remove unused import

build.rs

@@ -0,0 +1,7 @@
+use std::process::Command;
+
+fn main() {
+    let output = Command::new("git").args(&["rev-parse", "--short",  "HEAD"]).output().unwrap();
+    let git_hash = String::from_utf8(output.stdout).unwrap();
+    println!("cargo:rustc-env=GIT_HASH={}", git_hash);
+}

src/artifacts.rs

@@ -1,6 +1,7 @@
 use ratatui::style::Color;
-use crate::position::Position;
+
 use crate::player::Player;
+use crate::position::Position;
 
 pub trait Artifact {
     //! An artifact that can be collected by the player
@@ -8,7 +9,8 @@ pub trait Artifact {
     /// 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);
+    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;
 }
 
@@ -20,9 +22,11 @@ pub struct Chest {
 
 impl Chest {
     pub fn new(position: Position) -> Self {
+        let level = position.get_level();
         Self {
             position,
-            gold: 10,
+            // TODO maybe randomize this?
+            gold: (level + 1) * 10,
         }
     }
 }
@@ -33,8 +37,9 @@ impl Artifact for Chest {
     }
 
     fn get_immutable_position(&self) -> &Position { &self.position }
-    fn collect(&mut self, player: &mut Player) {
+    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;
     }
 
@@ -63,9 +68,17 @@ impl Artifact for Potion {
         ("P", Color::Green)
     }
     fn get_immutable_position(&self) -> &Position { &self.position }
-    fn collect(&mut self, player: &mut Player) {
+    fn collect(&mut self, player: &mut Player, messages: &mut Vec<String>) {
+        // only consume potion of the player can gain at least one health point
+        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 {} hp.", new - old).to_string());
             self.health = 0;
+        } else {
+            messages.insert(0, "not using the potion because you're healthy.".to_string());
+        }
     }
 
     fn was_collected(&self) -> bool {

src/game.rs

@@ -1,15 +1,29 @@
-use crate::artifacts::Artifact;
 use crate::level::{Level, StructureElement};
 use crate::level_generator::LevelGenerator;
-use crate::monster::Monster;
 use crate::player::Player;
-use crate::position::Position;
+use crate::position::{HasPosition, Position};
 
-pub const LEVELS: usize = 2;
+pub const LEVELS: usize = 10;
 
+#[derive(PartialEq)]
+/// represents a state of a game
+pub enum GameState {
+    /// the game is ongoing (neither won or lost)
+    RUNNING,
+    /// the player died
+    LOST,
+    /// the player reached the Ω
+    WON,
+}
+
+
+/// the main structure to hold all information about the ongoing game
 pub struct Game {
-    pub player: Player,
+    /// the player
-    pub levels: Vec<Level>,
+    player: Player,
+    /// the levels of the game
+    levels: Vec<Level>,
+    pub messages: Vec<String>,
 }
 
 impl Game {
@@ -21,6 +35,7 @@ impl Game {
         let mut g = Game {
             player: p,
             levels: v,
+            messages: Vec::with_capacity(10),
         };
         let start = {
             g.get_level(0).start
@@ -30,6 +45,29 @@ impl Game {
         g
     }
 
+    /// returns true if the player is standing on the End element
+    fn player_reached_goal(&mut self) -> bool {
+        match self.next_element(0, 0) {
+            None => {}
+            Some(a) => {
+                match a {
+                    StructureElement::End => { return true; }
+                    _ => {}
+                }
+            }
+        };
+        false
+    }
+    /// returns the state of the game (depending on player's life and position)
+    pub fn get_game_state(&mut self) -> GameState {
+        if self.player.is_dead() {
+            return GameState::LOST;
+        }
+        if self.player_reached_goal() {
+            return GameState::WON;
+        }
+        GameState::RUNNING
+    }
     pub fn get_player(&self) -> &Player {
         &self.player
     }
@@ -38,41 +76,39 @@ impl Game {
     }
     pub fn get_level(&self, level: usize) -> &Level { &self.levels[level] }
     pub fn get_mutable_level(&mut self, level: usize) -> &mut Level { &mut self.levels[level] }
+    /// check if the player can move in the given direction. This only checks for structure element
+    /// limitation as walls.
     fn can_move(&mut self, dx: i16, dy: i16) -> bool {
         let player_pos = &self.player.get_position();
-        let new_x: i16 = player_pos.get_x() as i16 + dx;
-        let new_y: i16 = player_pos.get_y() as i16 + dy;
         let level = &mut self.levels[player_pos.get_level()];
-        match level.get_element(new_x, new_y) {
+        level.can_player_move(&self.player, dx, dy)
-            (None, _, _) => { return false; }
-            (Some(t), _, _) => {
-                match t {
-                    StructureElement::Wall => { return false; }
-                    _ => {}
-                }
-            }
-        };
-        true
     }
+    /// returns the position (as tuple) of the next level's start point.
     fn next_start(&self) -> (usize, usize, usize) {
         let level = self.player.get_immutable_position().get_level() + 1;
         let (x, y) = self.levels[level].start;
         (level, x, y)
     }
+    /// returns the position (as tuple) of the previous level's end point.
     fn prev_end(&self) -> (usize, usize, usize) {
         let level = self.player.get_immutable_position().get_level() - 1;
         let (x, y) = self.levels[level].end;
         (level, x, y)
     }
-    fn next_element(&mut self, dx: i16, dy: i16) -> (Option<StructureElement>, Option<&mut Monster>, Option<&mut Box<(dyn Artifact + 'static)>>) {
+    /// get the next structure element sen from the player's position into the given direction.
+    fn next_element(&mut self, dx: i16, dy: i16) -> Option<StructureElement> {
         let player_pos = &self.player.get_position();
         let new_x: i16 = player_pos.get_x() as i16 + dx;
         let new_y: i16 = player_pos.get_y() as i16 + dy;
         let player_level = player_pos.get_level();
         let level = &mut self.levels[player_level];
-        level.get_element(new_x, new_y)
+        level.get_element(new_x, new_y).0
     }
 
