"""Tests for the 999 ACK migration + ORM + store helpers (SP3 P3 T13)."""
from __future__ import annotations

import json
from datetime import datetime, timezone
from pathlib import Path

import pytest
import sqlalchemy as sa

from cyclone import db, db_migrate
from cyclone.db import Ack
from cyclone.store import store


@pytest.fixture(autouse=True)
def _setup(tmp_path, monkeypatch):
    monkeypatch.setenv("CYCLONE_DB_URL", f"sqlite:///{tmp_path}/test.db")
    db._reset_for_tests()
    db.init_db()
    yield
    db._reset_for_tests()


def _make_batch(batch_id: str = "b-1") -> None:
    """Insert a stub batches row so the acks.source_batch_id FK resolves."""
    from cyclone.db import Batch
    with db.SessionLocal()() as s:
        s.add(Batch(
            id=batch_id, kind="837p", input_filename="x",
            parsed_at=datetime(2026, 6, 20, 12, 0, tzinfo=timezone.utc),
        ))
        s.commit()


def test_migration_0002_creates_acks_table():
    """On a fresh DB the migration runner must create the `acks` table."""
    inspector = sa.inspect(db.engine())
    assert "acks" in inspector.get_table_names()
    # The index declared in 0002_acks.sql must also exist.
    indexes = {ix["name"] for ix in inspector.get_indexes("acks")}
    assert "ix_acks_source_batch_id" in indexes
    # And the column list matches the spec.
    cols = {c["name"] for c in inspector.get_columns("acks")}
    expected = {
        "id", "source_batch_id", "accepted_count", "rejected_count",
        "received_count", "ack_code", "parsed_at", "raw_json",
    }
    assert expected <= cols  # spec columns are all present


def test_migration_latest_idempotent_on_fresh_db():
    """Re-running the migration on the same DB must be a no-op (PRAGMA
    user_version already at the latest version — currently 16 after
    0004-0006 line_reconciliation, 0005 ta1_acks, SP9's 0007
    providers/payers/clearhouse, SP10's 0008 payer_rejected,
    SP11's 0009 audit_log, SP14's 0010 payer_rejected_acknowledged,
    SP16's 0011 processed_inbound_files, SP17's 0012 db_backups,
    SP-auth's 0013 users + sessions, SP-audit's 0014 audit_log.user_id,
    SP22's 0015 drop_claims_unique_constraint, SP27-Task 11's 0016
    claims.matched_remittance_id index, SP27-Task 17's 0017
    claim.patient_control_number backfill UPDATE)."""
    with db.engine().begin() as c:
        v1 = c.exec_driver_sql("PRAGMA user_version").scalar() or 0
    assert v1 == 17
    # A second run should not raise and should not bump the version.
    db_migrate.run(db.engine())
    with db.engine().begin() as c:
        v2 = c.exec_driver_sql("PRAGMA user_version").scalar() or 0
    assert v2 == 17


def test_add_ack_persists_row():
    _make_batch("b-1")
    row = store.add_ack(
        source_batch_id="b-1",
        accepted_count=3,
        rejected_count=1,
        received_count=4,
        ack_code="P",
        raw_json={"envelope": {"control_number": "0001"}, "set_count": 1},
    )
    assert row.id is not None
    assert row.source_batch_id == "b-1"
    assert row.accepted_count == 3
    assert row.rejected_count == 1
    assert row.received_count == 4
    assert row.ack_code == "P"
    assert row.raw_json == {"envelope": {"control_number": "0001"}, "set_count": 1}
    # Round-trip: fetch from the same session.
    with db.SessionLocal()() as s:
        loaded = s.get(Ack, row.id)
        assert loaded is not None
        assert loaded.ack_code == "P"
        assert loaded.raw_json == {"envelope": {"control_number": "0001"}, "set_count": 1}


def test_list_acks_newest_first():
    _make_batch("b-1")
    # Insert two rows in a known order; the second must come first.
    a1 = store.add_ack(
        source_batch_id="b-1", accepted_count=1, rejected_count=0,
        received_count=1, ack_code="A", raw_json={"order": 1},
    )
    a2 = store.add_ack(
        source_batch_id="b-1", accepted_count=0, rejected_count=1,
        received_count=1, ack_code="R", raw_json={"order": 2},
    )
    rows = store.list_acks()
    assert len(rows) == 2
    # Newest first means a2 should be at index 0 (auto-increment id desc).
    assert rows[0].id == a2.id
    assert rows[1].id == a1.id
    assert rows[0].ack_code == "R"
    assert rows[1].ack_code == "A"


def test_get_ack_returns_none_for_missing():
    assert store.get_ack(99999) is None


def test_get_ack_returns_row_when_present():
    _make_batch("b-1")
    row = store.add_ack(
        source_batch_id="b-1", accepted_count=1, rejected_count=0,
        received_count=1, ack_code="A", raw_json={"hello": "world"},
    )
    fetched = store.get_ack(row.id)
    assert fetched is not None
    assert fetched.id == row.id
    assert fetched.source_batch_id == "b-1"
    assert fetched.raw_json == {"hello": "world"}


