"""Tests for Balabit Mouse Dynamics Challenge data adapter."""
from __future__ import annotations

import json
from pathlib import Path

import pytest


def test_module_exports():
    """The adapter module must export the public functions used by CLI."""
    from tools.data_adapters import balabit
    assert hasattr(balabit, "parse_session_csv")
    assert hasattr(balabit, "segment_by_clicks")
    assert hasattr(balabit, "filter_segments")
    assert hasattr(balabit, "process_session")
    assert hasattr(balabit, "MouseEvent")
    assert hasattr(balabit, "Segment")


def test_mouse_event_dataclass():
    """MouseEvent has expected fields."""
    from tools.data_adapters.balabit import MouseEvent
    e = MouseEvent(t_ms=100, button="NoButton", state="Move", x=300, y=400)
    assert e.t_ms == 100
    assert e.state == "Move"
    assert e.x == 300


def test_segment_dataclass():
    """Segment has expected fields."""
    from tools.data_adapters.balabit import MouseEvent, Segment
    events = [MouseEvent(t_ms=0, button="NoButton", state="Move", x=10, y=20)]
    s = Segment(events=events, click_x=100, click_y=200, click_t_ms=500, session_id="user1_s1")
    assert s.events == events
    assert s.click_x == 100
    assert s.session_id == "user1_s1"


def _write_csv(path: Path, rows: list[str]) -> None:
    """Helper to write a Balabit-format CSV with header."""
    header = "record timestamp,client timestamp,button,state,x,y"
    path.write_text(header + "\n" + "\n".join(rows) + "\n", encoding="utf-8")


class TestParseSessionCsv:
    def test_parses_basic_rows(self, tmp_path):
        from tools.data_adapters.balabit import parse_session_csv
        csv = tmp_path / "session_1"
        _write_csv(csv, [
            "1500000000.000,0.000,NoButton,Move,100,200",
            "1500000000.050,0.050,NoButton,Move,110,210",
            "1500000000.100,0.100,Left,Pressed,120,220",
        ])
        events = parse_session_csv(csv)
        assert len(events) == 3
        assert events[0].t_ms == 0
        assert events[0].state == "Move"
        assert events[0].x == 100
        assert events[2].t_ms == 100
        assert events[2].state == "Pressed"
        assert events[2].button == "Left"

    def test_handles_float_timestamps(self, tmp_path):
        """Client timestamps are floats in seconds; we convert to int ms."""
        from tools.data_adapters.balabit import parse_session_csv
        csv = tmp_path / "session_2"
        _write_csv(csv, [
            "0,1.234,NoButton,Move,50,60",
            "0,1.250,NoButton,Move,55,65",
        ])
        events = parse_session_csv(csv)
        assert events[0].t_ms == 1234
        assert events[1].t_ms == 1250

    def test_skips_malformed_rows(self, tmp_path):
        """Rows with bad data are logged and skipped, not raised."""
        from tools.data_adapters.balabit import parse_session_csv
        csv = tmp_path / "session_3"
        _write_csv(csv, [
            "0,0.000,NoButton,Move,100,200",
            "BROKEN_ROW",
            "0,abc,NoButton,Move,100,200",   # bad timestamp
            "0,0.100,NoButton,Move,150,250",
        ])
        events = parse_session_csv(csv)
        assert len(events) == 2
        assert events[0].x == 100
        assert events[1].x == 150

    def test_returns_empty_list_for_empty_file(self, tmp_path):
        from tools.data_adapters.balabit import parse_session_csv
        csv = tmp_path / "session_4"
        csv.write_text("record timestamp,client timestamp,button,state,x,y\n", encoding="utf-8")
        events = parse_session_csv(csv)
        assert events == []


class TestSegmentByClicks:
    def _make_event(self, t_ms: int, state: str, x: int, y: int, button: str = "NoButton"):
        from tools.data_adapters.balabit import MouseEvent
        return MouseEvent(t_ms=t_ms, button=button, state=state, x=x, y=y)

    def test_one_click_one_segment(self):
        from tools.data_adapters.balabit import segment_by_clicks
        events = [
            self._make_event(0, "Move", 10, 20),
            self._make_event(100, "Move", 50, 60),
            self._make_event(500, "Move", 100, 100),
            self._make_event(600, "Pressed", 110, 110, button="Left"),
        ]
        segments = segment_by_clicks(events, window_ms=1200, session_id="test_s1")
        assert len(segments) == 1
        seg = segments[0]
        assert seg.click_x == 110
        assert seg.click_y == 110
        assert seg.click_t_ms == 600
        assert len(seg.events) == 3
        assert seg.session_id == "test_s1"

    def test_window_excludes_old_events(self):
        """Move events earlier than (click_t - window_ms) are dropped."""
        from tools.data_adapters.balabit import segment_by_clicks
        events = [
            self._make_event(0, "Move", 10, 20),       # too old
            self._make_event(100, "Move", 20, 30),     # too old
            self._make_event(900, "Move", 30, 40),     # in window
            self._make_event(1000, "Pressed", 40, 50, button="Left"),
        ]
        segments = segment_by_clicks(events, window_ms=200, session_id="s")
        assert len(segments) == 1
        assert len(segments[0].events) == 1
        assert segments[0].events[0].t_ms == 900

    def test_multiple_clicks_multiple_segments(self):
        from tools.data_adapters.balabit import segment_by_clicks
        events = [
            self._make_event(0, "Move", 10, 20),
            self._make_event(100, "Pressed", 50, 50, button="Left"),
            self._make_event(200, "Released", 50, 50, button="Left"),
            self._make_event(300, "Move", 60, 60),
            self._make_event(400, "Move", 70, 70),
            self._make_event(500, "Pressed", 80, 80, button="Left"),
        ]
        segments = segment_by_clicks(events, window_ms=1200, session_id="s")
        assert len(segments) == 2
        assert segments[0].click_x == 50
        assert segments[1].click_x == 80
        # Second segment's events must not include the first Pressed
        for e in segments[1].events:
            assert e.state == "Move"

