"""Unit tests for the poll_once watcher logic."""
import logging
import pathlib
from typing import Any

import pytest

from coordinator.__main__ import poll_once
from coordinator.queue import DebateQueue
from coordinator.state import SeenState


# ---------------------------------------------------------------------------
# Fake client
# ---------------------------------------------------------------------------

class FakeMulticaClient:
    """Minimal stand-in for MulticaClient.

    ``responses`` is a list of lists; each call to ``list_issues_by_status``
    pops the next item from the front.  If the list is exhausted the last
    entry is repeated (steady-state behaviour).
    """

    def __init__(self, responses: list[list[dict[str, Any]]]):
        self._responses = list(responses)

    def list_issues_by_status(self, status: str, limit: int = 200) -> list[dict[str, Any]]:
        if len(self._responses) > 1:
            return self._responses.pop(0)
        return self._responses[0]


def _issue(iid: str, updated_at: str, identifier: str = "WYL-X", title: str = "T") -> dict:
    return {
        "id": iid,
        "updated_at": updated_at,
        "identifier": identifier,
        "title": title,
    }


@pytest.fixture
def setup(tmp_path):
    """Return (state, queue, logger) wired to tmp_path."""
    state = SeenState.load(tmp_path / "seen.json")
    queue = DebateQueue.load(tmp_path / "queue.json")
    logger = logging.getLogger("test.watcher")
    return state, queue, logger


# ---------------------------------------------------------------------------
# Scenario (a): first observation of a new in_review issue → enqueue
# ---------------------------------------------------------------------------

def test_first_observation_enqueues(setup):
    state, queue, logger = setup
    client = FakeMulticaClient([[_issue("id-1", "2026-01-01T00:00:00Z", "WYL-1", "Title A")]])

    poll_once(client, state, queue, logger)

    assert len(queue.rounds) == 1
    assert queue.rounds[0].issue_id == "id-1"
    assert queue.rounds[0].identifier == "WYL-1"
    assert queue.rounds[0].status == "pending"
    assert state.last_seen("id-1") == "2026-01-01T00:00:00Z"


# ---------------------------------------------------------------------------
# Scenario (b): same issue at same updated_at → no second enqueue
# ---------------------------------------------------------------------------

def test_same_updated_at_no_reenqueue(setup):
    state, queue, logger = setup
    issue = _issue("id-1", "2026-01-01T00:00:00Z")
    client = FakeMulticaClient([[issue]])  # steady-state

    poll_once(client, state, queue, logger)
    poll_once(client, state, queue, logger)

    assert len(queue.rounds) == 1  # only the first poll fired


# ---------------------------------------------------------------------------
# Scenario (c): updated_at changes while round still pending → dedupe, no re-enqueue
# ---------------------------------------------------------------------------

def test_updated_at_changes_while_pending_no_reenqueue(setup):
    state, queue, logger = setup
    client = FakeMulticaClient([
        [_issue("id-1", "2026-01-01T00:00:00Z")],  # first poll: enqueue
        [_issue("id-1", "2026-01-01T00:01:00Z")],  # second poll: new updated_at, but round pending
    ])

    poll_once(client, state, queue, logger)
    assert len(queue.rounds) == 1

    poll_once(client, state, queue, logger)
    assert len(queue.rounds) == 1  # dedupe fired, no second round


def test_updated_at_changes_while_running_no_reenqueue(setup):
    state, queue, logger = setup
    client = FakeMulticaClient([
        [_issue("id-1", "2026-01-01T00:00:00Z")],
        [_issue("id-1", "2026-01-01T00:01:00Z")],
    ])

    poll_once(client, state, queue, logger)
    queue.update_status(queue.rounds[0].round_id, "running")

    poll_once(client, state, queue, logger)
    assert len(queue.rounds) == 1


# ---------------------------------------------------------------------------
# After round completes, a *new* updated_at triggers a fresh round
# ---------------------------------------------------------------------------

def test_reenqueue_after_round_done(setup):
    state, queue, logger = setup
    client = FakeMulticaClient([
        [_issue("id-1", "2026-01-01T00:00:00Z")],  # first poll
        [_issue("id-1", "2026-01-01T00:02:00Z")],  # third poll: new updated_at, round done
    ])

    poll_once(client, state, queue, logger)
    queue.update_status(queue.rounds[0].round_id, "done")

    poll_once(client, state, queue, logger)
    assert len(queue.rounds) == 2
    assert queue.rounds[1].status == "pending"


# ---------------------------------------------------------------------------
# Multiple distinct issues in one poll
# ---------------------------------------------------------------------------

def test_multiple_issues_each_enqueued_once(setup):
    state, queue, logger = setup
    client = FakeMulticaClient([[
        _issue("id-1", "2026-01-01T00:00:00Z", "WYL-1"),
        _issue("id-2", "2026-01-01T00:00:00Z", "WYL-2"),
        _issue("id-3", "2026-01-01T00:00:00Z", "WYL-3"),
    ]])

    poll_once(client, state, queue, logger)
    assert len(queue.rounds) == 3


def test_mix_new_and_seen(setup):
    state, queue, logger = setup
    client = FakeMulticaClient([
        [_issue("id-1", "t1"), _issue("id-2", "t2")],  # first poll: both new
        [_issue("id-1", "t1"), _issue("id-2", "t2")],  # second poll: same updated_at
    ])

    poll_once(client, state, queue, logger)
    assert len(queue.rounds) == 2

    poll_once(client, state, queue, logger)
    assert len(queue.rounds) == 2  # nothing new