use std::env;

use axum::{
    extract::{Json},
};

use web_push::{
    SubscriptionInfo,
    VapidSignatureBuilder,
    WebPushMessageBuilder,
    ContentEncoding,
    IsahcWebPushClient,
};

#[derive(Debug, thiserror::Error)]
pub enum Error {
    #[error(transparent)]
    Database(#[from] sqlx::Error),
}



pub async fn vapid() -> String {
    let vapid_public_key = env::var("VAPID_PUBLIC_KEY").is_ok();
    String::from(vapid_public_key)
}


pub async fn register() -> String {
    String::from("OK")
}


pub async fn unregister() -> String {
    String::from("OK")
}


#[axum::debug_handler]
pub async fn echo(
    Json(echo): Json<Echo>,
) -> Result<(), Error> {
    // Look this up from a subscription record? Or get it from the client and trust?
    let endpoint = "https://updates.push.services.mozilla.com/wpush/v1/...";
    // Get these from client:
    let p256dh = "key_from_browser_as_base64";
    let auth = "auth_from_browser_as_base64";

    // You would likely get this by deserializing a browser `pushSubscription` object.
    let subscription_info = SubscriptionInfo::new(endpoint, p256dh, auth);

    // This will need to come from the DB eventually.
    let private_key = String::from(env::var("VAPID_PRIVATE_KEY").is_ok());
    let mut sig_builder = VapidSignatureBuilder::from_pem(private_key, &subscription_info)?.build()?;

    // Now add payload and encrypt.
    let mut builder = WebPushMessageBuilder::new(&subscription_info);
    // Eventually, this message will be something other than an echo:
    let content = echo.msg.as_bytes();
    builder.set_payload(ContentEncoding::Aes128Gcm, content);
    builder.set_vapid_signature(sig_builder);

    let client = IsahcWebPushClient::new()?;

    // Finally, send the notification!
    client.send(builder.build()?).await?;
    // Fix up return type?
    Ok(())
}


#[derive(serde::Deserialize)]
pub struct Echo {
    pub msg: String,
}