From 3ad7b61b7d6ff2693a9d78e5b57ff897e761a5be Mon Sep 17 00:00:00 2001
From: Alfred Melch <dev@melch.pro>
Date: Tue, 7 Jan 2020 19:27:05 +0100
Subject: [PATCH] Add a game loop

---
 srv/ebermergen/__init__.py            | 22 ++++++++++++
 srv/ebermergen/lib/ebermergen_game.py | 50 +++++++++++++++++++++++++++
 srv/ebermergen/lib/gameloop.py        | 46 ++++++++++++++++++++++++
 srv/ebermergen/models/game.py         |  2 ++
 4 files changed, 120 insertions(+)
 create mode 100644 srv/ebermergen/lib/ebermergen_game.py
 create mode 100644 srv/ebermergen/lib/gameloop.py

diff --git a/srv/ebermergen/__init__.py b/srv/ebermergen/__init__.py
index 3868d91..450633a 100644
--- a/srv/ebermergen/__init__.py
+++ b/srv/ebermergen/__init__.py
@@ -5,9 +5,13 @@ from flask_cors import CORS
 from ebermergen.models.game import Game
 from .lib import generate_map
 
+from .lib.ebermergen_game import EbermergenGame
+
 app = Flask(__name__)
 CORS(app)
 
+games = {}
+
 
 @app.route('/')
 def index():
@@ -29,3 +33,21 @@ def state():
     a = Game()
     a.seed_map()
     return jsonify(a.serialize())
+
+
+@app.route('/lala')
+def lala():
+    return jsonify({k: v.state for (k, v) in games.items()})
+
+
+@app.route('/new-game/<name>', methods=['GET', 'POST'])
+def new_game(name):
+    games[name] = EbermergenGame()
+    games[name].start_game()
+    return jsonify({'message': 'success'})
+
+
+@app.route('/action/<name>/<type>')
+def action(name, type):
+    games[name].perform_action(type, {})
+    return jsonify({'message': 'success'})
diff --git a/srv/ebermergen/lib/ebermergen_game.py b/srv/ebermergen/lib/ebermergen_game.py
new file mode 100644
index 0000000..5446548
--- /dev/null
+++ b/srv/ebermergen/lib/ebermergen_game.py
@@ -0,0 +1,50 @@
+import atexit
+import time
+import threading
+import queue
+
+from .gameloop import GameLoop
+
+
+def tick(dt, first, second):
+    print('%.2f' % dt, first, second)
+    pass
+
+
+def worker(state, action_queue):
+    state['counter'] = 0
+    state['actions'] = []
+    loop = GameLoop(tick=tick, fps=1, fixed_dt=True, args=(1, 2))
+    while True:
+        item = action_queue.get()
+        if item['action'] == 'STOP':
+            loop.stop()
+        if item['action'] == 'START':
+            loop.start()
+        state['counter'] += 1
+        state['actions'].append(item['action'])
+
+
+class EbermergenGame:
+    """Runs a single game instance
+
+    Holds the serialized state.
+    Provides methods to perform actions.
+    """
+
+    def __init__(self):
+        self.state = {}
+        self.actions = queue.Queue()
+        self.thread = threading.Thread(
+            target=worker, args=(self.state, self.actions))
+
+    def start_game(self):
+        self.thread.start()
+        atexit.register(self.interupt)
+
+    def interupt(self):
+        # handle gracefull shutdown
+        pass
+
+    def perform_action(self, action, payload={}):
+        self.actions.put({'action': action, 'payload': payload})
diff --git a/srv/ebermergen/lib/gameloop.py b/srv/ebermergen/lib/gameloop.py
new file mode 100644
index 0000000..b48a9a9
--- /dev/null
+++ b/srv/ebermergen/lib/gameloop.py
@@ -0,0 +1,46 @@
+import threading
+import time
+import random
+
+
+class GameLoop():
+    """Implements a loop that calls tick every 1/fps
+
+    tick gets called with the time delta to the last call as parameter
+    if fixed_dt is True the tick function gets called with 1/fps
+    """
+
+    def __init__(self, fps=1, tick=None, fixed_dt=False, args=None):
+        self.fps = fps
+        self.tick = tick if tick is not None else self.default_tick
+        self.args = args or tuple()
+        self.fixed_dt = fixed_dt
+        self.running = False
+        self.last_frame_time = time.time()
+        self.thread = threading.Thread(target=self.loop)
+
+    def loop(self):
+        while self.running:
+            current_time = time.time()
+            dt = current_time - self.last_frame_time
+            self.last_frame_time = current_time
+
+            if self.fixed_dt:
+                self.tick(1 / self.fps, *self.args)
+            else:
+                self.tick(dt, *self.args)
+
+            sleep_time = (1 / self.fps) - (time.time() - self.last_frame_time)
+            if sleep_time > 0:
+                time.sleep(sleep_time)
+
+    def start(self):
+        self.running = True
+        self.thread.start()
+
+    def stop(self):
+        self.running = False
+
+    def default_tick(self, dt):
+        print('ticked. Last tick was %.2f seconds ago' % dt)
+        time.sleep(random.choice([0.4, 0.5, 0.6, 1.4, 2.1]) * 1/self.fps)
diff --git a/srv/ebermergen/models/game.py b/srv/ebermergen/models/game.py
index a327800..9226306 100644
--- a/srv/ebermergen/models/game.py
+++ b/srv/ebermergen/models/game.py
@@ -5,6 +5,8 @@ from .player import Player
 from .map import Map
 from .entities import Town
 
+from ebermergen.lib.gameloop import GameLoop
+
 
 class Game:
     def __init__(self):