+    /// move the game's player into the given direction. If on the target field there is a stair,
+    /// the player follows the stair up/down to the next level.
+    /// Discovery is performed on the new location of the player.
+    /// The returned value is the direction that will bring the player back to his original field.
     pub fn move_player(&mut self, mut dx: i16, mut dy: i16) -> (i16, i16) {
         // verify the player can do the move
         if !self.can_move(dx, dy) {
@@ -81,7 +117,7 @@ impl Game {
 
         let player_pos = &self.player.get_position();
         let mut player_level = player_pos.get_level();
-        let (structure, _, _) = self.next_element(dx, dy);
+        let structure = self.next_element(dx, dy);
 
         // use stairs if walked onto one
         match structure {
@@ -91,12 +127,14 @@ impl Game {
                         (dx, dy) = (0, 0);
                         let (next_level, x, y) = self.next_start();
                         player_level = next_level;
+                        self.messages.insert(0, format!("you climb down to level {}.", next_level));
                         self.get_mutable_player().get_position().set(next_level, x, y);
                     }
                     StructureElement::StairUp => {
                         (dx, dy) = (0, 0);
                         let (next_level, x, y) = self.prev_end();
                         player_level = next_level;
+                        self.messages.insert(0, format!("you climb up to level {}.", next_level));
                         self.get_mutable_player().get_position().set(next_level, x, y);
                     }
                     _ => {}
@@ -121,6 +159,12 @@ impl Game {
                 // TODO fight the monster
                 self.player.change_life(-1);
                 m.decrease_life(1);
+                self.messages.insert(0, format!("{} hits you.", m.get_name()).to_string());
+                self.messages.insert(0, format!("you hit {}.", m.get_name()).to_string());
+                // monster died, player gains experience
+                if m.is_dead() {
+                    self.player.gain_experience(m.get_experience_gain());
+                }
                 return m.is_dead();
             }
         };
@@ -134,15 +178,16 @@ impl Game {
         match a {
             None => {}
             Some(a) => {
-                a.collect(&mut self.player);
+                a.collect(&mut self.player, &mut self.messages);
             }
         }
     }
-    pub fn update_level(&mut self) {
+    /// updates the player's current level. This will remove collected artifacts and dead monsters.
+    pub fn update_level(&mut self, ticks: u128) {
         let player_pos = &self.player.get_immutable_position();
         let player_level = player_pos.get_level();
         let level = &mut self.levels[player_level];
-        level.update();
+        level.update(ticks, &mut self.player, &mut self.messages);
     }
 }
 

src/level.rs

@@ -1,8 +1,16 @@
 use std::cmp::{max, min};
-use crate::artifacts::Artifact;
+
+use rand::Rng;
+use rand::rngs::ThreadRng;
+
 #[cfg(test)]
 use crate::artifacts::{Chest, Potion};
+use crate::artifacts::Artifact;
+#[cfg(test)]
+use crate::monster::{Orc, Rat};
 use crate::monster::Monster;
+use crate::player::Player;
+use crate::position::HasPosition;
 use crate::position::Position;
 
