Add error classes

Move version check to debug

g4f/debug.py

@@ -1,2 +1,39 @@
+from os import environ
+from requests import get
+from importlib.metadata import version, PackageNotFoundError
+from subprocess import check_output, CalledProcessError, PIPE
+from .errors import VersionNotFoundError
+
 logging = False
-version_check = True
+version_check = True
+
+def get_version() -> str:
+    # Read from package manager
+    try:
+        return version("g4f")
+    except PackageNotFoundError:
+        pass
+    # Read from docker environment
+    current_version = environ.get("G4F_VERSION")
+    if current_version:
+        return current_version
+    # Read from git repository
+    try:
+        command = ["git", "describe", "--tags", "--abbrev=0"]
+        return check_output(command, text=True, stderr=PIPE).strip()
+    except CalledProcessError:
+        pass
+    raise VersionNotFoundError("Version not found")
+    
+def get_lastet_version() -> str:
+    response = get("https://pypi.org/pypi/g4f/json").json()
+    return response["info"]["version"]
+
+def check_pypi_version() -> None:
+    try:
+        version = get_version()
+        latest_version = get_lastet_version()
+    except Exception as e:
+        print(f'Failed to check g4f pypi version: {e}')
+    if version != latest_version:
+        print(f'New pypi version: {latest_version} (current: {version}) | pip install -U g4f')