"""Scene/interaction tests: node items, port connect, move reroute, delete, undo."""
import pytest

from pipeline_editor.config import AppConfig
from pipeline_editor.controller import EditorController
from pipeline_editor.model.document import DiagramDocument
from pipeline_editor.model.node_library import default_library
from pipeline_editor.view.node_item import NodeItem
from pipeline_editor.view.edge_item import EdgeItem
from pipeline_editor.view.scene import DiagramScene


@pytest.fixture
def env(qapp):
    doc = DiagramDocument()
    lib = default_library()
    ctrl = EditorController(doc, lib)
    cfg = AppConfig()
    scene = DiagramScene(doc, cfg, controller=ctrl)
    return doc, lib, ctrl, cfg, scene


def test_add_node_creates_item(env):
    doc, lib, ctrl, cfg, scene = env
    node = scene.create_node("pump", 100, 100)
    assert node is not None
    assert node.node_id in scene.node_items
    assert isinstance(scene.node_items[node.node_id], NodeItem)


def test_connect_ports_creates_edge_item(env):
    doc, lib, ctrl, cfg, scene = env
    a = ctrl.add_node("source", 0, 100)
    b = ctrl.add_node("pump", 200, 100)
    src_port = scene.node_items[a.node_id].port_item("out")
    dst_port = scene.node_items[b.node_id].port_item("in")
    scene._begin_edge(src_port)
    scene._finish_edge(dst_port)
    assert len(scene.edge_items) == 1
    edge = next(doc.edges())
    assert edge.source_node == a.node_id and edge.target_node == b.node_id


def test_incompatible_ports_do_not_connect(env):
    doc, lib, ctrl, cfg, scene = env
    a = ctrl.add_node("source", 0, 100)        # water
    t = ctrl.add_node("transformer", 200, 100)  # power
    scene._begin_edge(scene.node_items[a.node_id].port_item("out"))
    scene._finish_edge(scene.node_items[t.node_id].port_item("hv"))
    assert len(scene.edge_items) == 0


def test_move_node_reroutes_edge(env):
    doc, lib, ctrl, cfg, scene = env
    a = ctrl.add_node("source", 0, 100)
    b = ctrl.add_node("pump", 200, 100)
    ctrl.connect(a.node_id, "out", b.node_id, "in")
    edge_item = next(iter(scene.edge_items.values()))
    before = edge_item.path_points()[-1]
    # move target node down; edge end should follow
    scene.node_items[b.node_id].setPos(200, 300)
    after = edge_item.path_points()[-1]
    assert after != before
    assert after[1] > before[1]


def test_selection_emits_model(env):
    doc, lib, ctrl, cfg, scene = env
    a = ctrl.add_node("pump", 0, 0)
    received = []
    scene.selection_changed.connect(lambda m: received.append(m))
    scene.node_items[a.node_id].setSelected(True)
    assert received and received[-1] is a


def test_delete_and_undo_roundtrip(env):
    doc, lib, ctrl, cfg, scene = env
    a = ctrl.add_node("source", 0, 100)
    b = ctrl.add_node("pump", 200, 100)
    ctrl.connect(a.node_id, "out", b.node_id, "in")
    assert len(scene.edge_items) == 1

    ctrl.delete(node_ids=[a.node_id])
    assert a.node_id not in scene.node_items
    assert len(scene.edge_items) == 0  # cascaded

    ctrl.undo()
    assert a.node_id in scene.node_items
    assert len(scene.edge_items) == 1  # edge restored


def test_move_undo(env):
    doc, lib, ctrl, cfg, scene = env
    a = ctrl.add_node("pump", 40, 40)
    ctrl.record_move(a.node_id, (40, 40), (120, 200))
    assert (a.x, a.y) == (120, 200)
    ctrl.undo()
    assert (a.x, a.y) == (40, 40)
    assert scene.node_items[a.node_id].pos().x() == 40