 pub const LEVEL_WIDTH: usize = 50;
@@ -23,34 +31,17 @@ pub struct Level {
     pub(crate) level: usize,
     pub(crate) structure: [[StructureElement; LEVEL_HEIGHT]; LEVEL_WIDTH],
     pub(crate) discovered: [[bool; LEVEL_HEIGHT]; LEVEL_WIDTH],
-    pub(crate) monsters: Vec<Monster>,
+    pub(crate) monsters: Vec<Box<dyn Monster>>,
     pub(crate) artifacts: Vec<Box<dyn Artifact>>,
     /// the position of the start in the level (either stair up or start point)
     pub(crate) start: (usize, usize),
     /// the position of the end in the level (either stair down or end point)
     pub(crate) end: (usize, usize),
+    pub(crate) rng: ThreadRng,
 }
 
 impl Level {
-    #[cfg(test)]
+    pub fn get_element(&mut self, x: i16, y: i16) -> (Option<StructureElement>, Option<&mut Box<(dyn Monster + 'static)>>, Option<&mut Box<(dyn Artifact + 'static)>>) {
-    pub fn new(level: usize) -> Level {
-        let mut s = [[StructureElement::Wall; LEVEL_HEIGHT]; LEVEL_WIDTH];
-        for x in 2..LEVEL_WIDTH - 2 {
-            for y in 2..LEVEL_HEIGHT - 2 {
-                s[x][y] = StructureElement::Floor;
-            }
-        }
-        Level {
-            level,
-            structure: s,
-            discovered: [[false; LEVEL_HEIGHT]; LEVEL_WIDTH],
-            monsters: Vec::with_capacity(10),
-            artifacts: Vec::with_capacity(10),
-            start: (0, 0),
-            end: (0, 0),
-        }
-    }
-    pub fn get_element(&mut self, x: i16, y: i16) -> (Option<StructureElement>, Option<&mut Monster>, Option<&mut Box<(dyn Artifact + 'static)>>) {
         if x < 0 || y < 0 {
             return (None, None, None);
         }
@@ -63,7 +54,7 @@ impl Level {
             return (Some(StructureElement::Unknown), None, None);
         }
         let search_pos = &Position::new(self.level, x, y);
-        let mut res_m: Option<&mut Monster> = None;
+        let mut res_m: Option<&mut Box<dyn Monster>> = None;
         for m in &mut self.monsters {
             if m.get_immutable_position() == search_pos {
                 res_m = Some(m);
@@ -77,33 +68,6 @@ impl Level {
         }
         (Some(self.structure[x][y]), res_m, res_a)
     }
-    #[cfg(test)]
-    pub fn add_monster(&mut self, mut monster: Monster) -> Result<(), String> {
-        if self.level != monster.get_position().get_level() {
-            return Err("Wrong Level".to_string());
-        }
-        for m in &mut self.monsters {
-            if m.get_position() == monster.get_position() {
-                return Err("Position already used".to_string());
-            }
-        }
-        self.monsters.push(monster);
-        Ok(())
-    }
-
-    #[cfg(test)]
-    pub fn add_artifact(&mut self, artifact: impl Artifact + 'static) -> Result<(), String> {
-        if self.level != artifact.get_immutable_position().get_level() {
-            return Err("Wrong Level".to_string());
-        }
-        for a in &mut self.artifacts {
-            if a.get_immutable_position() == artifact.get_immutable_position() {
-                return Err("Position already used".to_string());
-            }
-        }
-        self.artifacts.push(Box::new(artifact));
-        Ok(())
-    }
     /// discover the area with in the level around the given position
     pub fn discover(&mut self, pos: &Position) {
         let x = pos.get_x();
@@ -148,14 +112,45 @@ impl Level {
             }
         }
     }
-
+    pub fn update(&mut self, ticks: u128, player: &mut Player, messages: &mut Vec<String>) {
-    pub fn update(&mut self) {
         for (index, a) in &mut self.artifacts.iter().enumerate() {
             if a.was_collected() {
                 self.artifacts.remove(index);
                 break;
             }
         }
+        for index in 0..self.monsters.len() {
+            if self.monsters[index].is_dead() {
+                continue;
+            }
+            if ticks % self.monsters[index].get_ticks_between_steps() != 0 {
+                continue;
+            }
+            loop {
+                // calculate the direction the monster will try to walk
+                let (dx, dy) = match self.rng.gen_range(0..5) {
+                    1 => { (1, 0) }
+                    2 => { (-1, 0) }
+                    3 => { (0, 1) }
+                    4 => { (0, -1) }
+                    _ => { (0, 0) }
+                };
+                if self.can_monster_move(self.monsters[index].as_ref(), dx, dy) {
+                    let (new_x, new_y) = self.monsters[index].get_position().change(dx, dy);
+                    if player.get_immutable_position().get_x() == new_x && player.get_immutable_position().get_y() == new_y {
+                        self.monsters[index].decrease_life(1);
+                        player.change_life(-1);
+                        messages.insert(0, format!("{} hits you.", self.monsters[index].get_name()).to_string());
+                        messages.insert(0, format!("you hit {}.", self.monsters[index].get_name()).to_string());
+                        // if the attack did not kill the opponent, back down
+                        if !player.is_dead() {
+                            self.monsters[index].get_position().change(-dx, -dy);
+                        }
+                    }
+                    break;
+                }
+            }
+        }
         for (index, m) in &mut self.monsters.iter().enumerate() {
             if m.is_dead() {
                 self.monsters.remove(index);
@@ -163,6 +158,73 @@ impl Level {
             }
         }
     }
+
+    pub fn can_monster_move(&self, agent: &dyn Monster, dx: i16, dy: i16) -> bool {
+        let agent_pos = agent.get_immutable_position();
+        let new_x: usize = (agent_pos.get_x() as i16 + dx) as usize;
+        let new_y: usize = (agent_pos.get_y() as i16 + dy) as usize;
+
+        if new_x >= LEVEL_WIDTH || new_y >= LEVEL_HEIGHT {
+            return false;
+        }
+
+        for index in 0..self.monsters.len() {
+            let pos = self.monsters[index].get_immutable_position();
+            if pos.get_x() == new_x && pos.get_y() == new_y { return false; }
+        }
+        self.structure[new_x][new_y] != StructureElement::Wall
+    }
+    pub fn can_player_move(&self, agent: &Player, dx: i16, dy: i16) -> bool {
+        let agent_pos = agent.get_immutable_position();
+        let new_x: usize = (agent_pos.get_x() as i16 + dx) as usize;
+        let new_y: usize = (agent_pos.get_y() as i16 + dy) as usize;
+        self.structure[new_x][new_y] != StructureElement::Wall
+    }
+    #[cfg(test)]
+    pub fn new(level: usize) -> Level {
+        let mut s = [[StructureElement::Wall; LEVEL_HEIGHT]; LEVEL_WIDTH];
+        for x in 2..LEVEL_WIDTH - 2 {
+            for y in 2..LEVEL_HEIGHT - 2 {
+                s[x][y] = StructureElement::Floor;
+            }
+        }
+        Level {
+            level,
+            structure: s,
+            discovered: [[false; LEVEL_HEIGHT]; LEVEL_WIDTH],
+            monsters: Vec::with_capacity(10),
+            artifacts: Vec::with_capacity(10),
+            start: (0, 0),
+            end: (0, 0),
+            rng: rand::thread_rng(),
+        }
+    }
+    #[cfg(test)]
+    pub fn add_monster(&mut self, mut monster: impl Monster + 'static) -> Result<(), String> {
+        if self.level != monster.get_position().get_level() {
+            return Err("Wrong Level".to_string());
+        }
+        for m in &mut self.monsters {
+            if m.get_position() == monster.get_position() {
+                return Err("Position already used".to_string());
+            }
+        }
+        self.monsters.push(Box::new(monster));
+        Ok(())
+    }
+    #[cfg(test)]
+    pub fn add_artifact(&mut self, artifact: impl Artifact + 'static) -> Result<(), String> {
+        if self.level != artifact.get_immutable_position().get_level() {
+            return Err("Wrong Level".to_string());
+        }
+        for a in &mut self.artifacts {
+            if a.get_immutable_position() == artifact.get_immutable_position() {
+                return Err("Position already used".to_string());
+            }
+        }
+        self.artifacts.push(Box::new(artifact));
+        Ok(())
+    }
 }
 
