"""External-PR review dedup — review once per (project, PR, head commit).

``external_review_task_exists`` drives re-review off the PR's head SHA: an
unchanged PR (same head) is skipped, new commits (a new head SHA) open a fresh
review, and legacy/unknown-SHA tasks are never re-reviewed (no spam).
"""

from __future__ import annotations

from unittest.mock import AsyncMock, MagicMock
from uuid import uuid4

import pytest
from roboco.services.task import TaskService


def _service(quick_contexts: list[str | None]) -> TaskService:
    """A TaskService whose review-task query returns these quick_context values."""
    res = MagicMock()
    res.scalars.return_value.all.return_value = quick_contexts
    session = MagicMock()
    session.execute = AsyncMock(return_value=res)
    return TaskService(session)


@pytest.mark.asyncio
async def test_no_task_yet_ingests() -> None:
    svc = _service([])
    assert await svc.external_review_task_exists(uuid4(), 170, "abc") is False


@pytest.mark.asyncio
async def test_same_head_sha_skips() -> None:
    svc = _service(["external_pr_head=abc"])
    assert await svc.external_review_task_exists(uuid4(), 170, "abc") is True


@pytest.mark.asyncio
async def test_new_head_sha_rereviews() -> None:
    # PR got new commits since the last review → open a fresh review.
    svc = _service(["external_pr_head=abc"])
    assert await svc.external_review_task_exists(uuid4(), 170, "def") is False


@pytest.mark.asyncio
async def test_legacy_markerless_task_not_rereviewed() -> None:
    # A task ingested before head-SHA tracking existed → don't re-review it.
    svc = _service([None])
    assert await svc.external_review_task_exists(uuid4(), 170, "def") is True


@pytest.mark.asyncio
async def test_unknown_head_sha_does_not_spam() -> None:
    # Can't detect change (no SHA from GitHub) → treat as reviewed.
    svc = _service(["external_pr_head=abc"])
    assert await svc.external_review_task_exists(uuid4(), 170, None) is True


@pytest.mark.asyncio
async def test_multiple_old_shas_still_rereviews_new() -> None:
    svc = _service(["external_pr_head=abc", "external_pr_head=def"])
    assert await svc.external_review_task_exists(uuid4(), 170, "ghi") is False
    assert await svc.external_review_task_exists(uuid4(), 170, "def") is True


def _bind(svc: TaskService, name: str, value: object) -> None:
    object.__setattr__(svc, name, value)


@pytest.mark.asyncio
async def test_list_awaiting_decision_excludes_dismissed() -> None:
    pending = MagicMock(quick_context="external_pr_head=abc")
    dismissed = MagicMock(quick_context="external_pr_head=def dismissed=1")
    svc = _service([pending, dismissed])
    out = await svc.list_external_pr_reviews_awaiting_decision()
    assert out == [pending]


@pytest.mark.asyncio
async def test_list_external_pr_reviews_excludes_dismissed() -> None:
    # The panel queue surfaces in-flight reviews too (the status filter lives in
    # SQL); here we pin the post-query behavior: dismissed reviews drop out.
    reviewing = MagicMock(quick_context="external_pr_head=abc")
    dismissed = MagicMock(quick_context="external_pr_head=def dismissed=1")
    svc = _service([reviewing, dismissed])
    out = await svc.list_external_pr_reviews()
    assert out == [reviewing]


@pytest.mark.asyncio
async def test_dismiss_marks_and_is_idempotent() -> None:
    task = MagicMock(source="external_pr", quick_context="external_pr_head=abc")
    session = MagicMock()
    session.flush = AsyncMock()
    svc = TaskService(session)
    _bind(svc, "get", AsyncMock(return_value=task))
    await svc.dismiss_external_pr_review(uuid4())
    assert "dismissed=1" in task.quick_context.split()
    await svc.dismiss_external_pr_review(uuid4())  # idempotent
    assert task.quick_context.split().count("dismissed=1") == 1


@pytest.mark.asyncio
async def test_dismiss_rejects_non_external_pr() -> None:
    task = MagicMock(source="code")
    session = MagicMock()
    session.flush = AsyncMock()
    svc = TaskService(session)
    _bind(svc, "get", AsyncMock(return_value=task))
    assert await svc.dismiss_external_pr_review(uuid4()) is None