"""P2 integration test — aggregation → endpoint → response (TASK-10-03).

Requires Postgres (skips if PRAXIS_PG_DSN not set). End-to-end:
  1. Seed 15 mock sessions (12 distinct learners — above k-anon threshold).
  2. Run the aggregation hook for each → cohort_aggregates populated.
  3. GET /api/operator/cohort (with auth cookie) → non-suppressed cells.
  4. Seed 5 sessions (5 NEW learners) for a different path → suppressed cells.
  5. Run nightly reconciliation → all windows recomputed → last_updated updated.
  6. GET /api/operator/mastery → mastery progression data.
  7. GET /api/operator/failure-patterns → failure pattern data.
  8. Verify last_updated ≤ 24h old (REQ-NFR-DASH-02).

G-038 differencing-attack e2e: also verified at the API layer here.
"""

from __future__ import annotations

import asyncio
import datetime as _dt
import os
from unittest.mock import AsyncMock, MagicMock

import pytest

pytestmark = pytest.mark.skipif(
    not os.environ.get("PRAXIS_PG_DSN"),
    reason="PRAXIS_PG_DSN not set — P2 aggregation integration tests skipped.",
)


@pytest.fixture
async def pg_pool():
    import asyncpg

    pool = await asyncpg.create_pool(
        dsn=os.environ["PRAXIS_PG_DSN"], min_size=1, max_size=5, command_timeout=10,
    )
    try:
        yield pool
    finally:
        await pool.close()


@pytest.fixture
async def pg_store(pg_pool):
    from db.pg_migrate import apply_pg_migrations
    from db.pg_store import PgStore

    await apply_pg_migrations(pg_pool)
    # Clean cohort_aggregates + operators for an isolated run.
    async with pg_pool.acquire() as conn:
        await conn.execute("DELETE FROM cohort_aggregates")
        await conn.execute("DELETE FROM operators WHERE username = 'p2intop'")
        await conn.execute("DELETE FROM issued_credentials")
    return PgStore(pg_pool)


def _session(learner_ref: str, path: str = "customer_service",
             outcome: str = "pass") -> dict:
    return {
        "learner_ref": learner_ref,
        "path": path,
        "scenario_id": f"{path}_v01",
        "outcome": outcome,
        "rubric_scores": [
            {"criterion_id": "empathy", "score": 4.0},
            {"criterion_id": "resolution", "score": 3.5},
        ],
        "failure_mode": "missed_apology" if outcome == "fail" else None,
        "branch_path": ["accept"],
        "timestamp": _dt.datetime.now(_dt.timezone.utc).isoformat(),
    }


async def _seed_and_aggregate(pg_store, sessions):
    from server.cohort.hook import on_session_end

    for s in sessions:
        await on_session_end(pg_store, s)


async def _login_cookie(client, pg_store) -> None:
    from server.auth.passwords import hash_password

    op_id = await pg_store.insert_operator("p2intop", hash_password("pw"), "P2 Int")
    # Login via the test client.
    r = client.post("/api/operator/login", json={"username": "p2intop", "password": "pw"})
    assert r.status_code == 200, r.text


def _make_client(pg_store):
    from fastapi import FastAPI
    from fastapi.testclient import TestClient
    from starlette.middleware.sessions import SessionMiddleware

    from server.auth.rate_limit import reset_login_rate_limit
    from server.auth.routes import router as auth_router
    from server.operator.cohort import router as cohort_router
    from server.operator.credentials import router as credentials_router
    from server.operator.failure_patterns import router as failure_router
    from server.operator.mastery import router as mastery_router

    reset_login_rate_limit()
    app = FastAPI()
    app.state.pg_store = pg_store
    app.add_middleware(SessionMiddleware, secret_key="test-secret-1234567890abcdef")
    app.include_router(auth_router)
    app.include_router(cohort_router)
    app.include_router(mastery_router)
    app.include_router(failure_router)
    app.include_router(credentials_router)
    return TestClient(app)


# ── Main e2e test ─────────────────────────────────────────────────────────


@pytest.mark.asyncio
async def test_aggregation_to_endpoint_e2e(pg_store):
    """12 distinct learners → non-suppressed; 5 distinct → suppressed."""
    # 1. Seed 12 distinct learners across 15 sessions for 'customer_service'.
    sessions = []
    for i in range(12):
        sessions.append(_session(f"learner-{i}", "customer_service", "pass"))
    for i in range(3):
        sessions.append(_session(f"learner-{i}", "customer_service", "fail"))
    await _seed_and_aggregate(pg_store, sessions)

    # 2. Seed 5 distinct learners for 'sales' (below threshold).
    sales_sessions = [_session(f"sales-{i}", "sales", "pass") for i in range(5)]
    await _seed_and_aggregate(pg_store, sales_sessions)

    client = _make_client(pg_store)
    with client:
        await _login_cookie(client, pg_store)

