"""Vias keep hole-to-hole spacing, even within one net."""

from __future__ import annotations

import itertools
import math

from freeroute.dsn import parse_dsn
from freeroute.route.pipeline import route_dsn_board_exact

# four GND pads 0.5 mm apart over a GND plane: each drops a via to the plane
_DSN = """(pcb holes (parser) (resolution um 10) (unit um)
  (structure
    (layer F.Cu (type signal)) (layer In1.Cu (type power)) (layer In2.Cu (type power))
    (layer B.Cu (type signal))
    (boundary (path pcb 0  0 0  20000 0  20000 -20000  0 -20000  0 0))
    (plane GND (polygon In1.Cu 0  500 -500  19500 -500  19500 -19500  500 -19500  500 -500))
    (via "Via[0-3]_500:300_um") (rule (width 150) (clearance 150)))
  (placement (component S (place G1 9000 -10000 front 0) (place G2 9500 -10000 front 0)
                          (place G3 10000 -10000 front 0) (place G4 10500 -10000 front 0)))
  (library
    (image S (pin smd 1 0 0))
    (padstack smd (shape (rect F.Cu -150 -300 150 300)) (attach off))
    (padstack "Via[0-3]_500:300_um" (shape (circle F.Cu 500)) (shape (circle B.Cu 500)) (attach off)))
  (network (net GND (pins G1-1 G2-1 G3-1 G4-1))))"""


def test_a_nets_own_vias_keep_hole_to_hole_spacing():
    dsn = parse_dsn(_DSN)
    exact, scale, _ = route_dsn_board_exact(dsn, resolution=2)
    assert exact.result.failed == []
    vias = exact.result.vias[1]
    assert len(set(vias)) == len(vias), "a via written twice"
    need = (300 + 250) * scale  # drill + 0.25 mm, centre to centre
    for a, b in itertools.combinations(vias, 2):
        assert math.hypot(a.x - b.x, a.y - b.y) >= need, f"vias at {a} and {b} too close"


def test_connections_sharing_a_plane_via_write_it_once():
    # eight GND pads 0.4 mm apart: the hole spacing makes several of them
    # end on the same plane via, which must come out once, not once each
    pads = " ".join(f"(place G{i} {9000 + 400 * i} -10000 front 0)" for i in range(8))
    pins = " ".join(f"G{i}-1" for i in range(8))
    dsn = parse_dsn(
        _DSN.replace(
            "(place G1 9000 -10000 front 0) (place G2 9500 -10000 front 0)\n"
            "                          (place G3 10000 -10000 front 0) (place G4 10500 -10000 front 0)",
            pads,
        )
        .replace("(pins G1-1 G2-1 G3-1 G4-1)", f"(pins {pins})")
        .replace("(rect F.Cu -150 -300 150 300)", "(rect F.Cu -125 -300 125 300)")
    )
    exact, _scale, _ = route_dsn_board_exact(dsn, resolution=2)
    vias = exact.result.vias[1]
    assert len(vias) < 8, "no via is shared, so this board no longer tests sharing"
    assert len(set(vias)) == len(vias), "a shared via written more than once"