Working

cheekyfsm.py

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+import curses
+import random
+import sys
+import re
+
+ESCAPE = 27
+LETTERS = range(97, 122)
+NUMBERS = range(48, 57)
+
+
+class CheekyFSM(object):
+    def __init__(self):
+        self.lastkey = -1
+        self.buffer = ""
+        self.message = ""
+        self.edges = {}
+        self.state = "A"
+        self.history = " "*30
+
+    def show_edges(self):
+        """ Print the help menu """
+        y, x = self.w.getmaxyx()
+        for index, ((start, end), prob) in enumerate(self.edges.items()):
+            self.w.addstr(10 + index, 2, f"{start} -> {end} : {prob}%")
+
+    def update(self):
+        """ Update the FSM """
+        edges = list(self.edges.items())
+        random.shuffle(edges)
+        for ((start, end), prob) in edges:
+            if start == self.state:
+                if random.randint(0, 100) < prob:
+                    self.state = end
+
+        self.history = self.history[1:] + self.state
+
+    def show_state(self):
+        """ Show the state of the machine """
+        self.w.addstr(2, 2, f"Tempo: 120bpm")
+        self.w.addstr(4, 2, f"State: {self.state}")
+        self.w.addstr(5, 2, f"History: {self.history}")
+
+        offset = 6
+        for ((start, end), prob) in self.edges.items():
+            if start == self.state:
+                self.w.addstr(offset, 2,
+                              f"Going to {end} with probability {prob}%")
+                offset += 1
+
+    def show_status(self):
+        """ Print the status bar """
+        y, x = self.w.getmaxyx()
+        self.w.addstr(y - 2, 2, f"> {self.buffer}", curses.A_BOLD)
+
+    def quit(self):
+        """ Quit the program """
+        curses.nocbreak()
+        self.w.keypad(False)
+        curses.echo()
+        curses.endwin()
+        sys.exit(0)
+
+    def process_key(self):
+        """ Process a key """
+        key = self.w.getch()
+        self.lastkey = key
+        if key == ESCAPE:
+            quit(self.w)
+        elif key in LETTERS:
+            self.buffer += chr(key).upper()
+        elif key in NUMBERS:
+            self.buffer += chr(key)
+        elif key == 10:
+            self.accept()
+        elif key == 263 and len(self.buffer) > 0:
+            self.buffer = self.buffer[:-1]
+
+    def accept(self):
+        """ Accept the string """
+        match = re.match(r"([A-Z])([A-Z])(\d+)", self.buffer)
+        if not match:
+            self.message = "  Invalid command :("
+        else:
+            groups = match.groups()
+            start = groups[0]
+            end = groups[1]
+            prob = int(groups[2])
+            self.modify(start, end, prob)
+        self.buffer = ""
+
+    def modify(self, start, end, prob):
+        """ Make a modification """
+        key = (start, end)
+        self.edges[key] = prob
+        self.message = f"  {start} -> {end} : {prob}%"
+        if prob == 0 and key in self.edges:
+            self.message = f"  {start} -> {end} : deleted"
+            del self.edges[key]
+
+    def loop(self, w):
+        """ Run the loop """
+        self.w = w
+        curses.curs_set(0)  # invisible
+        w.timeout(100)
+        while True:
+            w.clear()
+            self.show_edges()
+            self.show_status()
+            self.show_state()
+            self.update()
+            w.refresh()
+            self.process_key()
+
+
+if __name__ == "__main__":
+    fsm = CheekyFSM()
+    curses.wrapper(fsm.loop)