 #[test]
@@ -190,20 +252,17 @@ fn test_discover_get_element() {
 #[test]
 fn test_discover_can_add_monster() {
     let mut l = Level::new(0);
-    let mut m = Monster::new(2);
+    let m = Rat::new_with_position(Position::new(1, 2, 3));
-    m.get_position().set(1, 2, 3);
     assert_eq!(l.add_monster(m), Err("Wrong Level".to_string()));
 
-    let mut m = Monster::new(2);
+    let mut m = Orc::new_with_position(Position::new(0, 2, 3));
     m.get_position().set(0, 2, 3);
     assert_eq!(l.add_monster(m), Ok(()));
 
-    let mut m = Monster::new(2);
+    let m = Rat::new_with_position(Position::new(0, 2, 3));
-    m.get_position().set(0, 2, 3);
     assert_eq!(l.add_monster(m), Err("Position already used".to_string()));
 
-    let mut m = Monster::new(2);
+    let m = Rat::new_with_position(Position::new(0, 2, 4));
-    m.get_position().set(0, 2, 4);
     assert_eq!(l.add_monster(m), Ok(()));
 }
 
@@ -231,18 +290,17 @@ fn test_discover_get_monster() {
     assert_eq!(l.get_element(10, 10).0.unwrap(), StructureElement::Floor);
     assert!(l.get_element(10, 10).1.is_none());
 
