"""
The renderer and the composer, tested the way a viewer can actually fail.

A picture that looks plausible while being wrong is worse than no picture, and
this is the first part of the system CIVICVS will judge by eye rather than by
test output. So the things asserted here are the ones an eye cannot check: that
the flip is applied exactly once, that holes are not filled in, that a cavity
really is larger than the stock inside it, and that a rejection reaches the
screen as a message rather than a stack trace.
"""

from __future__ import annotations

import re

import pytest

from mechcomp import svg

SQUARE = [[(0.0, 0.0), (10.0, 0.0), (10.0, 10.0), (0.0, 10.0)]]
WITH_HOLE = [
    [(0.0, 0.0), (10.0, 0.0), (10.0, 10.0), (0.0, 10.0)],
    [(4.0, 4.0), (6.0, 4.0), (6.0, 6.0), (4.0, 6.0)],
]


# ---------------------------------------------------------------------------
# The renderer
# ---------------------------------------------------------------------------

def test_every_ring_reaches_the_path():
    """A hole silently dropped would render as solid material."""
    d = svg.path_d(WITH_HOLE)
    assert d.count("M ") == 2, d
    assert d.count("Z") == 2
    assert "4 4" in d.replace(".0", "")


def test_holes_use_evenodd_so_winding_does_not_matter():
    """
    Ring winding is not something this module should have to know. evenodd
    renders a hole as a hole either way, and its absence is the difference
    between a bore and a solid plug.
    """
    out = svg.render(WITH_HOLE)
    assert out.count('fill-rule="evenodd"') >= 1


def test_degenerate_rings_are_skipped_not_emitted():
    assert svg.path_d([[(0.0, 0.0), (1.0, 1.0)]]) == ""
    assert svg.path_d([[]]) == ""


def test_the_vertical_flip_is_applied_exactly_once():
    """
    Geometry has +Y up, SVG has +Y down. Flipping twice, or not at all, gives a
    part that is upside down -- which for an asymmetric profile like T or A
    Frame is wrong in a way that is easy to miss and impossible to print
    around.
    """
    out = svg.render(SQUARE)
    assert out.count("scale(1,-1)") == 1
    assert len(re.findall(r"transform=", out)) == 1


def test_coordinates_are_left_in_geometry_space():
    """
    The flip is in the transform, so the numbers in the file are the geometry's
    own and can be read against the report. Negating them instead would make
    the file unreadable against anything.
    """
    out = svg.render(SQUARE)
    assert " 10 " in out or " 10 10" in out
    assert "-10" not in svg.path_d(SQUARE)


def test_viewbox_contains_the_geometry_plus_margin():
    out = svg.render(SQUARE, margin=3.0)
    vb = re.search(r'viewBox="([-\d. ]+)"', out).group(1).split()
    x0, y0, w, h = (float(v) for v in vb)
    assert x0 == pytest.approx(-3.0)
    assert y0 == pytest.approx(-3.0)
    assert w == pytest.approx(16.0)
    assert h == pytest.approx(16.0)


def test_layers_are_separately_classed():
    """
    ROADMAP section 4's stated reason for the port. A flattened silhouette
    would not have justified leaving OpenSCAD.
    """
    out = svg.render(SQUARE, cavities=WITH_HOLE, stock=[SQUARE[0]])
    for cls in ("mc-layer-material", "mc-layer-cavity", "mc-layer-stock"):
        assert cls in out, cls


def test_optional_layers_are_omitted_when_absent():
    out = svg.render(SQUARE)
    assert "mc-layer-material" in out
    assert "mc-layer-cavity" not in out
    assert "mc-layer-stock" not in out


def test_bounds_of_nothing_does_not_divide_by_zero():
    assert svg.bounds([]) == (-1.0, -1.0, 1.0, 1.0)
    assert svg.render([]).startswith("<svg")


# ---------------------------------------------------------------------------
# Against real geometry
# ---------------------------------------------------------------------------

def test_a_real_profile_renders_with_all_three_layers():
    build = pytest.importorskip("mechcomp.profiles").build

    result = build(family="3x", profile="Y", params={})
    out = svg.render_result(result)

    assert out.startswith("<svg") and out.rstrip().endswith("</svg>")
    for cls in ("mc-layer-material", "mc-layer-cavity", "mc-layer-stock"):
        assert cls in out, "%s missing from a real render" % cls
    assert out.count("scale(1,-1)") == 1


def test_the_cavity_is_drawn_larger_than_the_stock_in_it():
    """
    The fit gap is the reason to look at the picture at all. If cavity and stock
    render identically, the clearance is invisible and the viewer is useless for
    the one judgement it exists to support.
    """
    build = pytest.importorskip("mechcomp.profiles").build
    from mechcomp.geom.join import cavity_region
    from mechcomp.geom.records import strap_path
    from mechcomp.geom.region import area as region_area

    result = build(family="3x", profile="Y", params={"fit_clearance_mm": 0.4})
    cav = cavity_region(result.members, result.geo)
    stock = [strap_path(m, result.geo) for m in result.members]

    assert region_area(cav) > region_area(stock), (
        "cavity is not larger than the stock it holds")


def test_every_profile_in_both_families_renders():
    """A viewer that works for Y and breaks on Cross is not a catalogue."""
    profiles = pytest.importorskip("mechcomp.profiles")
    from mechcomp.web.app import families

    for name, family in families().items():
        for profile in sorted(family.catalogue):
            try:
                result = profiles.build(family=name, profile=profile, params={})
            except profiles.ProfileRejected:
                continue
            out = svg.render_result(result)
            assert out.startswith("<svg"), "%s/%s" % (name, profile)
            assert "mc-layer-material" in out, "%s/%s" % (name, profile)