# ---------------------------------------------------------------------------
# Hotfix 2026-06-29: acks list endpoint silently capped at limit=100
# without exposing the true total or full-set aggregates, so the Acks page
# rendered "100 on file" and KPI totals summed from the page only when the
# row count exceeded 100. These tests pin the new offset param + the
# server-side `aggregates` field so the silent-failure mode can't regress.
# ---------------------------------------------------------------------------


def _seed_acks(n: int) -> list[int]:
    """Insert n ack rows with deterministic per-row counts. Returns the ids."""
    _make_batch("b-hotfix")
    ids: list[int] = []
    for i in range(n):
        row = store.add_ack(
            source_batch_id="b-hotfix",
            accepted_count=i + 1,
            rejected_count=i,
            received_count=i + 1,
            ack_code="A",
            raw_json={"order": i},
        )
        ids.append(row.id)
    return ids


def test_list_acks_endpoint_pagination_offsets_correctly():
    """`offset` walks the full set, `has_more` flips at the boundary."""
    from fastapi.testclient import TestClient
    from cyclone.api import app
    from cyclone.auth.users import create
    from cyclone.db import SessionLocal

    with SessionLocal()() as s:
        create(s, username="u", password="p", role="admin")
        s.commit()
    client = TestClient(app)
    client.post("/api/auth/login", json={"username": "u", "password": "p"})

    _seed_acks(5)

    r = client.get("/api/acks?limit=2&offset=0")
    d = r.json()
    assert d["total"] == 5
    assert d["returned"] == 2
    assert d["has_more"] is True
    assert len(d["items"]) == 2

    r = client.get("/api/acks?limit=2&offset=4")
    d = r.json()
    assert d["total"] == 5
    assert d["returned"] == 1
    assert d["has_more"] is False
    assert len(d["items"]) == 1


def test_list_acks_endpoint_aggregates_reflect_full_set():
    """`aggregates` sums over the full row set, not the page.

    Without this the Acks KPI strip silently under-reports once the
    row count exceeds the page size — the silent-failure the operator
    flagged on 2026-06-29.
    """
    from fastapi.testclient import TestClient
    from cyclone.api import app
    from cyclone.auth.users import create
    from cyclone.db import SessionLocal

    with SessionLocal()() as s:
        create(s, username="u", password="p", role="admin")
        s.commit()
    client = TestClient(app)
    client.post("/api/auth/login", json={"username": "u", "password": "p"})

    # 5 rows: accepted = 1+2+3+4+5 = 15, rejected = 0+1+2+3+4 = 10,
    # received = same as accepted.
    _seed_acks(5)

    # Page 1 of 2 — full set is 5 rows, page only shows 2, but aggregates
    # must reflect all 5.
    r = client.get("/api/acks?limit=2&offset=0")
    d = r.json()
    assert d["total"] == 5
    assert d["returned"] == 2
    assert d["aggregates"]["accepted_count"] == 15
    assert d["aggregates"]["rejected_count"] == 10
    assert d["aggregates"]["received_count"] == 15

    # Page 2 must return identical aggregates — page slice mustn't shift them.
    r = client.get("/api/acks?limit=2&offset=2")
    d = r.json()
    assert d["aggregates"]["accepted_count"] == 15
    assert d["aggregates"]["rejected_count"] == 10
    assert d["aggregates"]["received_count"] == 15


def test_list_acks_endpoint_limit_cap_is_5000():
    """The validator still enforces an upper bound so a client can't
    request 1,000,000 rows and OOM the SQLite-backed list call."""
    from fastapi.testclient import TestClient
    from cyclone.api import app
    from cyclone.auth.users import create
    from cyclone.db import SessionLocal

    with SessionLocal()() as s:
        create(s, username="u", password="p", role="admin")
        s.commit()
    client = TestClient(app)
    client.post("/api/auth/login", json={"username": "u", "password": "p"})

    r = client.get("/api/acks?limit=10000")
    assert r.status_code == 422  # FastAPI validation error

    r = client.get("/api/acks?limit=5000")
    assert r.status_code == 200


def test_list_acks_endpoint_offset_past_end_returns_empty_page():
    """`offset` past the row count must yield an empty page, not 500.

    Pinning this so a future refactor that introduces streaming or
    cursor-based pagination can't accidentally error or 500 when the
    UI holds stale page state across a row count change.
    """
    from fastapi.testclient import TestClient
    from cyclone.api import app
    from cyclone.auth.users import create
    from cyclone.db import SessionLocal

    with SessionLocal()() as s:
        create(s, username="u", password="p", role="admin")
        s.commit()
    client = TestClient(app)
    client.post("/api/auth/login", json={"username": "u", "password": "p"})

    _seed_acks(3)

    r = client.get("/api/acks?limit=2&offset=99")
    assert r.status_code == 200
    d = r.json()
    assert d["total"] == 3
    assert d["returned"] == 0
    assert d["has_more"] is False
    assert d["items"] == []
    # Aggregates must still reflect the full 3-row set on the empty page —
    # otherwise a stale UI page state would silently zero out the KPI strip.
    assert d["aggregates"]["accepted_count"] == 1 + 2 + 3
    assert d["aggregates"]["rejected_count"] == 0 + 1 + 2
    assert d["aggregates"]["received_count"] == 1 + 2 + 3