    def test_skips_pressed_with_non_left_button(self):
        """Right-clicks and wheel-clicks don't anchor segments (only Left)."""
        from tools.data_adapters.balabit import segment_by_clicks
        events = [
            self._make_event(0, "Move", 10, 20),
            self._make_event(100, "Pressed", 50, 50, button="Right"),  # ignored
            self._make_event(200, "Move", 60, 60),
            self._make_event(300, "Pressed", 70, 70, button="Left"),   # anchor
        ]
        segments = segment_by_clicks(events, window_ms=1200, session_id="s")
        assert len(segments) == 1
        assert segments[0].click_x == 70

    def test_no_clicks_returns_empty(self):
        from tools.data_adapters.balabit import segment_by_clicks
        events = [
            self._make_event(0, "Move", 10, 20),
            self._make_event(100, "Move", 20, 30),
        ]
        segments = segment_by_clicks(events, window_ms=1200, session_id="s")
        assert segments == []

    def test_excludes_drag_events(self):
        """Drag events are not Move; segment should only include Move."""
        from tools.data_adapters.balabit import segment_by_clicks
        events = [
            self._make_event(0, "Move", 10, 20),
            self._make_event(100, "Drag", 30, 40),       # not Move
            self._make_event(200, "Move", 50, 60),
            self._make_event(300, "Pressed", 70, 80, button="Left"),
        ]
        segments = segment_by_clicks(events, window_ms=1200, session_id="s")
        assert len(segments) == 1
        # Drag event should not appear in seg.events
        assert all(e.state == "Move" for e in segments[0].events)
        assert len(segments[0].events) == 2


class TestFilterSegments:
    def _seg(self, events_data: list[tuple[int, int, int]], click=(500, 500), session="s"):
        """events_data: list of (t_ms, x, y) tuples."""
        from tools.data_adapters.balabit import MouseEvent, Segment
        events = [MouseEvent(t_ms=t, button="NoButton", state="Move", x=x, y=y)
                  for (t, x, y) in events_data]
        click_t = events[-1].t_ms + 50 if events else 100
        return Segment(events=events, click_x=click[0], click_y=click[1],
                       click_t_ms=click_t, session_id=session)

    def test_drops_segment_with_too_few_events(self):
        from tools.data_adapters.balabit import filter_segments
        seg = self._seg([(0, 100, 100), (50, 105, 105)])  # 2 events, min=5
        result = filter_segments([seg], min_events=5, min_dist=10,
                                  max_span_ms=5000, max_gap_ms=200)
        assert result == []

    def test_drops_segment_with_short_distance(self):
        from tools.data_adapters.balabit import filter_segments
        # Start (100,100), end click=(105,100) → dist=5, min_dist=50
        events = [(i*10, 100+i, 100) for i in range(10)]
        seg = self._seg(events, click=(105, 100))
        result = filter_segments([seg], min_events=5, min_dist=50,
                                  max_span_ms=5000, max_gap_ms=200)
        assert result == []

    def test_drops_segment_with_too_long_span(self):
        from tools.data_adapters.balabit import filter_segments
        # Span 6000ms, max_span=5000
        events = [(0, 100, 100), (2000, 200, 200), (4000, 300, 300), (6000, 400, 400),
                  (6010, 410, 400), (6020, 420, 400)]
        seg = self._seg(events, click=(500, 500))
        result = filter_segments([seg], min_events=5, min_dist=50,
                                  max_span_ms=5000, max_gap_ms=10000)
        assert result == []

    def test_drops_segment_with_gap(self):
        from tools.data_adapters.balabit import filter_segments
        # Gap of 500ms between events 2 and 3, max_gap=200
        events = [(0, 100, 100), (50, 110, 110), (100, 120, 120),
                  (600, 200, 200), (650, 210, 210), (700, 220, 220)]
        seg = self._seg(events, click=(300, 300))
        result = filter_segments([seg], min_events=5, min_dist=50,
                                  max_span_ms=5000, max_gap_ms=200)
        assert result == []

    def test_drops_segment_with_out_of_range_coords(self):
        from tools.data_adapters.balabit import filter_segments
        # x=10000 out of range
        events = [(i*10, 10000, 100) for i in range(6)]
        seg = self._seg(events, click=(10100, 100))
        result = filter_segments([seg], min_events=5, min_dist=50,
                                  max_span_ms=5000, max_gap_ms=200)
        assert result == []

    def test_drops_segment_with_short_arc_length(self):
        """Total arc < 50 even though endpoints are far → high-frequency jitter only."""
        from tools.data_adapters.balabit import filter_segments
        # Tiny back-and-forth with click 100px away — unrealistic, drop it
        events = [(i*10, 100 + (i % 2), 100) for i in range(10)]
        seg = self._seg(events, click=(200, 100))
        # arc length = sum of |Δp| ≈ 9 (alternating ±1) which is < 50
        result = filter_segments([seg], min_events=5, min_dist=50,
                                  max_span_ms=5000, max_gap_ms=200)
        assert result == []

    def test_keeps_valid_segment(self):
        from tools.data_adapters.balabit import filter_segments
        # Smooth 100→500 px straight line, 10 events, span 500ms
        events = [(i*50, 100 + i*40, 100) for i in range(10)]
        seg = self._seg(events, click=(500, 100))
        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 tools.config import BalabitAdapterConfig
        from tools.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 tools.config import BalabitAdapterConfig
        from tools.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 tools.config import BalabitAdapterConfig
        from tools.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