refactor main code, separate profile code

also:

- go through available wifi networks in sorted order, by rssi
- differentiate open from encrypted networks
- some debug prints

main.py

@@ -10,37 +10,44 @@ def check_connection():
     # First check if there already is any connection:
     if wlan_sta.isconnected():
         return True
+
+    connected = False
     try:
         # ESP connecting to WiFi takes time, wait a bit and try again:
         time.sleep(3)
-        if not wlan_sta.isconnected():
-            # inside passwd file, there is a list of WiFi networks (CSV format)
-            with open("passwd.dat") as f:
-                lines = f.readlines()
-            # Search WiFis in range
-            ssids_found = wlan_sta.scan()
-
-            # matching...
-            for line in lines:
-                ssid, password = line.strip("\n").split(";")
-                for ssid_found in ssids_found:
-                    if ssid in ssid_found[0]:
-                        print("OK. WiFi found.")
-                        if networkconfig.do_connect(ssid, password):
-                            return True
-
-            if not wlan_sta.isconnected():
-                if networkconfig.start():
-                    return True
-        else:
+        if wlan_sta.isconnected():
             return True
 
+        # Read known network profiles from file
+        profiles = networkconfig.read_profiles()
+
+        # Search WiFis in range
+        networks = wlan_sta.scan()
+
+        AUTHMODE = {0: "open", 1: "WEP", 2: "WPA-PSK", 3: "WPA2-PSK", 4: "WPA/WPA2-PSK"}
+        for ssid, bssid, channel, rssi, authmode, hidden in sorted(networks, key=lambda x: x[3], reverse=True):
+            ssid = ssid.decode('utf-8')
+            encrypted = authmode > 0
+            print("ssid: %s chan: %d rssi: %d authmode: %s" % (ssid, channel, rssi, AUTHMODE.get(authmode, '?')))
+            if encrypted:
+                if ssid in profiles:
+                    password = profiles[ssid]
+                    connected = networkconfig.do_connect(ssid, password)
+                else:
+                    print("skipping unknown encrypted network")
+            else:  # open
+                connected = networkconfig.do_connect(ssid, None)
+            if connected:
+                break
+
     except OSError:
-        # start web server for connection manager:
-        if networkconfig.start():
-            return True
+        pass
 
-    return False
+    # start web server for connection manager:
+    if not connected:
+        connected = networkconfig.start()
+
+    return connected
 
 
 if check_connection():

networkconfig.py

@@ -12,6 +12,27 @@ ssid_password = "tayfunulu"
 
 server_socket = None
 
+# list of WiFi networks (CSV format: ssid,password)
+NETWORK_PROFILES = 'passwd.dat'
+
+
+def read_profiles():
+    with open(NETWORK_PROFILES) as f:
+        lines = f.readlines()
+    profiles = {}
+    for line in lines:
+        ssid, password = line.strip("\n").split(";")
+        profiles[ssid] = password
+    return profiles
+
+
+def write_profiles(profiles):
+    lines = []
+    for ssid, password in profiles.items():
+        lines.append("%s;%s\n" % (ssid, password))
+    with open(NETWORK_PROFILES, "w") as f:
+        f.write(''.join(lines))
+
 
 def do_connect(ssid, password):
     sta_if = network.WLAN(network.STA_IF)
@@ -86,7 +107,7 @@ def handle_root(client):
             <h5>
                 <span style="color: #ff0000;">
                     Your ssid and password information will be saved into the
-                    "passwd.dat" file in your ESP module for future usage.
+                    "%(filename)s" file in your ESP module for future usage.
                     Be careful about security!
                 </span>
             </h5>
@@ -105,7 +126,7 @@ def handle_root(client):
                 </li>
             </ul>
         </html>
-    """)
+    """ % dict(filename=NETWORK_PROFILES))
     send_response(client, "\n".join(response))
 
 
@@ -143,13 +164,11 @@ def handle_configure(client, request):
         """ % dict(ssid=ssid)
         send_response(client, response)
         try:
-            with open("passwd.dat", "r") as f:
-                ex_data = f.read()
-        except:
-            ex_data = ""
-        ex_data = "%s;%s\n" % (ssid, password) + ex_data
-        with open("passwd.dat", "w") as f:
-            f.write(ex_data)
+            profiles = read_profiles()
+        except OSError:
+            profiles = {}
+        profiles[ssid] = password
+        write_profiles(profiles)
         return True
     else:
         response = """\