"""Tests for Muse Hub issue tracking endpoints.

Covers every acceptance criterion:
- POST /musehub/repos/{repo_id}/issues creates an issue in open state
- Issue numbers are sequential per repo starting at 1
- GET /musehub/repos/{repo_id}/issues returns open issues by default
- GET .../issues?label=<label> filters by label
- POST .../issues/{number}/close sets state to closed
- GET .../issues/{number} returns 404 for unknown issue numbers
- All endpoints require valid JWT

All tests use the shared ``client``, ``auth_headers``, and ``db_session``
fixtures from conftest.py.
"""
from __future__ import annotations

import pytest
from httpx import AsyncClient
from sqlalchemy.ext.asyncio import AsyncSession

from musehub.services import musehub_repository, musehub_issues


# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------


async def _create_repo(client: AsyncClient, auth_headers: dict[str, str], name: str = "test-repo") -> str:
    """Create a repo via the API and return its repo_id."""
    response = await client.post(
        "/api/v1/musehub/repos",
        json={"name": name, "owner": "testuser"},
        headers=auth_headers,
    )
    assert response.status_code == 201
    repo_id: str = response.json()["repoId"]
    return repo_id


async def _create_issue(
    client: AsyncClient,
    auth_headers: dict[str, str],
    repo_id: str,
    title: str = "Kick clashes with bass in measure 4",
    body: str = "",
    labels: list[str] | None = None,
) -> dict[str, object]:
    response = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues",
        json={"title": title, "body": body, "labels": labels or []},
        headers=auth_headers,
    )
    assert response.status_code == 201
    issue: dict[str, object] = response.json()
    return issue


# ---------------------------------------------------------------------------
# POST /musehub/repos/{repo_id}/issues
# ---------------------------------------------------------------------------


@pytest.mark.anyio
async def test_create_issue_returns_open_state(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """POST /issues creates an issue in 'open' state with all required fields."""
    repo_id = await _create_repo(client, auth_headers, "open-state-repo")
    response = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues",
        json={"title": "Hi-hat / synth pad clash", "body": "Measure 8 has a frequency clash.", "labels": ["bug"]},
        headers=auth_headers,
    )
    assert response.status_code == 201
    body = response.json()
    assert body["state"] == "open"
    assert body["title"] == "Hi-hat / synth pad clash"
    assert body["labels"] == ["bug"]
    assert "issueId" in body
    assert "number" in body
    assert "createdAt" in body


@pytest.mark.anyio
async def test_issue_numbers_sequential(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """Issue numbers within a repo are sequential starting at 1."""
    repo_id = await _create_repo(client, auth_headers, "seq-repo")

    first = await _create_issue(client, auth_headers, repo_id, title="First issue")
    second = await _create_issue(client, auth_headers, repo_id, title="Second issue")
    third = await _create_issue(client, auth_headers, repo_id, title="Third issue")

    assert first["number"] == 1
    assert second["number"] == 2
    assert third["number"] == 3


@pytest.mark.anyio
async def test_issue_numbers_independent_per_repo(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """Issue numbers restart at 1 for each repo independently."""
    repo_a = await _create_repo(client, auth_headers, "repo-a")
    repo_b = await _create_repo(client, auth_headers, "repo-b")

    issue_a = await _create_issue(client, auth_headers, repo_a, title="Repo A issue")
    issue_b = await _create_issue(client, auth_headers, repo_b, title="Repo B issue")

    assert issue_a["number"] == 1
    assert issue_b["number"] == 1


# ---------------------------------------------------------------------------
# GET /musehub/repos/{repo_id}/issues
# ---------------------------------------------------------------------------


@pytest.mark.anyio
async def test_list_issues_default_open_only(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """GET /issues with no params returns only open issues."""
    repo_id = await _create_repo(client, auth_headers, "default-open-repo")
    await _create_issue(client, auth_headers, repo_id, title="Open issue")

