Fix multi-line polygons

lib/nexrad/afos.py

@@ -30,6 +30,8 @@ RE_PRODUCT = re.compile(r'^(?P<product>[A-Z]{3})(?P<wfo>[A-Z]{3})$')
 
 RE_POLY = re.compile(r'^LAT\.\.\.LON (?P<coords>\d+(?: \d+)+)')
 
+RE_POLY_CONT = re.compile(r'^\s+(?P<coords>\d+(?: \d+)+)')
+
 RE_MOTION = re.compile(r'''
     ^ TIME
     \.\.\. MOT
@@ -58,37 +60,30 @@ TIMEZONES = {
 
 def parse_lon(text: str):
     size = len(text)
-    return 0 - float(text[0:size-2]) + (float(text[size-2:size]) / 100)
+
+    return 0 - float(text[0:size-2] + '.' + text[size-2:size])
 
 def parse_lat(text: str):
     size = len(text)
-    return float(text[0:size-2]) + (float(text[size-2:size]) / 100)
+    return float(text[0:size-2] + '.' + text[size-2:size])
 
 def parse_location(lon: str, lat: str):
     return shapely.Point(parse_lon(lon), parse_lat(lat))
 
-def parse_poly(text: str):
-    points = list()
-    coords = text.split(' ')
+def parse_poly_coords(text: str) -> list:
+    coords = list()
+    items  = text.split(' ')
 
-    for i in range(0, len(coords), 2):
-        lat = coords[i]
-        lon = coords[i+1]
+    for i in range(0, len(items), 2):
+        lat = items[i]
+        lon = items[i+1]
 
-        points.append([parse_lon(lon), parse_lat(lat)])
+        coords.append([parse_lon(lon), parse_lat(lat)])
 
-    points.append([parse_lon(coords[1]), parse_lat(coords[0])])
+    return coords
 
-    return shapely.Polygon(points)
-
-class AFOSMessageParserState(enum.Enum):
-    NONE     = 0
-    SERIAL   = enum.auto()
-    ISSUANCE = enum.auto()
-    PRODUCT  = enum.auto()
-    BODY     = enum.auto()
-    TAGS     = enum.auto()
-    FOOTER   = enum.auto()
+def poly_from_coords(coords: list) -> shapely.Polygon:
+    return shapely.Polygon([*coords, [coords[0][0], coords[0][1]]])
 
 class AFOSMessage(DatabaseTable):
     __table__ = 'nexrad_afos_message'
@@ -171,14 +166,32 @@ class AFOSMessage(DatabaseTable):
     def is_warning(self):
         return self.sig is not None and self.sig == 'W'
 
+class AFOSMessageParserState(enum.Enum):
+    NONE      = 0
+    SERIAL    = enum.auto()
+    ISSUANCE  = enum.auto()
+    PRODUCT   = enum.auto()
+    BODY      = enum.auto()
+    TAGS      = enum.auto()
+    TAGS_POLY = enum.auto()
+    FOOTER    = enum.auto()
+
 class AFOSMessageParser():
-    __slots__ = 'message', 'state', 'issuance', 'timestamp',
+    __slots__ = (
+        'message', 'state', 'issuance', 'timestamp', 'poly_coords'
+    )
+
+    message:     AFOSMessage
+    state:       AFOSMessageParserState
+    timestamp:   datetime.datetime
+    poly_coords: list
 
     def __init__(self):
         self.message     = None
         self.state       = None
         self.issuance    = None
         self.timestamp   = None
+        self.poly_coords = None
 
     def parse_vtec(self, line: str):
         vtec = VTECEvent.parse(line)
@@ -241,14 +254,25 @@ class AFOSMessageParser():
 
     def parse_tags(self, line: str):
         if line == '$$':
+            if len(self.poly_coords) > 0:
+                self.message.poly = shapely.Polygon(self.poly_coords)
+
             self.state = AFOSMessageParserState.FOOTER
             return
 
+        #
+        # Parsing for "LAT...LON"
+        #
         match = RE_POLY.match(line)
 
         if match is not None:
-            self.message.poly = parse_poly(match['coords'])
+            self.poly_coords.extend(parse_poly_coords(match['coords']))
+            self.state = AFOSMessageParserState.TAGS_POLY
+            return
 
+        #
+        # Parsing for "TIME...MOT...LOC"
+        #
         match = RE_MOTION.match(line)
 
         if match is not None:
@@ -256,6 +280,15 @@ class AFOSMessageParser():
             self.message.speed    = int(match['speed'])
             self.message.location = parse_location(match['lon'], match['lat'])
 
+    def parse_tags_poly(self, line: str):
+        match = RE_POLY_CONT.match(line)
+
+        if match is None:
+            self.state = AFOSMessageParserState.TAGS
+            return self.parse_tags(line)
+
+        self.poly_coords.extend(parse_poly_coords(match['coords']))
+
     def parse_footer(self, line: str):
         self.message.forecaster = line
 
@@ -280,6 +313,8 @@ class AFOSMessageParser():
             self.parse_body(line)
         elif self.state == AFOSMessageParserState.TAGS:
             self.parse_tags(line)
+        elif self.state == AFOSMessageParserState.TAGS_POLY:
+            self.parse_tags_poly(line)
         elif self.state == AFOSMessageParserState.FOOTER:
             self.parse_footer(line)
 
@@ -302,6 +337,9 @@ class AFOSMessageParser():
 
     def parse(self, text: str):
         self.message          = AFOSMessage()
+        self.message.text_raw = text
+
+        self.poly_coords = list()
         self.state       = AFOSMessageParserState.SERIAL
         self.issuance    = None
         self.timestamp   = None