        # 3. GET /api/operator/cohort → non-suppressed for customer_service.
        r = client.get("/api/operator/cohort")
        assert r.status_code == 200, r.text
        body = r.json()
        paths = {v["path"] for v in body["views"]}
        assert "customer_service" in paths
        # 4. sales path cells should be suppressed (5 < 10).
        sales_view = next((v for v in body["views"] if v["path"] == "sales"), None)
        if sales_view:
            suppressed = [c for c in sales_view["metrics"] if c["cell_suppressed"]]
            assert suppressed, "sales (5 learners) must be suppressed"

        # customer_service (12 learners) should have non-suppressed cells.
        cs_view = next((v for v in body["views"] if v["path"] == "customer_service"), None)
        assert cs_view is not None
        non_suppressed = [c for c in cs_view["metrics"] if not c["cell_suppressed"]]
        assert non_suppressed, "customer_service (12 learners) should have non-suppressed cells"

        # 6. GET /api/operator/mastery
        r = client.get("/api/operator/mastery")
        assert r.status_code == 200

        # 7. GET /api/operator/failure-patterns
        r = client.get("/api/operator/failure-patterns")
        assert r.status_code == 200

        # 8. last_updated ≤ 24h (REQ-NFR-DASH-02)
        if body.get("last_updated"):
            ts = _dt.datetime.fromisoformat(body["last_updated"].replace("Z", "+00:00"))
            age = _dt.datetime.now(_dt.timezone.utc) - ts
            assert age < _dt.timedelta(hours=24), "freshness must be ≤ 24h"


@pytest.mark.asyncio
async def test_nightly_reconciliation_updates_last_updated(pg_store):
    from server.cohort.nightly import NightlyScheduler

    # Seed a few events via the aggregation hook first.
    sessions = [_session(f"r-learner-{i}", "recon_path", "pass") for i in range(11)]
    await _seed_and_aggregate(pg_store, sessions)

    # Run nightly reconciliation.
    sched = NightlyScheduler()
    # mastery_gate_events is the source for nightly — seed a gate event.
    async with pg_store.pool.acquire() as conn:
        await conn.execute("DELETE FROM mastery_gate_events")
        for i in range(11):
            await conn.execute(
                "INSERT INTO mastery_gate_events (learner_ref, scenario_id, path_id, "
                "gate_outcome, rubric_scores_jsonb, source) "
                "VALUES ($1, $2, $3, $4, $5::jsonb, 'sync')",
                f"r-learner-{i}", "recon_v01", "recon_path", "open",
                '[{"criterion_id":"empathy","score":4.0}]',
            )
    await sched.reconcile_now(pg_store)

    client = _make_client(pg_store)
    with client:
        await _login_cookie(client, pg_store)
        r = client.get("/api/operator/cohort")
        assert r.status_code == 200
        # last_updated should be very recent after reconciliation.
        body = r.json()
        if body.get("last_updated"):
            ts = _dt.datetime.fromisoformat(body["last_updated"].replace("Z", "+00:00"))
            age = _dt.datetime.now(_dt.timezone.utc) - ts
            assert age < _dt.timedelta(minutes=1), "nightly reconcile should refresh last_updated"


# ── G-038 e2e: differencing-attack at the API layer ────────────────────────


@pytest.mark.asyncio
async def test_g038_differencing_attack_api_layer(pg_store):
    """G-038: 10 learners in window A, 9 in window B. Verify GET /cohort
    cannot isolate the dropped learner — window B is fully suppressed."""
    # Window A: 10 learners on path 'diff_a'.
    a_sessions = [_session(f"a-{i}", "diff_a", "pass") for i in range(10)]
    await _seed_and_aggregate(pg_store, a_sessions)

    # Window B: 9 learners on path 'diff_b' (learner a-9 dropped).
    b_sessions = [_session(f"a-{i}", "diff_b", "pass") for i in range(9)]
    await _seed_and_aggregate(pg_store, b_sessions)

    client = _make_client(pg_store)
    with client:
        await _login_cookie(client, pg_store)
        r = client.get("/api/operator/cohort")
        assert r.status_code == 200
        body_text = r.text
        # The dropped learner's ref must not appear anywhere in the response.
        assert "a-9" not in body_text, "dropped learner must not be isolatable via API"

        # diff_b cells must all be suppressed (9 < 10).
        body = r.json()
        diff_b = next((v for v in body["views"] if v["path"] == "diff_b"), None)
        assert diff_b is not None
        for c in diff_b["metrics"]:
            assert c["cell_suppressed"] is True, "window B (9 learners) must be fully suppressed"
            assert c["value"] is None