1 files changed, 117 insertions, 0 deletions
diff --git a/src/server.py b/src/server.py
new file mode 100644
index 0000000..0ab0e89
--- /dev/null
+++ b/src/server.py
@@ -0,0 +1,117 @@
+#!/usr/bin/env python
+
+import argparse
+import asyncio
+import json
+import sys
+
+from datetime import datetime, timezone
+from pathlib import Path
+from websockets.asyncio.server import serve
+from websockets.exceptions import ConnectionClosedOK
+
+class Context():
+    def __init__(self, output):
+        self.output = output
+        output.mkdir(parents = True, exist_ok = True)
+
+    def next(self):
+        ts = datetime.now(timezone.utc).timestamp()
+        return self.output / f"session-{ts}.json"
+
+
+def quote(instr):
+    return json.dumps(instr)
+
+def parse_header(message):
+    parts = message.split('|')
+    if len(parts) < 3:
+        return None
+    return {
+        'width': float(parts[0]),
+        'height': float(parts[1]),
+        'brands': '|'.join(parts[2:]),
+    }
+
+def parse_event(message):
+    parts = message.split('|')
+    if parts[0] == 'u' and len(parts) > 1:
+        return {
+            'type': 'url',
+            'url': '|'.join(parts[1:]),
+        }
+    if len(parts) < 3:
+        return None
+    return {
+        'type': 'click',
+        'x': float(parts[0]),
+        'y': float(parts[1]),
+        'tag': parts[2],
+    }
+
+async def handler(context, websocket):
+    filename = context.next()
+    with open(filename, "w", encoding="utf-8") as session_file:
+        try:
+            message = await websocket.recv()
+        except ConnectionClosedOK:
+            filename.unlink()
+            return
+
+        header = parse_header(message)
+        if not header:
+            print(f"Bad header: {message}", file=sys.stderr)
+            filename.unlink()
+            return
+
+        print(f'''{{
+  "format":"clicks",
+  "version":"1.0",
+  "width": {header['width']},
+  "height": {header['height']},
+  "brands": {quote(header['brands'])},
+  "events": [''',
+              file=session_file)
+
+        comma = ''
+
+        while True:
+            try:
+                message = await websocket.recv()
+                event = parse_event(message)
+                if event:
+                    if event['type'] == 'click':
+                        print(f'''{comma}{{
+"x": {event['x']}, "y": {event['y']}, "tag": {quote(event['tag'])}
+}}''',
+                              file=session_file)
+                    else:
+                        print(f'''{comma}{{"url": {quote(event['url'])}}}''',
+                              file=session_file)
+
+                    if not comma:
+                        comma = ','
+            except ConnectionClosedOK:
+                break
+
+        print(']}', file=session_file)
+
+
+async def server(output):
+    context = Context(output)
+    async with serve(lambda x: handler(context, x), "", 8001):
+        await asyncio.get_running_loop().create_future()
+
+def main():
+    parser = argparse.ArgumentParser(
+        description='Example server')
+
+    parser.add_argument('output', type=Path, help='output directory')
+
+    args = parser.parse_args()
+
+    asyncio.run(server(args.output))
+
+if __name__ == "__main__":
+    main()
+