Function oauth_init 

pub async fn oauth_init(
    http_client: &Client,
    oauth_client: &OAuthClient,
    login_hint: Option<&str>,
    par_url: &str,
    oauth_request_state: &OAuthRequestState,
) -> Result<ParResponse>

Initiates an OAuth authorization flow using Pushed Authorization Request (PAR).

This function starts the OAuth flow by sending a PAR request to the authorization server. PAR allows the client to push the authorization request parameters to the authorization server before redirecting the user, providing enhanced security.

Arguments

• http_client - The HTTP client to use for making requests
• oauth_client - OAuth client configuration with credentials
• handle - Optional user handle to pre-fill in the login form
• authorization_server - Authorization server metadata
• oauth_request_state - OAuth request state including PKCE challenge and state

Returns

Returns a ParResponse containing the request URI to redirect the user to, or an error if the PAR request fails.

Example

use atproto_oauth_aip::workflow::{oauth_init, OAuthClient};
use atproto_oauth::workflow::OAuthRequestState;
let oauth_client = OAuthClient {
    redirect_uri: "https://example.com/callback".to_string(),
    client_id: "client123".to_string(),
    client_secret: "secret456".to_string(),
};
let oauth_request_state = OAuthRequestState {
    state: "random-state".to_string(),
    nonce: "random-nonce".to_string(),
    code_challenge: "code-challenge".to_string(),
    scope: "atproto transition:generic".to_string(),
};
let par_response = oauth_init(
    &http_client,
    &oauth_client,
    Some("alice.bsky.social"),
    authorization_server,
    &oauth_request_state,
).await?;