    # Create a second issue and close it
    issue = await _create_issue(client, auth_headers, repo_id, title="Closed issue")
    await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}/close",
        headers=auth_headers,
    )

    response = await client.get(
        f"/api/v1/musehub/repos/{repo_id}/issues",
        headers=auth_headers,
    )
    assert response.status_code == 200
    issues = response.json()["issues"]
    assert len(issues) == 1
    assert issues[0]["state"] == "open"


@pytest.mark.anyio
async def test_list_issues_state_all_returns_all(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """?state=all returns both open and closed issues."""
    repo_id = await _create_repo(client, auth_headers, "state-all-repo")
    await _create_issue(client, auth_headers, repo_id, title="Open issue")
    issue = await _create_issue(client, auth_headers, repo_id, title="To close")
    await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}/close",
        headers=auth_headers,
    )

    response = await client.get(
        f"/api/v1/musehub/repos/{repo_id}/issues?state=all",
        headers=auth_headers,
    )
    assert response.status_code == 200
    assert len(response.json()["issues"]) == 2


@pytest.mark.anyio
async def test_list_issues_label_filter(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """GET /issues?label=bug returns only issues that have the 'bug' label."""
    repo_id = await _create_repo(client, auth_headers, "label-filter-repo")
    await _create_issue(client, auth_headers, repo_id, title="Bug issue", labels=["bug"])
    await _create_issue(client, auth_headers, repo_id, title="Feature issue", labels=["feature"])
    await _create_issue(client, auth_headers, repo_id, title="Multi-label", labels=["bug", "musical"])

    response = await client.get(
        f"/api/v1/musehub/repos/{repo_id}/issues?label=bug",
        headers=auth_headers,
    )
    assert response.status_code == 200
    issues = response.json()["issues"]
    assert len(issues) == 2
    for issue in issues:
        assert "bug" in issue["labels"]


# ---------------------------------------------------------------------------
# GET /musehub/repos/{repo_id}/issues/{issue_number}
# ---------------------------------------------------------------------------


@pytest.mark.anyio
async def test_get_issue_not_found_returns_404(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """GET /issues/{number} returns 404 for a number that doesn't exist."""
    repo_id = await _create_repo(client, auth_headers, "not-found-repo")

    response = await client.get(
        f"/api/v1/musehub/repos/{repo_id}/issues/999",
        headers=auth_headers,
    )
    assert response.status_code == 404


@pytest.mark.anyio
async def test_get_issue_returns_full_object(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """GET /issues/{number} returns the full issue object."""
    repo_id = await _create_repo(client, auth_headers, "get-issue-repo")
    created = await _create_issue(
        client, auth_headers, repo_id,
        title="Delay tail bleeds into next section",
        body="The reverb tail from the bridge extends 200ms into the verse.",
        labels=["musical", "mix"],
    )

    response = await client.get(
        f"/api/v1/musehub/repos/{repo_id}/issues/{created['number']}",
        headers=auth_headers,
    )
    assert response.status_code == 200
    body = response.json()
    assert body["issueId"] == created["issueId"]
    assert body["title"] == "Delay tail bleeds into next section"
    assert body["body"] == "The reverb tail from the bridge extends 200ms into the verse."
    assert body["labels"] == ["musical", "mix"]


# ---------------------------------------------------------------------------
# POST /musehub/repos/{repo_id}/issues/{issue_number}/close
# ---------------------------------------------------------------------------


@pytest.mark.anyio
async def test_close_issue_changes_state(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """POST /issues/{number}/close sets the issue state to 'closed'."""
    repo_id = await _create_repo(client, auth_headers, "close-state-repo")
    issue = await _create_issue(client, auth_headers, repo_id, title="Clipping at measure 12")
    assert issue["state"] == "open"

    response = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}/close",
        headers=auth_headers,
    )
    assert response.status_code == 200
    assert response.json()["state"] == "closed"


@pytest.mark.anyio
async def test_close_nonexistent_issue_returns_404(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """POST /issues/999/close returns 404 for an unknown issue number."""
    repo_id = await _create_repo(client, auth_headers, "close-404-repo")

    response = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/999/close",
        headers=auth_headers,
    )
    assert response.status_code == 404


# ---------------------------------------------------------------------------
# Auth guard
# ---------------------------------------------------------------------------


