use std::env;

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

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


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


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


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

async fn push_message(
    endpoint: String,
    keys: Keys,
    message: &String,
) -> Result<(), crate::error::Internal> {
    let content = message.as_bytes();

    let subscription_info = SubscriptionInfo::new(endpoint, keys.p256dh, keys.auth);
    // This will need to come from the DB eventually:
    let private_key = String::from(env::var("VAPID_PRIVATE_KEY").unwrap_or_default());
    let sig_builder = VapidSignatureBuilder::from_base64(&private_key, &subscription_info)?.build()?;
    let mut builder = WebPushMessageBuilder::new(&subscription_info);
    builder.set_payload(ContentEncoding::Aes128Gcm, content);
    builder.set_vapid_signature(sig_builder);
    let client = IsahcWebPushClient::new()?;
    client.send(builder.build()?).await?;

    Ok(())
}


#[axum::debug_handler]
pub async fn echo(
    Json(payload): Json<PushPayload>,
) -> Result<(), crate::error::Internal> {
    push_message(payload.endpoint, payload.keys, &payload.msg).await?;

    Ok(())
}


#[derive(serde::Deserialize)]
pub struct Keys {
    pub p256dh: String,
    pub auth: String,
}

#[derive(serde::Deserialize)]
pub struct PushPayload {
    pub msg: String,
    pub endpoint: String,
    pub keys: Keys,
}