use tui::widgets::ListState;

pub struct StatefulList<T> {
  pub state: ListState,
  pub items: Vec<T>,
}

impl<T> StatefulList<T> {
  pub fn push(&mut self, item: T) {
    self.items.push(item);
  }

  pub fn with_items(items: Vec<T>) -> StatefulList<T> {
    StatefulList {
      state: ListState::default(),
      items,
    }
  }

  pub fn next(&mut self) {
    if self.items.is_empty() {
      return;
    }
    let i = match self.state.selected() {
      Some(i) => {
        if i >= self.items.len() - 1 {
          0
        } else {
          i + 1
        }
      }
      None => 0,
    };
    self.state.select(Some(i));
  }

  pub fn previous(&mut self) {
    if self.items.is_empty() {
      return;
    }
    let i = match self.state.selected() {
      Some(i) => {
        if i == 0 {
          self.items.len() - 1
        } else {
          i - 1
        }
      }
      None => 0,
    };
    self.state.select(Some(i));
  }

  // pub fn unselect(&mut self) {
  //   self.state.select(None);
  // }
}