@pytest.mark.anyio
async def test_issue_write_endpoints_require_auth(client: AsyncClient) -> None:
    """POST issue endpoints return 401 without a Bearer token (always require auth)."""
    write_endpoints = [
        ("POST", "/api/v1/musehub/repos/some-repo/issues"),
        ("POST", "/api/v1/musehub/repos/some-repo/issues/1/close"),
    ]
    for method, url in write_endpoints:
        response = await client.post(url, json={})
        assert response.status_code == 401, f"{method} {url} should require auth"


@pytest.mark.anyio
async def test_issue_read_endpoints_return_404_for_nonexistent_repo_without_auth(
    client: AsyncClient,
) -> None:
    """GET issue endpoints return 404 for non-existent repos without a token.

    Read endpoints use optional_token — auth is visibility-based; the DB
    lookup happens before the auth check, so a missing repo returns 404.
    """
    read_endpoints = [
        "/api/v1/musehub/repos/non-existent-repo/issues",
        "/api/v1/musehub/repos/non-existent-repo/issues/1",
    ]
    for url in read_endpoints:
        response = await client.get(url)
        assert response.status_code == 404, f"GET {url} should return 404 for non-existent repo"


# ---------------------------------------------------------------------------
# Service layer — direct DB tests (no HTTP)
# ---------------------------------------------------------------------------


@pytest.mark.anyio
async def test_create_issue_service_persists_to_db(db_session: AsyncSession) -> None:
    """musehub_issues.create_issue() persists the row and returns correct fields."""
    repo = await musehub_repository.create_repo(
        db_session,
        name="service-issue-repo",
        owner="testuser",
        visibility="private",
        owner_user_id="user-abc",
    )
    await db_session.commit()

    issue = await musehub_issues.create_issue(
        db_session,
        repo_id=repo.repo_id,
        title="Bass note timing drift",
        body="Measure 4, beat 3 — bass is 10ms late.",
        labels=["timing", "bass"],
    )
    await db_session.commit()

    fetched = await musehub_issues.get_issue(db_session, repo.repo_id, issue.number)
    assert fetched is not None
    assert fetched.title == "Bass note timing drift"
    assert fetched.state == "open"
    assert fetched.labels == ["timing", "bass"]
    assert fetched.number == 1


@pytest.mark.anyio
async def test_list_issues_closed_state_filter(db_session: AsyncSession) -> None:
    """list_issues() with state='closed' returns only closed issues."""
    repo = await musehub_repository.create_repo(
        db_session,
        name="filter-state-repo",
        owner="testuser",
        visibility="private",
        owner_user_id="user-xyz",
    )
    await db_session.commit()

    open_issue = await musehub_issues.create_issue(
        db_session, repo_id=repo.repo_id, title="Still open", body="", labels=[]
    )
    closed_issue = await musehub_issues.create_issue(
        db_session, repo_id=repo.repo_id, title="Already closed", body="", labels=[]
    )
    await musehub_issues.close_issue(db_session, repo.repo_id, closed_issue.number)
    await db_session.commit()

    open_list = await musehub_issues.list_issues(db_session, repo.repo_id, state="open")
    closed_list = await musehub_issues.list_issues(db_session, repo.repo_id, state="closed")
    all_list = await musehub_issues.list_issues(db_session, repo.repo_id, state="all")

    assert len(open_list) == 1
    assert open_list[0].issue_id == open_issue.issue_id
    assert len(closed_list) == 1
    assert closed_list[0].issue_id == closed_issue.issue_id
    assert len(all_list) == 2


# ---------------------------------------------------------------------------
# Regression tests — author field on Issue, PR, Release
# ---------------------------------------------------------------------------


@pytest.mark.anyio
async def test_create_issue_author_in_response(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """POST /issues response includes the author field (JWT sub) — regression f."""
    repo_id = await _create_repo(client, auth_headers, "author-issue-repo")
    response = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues",
        json={"title": "Author field regression", "body": "", "labels": []},
        headers=auth_headers,
    )
    assert response.status_code == 201
    body = response.json()
    assert "author" in body
    # The author is the JWT sub from the test token — must be a non-None string
    assert isinstance(body["author"], str)