-    let mut m = Monster::new(23);
+    let m = Rat::new_with_position(Position::new(0, 10, 10));
-    m.get_position().set(0, 10, 10);
     assert_eq!(l.add_monster(m), Ok(()));
 
     let elem = l.get_element(10, 10);
     assert_eq!(elem.0.unwrap(), StructureElement::Floor);
     assert!(elem.1.is_some());
     let m = elem.1.unwrap();
-    assert_eq!(m.get_life(), 23);
+    assert_eq!(m.get_life(), 2);
 
     m.decrease_life(2);
-    assert_eq!(l.get_element(10, 10).1.unwrap().get_life(), 21);
+    assert_eq!(l.get_element(10, 10).1.unwrap().get_life(), 0);
 }
 
 #[test]
@@ -267,8 +325,7 @@ fn test_discover_get_monster_can_move() {
     let p = Position::new(0, 10, 10);
     l.discover(&p);
 
-    let mut m = Monster::new(23);
+    let m = Rat::new_with_position(Position::new(0, 10, 10));
-    m.get_position().set(0, 10, 10);
     l.add_monster(m).expect("Panic because of");
 
     let m = l.get_element(10, 10).1.unwrap();
@@ -278,5 +335,5 @@ fn test_discover_get_monster_can_move() {
     assert!(m.is_none());
     let m = l.get_element(11, 11).1;
     assert!(m.is_some());
-    assert_eq!(m.unwrap().get_life(), 23);
+    assert_eq!(m.unwrap().get_life(), 2);
 }

src/level_generator.rs

@@ -9,9 +9,9 @@ use rand::prelude::SliceRandom;
 use rand::Rng;
 use rand::rngs::ThreadRng;
 
-use crate::level::{Level, StructureElement};
-use crate::monster::Monster;
 use crate::artifacts::{Artifact, Chest, Potion};
+use crate::level::{Level, StructureElement};
+use crate::monster::{Monster, Orc, Rat};
 use crate::position::Position;
 
 const ROOMS_VERTICAL: usize = 7;
@@ -246,7 +246,7 @@ impl LevelGenerator {
         let mut rng = rand::thread_rng();
         let mut structure = [[StructureElement::Wall; 1 + ROOMS_HORIZONTAL * ROOM_HEIGHT]; 1 + ROOMS_VERTICAL * ROOM_WIDTH];
         let mut artifacts: Vec<Box<dyn Artifact>> = Vec::with_capacity(10);
-        let mut enemies: Vec<Monster> = Vec::with_capacity(10);
+        let mut enemies: Vec<Box<dyn Monster>> = Vec::with_capacity(10);
         let mut start_x: usize = 0;
         let mut start_y: usize = 0;
         let mut end_x: usize = 0;
@@ -274,7 +274,14 @@ impl LevelGenerator {
                     let t_x = left + room.offset_x + rng.gen_range(0..room.width);
                     let t_y = top + room.offset_y + rng.gen_range(0..room.height);
                     // TODO randomize enemies here
-                    enemies.push(Monster::new_with_position(2, Position::new(self.level, t_x, t_y)));
+                    match rng.gen_range(1..=100) {
+                        1..=50 => {
+                            enemies.push(Box::new(Orc::new_with_position(Position::new(self.level, t_x, t_y))));
+                        }
+                        _ => {
+                            enemies.push(Box::new(Rat::new_with_position(Position::new(self.level, t_x, t_y))));
+                        }
+                    };
                 }
 
                 if room.kind == RoomType::End || room.kind == RoomType::StairDown {
@@ -337,6 +344,7 @@ impl LevelGenerator {
             artifacts,
             start: (start_x, start_y),
             end: (end_x, end_y),
+            rng: rand::thread_rng(),
         }
     }
 }

src/level_widget.rs

@@ -5,6 +5,7 @@ use ratatui::widgets::{StatefulWidget, Widget};
 
 use crate::game::Game;
 use crate::level::StructureElement;
+use crate::position::HasPosition;
 
 const FG_BROWN: Color = Color::Rgb(186, 74, 0);
 
@@ -65,8 +66,9 @@ impl StatefulWidget for LevelWidget {
                                 }
                             }
                         }
-                        (_, Some(_), _) => {
+                        (_, Some(m), _) => {
-                            self.set_cell(buf, x, y, "M", Color::Red, Color::Gray);
+                            let (s, c) = m.get_representation();
+                            self.set_cell(buf, x, y, s, c, Color::Gray);
                         }
                         (_, _, Some(t)) => {
                             let (s, c) = t.get_representation();

src/main.rs

@@ -1,5 +1,6 @@
 use std::io::Result;
 use std::io::stdout;
+use std::time::Instant;
 
 use crossterm::{
     event::{self, KeyCode, KeyEventKind},
@@ -7,17 +8,18 @@ use crossterm::{
     terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
 };
 use ratatui::{
-    prelude::{CrosstermBackend, Stylize, Terminal},
+    prelude::{CrosstermBackend, Terminal},
     widgets::Paragraph,
 };
 use ratatui::prelude::*;
-use ratatui::widgets::Block;
+use ratatui::widgets::{Block, Borders, BorderType, Wrap};
+use ratatui::widgets::block::{Position, Title};
 use whoami::realname;
 
