"""Collector packets preserve whole sweeps, source windows and pair identity."""

import struct
import unittest

import numpy as np

from python_app.hardware_full.rph_radar.protocol import RphRadarStreamParser


def packet(*, source_id=1, cycle_id=1, start=100, end=200, combo=(1, 2), dirty=0, points=None):
    if points is None:
        points = [(0xA, 1, 10, -1), (0xA8, 1, 100, 5)]
    payload = b"".join(struct.pack("<HHhh", *point) for point in points)
    return struct.pack("<4sIQQQQHHI", b"RPH1", len(payload), source_id, cycle_id,
                       start, end, *combo, dirty) + payload


class RphRadarStreamParserTest(unittest.TestCase):
    def test_fragmented_packets_keep_source_window_and_identity(self):
        parser = RphRadarStreamParser()
        sweeps = []
        for byte in b"preroll" + packet(source_id=73, cycle_id=9):
            sweeps.extend(parser.feed(bytes([byte])))
        self.assertEqual(len(sweeps), 1)
        sweep = sweeps[0]
        self.assertEqual((sweep.source_id, sweep.cycle_id, sweep.capture_start_ns, sweep.capture_end_ns),
                         (73, 9, 100, 200))
        self.assertEqual(sweep.combo, (1, 2))
        self.assertEqual(sweep.main.tolist(), [10-1j])
        self.assertEqual(sweep.reference.tolist(), [100+5j])
        self.assertEqual(sweep.main.dtype, np.complex64)

    def test_whole_packet_loss_does_not_merge_pairs(self):
        parser = RphRadarStreamParser()
        first, last = parser.feed(packet(source_id=1) + packet(source_id=3, combo=(2, 3),
            points=[(0xA, 2, 20, 0), (0xA8, 2, 200, 0)]))
        self.assertEqual((first.combo, first.steps.tolist()), ((1, 2), [1]))
        self.assertEqual((last.combo, last.steps.tolist()), ((2, 3), [2]))
        self.assertEqual(last.source_id, 3)

    def test_aligns_both_channels_and_keeps_only_shared_steps(self):
        parser = RphRadarStreamParser()
        (sweep,) = parser.feed(packet(points=[(0xA, 3, 3, 0), (0xA8, 3, 30, 0),
            (0xA, 1, 1, 0), (0xA8, 1, 10, 0), (0xA, 2, 2, 0)]))
        self.assertEqual(sweep.steps.tolist(), [1, 3])
        self.assertEqual(sweep.main.real.tolist(), [1, 3])
        self.assertEqual(sweep.reference.real.tolist(), [10, 30])

    def test_bad_window_size_flags_and_point_marker_fail_fast(self):
        for encoded in (packet(start=0), packet(start=200, end=100), packet(dirty=2),
                        packet(source_id=0), packet(cycle_id=0),
                        packet(points=[(0x1A, 1, 1, 1)]),
                        b"RPH1" + struct.pack("<I", 0xFFFFFFFF) + bytes(40)):
            with self.subTest(encoded=encoded), self.assertRaisesRegex(ValueError, "protocol"):
                RphRadarStreamParser().feed(encoded)

    def test_reset_discards_partial_packet(self):
        parser = RphRadarStreamParser()
        self.assertEqual(parser.feed(packet()[:53]), [])
        parser.reset()
        (sweep,) = parser.feed(packet(source_id=2, dirty=1, combo=(65535, 65535)))
        self.assertEqual(sweep.source_id, 2)
        self.assertIsNone(sweep.combo)
        self.assertTrue(sweep.dirty)


if __name__ == "__main__":
    unittest.main()