@pytest.mark.anyio
async def test_create_issue_author_persisted_in_list(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """Author field is persisted and returned in the issue list endpoint — regression f."""
    repo_id = await _create_repo(client, auth_headers, "author-list-repo")
    await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues",
        json={"title": "Authored issue", "body": "", "labels": []},
        headers=auth_headers,
    )
    list_response = await client.get(
        f"/api/v1/musehub/repos/{repo_id}/issues",
        headers=auth_headers,
    )
    assert list_response.status_code == 200
    issues = list_response.json()["issues"]
    assert len(issues) == 1
    assert "author" in issues[0]
    assert isinstance(issues[0]["author"], str)


@pytest.mark.anyio
async def test_issue_detail_page_shows_author_label(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """issue_detail.html template contains the 'Author' meta-label — regression f."""
    repo_id = await _create_repo(client, auth_headers, "author-detail-beats")
    issue = await _create_issue(
        client,
        auth_headers,
        repo_id,
        title="Author label regression check",
    )
    number = issue["number"]

    response = await client.get(f"/musehub/ui/testuser/author-detail-beats/issues/{number}")
    assert response.status_code == 200
    body = response.text
    # The SSR template renders author inline: "Opened … by <strong>…</strong>"
    assert "by <strong>" in body


# ---------------------------------------------------------------------------
# Issue #218 — enhanced issue detail: comments, assignees, milestones
# ---------------------------------------------------------------------------


@pytest.mark.anyio
async def test_create_issue_comment(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """POST /issues/{number}/comments creates a comment with body and author."""
    repo_id = await _create_repo(client, auth_headers, "comment-repo-create")
    issue = await _create_issue(client, auth_headers, repo_id, title="Bass clash in chorus")

    response = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}/comments",
        json={"body": "The section:chorus beats:16-24 has a frequency clash with track:bass."},
        headers=auth_headers,
    )
    assert response.status_code == 201
    data = response.json()
    assert "comments" in data
    assert len(data["comments"]) == 1
    comment = data["comments"][0]
    assert comment["body"] == "The section:chorus beats:16-24 has a frequency clash with track:bass."
    assert isinstance(comment["author"], str)
    assert comment["parentId"] is None


@pytest.mark.anyio
async def test_list_issue_comments(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """GET /issues/{number}/comments returns comments chronologically."""
    repo_id = await _create_repo(client, auth_headers, "comment-repo-list")
    issue = await _create_issue(client, auth_headers, repo_id, title="Kick timing issue")

    await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}/comments",
        json={"body": "First comment."},
        headers=auth_headers,
    )
    await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}/comments",
        json={"body": "Second comment."},
        headers=auth_headers,
    )

    response = await client.get(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}/comments",
        headers=auth_headers,
    )
    assert response.status_code == 200
    data = response.json()
    assert data["total"] == 2
    assert data["comments"][0]["body"] == "First comment."
    assert data["comments"][1]["body"] == "Second comment."


@pytest.mark.anyio
async def test_musical_context_parsed(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """Musical context references (track:X, section:X, beats:X-Y) are parsed into musicalRefs."""
    repo_id = await _create_repo(client, auth_headers, "musical-ref-repo")
    issue = await _create_issue(client, auth_headers, repo_id, title="Musical context test")

    response = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}/comments",
        json={"body": "Check track:bass at section:chorus around beats:16-24 please."},
        headers=auth_headers,
    )
    assert response.status_code == 201
    comment = response.json()["comments"][0]
    refs = comment["musicalRefs"]
    assert len(refs) == 3
    ref_types = {r["type"]: r["value"] for r in refs}
    assert ref_types.get("track") == "bass"
    assert ref_types.get("section") == "chorus"
    assert ref_types.get("beats") == "16-24"


