from __future__ import annotations

import pytest
from fastapi import Depends, FastAPI
from fastapi.testclient import TestClient
from sqlalchemy import create_engine
from sqlalchemy.orm import Session, sessionmaker
from sqlalchemy.pool import StaticPool

from app.core.access import (
    INTERNAL_USER_SUBJECT,
    get_user_permissions,
    require_all_permissions,
    require_any_permission,
    require_permission,
    user_has_permission,
)
from app.core.security import issue_token
from app.db.session import Base, get_db
from app.models.access import Permission, Role, User
from app.seed_access import PERMISSION_DEFINITIONS, ROLE_DEFINITIONS, SEED_USERS, seed_access


def _build_session() -> Session:
    engine = create_engine(
        "sqlite:///:memory:",
        connect_args={"check_same_thread": False},
        poolclass=StaticPool,
    )
    Base.metadata.create_all(bind=engine)
    return sessionmaker(bind=engine, expire_on_commit=False)()


# --- Seed + permission lookup ----------------------------------------------


def test_seed_creates_roles_permissions_and_users():
    db = _build_session()
    seed_access(db)
    db.commit()

    assert {role.name for role in db.query(Role).all()} == set(ROLE_DEFINITIONS.keys())
    assert {p.key for p in db.query(Permission).all()} == {key for key, _ in PERMISSION_DEFINITIONS}
    assert {user.email for user in db.query(User).all()} == {entry["email"] for entry in SEED_USERS}


def test_seed_is_idempotent():
    db = _build_session()
    seed_access(db)
    db.commit()
    seed_access(db)
    db.commit()

    assert db.query(User).count() == len(SEED_USERS)
    assert db.query(Role).count() == len(ROLE_DEFINITIONS)
    assert db.query(Permission).count() == len(PERMISSION_DEFINITIONS)


def test_admin_role_permissions_match_spec():
    db = _build_session()
    seed_access(db)

    admin = db.query(User).filter_by(email="admin@hunterstockfeeds.com").one()
    granted = get_user_permissions(admin)

    assert granted == set(ROLE_DEFINITIONS["Admin"]["permissions"])
    assert "manage_users" in granted
    assert "manage_permissions" in granted
    # Admin spec deliberately excludes edit_products / edit_mixes.
    assert "edit_products" not in granted
    assert "edit_mixes" not in granted


def test_operations_role_is_mix_calculator_only():
    db = _build_session()
    seed_access(db)

    ops = db.query(User).filter_by(email="ops@hunterstockfeeds.com").one()
    granted = get_user_permissions(ops)

    assert granted == {"view_mix_calculator", "use_mix_calculator", "save_mix_calculator_session"}
    assert not user_has_permission(ops, "edit_raw_materials")
    assert not user_has_permission(ops, "view_dashboard")
    assert not user_has_permission(ops, "manage_users")


def test_full_access_role_can_edit_operational_data_but_not_users():
    db = _build_session()
    seed_access(db)

    craig = db.query(User).filter_by(email="craig@hunterstockfeeds.com").one()
    granted = get_user_permissions(craig)

    assert {"edit_raw_materials", "edit_products", "edit_mixes", "save_mix_calculator_session"} <= granted
    assert "manage_users" not in granted
    assert "manage_permissions" not in granted


def test_inactive_user_has_no_permissions():
    db = _build_session()
    seed_access(db)

    admin = db.query(User).filter_by(email="admin@hunterstockfeeds.com").one()
    admin.is_active = False

    assert get_user_permissions(admin) == set()
    assert not user_has_permission(admin, "view_dashboard")


def test_unknown_user_has_no_permissions():
    assert get_user_permissions(None) == set()
    assert not user_has_permission(None, "view_dashboard")


def test_user_without_role_has_no_permissions():
    db = _build_session()
    seed_access(db)

    orphan = User(email="nobody@hunterstockfeeds.com", name="Nobody", role_id=None, is_active=True)
    db.add(orphan)
    db.flush()

    assert get_user_permissions(orphan) == set()


