from __future__ import annotations

from pathlib import Path

import pytest

from yovision_brain.config import parse_input_config
from yovision_brain.input import CancellationToken, InputError, LocalFileInput, SyntheticInput, build_input_source


def synthetic_config(seed: int = 9, frame_count: int = 3):
    return parse_input_config(
        {
            "schema": "brain.internal.input/v1",
            "logical_device_id": "camera-lab-01",
            "profile": {"id": "main", "width": 3, "height": 2, "fps": 4},
            "source": {"kind": "synthetic", "seed": seed, "frame_count": frame_count},
        }
    )


def local_config(path: Path, *, chunk_size: int = 4):
    return parse_input_config(
        {
            "schema": "brain.internal.input/v1",
            "logical_device_id": "local-video-01",
            "profile": {"id": "archive", "width": 1920, "height": 1080, "fps": 25},
            "source": {"kind": "local_file", "path": str(path), "chunk_size": chunk_size},
        }
    )


def test_synthetic_input_is_deterministic_and_carries_metadata() -> None:
    first = list(SyntheticInput(synthetic_config()).packets())
    second = list(build_input_source(synthetic_config()).packets())
    different = list(SyntheticInput(synthetic_config(seed=10)).packets())

    assert first == second
    assert [packet.sequence for packet in first] == [0, 1, 2]
    assert [packet.timestamp_ns for packet in first] == [0, 250_000_000, 500_000_000]
    assert first[0].logical_device_id == "camera-lab-01"
    assert first[0].profile_id == "main"
    assert first[0].media_format == "rgb24"
    assert len(first[0].payload) == 3 * 2 * 3
    assert first[0].payload != different[0].payload


def test_synthetic_input_honors_cancellation() -> None:
    token = CancellationToken()
    packets = SyntheticInput(synthetic_config(frame_count=10)).packets(token)
    assert next(packets).sequence == 0
    token.cancel()
    assert list(packets) == []


def test_local_file_input_reads_chunks_and_finishes_at_eof(tmp_path: Path) -> None:
    video = tmp_path / "anonymous-fixture.bin"
    video.write_bytes(b"abcdefghij")
    source = LocalFileInput(local_config(video))
    packets = list(source.packets())

    assert source.source_label == "anonymous-fixture.bin"
    assert [packet.payload for packet in packets] == [b"abcd", b"efgh", b"ij"]
    assert [packet.sequence for packet in packets] == [0, 1, 2]
    assert all(packet.timestamp_ns is None for packet in packets)
    assert all(packet.media_format == "container-bytes" for packet in packets)


def test_local_file_input_honors_cancellation(tmp_path: Path) -> None:
    video = tmp_path / "anonymous-fixture.bin"
    video.write_bytes(b"abcdefghij")
    token = CancellationToken()
    packets = LocalFileInput(local_config(video)).packets(token)
    assert next(packets).payload == b"abcd"
    token.cancel()
    assert list(packets) == []


def test_missing_file_error_is_actionable_without_absolute_path(tmp_path: Path) -> None:
    missing = tmp_path / "missing-video.mp4"
    with pytest.raises(InputError, match="local video source not found: missing-video.mp4") as caught:
        list(LocalFileInput(local_config(missing)).packets())
    assert str(tmp_path) not in str(caught.value)