"""Unit tests for app.replay.api."""

from __future__ import annotations

from unittest.mock import AsyncMock, MagicMock

import pytest
from fastapi import FastAPI
from fastapi.testclient import TestClient

pytestmark = pytest.mark.unit


def _build_app() -> FastAPI:
    from app.replay.api import router

    app = FastAPI()
    app.include_router(router)
    return app


def _make_mock_pool(fetchall_result: list[dict]) -> MagicMock:
    """Build a mock pool that returns the given rows from fetchall."""
    mock_cursor = AsyncMock()
    mock_cursor.fetchall = AsyncMock(return_value=fetchall_result)

    mock_conn = AsyncMock()
    mock_conn.execute = AsyncMock(return_value=mock_cursor)

    mock_ctx = AsyncMock()
    mock_ctx.__aenter__ = AsyncMock(return_value=mock_conn)
    mock_ctx.__aexit__ = AsyncMock(return_value=None)

    mock_pool = MagicMock()
    mock_pool.connection.return_value = mock_ctx
    return mock_pool


class TestListConversations:
    def test_returns_200_with_empty_list(self) -> None:
        app = _build_app()
        app.state.pool = _make_mock_pool([])

        with TestClient(app) as client:
            resp = client.get("/api/conversations")
        assert resp.status_code == 200
        body = resp.json()
        assert body["success"] is True
        assert isinstance(body["data"], list)
        assert body["error"] is None

    def test_returns_conversations_list(self) -> None:
        app = _build_app()
        mock_rows = [
            {
                "thread_id": "t1",
                "created_at": "2026-01-01T00:00:00",
                "last_activity": "2026-01-01T00:01:00",
                "status": "active",
                "total_tokens": 100,
                "total_cost_usd": 0.01,
            }
        ]
        app.state.pool = _make_mock_pool(mock_rows)

        with TestClient(app) as client:
            resp = client.get("/api/conversations")
        body = resp.json()
        assert resp.status_code == 200
        assert len(body["data"]) == 1
        assert body["data"][0]["thread_id"] == "t1"

    def test_pagination_defaults(self) -> None:
        app = _build_app()
        app.state.pool = _make_mock_pool([])

        with TestClient(app) as client:
            resp = client.get("/api/conversations")
        assert resp.status_code == 200

    def test_pagination_custom_params(self) -> None:
        app = _build_app()
        app.state.pool = _make_mock_pool([])

        with TestClient(app) as client:
            resp = client.get("/api/conversations?page=2&per_page=10")
        assert resp.status_code == 200

    def test_per_page_max_capped_at_100(self) -> None:
        app = _build_app()
        app.state.pool = _make_mock_pool([])

        with TestClient(app) as client:
            resp = client.get("/api/conversations?per_page=200")
        # FastAPI validation rejects values > 100
        assert resp.status_code in (200, 422)


class TestGetReplay:
    def test_thread_not_found_returns_404(self) -> None:
        app = _build_app()
        app.state.pool = _make_mock_pool([])

        with TestClient(app) as client:
            resp = client.get("/api/replay/nonexistent-thread")
        assert resp.status_code == 404

    def test_returns_replay_page_for_existing_thread(self) -> None:
        app = _build_app()
        mock_rows = [
            {
                "thread_id": "thread-123",
                "checkpoint_id": "cp-001",
                "checkpoint": {
                    "channel_values": {
                        "messages": [{"type": "human", "content": "Hello"}]
                    }
                },
                "metadata": {},
            }
        ]
        app.state.pool = _make_mock_pool(mock_rows)

        with TestClient(app) as client:
            resp = client.get("/api/replay/thread-123")
        assert resp.status_code == 200
        body = resp.json()
        assert body["success"] is True
        assert body["data"]["thread_id"] == "thread-123"
        assert "steps" in body["data"]
        assert "total_steps" in body["data"]
        assert "page" in body["data"]
        assert "per_page" in body["data"]

    def test_replay_pagination_params(self) -> None:
        app = _build_app()
        mock_rows = [
            {
                "thread_id": "t1",
                "checkpoint_id": "cp-001",
                "checkpoint": {
                    "channel_values": {"messages": [{"type": "human", "content": "Hi"}]}
                },
                "metadata": {},
            }
        ]
        app.state.pool = _make_mock_pool(mock_rows)

        with TestClient(app) as client:
            resp = client.get("/api/replay/t1?page=1&per_page=5")
        assert resp.status_code == 200

    def test_error_response_has_envelope(self) -> None:
        app = _build_app()
        app.state.pool = _make_mock_pool([])

        with TestClient(app) as client:
            resp = client.get("/api/replay/missing")
        body = resp.json()
        assert "detail" in body or "error" in body or resp.status_code == 404