"""TDD — HttpTransport.push_mpack_presign: client-side Step 1 of the mpack push protocol.

PP-1  Happy path: POST returns {upload_url, mpack_key} — both echoed back correctly.
PP-2  The POST body contains mpack_key == blob_id(mpack_bytes) and correct size_bytes.
PP-3  The POST is sent to /{owner}/{slug}/push/mpack-presign.
PP-4  Non-200 response raises TransportError.
PP-5  Response missing upload_url raises TransportError.
"""
from __future__ import annotations

from unittest.mock import patch

import msgpack
import pytest

from muse.core.transport import HttpTransport, TransportError
from muse.core.types import blob_id

_URL = "https://staging.musehub.ai/gabriel/muse"
_UPLOAD_URL = "https://minio.example.com/mpacks/sha256:abc?sig=fake"


def _presign_response(mpack_key: str, upload_url: str = _UPLOAD_URL) -> bytes:
    return msgpack.packb(
        {"upload_url": upload_url, "mpack_key": mpack_key},
        use_bin_type=True,
    )


def _mock_urllib_do(body: bytes, status: int = 200) -> "Callable[..., bytes]":
    calls: list[tuple[str, str, dict, bytes | None]] = []

    def _side_effect(method: str, url: str, headers: "dict[str, str]", data: "bytes | None" = None, **kwargs: "str | int | bool") -> bytes:
        calls.append((method, url, headers, data))
        if status >= 400:
            raise TransportError(f"HTTP {status}", status)
        return body

    _side_effect.calls = calls
    return _side_effect


# ── PP-1 ──────────────────────────────────────────────────────────────────────

def test_pp1_happy_path_returns_upload_url_and_mpack_key() -> None:
    mpack_bytes = b"fake mpack content"
    mpack_key = blob_id(mpack_bytes)
    do = _mock_urllib_do(_presign_response(mpack_key))

    with patch("muse.core.transport._urllib_do", side_effect=do):
        result = HttpTransport().push_mpack_presign(_URL, None, mpack_bytes)

    assert result["upload_url"] == _UPLOAD_URL
    assert result["mpack_key"] == mpack_key


# ── PP-2 ──────────────────────────────────────────────────────────────────────

def test_pp2_post_body_contains_correct_key_and_size() -> None:
    mpack_bytes = b"x" * 512
    mpack_key = blob_id(mpack_bytes)
    do = _mock_urllib_do(_presign_response(mpack_key))

    with patch("muse.core.transport._urllib_do", side_effect=do):
        HttpTransport().push_mpack_presign(_URL, None, mpack_bytes)

    _, _, _, sent_data = do.calls[0]
    payload = msgpack.unpackb(sent_data, raw=False)
    assert payload["mpack_key"] == mpack_key
    assert payload["size_bytes"] == 512


# ── PP-3 ──────────────────────────────────────────────────────────────────────

def test_pp3_posts_to_correct_endpoint() -> None:
    mpack_bytes = b"data"
    mpack_key = blob_id(mpack_bytes)
    do = _mock_urllib_do(_presign_response(mpack_key))

    with patch("muse.core.transport._urllib_do", side_effect=do):
        HttpTransport().push_mpack_presign(_URL, None, mpack_bytes)

    _, url, _, _ = do.calls[0]
    assert url.endswith("/push/mpack-presign")


# ── PP-4 ──────────────────────────────────────────────────────────────────────

def test_pp4_non_200_raises_transport_error() -> None:
    do = _mock_urllib_do(b"quota exceeded", status=429)

    with patch("muse.core.transport._urllib_do", side_effect=do):
        with pytest.raises(TransportError):
            HttpTransport().push_mpack_presign(_URL, None, b"bytes")


# ── PP-5 ──────────────────────────────────────────────────────────────────────

def test_pp5_missing_upload_url_raises_transport_error() -> None:
    mpack_bytes = b"data"
    mpack_key = blob_id(mpack_bytes)
    bad_resp = msgpack.packb({"mpack_key": mpack_key}, use_bin_type=True)
    do = _mock_urllib_do(bad_resp)

    with patch("muse.core.transport._urllib_do", side_effect=do):
        with pytest.raises(TransportError, match="upload_url"):
            HttpTransport().push_mpack_presign(_URL, None, mpack_bytes)