el_diablo/src/artifacts.rs

use rand::Rng;
use ratatui::style::Color;

use crate::player::Player;
use crate::position::Position;

pub trait Artifact {
    //! An artifact that can be collected by the player
    /// get the character and color used to draw the artifact into the level
    fn get_representation(&self) -> (&str, Color);
    /// get the position of the artifact in the level
    fn get_immutable_position(&self) -> &Position;
    /// call to apply the effects of the artifact to the player
    fn collect(&mut self, player: &mut Player, messages: &mut Vec<String>);
    /// returns if the artifact was collected and can be removed from the level
    fn was_collected(&self) -> bool;
}

/// An artifact that contains a random amount of gold pieces.
pub struct Chest {
    /// the chests position
    position: Position,
    /// the chests value
    gold: usize,
}

impl Chest {
    /// create a chest at the given position with a random amount of gold.
    /// The gold amount depends on the level, the deeper you go, the more you get.
    pub fn new(position: Position) -> Self {
        let min_gold = 10 * (position.get_level() + 1);
        let max_gold = min_gold + 10 * position.get_level();
        Self {
            position,
            gold: rand::thread_rng().gen_range(min_gold..=max_gold),
        }
    }
}

impl Artifact for Chest {
    fn get_representation(&self) -> (&str, Color) {
        ("C", Color::Cyan)
    }

    fn get_immutable_position(&self) -> &Position {
        &self.position
    }
    fn collect(&mut self, player: &mut Player, messages: &mut Vec<String>) {
        player.retrieve_gold(self.gold);
        messages.insert(
            0,
            format!("opened chest and collected {} gold.", self.gold).to_string(),
        );
        self.gold = 0;
    }

    fn was_collected(&self) -> bool {
        self.gold == 0
    }
}

#[derive(Clone, Copy)]
/// An artifact that gives the player some health on consumption.
pub struct Potion {
    /// a potion that restores some health
    position: Position,
    health: usize,
    was_collected: bool,
}

impl Potion {
    pub fn new(position: Position) -> Self {
        let min_health_gain = 5 + position.get_level();
        let max_health_gain = min_health_gain + 3 * position.get_level();
        Self {
            position,
            health: rand::thread_rng().gen_range(min_health_gain..=max_health_gain),
            was_collected: false,
        }
    }

    pub fn get_health(&self) -> usize {
        self.health
    }
}

impl Artifact for Potion {
    fn get_representation(&self) -> (&str, Color) {
        ("P", Color::Green)
    }

    fn get_immutable_position(&self) -> &Position {
        &self.position
    }

    fn collect(&mut self, player: &mut Player, messages: &mut Vec<String>) {
        //! called when the player walked on to a potion.
        //!
        //! Depending on health status and inventory usage the potion will
        //! be consumed directly or moved to inventory.
        if !player.is_healthy() {
            let old = player.get_life();
            player.change_life(self.health.try_into().unwrap());
            let new = player.get_life();
            messages.insert(
                0,
                format!("picked up potion and gained {} health.", new - old).to_string(),
            );
            self.health = 0;
            self.was_collected = true;
        } else if player.add_to_inventory(self) {
            messages.insert(0, "move potion to inventory.".to_string());
            self.was_collected = true;
        } else {
            messages.insert(0, "inventory is full.".to_string());
        }
    }

    fn was_collected(&self) -> bool {
        self.was_collected
    }
}