@pytest.mark.anyio
async def test_assign_issue(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """POST /issues/{number}/assign sets the assignee field."""
    repo_id = await _create_repo(client, auth_headers, "assignee-repo")
    issue = await _create_issue(client, auth_headers, repo_id, title="Assign test issue")

    response = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}/assign",
        json={"assignee": "miles_davis"},
        headers=auth_headers,
    )
    assert response.status_code == 200
    data = response.json()
    assert data["assignee"] == "miles_davis"


@pytest.mark.anyio
async def test_unassign_issue(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """POST /issues/{number}/assign with null assignee clears the field."""
    repo_id = await _create_repo(client, auth_headers, "unassign-repo")
    issue = await _create_issue(client, auth_headers, repo_id, title="Unassign test")

    await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}/assign",
        json={"assignee": "coltrane"},
        headers=auth_headers,
    )
    response = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}/assign",
        json={"assignee": None},
        headers=auth_headers,
    )
    assert response.status_code == 200
    assert response.json()["assignee"] is None


@pytest.mark.anyio
async def test_create_milestone(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """POST /milestones creates a milestone with title and sequential number."""
    repo_id = await _create_repo(client, auth_headers, "milestone-create-repo")

    response = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/milestones",
        json={"title": "Album v1.0", "description": "First release cut"},
        headers=auth_headers,
    )
    assert response.status_code == 201
    data = response.json()
    assert data["title"] == "Album v1.0"
    assert data["state"] == "open"
    assert data["number"] == 1
    assert data["openIssues"] == 0
    assert data["closedIssues"] == 0


@pytest.mark.anyio
async def test_assign_issue_to_milestone(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """POST /issues/{number}/milestone links the issue to a milestone."""
    repo_id = await _create_repo(client, auth_headers, "milestone-assign-repo")
    issue = await _create_issue(client, auth_headers, repo_id, title="Milestone target issue")

    ms_resp = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/milestones",
        json={"title": "Mix Revision 2"},
        headers=auth_headers,
    )
    milestone_id: str = ms_resp.json()["milestoneId"]

    response = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}/milestone",
        params={"milestone_id": milestone_id},
        headers=auth_headers,
    )
    assert response.status_code == 200
    data = response.json()
    assert data["milestoneId"] == milestone_id
    assert data["milestoneTitle"] == "Mix Revision 2"


@pytest.mark.anyio
async def test_reopen_issue(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """POST /issues/{number}/reopen transitions a closed issue back to open."""
    repo_id = await _create_repo(client, auth_headers, "reopen-repo")
    issue = await _create_issue(client, auth_headers, repo_id, title="Reopen test")
    number = issue["number"]

    await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/{number}/close",
        headers=auth_headers,
    )

    response = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/{number}/reopen",
        headers=auth_headers,
    )
    assert response.status_code == 200
    assert response.json()["state"] == "open"


@pytest.mark.anyio
async def test_threaded_comment_reply(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """POST /comments with parentId creates a threaded reply."""
    repo_id = await _create_repo(client, auth_headers, "thread-repo")
    issue = await _create_issue(client, auth_headers, repo_id, title="Threading test")
    number = issue["number"]

    first_resp = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/{number}/comments",
        json={"body": "Top-level comment."},
        headers=auth_headers,
    )
    parent_id = first_resp.json()["comments"][0]["commentId"]

    reply_resp = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/{number}/comments",
        json={"body": "Reply to the top-level.", "parentId": parent_id},
        headers=auth_headers,
    )
    assert reply_resp.status_code == 201
    comments = reply_resp.json()["comments"]
    replies = [c for c in comments if c["parentId"] == parent_id]
    assert len(replies) == 1
    assert replies[0]["body"] == "Reply to the top-level."


