use std::time::SystemTime;
use serde_json::Value;

use crate::secure;

const PERSIST_TIME:         u64 = 60 * 3;
const PERSIST_PATH:         &str = "/var/run/crab";

pub fn get_persist(user: &str) -> bool {
  let json = match get_terminal_config() {
      Some(data) => data,
      None => return false
  };
  let timestamp = match json[user].as_u64() {
      Some(data) => data,
      None => return false
  };
  return now() - timestamp < PERSIST_TIME && timestamp - 1 < now();
}

pub fn set_persist(user: &str) {
  let mut json = match get_terminal_config() {
      Some(data) => data,
      None => serde_json::from_str("{}").unwrap()
  };
  json[user] = Value::from(now());
  let id = match get_terminal_process() {
      Some(data) => data,
      None => return
  };
  match secure::write_file(PERSIST_PATH, &format!("{}", id), &json.to_string())  {
    Ok(_) => {},
    Err(_) => {
        eprintln!("crab: An Internal Has Error")
    }
  };
}

fn get_terminal_process() -> Option<i32> {
  let pid: i32 = match std::process::id().try_into() {
      Ok(data) => data,
      Err(_) => return None
  };
  let pid_stat = match procinfo::pid::stat(pid) {
      Ok(data) => data,
      Err(_) => return None
  };
  Some(pid_stat.session)
}

fn get_terminal_config() -> Option<Value> {
  let id = match get_terminal_process() {
      Some(data) => data,
      None => return None
  };
  let data = match secure::read_file(PERSIST_PATH, &format!("{}", id)) {
      Some(data) => data,
      None => "{}".to_string()
  };
  let json: Value = match serde_json::from_str(&data) {
      Ok(data) => data,
      Err(_) => return None
  };
  Some(json)
}

fn now() -> u64 {
  return SystemTime::now().duration_since(SystemTime::UNIX_EPOCH).unwrap().as_secs();
}