access to global configuration using set_config and get_config
[electrum-nvc.git] / lib / simple_config.py
index 810bf8c..30c7f9d 100644 (file)
 import json
+import ast
+import threading
 import os
-from util import user_dir
+
+from util import user_dir, print_error, print_msg
+
+
+config = None
+def get_config():
+    global config
+    return config
+
+def set_config(c):
+    global config
+    config = c
+
 
 class SimpleConfig:
+    """
+The SimpleConfig class is responsible for handling operations involving
+configuration files.  The constructor reads and stores the system and 
+user configurations from electrum.conf into separate dictionaries within
+a SimpleConfig instance then reads the wallet file.
+"""
+    def __init__(self, options={}):
+        self.lock = threading.Lock()
 
+        # system conf, readonly
+        self.system_config = {}
+        if options.get('portable') is not True:
+            self.read_system_config()
+
+        # command-line options
+        self.options_config = options
+
+        # init path
+        self.init_path()
+
+        # user conf, writeable
+        self.user_config = {}
+        self.read_user_config()
+
+        set_config(self)
 
-    default_options = {
-        "gui": "lite",
-        "proxy": None,
-        "winpos-qt": [100, 100, 840, 400],
-        "winpos-lite": [4, 25, 351, 149],
-        "history": False
-        }
-    
-    def __init__(self):
-        # Find electrum data folder
-        self.config_folder = user_dir()
-        # Read the file
-        if os.path.exists(self.config_file_path()):
-            self.load_config()
-        else:
-            self.config = self.default_options
-            # Make config directory if it does not yet exist.
-            if not os.path.exists(self.config_folder):
-                os.mkdir(self.config_folder)
-            self.save_config()
 
+
+    def init_path(self):
+
+        # Read electrum path in the command line configuration
+        self.path = self.options_config.get('electrum_path')
+
+        # Read electrum path in the system configuration
+        if self.path is None:
+            self.path = self.system_config.get('electrum_path')
+
+        # If not set, use the user's default data directory.
+        if self.path is None:
+            self.path = user_dir()
+
+        # Make directory if it does not yet exist.
+        if not os.path.exists(self.path):
+            os.mkdir(self.path)
+
+        print_error( "electrum directory", self.path)
+
+        # portable wallet: use the same directory for wallet and headers file
+        #if options.get('portable'):
+        #    self.wallet_config['blockchain_headers_path'] = os.path.dirname(self.path)
+            
     def set_key(self, key, value, save = True):
-        self.config[key] = value
-        if save == True:
-            self.save_config()
-
-    def save_config(self):
-        if not os.path.exists(self.config_folder):
-            os.mkdir(self.config_folder)
-        f = open(self.config_file_path(), "w+")
-        f.write(json.dumps(self.config))
-
-    def load_config(self):
-        f = open(self.config_file_path(), "r")
-        file_contents = f.read()
-        if file_contents:
-            user_config = json.loads(file_contents)
-            for i in user_config:
-                self.config[i] = user_config[i]
+        # find where a setting comes from and save it there
+        if self.options_config.get(key) is not None:
+            print "Warning: not changing '%s' because it was passed as a command-line option"%key
+            return
+
+        elif self.system_config.get(key) is not None:
+            if str(self.system_config[key]) != str(value):
+                print "Warning: not changing '%s' because it was set in the system configuration"%key
+
+        else:
+
+            with self.lock:
+                self.user_config[key] = value
+                if save: 
+                    self.save_user_config()
+
+
+
+    def get(self, key, default=None):
+
+        out = None
+
+        # 1. command-line options always override everything
+        if self.options_config.has_key(key) and self.options_config.get(key) is not None:
+            out = self.options_config.get(key)
+
+        # 2. user configuration 
+        elif self.user_config.has_key(key):
+            out = self.user_config.get(key)
+
+        # 2. system configuration
+        elif self.system_config.has_key(key):
+            out = self.system_config.get(key)
+
+        if out is None and default is not None:
+            out = default
+
+        # try to fix the type
+        if default is not None and type(out) != type(default):
+            import ast
+            try:
+                out = ast.literal_eval(out)
+            except Exception:
+                print "type error for '%s': using default value"%key
+                out = default
+
+        return out
+
+
+    def is_modifiable(self, key):
+        """Check if the config file is modifiable."""
+        if self.options_config.has_key(key):
+            return False
+        elif self.user_config.has_key(key):
+            return True
+        elif self.system_config.has_key(key):
+            return False
         else:
-            self.config = self.default_options
-            self.save_config()
-  
-    def config_file_path(self):
-        return "%s" % (self.config_folder + "/config.json")
-
-    def __init__(self):
-        # Find electrum data folder
-        self.config_folder = user_dir()
-        self.config = self.default_options
-        # Read the file
-        if os.path.exists(self.config_file_path()):
-            self.load_config()
-        self.save_config()
+            return True
+
+
+    def read_system_config(self):
+        """Parse and store the system config settings in electrum.conf into system_config[]."""
+        name = '/etc/electrum.conf'
+        if os.path.exists(name):
+            try:
+                import ConfigParser
+            except ImportError:
+                print "cannot parse electrum.conf. please install ConfigParser"
+                return
+                
+            p = ConfigParser.ConfigParser()
+            p.read(name)
+            try:
+                for k, v in p.items('client'):
+                    self.system_config[k] = v
+            except ConfigParser.NoSectionError:
+                pass
+
+
+    def read_user_config(self):
+        """Parse and store the user config settings in electrum.conf into user_config[]."""
+        if not self.path: return
+
+        path = os.path.join(self.path, "config")
+        if os.path.exists(path):
+            try:
+                with open(path, "r") as f:
+                    data = f.read()
+            except IOError:
+                return
+            try:
+                d = ast.literal_eval( data )  #parse raw data from reading wallet file
+            except Exception:
+                print_msg("Error: Cannot read config file.")
+                return
+
+            self.user_config = d
+
 
+    def save_user_config(self):
+        if not self.path: return
 
+        path = os.path.join(self.path, "config")
+        s = repr(self.user_config)
+        f = open(path,"w")
+        f.write( s )
+        f.close()
+        if self.get('gui') != 'android':
+            import stat
+            os.chmod(path, stat.S_IREAD | stat.S_IWRITE)