-use crate::game::Game;
+use crate::game::{Game, GameState};
 use crate::level_widget::LevelWidget;
-// use crate::level_widget::LevelWidget;
 use crate::player::Player;
+use crate::position::HasPosition;
 
 mod game;
 mod player;
@@ -28,6 +30,9 @@ mod level_generator;
 mod artifacts;
 mod monster;
 
+/// length of a game frame in ms
+pub const FRAME_LENGTH: u64 = 100;
+
 //
 fn main() -> Result<()> {
     let mut game = Game::new(Player::new(realname().as_str(), 10));
@@ -37,11 +42,29 @@ fn main() -> Result<()> {
     let mut terminal = Terminal::new(CrosstermBackend::new(stdout()))?;
     terminal.clear()?;
 
+    let start_time = Instant::now();
+    let mut ticks = 0;
     loop {
         terminal.draw(|frame| {
             let mut area = frame.size();
             frame.render_widget(Block::default().style(Style::default().bg(Color::Green)), area);
 
+            // don't draw stuff except an info box if the terminal is too small (less than 80x25)
+            // to prevent the read drawing code from crashing the game.
+            if area.width < 80 || area.height < 25 {
+                let block = Block::default()
+                    .title("Info")
+                    .borders(Borders::ALL)
+                    .border_style(Style::default().fg(Color::White))
+                    .border_type(BorderType::Rounded)
+                    .style(Style::default().bg(Color::Black));
+                let paragraph = Paragraph::new("Terminal needs to be at leas 80x25!")
+                    .block(block)
+                    .wrap(Wrap { trim: true });
+                frame.render_widget(paragraph, area);
+                return;
+            }
+
             if area.width > 80 {
                 area.x = (area.width - 80) / 2;
                 area.width = 80;
@@ -63,22 +86,54 @@ fn main() -> Result<()> {
                 x: area.x + 50,
                 y: area.y,
                 width: 30,
-                height: 25,
+                height: 15,
             };
+            let block = Block::default()
+                .title(
+                    Title::from(
+                        format!(" {} ", game.get_player().get_name()))
+                        .alignment(Alignment::Center)
+                        .position(Position::Top)
+                )
+                .borders(Borders::TOP)
+                .border_style(Style::default().fg(Color::White))
+                .border_type(BorderType::Rounded)
+                .style(Style::default().bg(Color::Blue));
             frame.render_widget(
-                Paragraph::new(format!("{}\nHealth: {}/{}\nGold: {}\nLevel: {}",
+                Paragraph::new(format!("Health: {}/{}\nExp: {}\nGold: {}\nLevel: {}",
-                                       game.get_player().get_name(),
                                        game.get_player().get_life(),
                                        game.get_player().get_max_life(),
+                                       game.get_player().get_experience(),
                                        game.get_player().get_gold(),
                                        game.get_player().get_immutable_position().get_level()))
-                    .white()
+                    .block(block).wrap(Wrap { trim: true }),
-                    .on_blue(),
                 stats_area,
             );
+            let messages_area = Rect {
+                x: area.x + 50,
+                y: area.y + 15,
+                width: 30,
+                height: 10,
+            };
+            // Display the latest messages from the game to the user
+            let block = Block::default()
+                .title(Title::from(" messages ").alignment(Alignment::Center).position(Position::Top))
+                .borders(Borders::TOP)
+                .border_style(Style::default().fg(Color::White))
+                .border_type(BorderType::Rounded)
+                .style(Style::default().bg(Color::Blue));
+
+            let paragraph1 = if game.messages.is_empty() { "".to_string() } else { format!("> {}", game.messages.join("\n> ")) };
+            frame.render_widget(
+                Paragraph::new(paragraph1).block(block).wrap(Wrap { trim: true }),
+                messages_area,
+            );
         })?;
-        if event::poll(std::time::Duration::from_millis(16))? {
+        if event::poll(std::time::Duration::from_millis(FRAME_LENGTH))? {
             if let event::Event::Key(key) = event::read()? {
+                if key.kind == KeyEventKind::Press && key.code == KeyCode::Char('v') {
+                    game.messages.insert(0, format!("You are playing version '{}'.", env!("GIT_HASH")).to_string());
+                }
                 if key.kind == KeyEventKind::Press && key.code == KeyCode::Char('q') {
                     break;
                 }
@@ -95,12 +150,57 @@ fn main() -> Result<()> {
                         game.move_player(new_pos.0, new_pos.1);
                     }
                     game.player_collects_artifact();
-                    game.update_level();
+                }
+            }
+        }
+        game.update_level(ticks);
+        if game.get_game_state() != GameState::RUNNING {
+            break;
+        }
+        ticks += 1;
+    }
+    let playtime = start_time.elapsed();
+    loop {
+        let _ = terminal.draw(|frame| {
+            let mut area = frame.size();
+            let w = area.width / 2;
+            let h = area.height / 2;
+            area.x += w - 20;
+            area.y += h - 10;
+            area.width = 40;
+            area.height = 20;
+            let block = Block::default()
+                .title(Title::from(" Game ended ").alignment(Alignment::Center).position(Position::Top))
+                .title(Title::from("Press `q` to quit!").position(Position::Bottom))
+                .borders(Borders::ALL)
+                .border_style(Style::default().fg(Color::White))
+                .border_type(BorderType::Rounded)
+                .style(Style::default().bg(Color::Black));
+            let mut text = match game.get_game_state() {
+                GameState::RUNNING => {
+                    "Quitting is for cowards! You'll better try again!".to_string()
+                }
+                GameState::LOST => {
+                    "Sorry, you died in the dungeon. Better luck next time!".to_string()
+                }
+                GameState::WON => {
+                    "Congratulation! You mastered your way through the dungeon and won the game.".to_string()
+                }
+            };
+            text += format!("\nYou gained {} experience.", game.get_player().get_experience()).as_str();
+            text += format!("\nYou collected {} gold.", game.get_player().get_gold()).as_str();
+            text += format!("\nYou played {} seconds.", playtime.as_secs()).as_str();
+            let paragraph = Paragraph::new(text).block(block).wrap(Wrap { trim: true });
+            frame.render_widget(paragraph, area);
+        });
+        if event::poll(std::time::Duration::from_millis(16))? {
+            if let event::Event::Key(key) = event::read()? {
+                if key.kind == KeyEventKind::Press && key.code == KeyCode::Char('q') {
+                    break;
                 }
             }
         }
     }
-
     stdout().execute(LeaveAlternateScreen)?;
     disable_raw_mode()?;
     Ok(())

