use rusqlite::{Connection, params, Result, Transaction, Row};
use serde::{Serialize};


#[derive(Debug, Serialize)]
pub struct User {
    pub id: i32,
    name: String,
    public_key: String,
}

pub fn create_user(tx: & Transaction, name: &String, public_key: &String) -> Result<User>{
    tx.execute("INSERT INTO users (name, public_key) VALUES (?1, ?2)",
               (name, public_key))?;
    return get_user_by_id(tx, tx.last_insert_rowid() as i32);
}

fn _user_from_row(row: &Row) -> Result<User>{
    Ok(User {
        id: row.get(0)?,
        name: row.get(1)?,
        public_key: row.get(2)?,
    })
}

fn get_user_by_id(tx: & Transaction, id: i32) -> Result<User>{
    let q = "SELECT id, name, public_key
                   FROM users
                   WHERE id = ?1";
    tx.query_row(q, params![id], _user_from_row)
}

pub fn list_users(conn: & Connection) -> Result<Vec<User>>{

    let mut stmt = conn.prepare("SELECT id, name, public_key FROM users")?;
    let ret: Vec<User> = stmt.query_map([], _user_from_row)?
        .filter(Result::is_ok)
        .map(Result::unwrap)
        .collect();
    return Ok(ret);
}