use argon2::{
    password_hash::{rand_core::OsRng, PasswordHash, PasswordHasher, PasswordVerifier, SaltString},
    Argon2,
};
use uuid::Uuid;

const CREATE_QUERY: &str = "insert into witches (id, username, pwhash) values ($1, $2, $3)";

pub struct User {
    id: Uuid,
    username: String,
    displayname: Option<String>,
    email: Option<String>,
}

#[derive(Debug, Clone, sqlx::FromRow, sqlx::Encode)]
struct DbUser {
    id: Uuid,
    username: String,
    displayname: Option<String>,
    email: Option<String>,
    last_seen: Option<u64>,
    pwhash: String,
}

impl From<DbUser> for User {
    fn from(dbu: DbUser) -> Self {
        User {
            id: dbu.id,
            username: dbu.username,
            displayname: dbu.displayname,
            email: dbu.email,
        }
    }
}

async fn create_user(username: &User, password: &[u8]) -> Result<Uuid, CreateUserError> {
    // Argon2 with default params (Argon2id v19)
    let argon2 = Argon2::default();

    let salt = SaltString::generate(&mut OsRng);
    let password_hash = argon2
        .hash_password(password, &salt)
        .unwrap() // safe to unwrap, we know the salt is valid
        .to_string();

    todo!()
}

#[Error(desc = "Could not create user.")]
#[non_exhaustive]
pub struct CreateUserError(#[from] CreateUserErrorKind);

#[Error]
#[non_exhaustive]
pub enum CreateUserErrorKind {
    AlreadyExists,
    PasswordMismatch,
    MissingFields,
    Unknown,
}