Move colorization to the display layer

Color output isn't necessarily always going to be a terminal output
thing, and terminals don't always support the same escape codes (e.g. on
Windows). Thus, all colorization efforts are done in the Display rather
than in the Game.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

agame/display/unix.py

@@ -1,7 +1,7 @@
+import re
 import sys
 import termios
 from typing import Optional, Sequence, TextIO, Tuple, TYPE_CHECKING
-from agame.color import colorize
 from agame.action import Action
 from agame.dialog import DialogOption
 from .display import Display
@@ -9,8 +9,44 @@ from .display import Display
 if TYPE_CHECKING:
     from agame.game import Game
 
+__all__ = ("ANSIDisplay",)
+
 ESC = "\u001b"
 ANSI_MOVE_BOTTOM = f"{ESC}[999;0f"
+ANSI_BOLD_COL = f"{ESC}[1m"
+ANSI_ITALIC_COL = f"{ESC}[3m"
+ANSI_INTEREST_COL = f"{ESC}[34;1m"
+ANSI_SHADOW_COL = f"{ESC}[30;1m"
+ANSI_RESET_COL = f"{ESC}[0m"
+
+BOLD_PAT = re.compile(r"\*\*(.+?)\*\*", re.MULTILINE)
+ITALIC_PAT = re.compile(r"//(.+?)//", re.MULTILINE)
+INTEREST_PAT = re.compile(r"\(\((.+?)\)\)", re.MULTILINE)
+SHADOW_PAT = re.compile(r"\{\{(.+?)\}\}", re.MULTILINE)
+
+
+def colorize(text: str) -> str:
+    """
+    Colorizes text for output on an ANSI terminal.
+
+    This will use escape codes to replace things.
+
+    Style guide:
+        ((This)) is "interest" styling. This will make the text blue.
+        {{This}} is "shadow" styling. This will make the text a dark grey (or at
+                 least, more subtle.)
+    """
+    replacements = [
+        (INTEREST_PAT, ANSI_INTEREST_COL),
+        (SHADOW_PAT, ANSI_SHADOW_COL),
+        (BOLD_PAT, ANSI_BOLD_COL),
+        (ITALIC_PAT, ANSI_ITALIC_COL),
+    ]
+
+    for (pat, col) in replacements:
+        text = pat.sub(col + r"\1" + ANSI_RESET_COL, text)
+
+    return text
 
 
 class ANSIDisplay(Display):
@@ -47,6 +83,7 @@ class ANSIDisplay(Display):
         self.clear()
 
     def line(self, line: str = ""):
+        line = colorize(line)
         self.stdout.write(line)
         self.stdout.write("\n")