use axum::{
    extract::{Json as ExtractJson, State},
    response::IntoResponse,
    http::StatusCode
};
use serde::Deserialize;
use bb8::Pool;
use bb8_postgres::PostgresConnectionManager;
use tokio_postgres::NoTls;
use argon2_kdf::{Algorithm, Hasher};
use std::sync::Arc;



#[derive(Deserialize)]
pub struct RegisterRequest {
    username: String,
    password: String,
    email: String,
}

// Регистрация
pub async fn register (
    State(pool): State<Arc<Pool<PostgresConnectionManager<NoTls>>>>,
    ExtractJson(payload): ExtractJson<RegisterRequest>,
) -> impl IntoResponse {
    // Валидация данных
    if payload.password.len() < 8 { return (StatusCode::BAD_REQUEST, "Password must be at least 8 characters long").into_response() }
    if payload.username.len() < 4 { return (StatusCode::BAD_REQUEST, "Username must be at least 4 characters long").into_response() }
    let conn = match pool.get().await {
        Ok(conn) => conn, Err(_e) => return (StatusCode::INTERNAL_SERVER_ERROR, "Failed to get DB connection").into_response()
    };

    // ГЕНЕРАЦИЯ ПАРОЛЯ
    let hashed_password = generate_hash(&payload.password);

    let insert_query = "INSERT INTO accounts (username, password, email) VALUES ($1, $2, $3)";
    if conn.execute(insert_query, &[&payload.username, &hashed_password, &payload.email]).await.is_err() {
        return (StatusCode::INTERNAL_SERVER_ERROR, "Failed to register user").into_response();
    }

    (StatusCode::OK, "User registered successfully").into_response()
}

fn generate_hash(password: &str) -> String {
    Hasher::new()
        .algorithm(Algorithm::Argon2d)
        .salt_length(24)
        .hash_length(42)
        .iterations(1)
        .memory_cost_kib(262144)
        .threads(10)
        .hash(password.as_bytes())
        .unwrap()
        .to_string()
}