"""/api/v1 contract tests with monkeypatched post_service + filter engine.

No live Postgres and no real filter pipeline: ``post_service`` is replaced with
an in-memory stub and ``get_filter_engine`` with a passthrough stub. These
assert the JSON shape the templates/SPA consume, so refactor regressions are
caught without a runtime stack.
"""

import pytest

from conftest import StubPostService, _StubFilterEngine


SAMPLE_POST = {
    "uuid": "post-1",
    "title": "Sample post",
    "author": "alice",
    "platform": "hackernews",
    "source": "programming",
    "score": 42,
    "timestamp": 1700000000,
    "url": "https://example.com/1",
    "content": "Hello world",
    "tags": ["tech"],
}

SAMPLE_COMMENTS = [
    {"uuid": "c1", "post_uuid": "post-1", "content": "top", "score": 3,
     "depth": 0, "parent_comment_uuid": None},
    {"uuid": "c2", "post_uuid": "post-1", "content": "reply", "score": 1,
     "depth": 1, "parent_comment_uuid": "c1"},
]


@pytest.fixture
def api_client(app, monkeypatch):
    """App + client with stubbed post_service and filter engine."""
    import app as app_module
    import blueprints.api as api_module

    monkeypatch.setattr(app_module, "get_filter_engine", lambda: _StubFilterEngine())
    monkeypatch.setattr(app_module, "get_polling_service", lambda: _StubPolling())
    monkeypatch.setattr(api_module, "get_filter_engine", lambda: _StubFilterEngine())
    monkeypatch.setattr(
        api_module, "post_service",
        StubPostService(posts={"post-1": SAMPLE_POST}, comments={"post-1": SAMPLE_COMMENTS}),
    )
    return app.test_client()


def test_posts_endpoint_returns_paginated_shape(api_client):
    resp = api_client.get("/api/v1/posts")
    assert resp.status_code == 200
    data = resp.get_json()
    assert set(data.keys()) >= {"posts", "pagination"}
    assert set(data["pagination"].keys()) >= {
        "current_page", "total_pages", "total_posts", "per_page", "has_next", "has_prev"
    }
    assert data["pagination"]["total_posts"] == 1
    post = data["posts"][0]
    assert post["id"] == "post-1"
    assert post["title"] == "Sample post"
    assert post["platform"] == "hackernews"
    assert post["url"] == "/post/post-1"
    assert "filter_score" in post


def test_post_detail_returns_post_and_comments(api_client):
    resp = api_client.get("/api/v1/posts/post-1")
    assert resp.status_code == 200
    data = resp.get_json()
    assert data["post"]["uuid"] == "post-1"
    assert isinstance(data["comments"], list)
    # The tree has one root with one nested reply.
    assert data["comments"][0]["uuid"] == "c1"
    assert data["comments"][0]["replies"][0]["uuid"] == "c2"


def test_post_detail_404_for_unknown(api_client):
    resp = api_client.get("/api/v1/posts/does-not-exist")
    assert resp.status_code == 404


def test_comments_endpoint_returns_tree(api_client):
    resp = api_client.get("/api/v1/comments/post-1")
    assert resp.status_code == 200
    data = resp.get_json()
    assert data["comments"][0]["uuid"] == "c1"
    assert data["comments"][0]["replies"][0]["uuid"] == "c2"


def test_filters_endpoint_lists_filtersets(api_client):
    resp = api_client.get("/api/v1/filters")
    assert resp.status_code == 200
    data = resp.get_json()
    assert "filters" in data
    # Stub engine advertises no_filter; the list may be empty or contain it.
    assert isinstance(data["filters"], list)


# Imported via the api_client fixture's monkeypatch; keep the name available.
from conftest import _StubPolling  # noqa: E402, F401