"""Regression tests for KIN-ARCH-023 — Analyst injection into actual executed pipeline.

Two concerns:
1. At revise_count >= 2, analyst MUST be the first step in pending_steps saved to DB
   (not just in the response body). The subprocess picks steps from pending_steps,
   so a test that only checks the response body misses the real execution path.
2. The condition simplification at api.py ~1056 is semantically correct:
   `steps and (not steps or steps[0].get('role') != 'analyst')`
   is equivalent to:
   `steps and steps[0].get('role') != 'analyst'`
   because when `steps` is truthy, `not steps` is always False.
"""

import pytest
from unittest.mock import patch

from core.db import init_db
from core import models


# ---------------------------------------------------------------------------
# Fixtures
# ---------------------------------------------------------------------------

@pytest.fixture
def api_client(tmp_path):
    """FastAPI TestClient with isolated DB (same pattern as test_kin_128_regression.py)."""
    import web.api as api_module
    api_module.DB_PATH = tmp_path / "test.db"
    from web.api import app
    from fastapi.testclient import TestClient
    client = TestClient(app)
    client.post("/api/projects", json={"id": "p1", "name": "P1", "path": "/p1"})
    client.post("/api/tasks", json={"project_id": "p1", "title": "Fix bug"})
    return client


@pytest.fixture
def api_client_with_conn(tmp_path):
    """Returns (TestClient, db_path) so tests can query DB directly."""
    import web.api as api_module
    db_path = tmp_path / "test.db"
    api_module.DB_PATH = db_path
    from web.api import app
    from fastapi.testclient import TestClient
    client = TestClient(app)
    client.post("/api/projects", json={"id": "p1", "name": "P1", "path": "/p1"})
    client.post("/api/tasks", json={"project_id": "p1", "title": "Fix bug"})
    return client, db_path


# ---------------------------------------------------------------------------
# 1. Analyst actually persisted to pending_steps in DB (subprocess-visible path)
# ---------------------------------------------------------------------------

class TestAnalystInjectedIntoPendingSteps:
    """The subprocess reads steps from pending_steps in DB, not from the HTTP response.
    These tests verify the DB state, not just the response body.
    """

    def test_second_revise_saves_analyst_first_in_pending_steps(self, api_client_with_conn):
        """revise_count=2: pending_steps[0].role == 'analyst' in DB after revise call."""
        client, db_path = api_client_with_conn
        steps = [{"role": "backend_dev", "model": "sonnet"}]

        with patch("web.api._launch_pipeline_subprocess"):
            client.post("/api/tasks/P1-001/revise", json={"comment": "r1", "steps": steps})
            client.post("/api/tasks/P1-001/revise", json={"comment": "r2", "steps": steps})

        conn = init_db(str(db_path))
        task = models.get_task(conn, "P1-001")
        conn.close()

        pending = task.get("pending_steps") or []
        assert pending, "pending_steps не должен быть пустым после 2-й ревизии"
        assert pending[0].get("role") == "analyst", (
            f"KIN-ARCH-023: analyst должен быть первым в pending_steps (subprocess читает именно их), "
            f"получили: {pending[0].get('role')}"
        )

    def test_first_revise_does_not_add_analyst_to_pending_steps(self, api_client_with_conn):
        """revise_count=1: analyst НЕ добавляется в pending_steps."""
        client, db_path = api_client_with_conn
        steps = [{"role": "backend_dev", "model": "sonnet"}]

        with patch("web.api._launch_pipeline_subprocess"):
            client.post("/api/tasks/P1-001/revise", json={"comment": "r1", "steps": steps})

        conn = init_db(str(db_path))
        task = models.get_task(conn, "P1-001")
        conn.close()

        pending = task.get("pending_steps") or []
        assert not pending or pending[0].get("role") != "analyst", (
            "analyst не должен быть первым шагом в pending_steps при revise_count=1"
        )

    def test_third_revise_saves_analyst_first_in_pending_steps(self, api_client_with_conn):
        """revise_count=3: analyst также является первым в pending_steps."""
        client, db_path = api_client_with_conn
        steps = [{"role": "frontend_dev", "model": "sonnet"}]

        with patch("web.api._launch_pipeline_subprocess"):
            for comment in ("r1", "r2", "r3"):
                client.post("/api/tasks/P1-001/revise", json={"comment": comment, "steps": steps})

        conn = init_db(str(db_path))
        task = models.get_task(conn, "P1-001")
        conn.close()

        pending = task.get("pending_steps") or []
        assert pending, "pending_steps не должен быть пустым после 3-й ревизии"
        assert pending[0].get("role") == "analyst", (
            f"revise_count=3: первым в pending_steps должен быть analyst, получили: {pending[0].get('role')}"
        )

