feat: add config module with INI-based configuration management

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/jianda_proxy/config.py

@@ -0,0 +1,70 @@
+import os
+import configparser
+from pathlib import Path
+
+SECTION = "proxy"
+DEFAULTS = {
+    "remote_domain": "git.zz.com",
+    "upstream_host": "62.234.191.215",
+    "upstream_port": "3000",
+    "listen_port": "13000",
+    "listen_host": "127.0.0.1",
+}
+
+
+def get_config_dir():
+    if os.name == "nt":
+        base = os.environ.get("APPDATA", os.path.expanduser("~"))
+    else:
+        base = os.environ.get("XDG_CONFIG_HOME", os.path.expanduser("~/.config"))
+    return os.path.join(base, "jianda-proxy")
+
+
+def _ensure_dir(path):
+    os.makedirs(path, exist_ok=True)
+
+
+def get_config_path():
+    return os.path.join(get_config_dir(), "config.ini")
+
+
+def get_pid_path():
+    return os.path.join(get_config_dir(), "daemon.pid")
+
+
+def get_log_path():
+    return os.path.join(get_config_dir(), "proxy.log")
+
+
+def load_config():
+    path = get_config_path()
+    _ensure_dir(get_config_dir())
+    parser = configparser.ConfigParser()
+    if not os.path.exists(path):
+        parser[SECTION] = dict(DEFAULTS)
+        with open(path, "w") as f:
+            parser.write(f)
+    else:
+        parser.read(path)
+        if SECTION not in parser:
+            parser[SECTION] = dict(DEFAULTS)
+    return parser
+
+
+def set_config_value(key, value):
+    if key not in DEFAULTS:
+        raise ValueError(f"Unknown config key: {key}. Valid keys: {', '.join(DEFAULTS)}")
+    parser = load_config()
+    parser[SECTION][key] = value
+    with open(get_config_path(), "w") as f:
+        parser.write(f)
+
+
+def get_config_value(key):
+    parser = load_config()
+    return parser.get(SECTION, key)
+
+
+def list_config():
+    parser = load_config()
+    return dict(parser[SECTION])