feat(adapter): implement process_session and CLI

tests/test_balabit_adapter.py

@@ -1,6 +1,7 @@
 """Tests for Balabit Mouse Dynamics Challenge data adapter."""
 from __future__ import annotations
 
+import json
 from pathlib import Path
 
 import pytest
@@ -261,3 +262,75 @@ class TestFilterSegments:
         result = filter_segments([seg], min_events=5, min_dist=50,
                                   max_span_ms=5000, max_gap_ms=200)
         assert len(result) == 1
+
+
+class TestProcessSession:
+    def test_writes_jsonl_in_expected_format(self, tmp_path):
+        from ai_mouse.config import BalabitAdapterConfig
+        from ai_mouse.data_adapters.balabit import process_session
+
+        # Construct a Balabit-format CSV with one valid segment
+        csv_path = tmp_path / "user_session_42"
+        rows = []
+        # 10 Move events going from (100,100) to (500,200) over 500ms
+        for i in range(10):
+            t = i * 0.05
+            x = 100 + i * 40
+            y = 100 + i * 10
+            rows.append(f"0,{t:.3f},NoButton,Move,{x},{y}")
+        rows.append(f"0,0.550,Left,Pressed,510,210")
+        _write_csv(csv_path, rows)
+
+        out = tmp_path / "out.jsonl"
+        config = BalabitAdapterConfig(
+            window_ms=1200, min_dist=50, min_events=5,
+            max_span_ms=5000, max_gap_ms=200,
+        )
+        n = process_session(csv_path, out, config)
+        assert n == 1
+        assert out.exists()
+
+        line = out.read_text(encoding="utf-8").strip()
+        record = json.loads(line)
+        assert record["meta"]["start"] == [100, 100]
+        assert record["meta"]["end"] == [510, 210]
+        assert record["meta"]["dist"] > 0
+        assert record["meta"]["source"] == "balabit"
+        assert record["meta"]["session_id"] == "user_session_42"
+        # Events: only move events, no down/up
+        assert all(e["type"] == "move" for e in record["events"])
+        # Timestamps relative (start at 0)
+        assert record["events"][0]["t"] == 0
+
+    def test_returns_zero_for_session_with_no_valid_segments(self, tmp_path):
+        from ai_mouse.config import BalabitAdapterConfig
+        from ai_mouse.data_adapters.balabit import process_session
+
+        csv_path = tmp_path / "empty_session"
+        _write_csv(csv_path, ["0,0.000,NoButton,Move,100,100"])  # no clicks
+
+        out = tmp_path / "out.jsonl"
+        config = BalabitAdapterConfig()
+        n = process_session(csv_path, out, config)
+        assert n == 0
+        # File may not exist or may be empty — both acceptable
+        if out.exists():
+            assert out.read_text() == ""
+
+    def test_appends_to_existing_jsonl(self, tmp_path):
+        from ai_mouse.config import BalabitAdapterConfig
+        from ai_mouse.data_adapters.balabit import process_session
+
+        out = tmp_path / "out.jsonl"
+        out.write_text('{"meta":{"start":[0,0],"end":[1,1]},"events":[]}\n', encoding="utf-8")
+
+        csv_path = tmp_path / "session_x"
+        rows = [f"0,{i*0.05:.3f},NoButton,Move,{100+i*40},100" for i in range(10)]
+        rows.append("0,0.550,Left,Pressed,510,100")
+        _write_csv(csv_path, rows)
+
+        config = BalabitAdapterConfig()
+        process_session(csv_path, out, config)
+
+        lines = out.read_text(encoding="utf-8").strip().split("\n")
+        assert len(lines) == 2  # original + appended