    def test_pending_steps_length_increases_by_one_after_analyst_injection(self, api_client_with_conn):
        """После инжекции analyst длина pending_steps на 1 больше исходного списка шагов."""
        client, db_path = api_client_with_conn
        original_steps = [
            {"role": "backend_dev", "model": "sonnet"},
            {"role": "reviewer", "model": "sonnet"},
        ]

        with patch("web.api._launch_pipeline_subprocess"):
            client.post("/api/tasks/P1-001/revise", json={"comment": "r1", "steps": original_steps})
            client.post("/api/tasks/P1-001/revise", json={"comment": "r2", "steps": original_steps})

        conn = init_db(str(db_path))
        task = models.get_task(conn, "P1-001")
        conn.close()

        pending = task.get("pending_steps") or []
        assert len(pending) == len(original_steps) + 1, (
            f"Ожидали {len(original_steps) + 1} шагов (с analyst), получили {len(pending)}"
        )

    def test_analyst_not_duplicated_in_pending_steps_if_already_first(self, api_client_with_conn):
        """Если analyst уже первый шаг — pending_steps не содержит дублей analyst."""
        client, db_path = api_client_with_conn
        steps = [{"role": "analyst", "model": "sonnet"}, {"role": "backend_dev", "model": "sonnet"}]

        with patch("web.api._launch_pipeline_subprocess"):
            client.post("/api/tasks/P1-001/revise", json={"comment": "r1", "steps": steps})
            client.post("/api/tasks/P1-001/revise", json={"comment": "r2", "steps": steps})

        conn = init_db(str(db_path))
        task = models.get_task(conn, "P1-001")
        conn.close()

        pending = task.get("pending_steps") or []
        analyst_count = sum(1 for s in pending if s.get("role") == "analyst")
        assert analyst_count == 1, (
            f"analyst не должен дублироваться в pending_steps, нашли {analyst_count} вхождений"
        )


# ---------------------------------------------------------------------------
# 2. Condition simplification semantics (api.py ~1056)
# ---------------------------------------------------------------------------

def _original_condition(steps):
    """Original (verbose) condition from before the simplification."""
    return steps and (not steps or steps[0].get("role") != "analyst")


def _simplified_condition(steps):
    """Simplified condition after KIN-ARCH-023 fix."""
    return steps and steps[0].get("role") != "analyst"


class TestConditionSimplificationEquivalence:
    """Verify that the simplified condition produces identical results to the original
    across all meaningful input variants. This guards against future refactors
    accidentally diverging the two forms.
    """

    def test_empty_list_both_return_falsy(self):
        """steps=[] → оба варианта возвращают falsy (инжекция не происходит)."""
        assert not _original_condition([])
        assert not _simplified_condition([])

    def test_none_both_return_falsy(self):
        """steps=None → оба варианта возвращают falsy."""
        assert not _original_condition(None)
        assert not _simplified_condition(None)

    def test_analyst_first_both_return_falsy(self):
        """Если analyst уже первый — оба варианта возвращают falsy (инжекция пропускается)."""
        steps = [{"role": "analyst"}, {"role": "backend_dev"}]
        assert not _original_condition(steps)
        assert not _simplified_condition(steps)

    def test_non_analyst_first_both_return_truthy(self):
        """Если первый шаг не analyst — оба варианта truthy (инжекция происходит)."""
        steps = [{"role": "backend_dev"}, {"role": "reviewer"}]
        assert _original_condition(steps)
        assert _simplified_condition(steps)

    def test_single_step_non_analyst_both_truthy(self):
        """Одиночный шаг не-analyst → оба truthy."""
        steps = [{"role": "debugger"}]
        assert _original_condition(steps)
        assert _simplified_condition(steps)

    def test_step_without_role_key_both_truthy(self):
        """Шаг без ключа 'role' → steps[0].get('role') возвращает None ≠ 'analyst' → truthy."""
        steps = [{"model": "sonnet"}]
        assert _original_condition(steps)
        assert _simplified_condition(steps)

    @pytest.mark.parametrize("steps", [
        [],
        None,
        [{"role": "analyst"}],
        [{"role": "backend_dev"}],
        [{"role": "reviewer"}, {"role": "backend_dev"}],
        [{"role": "analyst"}, {"role": "backend_dev"}],
        [{"model": "sonnet"}],
    ])
    def test_parametrized_equivalence(self, steps):
        """Для всех входных данных упрощённое условие идентично исходному."""
        original = bool(_original_condition(steps))
        simplified = bool(_simplified_condition(steps))
        assert original == simplified, (
            f"Условия расходятся для steps={steps}: "
            f"original={original}, simplified={simplified}"
        )