from __future__ import annotations

import hashlib
import json
import stat
import struct
from pathlib import Path

import lz4.block
import pytest
from typer.testing import CliRunner

from k1link.analyze.stream_summary import summarize_mqtt_streams
from k1link.cli import app
from k1link.mqtt.capture import FRAME_HEADER, RAW_MAGIC, CaptureFormatError

runner = CliRunner()


def _varint(value: int) -> bytes:
    encoded = bytearray()
    while value > 0x7F:
        encoded.append((value & 0x7F) | 0x80)
        value >>= 7
    encoded.append(value)
    return bytes(encoded)


def _key(number: int, wire_type: int) -> bytes:
    return _varint((number << 3) | wire_type)


def _uint(number: int, value: int) -> bytes:
    return _key(number, 0) + _varint(value)


def _sint(number: int, value: int) -> bytes:
    zigzag = (value << 1) ^ (value >> 63)
    return _uint(number, zigzag & 0xFFFFFFFFFFFFFFFF)


def _bytes(number: int, value: bytes) -> bytes:
    return _key(number, 2) + _varint(len(value)) + value


def _fixed64(number: int, value: float) -> bytes:
    return _key(number, 1) + struct.pack("<d", value)


def _header(*, scaler: int) -> bytes:
    return b"".join(
        (
            _uint(1, 7),
            _sint(2, 123456),
            _sint(3, scaler),
            _bytes(4, b"device-super-secret"),
            _bytes(5, b"session-super-secret"),
            _bytes(6, b"openapi-super-secret"),
        )
    )


def _pcl_payload(*, scaler: int, point_count: int) -> bytes:
    points = []
    for index in range(point_count):
        point = (
            _sint(1, 1000 + index)
            + _sint(2, -2000 - index)
            + _sint(3, 500 + index)
            + _uint(4, index)
        )
        points.append(_bytes(2, point))
    report = _bytes(1, _header(scaler=scaler)) + b"".join(points)
    compressed = lz4.block.compress(report, store_size=False)
    return _uint(3, len(report)) + _bytes(4, compressed)


def _pose_payload(position_xyz: tuple[float, float, float]) -> bytes:
    position = b"".join(
        _fixed64(field_number, value) for field_number, value in enumerate(position_xyz, start=1)
    )
    orientation = _fixed64(1, 0.0) + _fixed64(2, 0.0) + _fixed64(3, 0.0) + _fixed64(4, 1.0)
    pose = _bytes(1, position) + _bytes(2, orientation)
    stamped = _sint(1, 987654321) + _bytes(2, pose)
    return _bytes(1, _header(scaler=1000)) + _bytes(2, stamped)


def _write_capture(path: Path, frames: list[tuple[str, bytes]]) -> bytes:
    raw = bytearray(RAW_MAGIC)
    for topic, payload in frames:
        topic_bytes = topic.encode()
        raw.extend(FRAME_HEADER.pack(len(topic_bytes), len(payload)))
        raw.extend(topic_bytes)
        raw.extend(payload)
    value = bytes(raw)
    path.write_bytes(value)
    return value


def test_summary_is_bounded_aggregate_only_and_hashes_capture(tmp_path: Path) -> None:
    frames = [
        ("lixel/application/report/lio_pcl", _pcl_payload(scaler=1000, point_count=2)),
        ("lixel/application/report/lio_pcl", _pcl_payload(scaler=2000, point_count=1)),
        ("lixel/application/report/lio_pcl", b"bad-protobuf"),
        ("lixel/application/report/lio_pose", _pose_payload((1.0, 2.0, 3.0))),
        ("lixel/application/report/lio_pose", _pose_payload((4.0, 6.0, 3.0))),
        ("lixel/application/report/lio_pose", b"bad-protobuf"),
        ("device-super-secret/session-super-secret", b"openapi-super-secret"),
    ]
    capture = tmp_path / "mqtt.raw.k1mqtt"
    raw = _write_capture(capture, frames)

    summary = summarize_mqtt_streams(capture)

    assert summary["source"] == {
        "bytes": len(raw),
        "sha256": hashlib.sha256(raw).hexdigest(),
    }
    assert summary["frames"] == {
        "count": 7,
        "payload_bytes": sum(len(payload) for _, payload in frames),
        "encoded_frame_bytes": len(raw) - len(RAW_MAGIC),
        "other_count": 1,
        "other_payload_bytes": len(b"openapi-super-secret"),
    }
    assert summary["decoding"] == {"attempted": 6, "successes": 4, "errors": 2}
    assert summary["point_cloud"]["frame_count"] == 3
    assert summary["point_cloud"]["decode_successes"] == 2
    assert summary["point_cloud"]["decode_errors"] == 1
    assert summary["point_cloud"]["points"] == {
        "total": 3,
        "per_frame": {"min": 1, "max": 2},
    }
    assert summary["point_cloud"]["scalers"] == {
        "min": 1000,
        "max": 2000,
        "constant": False,
    }
    assert summary["pose"]["frame_count"] == 3
    assert summary["pose"]["decode_successes"] == 2
    assert summary["pose"]["decode_errors"] == 1
    assert summary["pose"]["first_to_last_displacement_meters"] == 5.0

    serialized = json.dumps(summary)
    for secret in (
        "device-super-secret",
        "session-super-secret",
        "openapi-super-secret",
        "bad-protobuf",
    ):
        assert secret not in serialized
    assert "position_xyz" not in serialized
    assert "points" in summary["point_cloud"]


def test_summary_rejects_a_frame_above_the_operator_limit(tmp_path: Path) -> None:
    capture = tmp_path / "mqtt.raw.k1mqtt"
    _write_capture(capture, [("other", b"12345")])

    with pytest.raises(CaptureFormatError, match="exceeds 4"):
        summarize_mqtt_streams(capture, max_payload_bytes=4)


def test_mqtt_streams_cli_writes_atomic_private_summary(tmp_path: Path) -> None:
    capture = tmp_path / "mqtt.raw.k1mqtt"
    raw = _write_capture(capture, [])
    out = tmp_path / "captures" / "summary.json"

    result = runner.invoke(
        app,
        [
            "analyze",
            "mqtt-streams",
            "--capture",
            str(capture),
            "--out",
            str(out),
            "--max-payload-bytes",
            "1024",
        ],
    )

    assert result.exit_code == 0
    saved = json.loads(out.read_text())
    assert saved["source"]["sha256"] == hashlib.sha256(raw).hexdigest()
    assert saved["limits"]["max_payload_bytes"] == 1024
    assert saved["frames"]["count"] == 0
    assert "aggregate-only" in result.stdout
    assert stat.S_IMODE(out.stat().st_mode) == 0o600