src/monster.rs

@@ -1,42 +1,100 @@
-use crate::position::Position;
+use ratatui::prelude::Color;
 
-pub struct Monster {
+use crate::position::{HasPosition, Position};
-    life: usize,
+
-    position: Position,
+pub trait Monster: HasPosition {
+    fn get_name(&self) -> &str;
+    fn is_dead(&self) -> bool;
+    fn get_representation(&self) -> (&str, Color);
+    fn decrease_life(&mut self, by: usize);
+    // fn get_immutable_position(&self) -> &Position;
+    fn get_experience_gain(&self) -> usize;
+    fn get_ticks_between_steps(&self) -> u128;
+    #[cfg(test)]
+    fn get_life(&self) -> usize;
 }
 
-impl Monster {
+macro_rules! default_monster {
-    #[cfg(test)]
+    ($($t:ty),+ $(,)?) => ($(
-    pub fn new(life: usize) -> Self {
+        impl Monster for $t {
-        Monster {
+            fn get_name(&self) -> &str { &self.name }
-            life,
+            fn is_dead(&self) -> bool { self.life <= 0 }
-            position: Position::new(0, 0, 0),
+            fn get_experience_gain(&self) -> usize { self.experience_gain }
-        }
+            fn get_representation(&self) -> (&str, Color) { (&self.symbol, self.color) }
-    }
+            fn decrease_life(&mut self, by: usize) {
-    pub fn new_with_position(life: usize, position: Position) -> Self {
-        Monster {
-            life,
-            position,
-        }
-    }
-    #[cfg(test)]
-    pub fn get_life(&self) -> usize { self.life }
-    pub fn is_dead(&self) -> bool { self.life <= 0 }
-    pub fn decrease_life(&mut self, by: usize) {
                 self.life = self.life.saturating_sub(by);
             }
+            fn get_ticks_between_steps(&self) -> u128 { self.ticks_between_steps }
+
             #[cfg(test)]
-    pub fn get_position(&mut self) -> &mut Position {
+            fn get_life(&self) -> usize { self.life }
+        }
+        impl HasPosition for $t {
+            fn get_position(&mut self) -> &mut Position {
                 &mut self.position
             }
-    pub fn get_immutable_position(&self) -> &Position {
+            fn get_immutable_position(&self) -> &Position {
                 &self.position
             }
         }
+    )+)
+}
+
+pub struct Rat {
+    name: String,
+    life: usize,
+    position: Position,
+    symbol: String,
+    color: Color,
+    experience_gain: usize,
+    ticks_between_steps: u128,
+}
+
+impl Rat {
+    pub fn new_with_position(position: Position) -> Self {
+        Self {
+            name: "rat".to_string(),
+            life: 2,
+            position,
+            symbol: String::from("R"),
+            color: Color::Black,
+            experience_gain: 5,
+            ticks_between_steps: 5,
+        }
+    }
+}
+default_monster!(Rat);
+
+pub struct Orc {
+    name: String,
+    life: usize,
+    position: Position,
+    symbol: String,
+    color: Color,
+    experience_gain: usize,
+    ticks_between_steps: u128,
+}
+
+impl Orc {
+    pub fn new_with_position(position: Position) -> Self {
+        Self {
+            name: "orc".to_string(),
+            life: 4,
+            position,
+            symbol: String::from("O"),
+            color: Color::DarkGray,
+            experience_gain: 10,
+            ticks_between_steps: 10,
+        }
+    }
+}
+
+default_monster!(Orc);
+
 
