use indexmap::IndexMap;

use crate::Random;
use crate::StringKey;

/// A data library is a collection of methods to set up a default library, where values are stored
/// by both key, while keeping their insertion order.
pub trait DataLibrary<'a, T: 'a> {
    /// Returns the underlying map.
    fn map(&self) -> &IndexMap<StringKey, T>;
    /// Returns the underlying map in mutable manner.
    fn get_modify(&mut self) -> &mut IndexMap<StringKey, T>;

    /// Adds a new value to the library.
    fn add(&mut self, key: &StringKey, value: T) {
        self.get_modify().insert(key.clone(), value);
    }

    /// Removes a value from the library.
    fn remove(&mut self, key: &StringKey) {
        self.get_modify().remove(key);
    }

    /// Gets a value from the library.
    fn get(&'a self, key: &StringKey) -> Option<&'a T> {
        self.map().get::<StringKey>(key)
    }

    /// Gets a mutable value from the library.
    fn get_mut(&mut self, key: &StringKey) -> Option<&mut T> {
        self.get_modify().get_mut(key)
    }

    /// Gets the amount of values in the library.
    fn len(&self) -> usize {
        self.map().len()
    }
    /// Returns whether the library has no values.
    fn is_empty(&self) -> bool {
        self.map().is_empty()
    }

    /// Gets a random value from the library.
    fn random_value(&self, rand: &mut Random) -> &T {
        let i = rand.get_between(0, self.len() as i32);
        return &self.map().get_index(i as usize).unwrap().1;
    }
}