@pytest.mark.anyio
async def test_issue_comment_count_in_response(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """GET /issues/{number} returns commentCount reflecting current non-deleted comments."""
    repo_id = await _create_repo(client, auth_headers, "comment-count-repo")
    issue = await _create_issue(client, auth_headers, repo_id, title="Count test")
    number = issue["number"]

    await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/{number}/comments",
        json={"body": "Comment one."},
        headers=auth_headers,
    )
    await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/{number}/comments",
        json={"body": "Comment two."},
        headers=auth_headers,
    )

    response = await client.get(
        f"/api/v1/musehub/repos/{repo_id}/issues/{number}",
        headers=auth_headers,
    )
    assert response.status_code == 200
    assert response.json()["commentCount"] == 2


@pytest.mark.anyio
async def test_edit_issue_title_and_body(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """PATCH /issues/{number} updates title and body."""
    repo_id = await _create_repo(client, auth_headers, "edit-issue-repo")
    issue = await _create_issue(client, auth_headers, repo_id, title="Original title")

    response = await client.patch(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}",
        json={"title": "Updated title", "body": "Updated body."},
        headers=auth_headers,
    )
    assert response.status_code == 200
    data = response.json()
    assert data["title"] == "Updated title"
    assert data["body"] == "Updated body."


@pytest.mark.anyio
async def test_list_milestones(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """GET /milestones returns all open milestones."""
    repo_id = await _create_repo(client, auth_headers, "milestone-list-repo")

    await client.post(
        f"/api/v1/musehub/repos/{repo_id}/milestones",
        json={"title": "Phase 1"},
        headers=auth_headers,
    )
    await client.post(
        f"/api/v1/musehub/repos/{repo_id}/milestones",
        json={"title": "Phase 2"},
        headers=auth_headers,
    )

    response = await client.get(
        f"/api/v1/musehub/repos/{repo_id}/milestones",
        headers=auth_headers,
    )
    assert response.status_code == 200
    data = response.json()
    assert len(data["milestones"]) == 2
    assert data["milestones"][0]["title"] == "Phase 1"
    assert data["milestones"][1]["title"] == "Phase 2"


@pytest.mark.anyio
async def test_get_milestone_by_number(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """GET /milestones/{number} returns a single milestone with issue counts."""
    repo_id = await _create_repo(client, auth_headers, "milestone-get-repo")

    ms_resp = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/milestones",
        json={"title": "Single Milestone", "description": "Only one here"},
        headers=auth_headers,
    )
    assert ms_resp.status_code == 201
    number = ms_resp.json()["number"]

    response = await client.get(
        f"/api/v1/musehub/repos/{repo_id}/milestones/{number}",
        headers=auth_headers,
    )
    assert response.status_code == 200
    data = response.json()
    assert data["title"] == "Single Milestone"
    assert data["description"] == "Only one here"
    assert data["state"] == "open"
    assert data["openIssues"] == 0
    assert data["closedIssues"] == 0


@pytest.mark.anyio
async def test_get_milestone_not_found(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """GET /milestones/{number} returns 404 for a non-existent milestone number."""
    repo_id = await _create_repo(client, auth_headers, "milestone-get-404-repo")

    response = await client.get(
        f"/api/v1/musehub/repos/{repo_id}/milestones/999",
        headers=auth_headers,
    )
    assert response.status_code == 404


@pytest.mark.anyio
async def test_update_milestone_title_and_state(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """PATCH /milestones/{number} updates only the provided fields."""
    repo_id = await _create_repo(client, auth_headers, "milestone-patch-repo")

    ms_resp = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/milestones",
        json={"title": "Initial Title"},
        headers=auth_headers,
    )
    number = ms_resp.json()["number"]

    response = await client.patch(
        f"/api/v1/musehub/repos/{repo_id}/milestones/{number}",
        json={"title": "Revised Title", "state": "closed"},
        headers=auth_headers,
    )
    assert response.status_code == 200
    data = response.json()
    assert data["title"] == "Revised Title"
    assert data["state"] == "closed"


@pytest.mark.anyio
async def test_update_milestone_clear_due_on(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """PATCH /milestones/{number} with due_on=null clears the due date."""
    repo_id = await _create_repo(client, auth_headers, "milestone-clear-due-repo")

    ms_resp = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/milestones",
        json={"title": "Dated Milestone", "dueOn": "2026-12-31T00:00:00Z"},
        headers=auth_headers,
    )
    number = ms_resp.json()["number"]

    response = await client.patch(
        f"/api/v1/musehub/repos/{repo_id}/milestones/{number}",
        json={"dueOn": None},
        headers=auth_headers,
    )
    assert response.status_code == 200
    assert response.json()["dueOn"] is None


