth.id);
    println!("Client Secret: {}", client_auth.secret);

    let access_token = get_api_token(client_auth.id, client_auth.secret)?;

    println!("Access Token: {access_token:#?}");

    Ok(())
}

fn read_client_auth() -> Result<ClientAuth, Box<dyn Error>> {
    let mut id = String::new();
    let mut secret = String::new();

    for line in read_to_string(".client-auth")?.lines() {
        let line_str = line.to_string();
        let cur_line: Vec<&str> = line_str.split('=').collect();
        if cur_line[0] == "client_id" {
            id = cur_line[1].to_string();
        } else if cur_line[0] == "client_secret" {
            secret = cur_line[1].to_string();
        }
    }

    Ok(ClientAuth { id, secret })
}

fn get_api_token(client_id: String, client_secret: String) -> Result<AccessToken, Box<dyn Error>> {
    let client = BasicClient::new(
        ClientId::new(client_id),
        Some(ClientSecret::new(client_secret)),
        AuthUrl::new("https://api.tailscale.com/api/v2/oauth/token".to_string())?,
        Some(TokenUrl::new(
            "https://api.tailscale.com/api/v2/oauth/token".to_string(),
        )?),
    );

    let token_result = client.exchange_client_credentials().request(http_client)?;

    let access_token = token_result.access_token().to_owned();

    Ok(access_token)
}