from __future__ import annotations

import pytest

from bedit_core.bondgraph import flatten_bondgraph
from bedit_core.models import (
    BondConnection,
    BondPort,
    Component,
    ComponentID,
    ConnectionID,
    EquationImplementation,
    Graph,
    GraphImplementation,
    Interface,
    PortID,
    SignalDirection,
)


def _leaf(name: str, port_id: PortID) -> Component:
    return Component(
        name=name,
        interface=Interface(
            {port_id: BondPort(name="p", direction=SignalDirection.INPUT)}
        ),
        parameters={},
        implementation=EquationImplementation(),
    )


@pytest.mark.unit
def test_flattens_bonds_across_a_component_boundary() -> None:
    boundary_id = PortID("boundary")
    inner_id = PortID("inner")
    outer_id = PortID("outer")
    inner = _leaf("Inner", inner_id)
    subsystem = Component(
        name="Subsystem",
        interface=Interface(
            {
                boundary_id: BondPort(
                    name="boundary",
                    direction=SignalDirection.INPUT,
                )
            }
        ),
        parameters={},
        implementation=GraphImplementation(
            Graph(
                components={ComponentID("inner"): inner},
                connections={
                    ConnectionID("inside"): BondConnection(
                        boundary_id,
                        inner_id,
                    )
                },
            )
        ),
    )
    outer = _leaf("Outer", outer_id)
    root = Component(
        name="Root",
        interface=Interface(),
        parameters={},
        implementation=GraphImplementation(
            Graph(
                components={
                    ComponentID("subsystem"): subsystem,
                    ComponentID("outer"): outer,
                },
                connections={
                    ConnectionID("outside"): BondConnection(
                        outer_id,
                        boundary_id,
                    )
                },
            )
        ),
    )

    network = flatten_bondgraph(root)
    boundary = next(port for port in network.ports if port.port_id == boundary_id)

    assert len(network.components) == 4
    assert len(network.ports) == 3
    assert len(network.bonds) == 2
    assert len(network.bonds_for(boundary)) == 2