# --- Route-level enforcement -----------------------------------------------


@pytest.fixture()
def app_and_db():
    db = _build_session()
    seed_access(db)
    db.commit()

    app = FastAPI()

    def override_get_db():
        yield db

    app.dependency_overrides[get_db] = override_get_db

    @app.get("/needs-edit-raw")
    def needs_edit_raw(_: User = Depends(require_permission("edit_raw_materials"))):
        return {"ok": True}

    @app.get("/needs-any")
    def needs_any(_: User = Depends(require_any_permission(["edit_raw_materials", "manage_users"]))):
        return {"ok": True}

    @app.get("/needs-all")
    def needs_all(_: User = Depends(require_all_permissions(["view_raw_materials", "edit_raw_materials"]))):
        return {"ok": True}

    return TestClient(app), db


def _token_for(user: User) -> str:
    return issue_token({"sub": INTERNAL_USER_SUBJECT, "user_id": user.id, "email": user.email})


def test_route_allows_user_with_permission(app_and_db):
    client, db = app_and_db
    craig = db.query(User).filter_by(email="craig@hunterstockfeeds.com").one()

    response = client.get("/needs-edit-raw", headers={"Authorization": f"Bearer {_token_for(craig)}"})
    assert response.status_code == 200


def test_route_denies_user_without_permission(app_and_db):
    client, db = app_and_db
    ops = db.query(User).filter_by(email="ops@hunterstockfeeds.com").one()

    response = client.get("/needs-edit-raw", headers={"Authorization": f"Bearer {_token_for(ops)}"})
    assert response.status_code == 403
    assert "edit_raw_materials" in response.json()["detail"]


def test_route_denies_inactive_user(app_and_db):
    client, db = app_and_db
    craig = db.query(User).filter_by(email="craig@hunterstockfeeds.com").one()
    craig.is_active = False
    db.commit()

    response = client.get("/needs-edit-raw", headers={"Authorization": f"Bearer {_token_for(craig)}"})
    assert response.status_code == 403


def test_route_denies_missing_token(app_and_db):
    client, _ = app_and_db
    response = client.get("/needs-edit-raw")
    assert response.status_code == 401


def test_route_denies_token_with_wrong_subject(app_and_db):
    client, db = app_and_db
    craig = db.query(User).filter_by(email="craig@hunterstockfeeds.com").one()
    forged = issue_token({"sub": "client", "user_id": craig.id})

    response = client.get("/needs-edit-raw", headers={"Authorization": f"Bearer {forged}"})
    assert response.status_code == 401


def test_route_denies_unknown_user_id(app_and_db):
    client, _ = app_and_db
    forged = issue_token({"sub": INTERNAL_USER_SUBJECT, "user_id": 999_999})

    response = client.get("/needs-edit-raw", headers={"Authorization": f"Bearer {forged}"})
    assert response.status_code == 401


def test_require_any_permission_passes_with_one_match(app_and_db):
    client, db = app_and_db
    craig = db.query(User).filter_by(email="craig@hunterstockfeeds.com").one()  # has edit_raw_materials

    response = client.get("/needs-any", headers={"Authorization": f"Bearer {_token_for(craig)}"})
    assert response.status_code == 200


def test_require_any_permission_denies_when_none_match(app_and_db):
    client, db = app_and_db
    ops = db.query(User).filter_by(email="ops@hunterstockfeeds.com").one()

    response = client.get("/needs-any", headers={"Authorization": f"Bearer {_token_for(ops)}"})
    assert response.status_code == 403


def test_require_all_permissions(app_and_db):
    client, db = app_and_db
    admin = db.query(User).filter_by(email="admin@hunterstockfeeds.com").one()
    ops = db.query(User).filter_by(email="ops@hunterstockfeeds.com").one()

    ok = client.get("/needs-all", headers={"Authorization": f"Bearer {_token_for(admin)}"})
    assert ok.status_code == 200

    denied = client.get("/needs-all", headers={"Authorization": f"Bearer {_token_for(ops)}"})
    assert denied.status_code == 403