"""TDD — Phase 4: fetch_mpack wired into clone and pull commands (issue #47).

All clone and pull paths must call transport.fetch_mpack exclusively.

Tests:
  CW0  clone (depth=None) calls fetch_mpack.
  CW1  clone --depth 1 also calls fetch_mpack.
  CW2  pull calls fetch_mpack.
"""
from __future__ import annotations

import argparse
import contextlib
import pathlib
from typing import TYPE_CHECKING, Callable
from unittest.mock import MagicMock, patch

import pytest

from muse.core.types import blob_id, fake_id

if TYPE_CHECKING:
    from muse.core.transport import SigningIdentity

_FetchResult = dict[str, str | list[str] | int]  # transport fetch response
_KwVal = str | int | bool | None

# ── helpers ───────────────────────────────────────────────────────────────────

_COMMIT_ID = fake_id("commit-1")
_SNAP_ID = fake_id("snap-1")
_REPO_ID = fake_id("repo-1")

_FETCH_RESULT = {
    "repo_id": _REPO_ID,
    "domain": "code",
    "default_branch": "main",
    "branch_heads": {"main": _COMMIT_ID},
    "commits": [],
    "snapshots": [],
    "blobs_received": 0,
    "shallow_commits": [],
}

_APPLY_RESULT = {
    "commits_written": 1,
    "snapshots_written": 1,
    "blobs_written": 0,
    "blobs_skipped": 0,
}

_REMOTE_INFO = {
    "repo_id": _REPO_ID,
    "domain": "code",
    "default_branch": "main",
    "branch_heads": {"main": _COMMIT_ID},
    "object_count": 1,
    "size_bytes": 100,
}


def _make_transport() -> MagicMock:
    """Transport mock: fetch_mpack returns _FETCH_RESULT."""
    t = MagicMock()
    t.fetch_remote_info.return_value = _REMOTE_INFO
    t.fetch_mpack.return_value = _FETCH_RESULT
    return t


def _clone_patches(t: MagicMock) -> list[contextlib.AbstractContextManager[MagicMock]]:
    return [
        patch("muse.cli.commands.clone.get_signing_identity", return_value=None),
        patch("muse.cli.commands.clone.make_transport", return_value=t),
        patch("muse.cli.commands.clone.apply_mpack", return_value=_APPLY_RESULT),
        patch("muse.cli.commands.clone.set_remote"),
        patch("muse.cli.commands.clone.set_remote_head"),
        patch("muse.cli.commands.clone.set_upstream"),
        patch("muse.cli.commands.clone.apply_manifest"),
        patch("muse.cli.commands.clone.read_commit", return_value=MagicMock(snapshot_id=_SNAP_ID)),
        patch("muse.cli.commands.clone.read_snapshot", return_value=MagicMock(manifest={})),
    ]


# ══════════════════════════════════════════════════════════════════════════════
# CW0 — clone (depth=None) calls fetch_mpack
# ══════════════════════════════════════════════════════════════════════════════

def test_cw0_clone_full_calls_fetch_mpack(tmp_path: pathlib.Path) -> None:
    """Full clone (no --depth) must call transport.fetch_mpack, not fetch_presign_or_stream."""
    from muse.cli.commands.clone import run

    t = _make_transport()
    args = argparse.Namespace(
        url="https://hub.example.com/gabriel/repo",
        directory=str(tmp_path / "cloned"),
        branch=None,
        depth=None,
        dry_run=False,
        no_checkout=False,
        json_out=False,
    )

    patches = _clone_patches(t)
    with patches[0], patches[1], patches[2], patches[3], patches[4], patches[5], patches[6], patches[7], patches[8]:
        run(args)

    t.fetch_mpack.assert_called_once()


# ══════════════════════════════════════════════════════════════════════════════
# CW1 — clone --depth 1 calls fetch_mpack (presign-only policy)
# ══════════════════════════════════════════════════════════════════════════════

def test_cw1_clone_shallow_calls_fetch_mpack(tmp_path: pathlib.Path) -> None:
    """--depth clone must call transport.fetch_mpack — presign-only policy, no stream path."""
    from muse.cli.commands.clone import run

    t = _make_transport()
    args = argparse.Namespace(
        url="https://hub.example.com/gabriel/repo",
        directory=str(tmp_path / "cloned"),
        branch=None,
        depth=1,
        dry_run=False,
        no_checkout=False,
        json_out=False,
    )

    patches = _clone_patches(t)
    with patches[0], patches[1], patches[2], patches[3], patches[4], patches[5], patches[6], patches[7], patches[8]:
        run(args)

    t.fetch_mpack.assert_called_once()


# ══════════════════════════════════════════════════════════════════════════════
# CW2 — pull calls fetch_mpack
# ══════════════════════════════════════════════════════════════════════════════

def test_cw2_pull_calls_fetch_mpack(tmp_path: pathlib.Path) -> None:
    """pull must call transport.fetch_mpack, not fetch_presign_or_stream."""
    import argparse
    from muse.cli.commands.pull import run

    def _fetch_mpack(
        url: str,
        signing: "SigningIdentity | None",
        *,
        want: str,
        have: list[str],
        on_object: Callable[[str, bytes], None] | None = None,
        **kw: _KwVal,
    ) -> _FetchResult:
        return _FETCH_RESULT

    t = MagicMock()
    t.fetch_remote_info.return_value = _REMOTE_INFO
    t.fetch_mpack.side_effect = _fetch_mpack

    args = argparse.Namespace(
        remote="origin",
        branch_flag=None,
        branch_pos=None,
        no_merge=False,
        ff_only=False,
        dry_run=False,
        message=None,
        json_out=False,
    )

    with (
        patch("muse.cli.commands.pull.require_repo", return_value=tmp_path),
        patch("muse.cli.commands.pull.get_remote", return_value="https://hub.example.com"),
        patch("muse.cli.commands.pull.get_signing_identity", return_value=None),
        patch("muse.cli.commands.pull.read_current_branch", return_value="main"),
        patch("muse.cli.commands.pull.get_upstream", return_value=None),
        patch("muse.cli.commands.pull.make_transport", return_value=t),
        patch("muse.cli.commands.pull.get_remote_head", return_value=None),  # not up-to-date
        patch("muse.cli.commands.pull.get_head_commit_id", return_value=None),
        patch("muse.cli.commands.pull.get_all_commits", return_value=[]),
        patch("muse.cli.commands.pull.apply_mpack", return_value=_APPLY_RESULT),
        patch("muse.cli.commands.pull.set_remote_head"),
        patch("muse.cli.commands.pull.apply_manifest"),
        patch("muse.cli.commands.pull.read_commit", return_value=MagicMock(snapshot_id=_SNAP_ID)),
        patch("muse.cli.commands.pull.read_snapshot", return_value=MagicMock(manifest={})),
    ):
        try:
            run(args)
        except SystemExit:
            pass  # exit after pull is OK — we only care which transport method was called

    t.fetch_mpack.assert_called_once()