"""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 RfgSweepAssembler, 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)


def rfg_datagram(sweep_id, *steps, values=(3, 1, 5, 4, 2, 6), q_shift=27):
    """RFG SWEEP_AVG datagram; ``values`` are in units of 2**(q_shift - 7)."""
    return struct.pack("<HH", 6, q_shift) + b"".join(
        struct.pack("<I6i", (sweep_id << 24) | step, *[value << (q_shift - 7) for value in values]) for step in steps)


class RfgSweepAssemblerTest(unittest.TestCase):
    STEP_NS = 50_000
    PERIOD_NS = 20_000_000

    def feed(self, assembler, sweep_id, steps, start_ns, delay_ns=7_000):
        sweeps = []
        for step in steps:
            sweeps += assembler.feed(rfg_datagram(sweep_id, step), start_ns + (step + 1) * self.STEP_NS + delay_ns)
        return sweeps

    def test_complete_sweep_maps_sync_detector_and_reference_and_its_true_window(self):
        assembler = RfgSweepAssembler(steps=3, step_ns=self.STEP_NS, period_ns=self.PERIOD_NS)
        self.feed(assembler, 9, [0, 1, 2], 1_000_000_000)
        (sweep,) = assembler.feed(rfg_datagram(10, 0), 1_020_000_000)
        self.assertFalse(sweep.dirty)
        self.assertEqual(sweep.steps.tolist(), [0, 1, 2])
        np.testing.assert_allclose(sweep.main, [(3 - 1 + 1j * (4 - 2)) / 128] * 3)  # ch0 - ch1
        np.testing.assert_allclose(sweep.reference, [(5 + 6j) / 128] * 3)          # ch2
        self.assertEqual(sweep.capture_start_ns, 1_000_007_000)
        self.assertEqual(sweep.capture_end_ns - sweep.capture_start_ns, 3 * self.STEP_NS)

    def test_window_takes_the_least_delayed_point_when_the_board_batches(self):
        assembler = RfgSweepAssembler(steps=3, step_ns=self.STEP_NS, period_ns=self.PERIOD_NS)
        start = 2_000_000_000
        assembler.feed(rfg_datagram(1, 0, 1), start + 2 * self.STEP_NS + 10_000)  # steps 0-1 batched
        assembler.feed(rfg_datagram(1, 2), start + 3 * self.STEP_NS + 10_000)
        (sweep,) = assembler.feed(rfg_datagram(2, 0), start + 30_000_000)
        self.assertEqual(sweep.capture_start_ns, start + 10_000)

    def test_points_of_older_sweeps_are_ignored_until_the_id_space_could_have_wrapped(self):
        assembler = RfgSweepAssembler(steps=3, step_ns=self.STEP_NS, period_ns=self.PERIOD_NS)
        sweeps = []
        for sweep_id, start in ((1, 0), (3, 20_000_000), (2, 40_000_000), (4, 60_000_000), (3, 80_000_000)):
            sweeps += self.feed(assembler, sweep_id, [0, 1, 2], start)
        self.assertEqual([sweep.source_id for sweep in sweeps], [1, 2])  # late 2 and replayed 3 are dropped
        sweeps = self.feed(assembler, 2, [0, 1, 2], 80_000_000 + 128 * self.PERIOD_NS)  # 4 closes, 2 is new
        sweeps += self.feed(assembler, 3, [0], 100_000_000 + 128 * self.PERIOD_NS)
        self.assertEqual([(sweep.source_id, sweep.dirty) for sweep in sweeps], [(3, False), (4, False)])

    def test_reset_turns_the_rest_of_the_sweep_in_progress_dirty(self):
        assembler = RfgSweepAssembler(steps=3, step_ns=self.STEP_NS, period_ns=self.PERIOD_NS)
        self.feed(assembler, 4, [0], 0)
        assembler.reset()
        self.feed(assembler, 4, [1, 2], 0)
        (sweep,) = self.feed(assembler, 5, [0], 20_000_000)
        self.assertTrue(sweep.dirty)

    def test_partial_gapped_shortened_or_reordered_sweeps_are_dirty(self):
        for steps in ([1, 2], [0, 2], [0, 1], [0, 2, 1], [0, 1, 1, 2]):
            assembler = RfgSweepAssembler(steps=3, step_ns=self.STEP_NS, period_ns=self.PERIOD_NS)
            self.feed(assembler, 255, steps, 0)
            with self.subTest(steps=steps):
                (sweep,) = assembler.feed(rfg_datagram(0, 0), 10_000_000)  # 255 -> 0 wraps normally
                self.assertTrue(sweep.dirty)

    def test_a_reused_id_after_an_outage_does_not_splice_two_sweeps(self):
        assembler = RfgSweepAssembler(steps=3, step_ns=self.STEP_NS, period_ns=self.PERIOD_NS)
        self.feed(assembler, 5, [0], 0)
        self.feed(assembler, 5, [1, 2], 4_920_000_000)  # 256 sweep periods later
        (sweep,) = self.feed(assembler, 6, [0], 4_940_000_000)
        self.assertTrue(sweep.dirty)

    def test_unexpected_layout_fails_fast(self):
        for datagram in (b"\x06", struct.pack("<HH", 5, 27), struct.pack("<HH", 6, 31) + rfg_datagram(1, 0)[4:],
                         rfg_datagram(1, 0)[:-1]):
            with self.subTest(datagram=datagram), self.assertRaisesRegex(ValueError, "protocol"):
                RfgSweepAssembler(steps=3, step_ns=1, period_ns=1).feed(datagram, 1)


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