@pytest.mark.anyio
async def test_delete_milestone_unlinks_issues(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """DELETE /milestones/{number} removes the milestone but leaves issues intact."""
    repo_id = await _create_repo(client, auth_headers, "milestone-delete-repo")

    ms_resp = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/milestones",
        json={"title": "Ephemeral Milestone"},
        headers=auth_headers,
    )
    number = ms_resp.json()["number"]
    milestone_id: str = ms_resp.json()["milestoneId"]

    issue = await _create_issue(client, auth_headers, repo_id, title="Issue to unlink")
    await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}/milestone",
        params={"milestone_id": milestone_id},
        headers=auth_headers,
    )

    delete_resp = await client.delete(
        f"/api/v1/musehub/repos/{repo_id}/milestones/{number}",
        headers=auth_headers,
    )
    assert delete_resp.status_code == 204

    # Milestone is gone
    get_resp = await client.get(
        f"/api/v1/musehub/repos/{repo_id}/milestones/{number}",
        headers=auth_headers,
    )
    assert get_resp.status_code == 404

    # Issue still exists with milestone unlinked
    issue_resp = await client.get(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}",
        headers=auth_headers,
    )
    assert issue_resp.status_code == 200
    assert issue_resp.json()["milestoneId"] is None


@pytest.mark.anyio
async def test_list_milestones_sort_by_title(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """GET /milestones?sort=title returns milestones sorted alphabetically."""
    repo_id = await _create_repo(client, auth_headers, "milestone-sort-title-repo")

    for title in ["Zeta", "Alpha", "Mu"]:
        await client.post(
            f"/api/v1/musehub/repos/{repo_id}/milestones",
            json={"title": title},
            headers=auth_headers,
        )

    response = await client.get(
        f"/api/v1/musehub/repos/{repo_id}/milestones",
        params={"sort": "title"},
        headers=auth_headers,
    )
    assert response.status_code == 200
    titles = [m["title"] for m in response.json()["milestones"]]
    assert titles == sorted(titles)


# ---------------------------------------------------------------------------
# Issue #419 — milestone and label assignment endpoints
# ---------------------------------------------------------------------------


@pytest.mark.anyio
async def test_delete_issue_milestone_removes_link(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """DELETE /issues/{number}/milestone clears the milestone link on an issue."""
    repo_id = await _create_repo(client, auth_headers, "del-milestone-repo")
    issue = await _create_issue(client, auth_headers, repo_id, title="Issue with milestone")

    ms_resp = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/milestones",
        json={"title": "Temp Milestone"},
        headers=auth_headers,
    )
    milestone_id: str = ms_resp.json()["milestoneId"]

    # Link milestone
    await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}/milestone",
        params={"milestone_id": milestone_id},
        headers=auth_headers,
    )

    # Remove milestone via DELETE
    response = await client.delete(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}/milestone",
        headers=auth_headers,
    )
    assert response.status_code == 200
    data = response.json()
    assert data["milestoneId"] is None
    assert data["milestoneTitle"] is None


@pytest.mark.anyio
async def test_delete_issue_milestone_idempotent(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """DELETE /milestone on an issue with no milestone succeeds silently."""
    repo_id = await _create_repo(client, auth_headers, "del-milestone-idempotent-repo")
    issue = await _create_issue(client, auth_headers, repo_id, title="No milestone issue")

    response = await client.delete(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}/milestone",
        headers=auth_headers,
    )
    assert response.status_code == 200
    assert response.json()["milestoneId"] is None


@pytest.mark.anyio
async def test_delete_issue_milestone_not_found(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """DELETE /issues/999/milestone returns 404 for an unknown issue."""
    repo_id = await _create_repo(client, auth_headers, "del-milestone-404-repo")

    response = await client.delete(
        f"/api/v1/musehub/repos/{repo_id}/issues/999/milestone",
        headers=auth_headers,
    )
    assert response.status_code == 404


