"""
Integration tests for the architecture session flow.

Tests: create → generate → compare → select → refine.
Uses real NVIDIA LLM API calls.

**Why fixtures rather than test ordering.** These tests previously stashed the
session id on the `pytest` module in `test_create_session` and read it back with
`getattr(pytest, "arch_session_id", None)`, skipping when it was absent. A failed
create therefore turned the remaining six tests into silent skips, and the suite
still reported green. The shared state now lives in module-scoped fixtures: if
create or generate fails, every dependent test ERRORs loudly instead.

Generation costs several minutes of live LLM time, so `generated_options` runs
once per module and is shared by compare / select / refine.
"""
import json

import pytest

from tests.integration.conftest import _require_env, require_ok


def _parse_sse(body: str) -> tuple[list[dict], list[str]]:
    """Return (option payloads, event types) parsed from an SSE response body.

    The generate stream emits `{"type": "agent"|"option"|"done"|"error"}` frames;
    see `architecture_generation.generate_options_stream`.
    """
    options: list[dict] = []
    types: list[str] = []
    for line in body.splitlines():
        if not line.startswith("data: "):
            continue
        event = json.loads(line[len("data: ") :])
        types.append(event.get("type"))
        if event.get("type") == "option":
            options.append(event["option"])
    return options, types


@pytest.fixture(scope="module")
def created_session(live_client, auth_headers) -> dict:
    """Create one architecture session shared by every test in this module."""
    response = live_client.post(
        "/architecture/sessions",
        json={
            "project_name": "E-Commerce Platform",
            "requirements": (
                "A scalable e-commerce platform with product catalog, shopping cart, "
                "payment processing, and order management. Must support 10k concurrent users."
            ),
            "constraints": "Budget: $500/month cloud costs. Team: 3 developers. Timeline: 3 months MVP.",
        },
        headers=auth_headers,
    )
    require_ok(response, "POST /architecture/sessions")
    return response.json()


@pytest.fixture(scope="module")
def generated_options(live_client, auth_headers, created_session) -> list[dict]:
    """Generate architecture options once. Several minutes of live LLM time."""
    _require_env("NVIDIA_API_KEY")
    session_id = created_session["id"]
    response = live_client.post(
        f"/architecture/sessions/{session_id}/generate",
        json={"num_options": 3},
        headers=auth_headers,
    )
    require_ok(response, f"POST /architecture/sessions/{session_id}/generate")

    options, types = _parse_sse(response.text)
    assert "error" not in types, f"generate emitted an error event: {response.text[:800]}"
    assert options, f"generate produced no option events: {response.text[:800]}"
    assert "done" in types, f"generate never emitted a done event: {response.text[-800:]}"
    return options


class TestArchitectureSession:
    """Test architecture session lifecycle with live LLM."""

    def test_create_session(self, created_session):
        """POST /architecture/sessions creates a new session."""
        assert created_session["id"]
        assert created_session["project_name"] == "E-Commerce Platform"
        assert "10k concurrent users" in created_session["requirements"]

    def test_get_session(self, live_client, auth_headers, created_session):
        """GET /architecture/sessions/{id} retrieves session."""
        session_id = created_session["id"]
        response = live_client.get(
            f"/architecture/sessions/{session_id}",
            headers=auth_headers,
        )
        require_ok(response, f"GET /architecture/sessions/{session_id}")
        data = response.json()
        assert data["id"] == session_id
        assert data["requirements"] == created_session["requirements"]

    def test_list_sessions(self, live_client, auth_headers, created_session):
        """GET /architecture/sessions lists all sessions."""
        response = live_client.get("/architecture/sessions", headers=auth_headers)
        require_ok(response, "GET /architecture/sessions")
        data = response.json()
        assert isinstance(data, list)
        assert created_session["id"] in [s["id"] for s in data], (
            "the session created by this module is missing from the listing"
        )

    def test_generate_options(self, generated_options):
        """POST /architecture/sessions/{id}/generate creates options via SSE.

        The fixture does the work and asserts the stream shape; this test pins
        the contract callers depend on - real options, each with an id and name.
        """
        assert len(generated_options) >= 1
        for option in generated_options:
            assert option.get("id"), f"option is missing an id: {option}"
            assert option.get("name"), f"option is missing a name: {option}"

    def test_compare_options(self, live_client, auth_headers, created_session, generated_options):
        """POST /architecture/sessions/{id}/compare compares options."""
        _require_env("NVIDIA_API_KEY")
        session_id = created_session["id"]
        response = live_client.post(
            f"/architecture/sessions/{session_id}/compare",
            headers=auth_headers,
        )
        require_ok(response, f"POST /architecture/sessions/{session_id}/compare")
        data = response.json()
        assert "recommendation" in data, f"comparison has no recommendation: {data}"

    def test_select_option(self, live_client, auth_headers, created_session, generated_options):
        """POST /architecture/sessions/{id}/select selects an option.

        Selects an id that actually came out of generate. The old version sent a
        hardcoded "opt_1" and accepted `status_code in (200, 400, 404, 500)` -
        an exhaustive set, so it could not fail.
        """
        session_id = created_session["id"]
        option_id = generated_options[0]["id"]
        response = live_client.post(
            f"/architecture/sessions/{session_id}/select",
            json={"option_id": option_id},
            headers=auth_headers,
        )
        require_ok(response, f"POST /architecture/sessions/{session_id}/select")
        data = response.json()
        assert data["selected_option"]["id"] == option_id
        assert data["session_id"] == session_id

    def test_select_unknown_option_is_404(self, live_client, auth_headers, created_session, generated_options):
        """Selecting an option that does not exist is rejected, not accepted."""
        session_id = created_session["id"]
        response = live_client.post(
            f"/architecture/sessions/{session_id}/select",
            json={"option_id": "opt_does_not_exist"},
            headers=auth_headers,
        )
        assert response.status_code == 404, response.text

    def test_refine_option(self, live_client, auth_headers, created_session, generated_options):
        """POST /architecture/sessions/{id}/refine refines an option."""
        _require_env("NVIDIA_API_KEY")
        session_id = created_session["id"]
        option_id = generated_options[0]["id"]
        response = live_client.post(
            f"/architecture/sessions/{session_id}/refine",
            json={
                "target_option_id": option_id,
                "feedback": "Make it more cost-effective and reduce operational complexity.",
            },
            headers=auth_headers,
        )
        require_ok(response, f"POST /architecture/sessions/{session_id}/refine")
        data = response.json()
        assert data["refined_option"]["id"] == option_id
        assert data["iteration"] >= 1