 #[test]
 fn monsters_can_move() {
-    let mut m = Monster::new(2);
+    let mut m = Rat::new_with_position(Position::new(0, 0, 0));
     assert_eq!(m.get_position(), &Position::new(0, 0, 0));
     m.get_position().change(1, 2);
     assert_eq!(m.get_position(), &Position::new(0, 1, 2));
@@ -49,7 +107,7 @@ fn monsters_can_move() {
 
 #[test]
 fn monsters_can_die() {
-    let mut m = Monster::new(2);
+    let mut m = Rat::new_with_position(Position::new(0, 0, 0));
     assert_eq!(m.get_life(), 2);
     assert_eq!(m.is_dead(), false);
     m.decrease_life(1);

src/player.rs

@@ -1,5 +1,6 @@
 use std::cmp::{max, min};
-use crate::position::Position;
+
+use crate::position::{HasPosition, Position};
 
 pub struct Player {
     name: String,
@@ -7,6 +8,7 @@ pub struct Player {
     life: i16,
     max_life: i16,
     gold: usize,
+    experience: usize,
 }
 
 impl Player {
@@ -17,6 +19,7 @@ impl Player {
             life: max_life,
             max_life,
             gold: 0,
+            experience: 0,
         }
     }
     pub fn get_name(&self) -> String {
@@ -28,21 +31,32 @@ impl Player {
     pub fn get_life(&self) -> i16 {
         self.life
     }
+    /// returns true if the player is dead (life <= 0)
+    pub fn is_dead(&self) -> bool { self.life <= 0 }
+    /// returns true if the player's life is at maximum
+    pub fn is_healthy(&self) -> bool { self.life == self.max_life }
     pub fn get_max_life(&self) -> i16 {
         self.max_life
     }
-    pub fn get_position(&mut self) -> &mut Position {
-        &mut self.position
-    }
-    pub fn get_immutable_position(&self) -> &Position {
-        &self.position
-    }
 
     /// add the given amount to the players gold stash
     pub fn retrieve_gold(&mut self, amount: usize) { self.gold += amount }
 
     /// return the size of the players gold stash
     pub fn get_gold(&self) -> usize { self.gold }
+
+    pub fn gain_experience(&mut self, amount: usize) { self.experience += amount }
+
+    pub fn get_experience(&self) -> usize { self.experience }
+}
+
+impl HasPosition for Player {
+    fn get_position(&mut self) -> &mut Position {
+        &mut self.position
+    }
+    fn get_immutable_position(&self) -> &Position {
+        &self.position
+    }
 }
 
 #[test]
@@ -53,6 +67,7 @@ fn test_get_name() {
         life: 5,
         max_life: 10,
         gold: 0,
+        experience: 0,
     };
     assert_eq!(p.get_name(), "Teddy Tester");
 }
@@ -75,6 +90,7 @@ fn test_change_life() {
         life: 5,
         max_life: 10,
         gold: 0,
+        experience: 0,
     };
     assert_eq!(p.get_life(), 5);
     p.change_life(-2);
@@ -107,6 +123,7 @@ fn test_max_life() {
         life: 5,
         max_life: 10,
         gold: 0,
+        experience: 0,
     };
     assert_eq!(p.get_max_life(), 10);
 }

src/position.rs

@@ -1,5 +1,13 @@
 use std::cmp::max;
 
+/// describes an character (PC or NPC) in the dungeon that has a position.
+pub trait HasPosition {
+    /// returns a mutable position
+    fn get_position(&mut self) -> &mut Position;
+    /// returns an immutable position
+    fn get_immutable_position(&self) -> &Position;
+}
+
 #[derive(PartialEq, Debug)]
 pub struct Position {
     level: usize,