@pytest.mark.anyio
async def test_assign_issue_labels_replaces_labels(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """POST /issues/{number}/labels replaces the entire label list."""
    repo_id = await _create_repo(client, auth_headers, "label-assign-repo")
    issue = await _create_issue(
        client, auth_headers, repo_id, title="Label test issue", labels=["old-label"]
    )
    assert issue["labels"] == ["old-label"]

    response = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}/labels",
        json={"labels": ["harmony", "needs-review"]},
        headers=auth_headers,
    )
    assert response.status_code == 200
    data = response.json()
    assert data["labels"] == ["harmony", "needs-review"]
    assert "old-label" not in data["labels"]


@pytest.mark.anyio
async def test_assign_issue_labels_empty_clears_labels(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """POST /issues/{number}/labels with empty list clears all labels."""
    repo_id = await _create_repo(client, auth_headers, "label-clear-repo")
    issue = await _create_issue(
        client, auth_headers, repo_id, title="Labelled issue", labels=["bug", "musical"]
    )

    response = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}/labels",
        json={"labels": []},
        headers=auth_headers,
    )
    assert response.status_code == 200
    assert response.json()["labels"] == []


@pytest.mark.anyio
async def test_assign_issue_labels_not_found(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """POST /issues/999/labels returns 404 for an unknown issue."""
    repo_id = await _create_repo(client, auth_headers, "label-assign-404-repo")

    response = await client.post(
        f"/api/v1/musehub/repos/{repo_id}/issues/999/labels",
        json={"labels": ["bug"]},
        headers=auth_headers,
    )
    assert response.status_code == 404


@pytest.mark.anyio
async def test_remove_issue_label_removes_single_label(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """DELETE /issues/{number}/labels/{name} removes one label and leaves the rest."""
    repo_id = await _create_repo(client, auth_headers, "label-remove-repo")
    issue = await _create_issue(
        client,
        auth_headers,
        repo_id,
        title="Multi-label issue",
        labels=["bug", "harmony", "needs-review"],
    )

    response = await client.delete(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}/labels/harmony",
        headers=auth_headers,
    )
    assert response.status_code == 200
    remaining = response.json()["labels"]
    assert "harmony" not in remaining
    assert "bug" in remaining
    assert "needs-review" in remaining


@pytest.mark.anyio
async def test_remove_issue_label_idempotent(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """DELETE /labels/{name} silently succeeds when the label is not present."""
    repo_id = await _create_repo(client, auth_headers, "label-remove-idempotent-repo")
    issue = await _create_issue(
        client, auth_headers, repo_id, title="No such label issue", labels=["bug"]
    )

    response = await client.delete(
        f"/api/v1/musehub/repos/{repo_id}/issues/{issue['number']}/labels/nonexistent",
        headers=auth_headers,
    )
    assert response.status_code == 200
    assert response.json()["labels"] == ["bug"]


@pytest.mark.anyio
async def test_remove_issue_label_not_found(
    client: AsyncClient,
    auth_headers: dict[str, str],
) -> None:
    """DELETE /issues/999/labels/{name} returns 404 for an unknown issue."""
    repo_id = await _create_repo(client, auth_headers, "label-remove-404-repo")

    response = await client.delete(
        f"/api/v1/musehub/repos/{repo_id}/issues/999/labels/bug",
        headers=auth_headers,
    )
    assert response.status_code == 404


@pytest.mark.anyio
async def test_new_endpoints_require_auth(client: AsyncClient) -> None:
    """DELETE /milestone, POST /labels, DELETE /labels/{name} all require authentication."""
    endpoints: list[tuple[str, str, dict[str, object]]] = [
        ("DELETE", "/api/v1/musehub/repos/some-repo/issues/1/milestone", {}),
        ("POST", "/api/v1/musehub/repos/some-repo/issues/1/labels", {"labels": ["bug"]}),
        ("DELETE", "/api/v1/musehub/repos/some-repo/issues/1/labels/bug", {}),
    ]
    for method, url, payload in endpoints:
        if method == "DELETE":
            response = await client.delete(url)
        else:
            response = await client.post(url, json=payload)
        assert response.status_code == 401, f"{method} {url} should require auth"