Add colors support (#16)

src/safaribookmarks/cli.py

@@ -1,19 +1,46 @@
+from io import UnsupportedOperation
+import os
 from typing import IO, List, Optional
 from .safaribookmarks import SafariBookmarks, SafariBookmarkItem
 
-DEFAULT_LIST_FORMAT = "{icon} {title: <50} {id: <38}{url}"
-SIMPLE_FORMAT = "{icon} {title: <50} {url}"
+DEFAULT_LIST_FORMAT = (
+    "{grey}{icon}{reset} {title: <50} {dark_grey}{id: <38}{cyan}{url}{reset}"
+)
+SIMPLE_FORMAT = "{grey}{icon}{reset} {title: <50} {cyan}{url}{reset}"
 ICON_FIRST_LEAF = "┌"
 ICON_MIDDLE_LEAF = "├"
 ICON_LAST_LEAF = "└"
 ICON_SINGLE_LEAF = "─"
 ICON_LIST_CONTAINER = "│"
 
+# Source: https://github.com/termcolor/termcolor/blob/main/src/termcolor/termcolor.py
+COLORS: dict[str, int] = {
+    "reset": 0,
+    "black": 30,
+    "grey": 30,
+    "red": 31,
+    "green": 32,
+    "yellow": 33,
+    "blue": 34,
+    "magenta": 35,
+    "cyan": 36,
+    "light_grey": 37,
+    "dark_grey": 90,
+    "light_red": 91,
+    "light_green": 92,
+    "light_yellow": 93,
+    "light_blue": 94,
+    "light_magenta": 95,
+    "light_cyan": 96,
+    "white": 97,
+}
+
 
 class CLI:
     def __init__(self, path: str, out: IO) -> None:
         self.bookmarks = SafariBookmarks.open(path)
         self.output = out
+        self.colors = generate_colors(out)
 
     @property
     def path(self) -> str:
@@ -42,6 +69,7 @@ def _render_item(
     ):
         self.output.write(
             f"{format}\n".format(
+                **self.colors,
                 icon=icon,
                 depth=depth,
                 title=item.title.replace("\n", ""),
@@ -161,3 +189,27 @@ def empty(self, path: List[str]):
             raise ValueError("Target is not a list")
         target.empty()
         self._save()
+
+
+def generate_colors(output: IO) -> dict[str, str]:
+    if supports_colors(output):
+        return {name: "\033[%dm" % code for name, code in COLORS.items()}
+    else:
+        return {name: "" for name in COLORS.keys()}
+
+
+def supports_colors(tty: IO) -> bool:
+    if "ANSI_COLORS_DISABLED" in os.environ:
+        return False
+    if "NO_COLOR" in os.environ:
+        return False
+    if "FORCE_COLOR" in os.environ:
+        return True
+    if os.environ.get("TERM") == "dumb":
+        return False
+    if not hasattr(tty, "fileno"):
+        return False
+    try:
+        return os.isatty(tty.fileno())
+    except UnsupportedOperation:
+        return tty.isatty()