# ---------------------------------------------------------------------------
# The composer payload
# ---------------------------------------------------------------------------

def test_binding_comes_from_the_deployment_not_from_a_guess(tmp_path,
                                                          monkeypatch):
    """
    The deployment already declares where this service lives. Inventing a
    port put it somewhere nginx does not look and, worse, on every interface
    the container has.
    """
    from mechcomp.web.app import base_url, resolve_binding

    for key in ("MECHCOMP_BIND", "MECHCOMP_PORT", "MECHCOMP_BASE_URL"):
        monkeypatch.delenv(key, raising=False)

    envf = tmp_path / "mechcomp.env"
    envf.write_text(
        "# staging\n"
        "MECHCOMP_ENV=staging\n"
        "MECHCOMP_BIND=10.20.0.10          # scalar; loopback is NOT bound\n"
        "MECHCOMP_PORT=8770\n"
        "MECHCOMP_BASE_URL=https://mechanical-compiler.dev.infra\n")

    assert resolve_binding(str(envf)) == ("10.20.0.10", 8770)
    assert base_url(str(envf)) == "https://mechanical-compiler.dev.infra"


def test_a_real_environment_variable_wins_over_the_file(tmp_path, monkeypatch):
    from mechcomp.web.app import resolve_binding

    envf = tmp_path / "mechcomp.env"
    envf.write_text("MECHCOMP_BIND=10.20.0.10\nMECHCOMP_PORT=8770\n")
    monkeypatch.setenv("MECHCOMP_PORT", "9001")
    monkeypatch.delenv("MECHCOMP_BIND", raising=False)

    assert resolve_binding(str(envf)) == ("10.20.0.10", 9001)


def test_the_fallback_is_loopback_never_every_interface(tmp_path, monkeypatch):
    """
    Behind a reverse proxy, binding too narrowly fails loudly as a 502 and
    binding too widely fails silently as an open service. If this ever
    returns 0.0.0.0 by default, the quiet failure is back.
    """
    from mechcomp.web.app import resolve_binding

    for key in ("MECHCOMP_BIND", "MECHCOMP_PORT"):
        monkeypatch.delenv(key, raising=False)

    host, port = resolve_binding(str(tmp_path / "absent.env"))
    assert host == "127.0.0.1", host
    assert host not in ("0.0.0.0", "::", ""), "bound every interface"
    assert port == 8770


def test_a_malformed_env_file_does_not_widen_the_binding(tmp_path, monkeypatch):
    from mechcomp.web.app import resolve_binding

    for key in ("MECHCOMP_BIND", "MECHCOMP_PORT"):
        monkeypatch.delenv(key, raising=False)

    envf = tmp_path / "mechcomp.env"
    envf.write_text("garbage\nMECHCOMP_PORT=not-a-number\n[section]\n")

    host, port = resolve_binding(str(envf))
    assert host == "127.0.0.1"
    assert port == 8770


def test_payload_carries_a_picture_a_report_and_an_identity():
    pytest.importorskip("mechcomp.profiles")
    from mechcomp.web.app import build_payload

    p = build_payload("3x", "Y", {})
    assert p["ok"] is True
    assert p["svg"].startswith("<svg")
    assert p["report"]["PROFILE"] == "Y"
    assert p["input_id"], "no design id on the payload"
    assert "MECHCOMP DESIGN RECORD" in p["record"]


def test_changing_a_control_changes_the_part_and_its_identity():
    """The composer's whole premise, end to end."""
    pytest.importorskip("mechcomp.profiles")
    from mechcomp.web.app import build_payload

    a = build_payload("3x", "Y", {"fit_clearance_mm": "0.15"})
    b = build_payload("3x", "Y", {"fit_clearance_mm": "0.35"})
    assert a["ok"] and b["ok"]
    assert a["svg"] != b["svg"], "the drawing did not change"
    assert a["input_id"] != b["input_id"], "two settings share one design id"


def test_form_strings_are_coerced_to_the_types_the_compiler_expects():
    """Everything arrives from a browser as text; ints must not become floats."""
    pytest.importorskip("mechcomp.profiles")
    from mechcomp.web.app import build_payload

    p = build_payload("3x", "Y", {"bundle_count": "2", "fit_clearance_mm": "0.3"})
    assert p["ok"] is True
    assert p["values"]["bundle_count"] == 2
    assert isinstance(p["values"]["bundle_count"], int)
    assert p["values"]["fit_clearance_mm"] == 0.3


def test_a_rejection_is_a_message_not_a_crash():
    """
    A rejection is the compiler working. It must read as an explanation on the
    screen, and it must still name the parameter and the limit.
    """
    pytest.importorskip("mechcomp.profiles")
    from mechcomp.web.app import build_payload

    p = build_payload("3x", "Y", {"min_wall_mm": "0"})
    assert p["ok"] is False
    assert p["message"].strip()
    assert "trace" not in p
    assert "min_wall_mm" in p["message"]


def test_nonsense_input_does_not_take_the_page_down():
    pytest.importorskip("mechcomp.profiles")
    from mechcomp.web.app import build_payload

    p = build_payload("3x", "Y", {"fit_clearance_mm": "banana",
                                  "not_a_parameter": "7"})
    assert "ok" in p
    assert "not_a_parameter" not in p["values"]


def test_controls_offered_are_relevant_to_the_selected_profile():
    """
    Thirty controls of which twenty do nothing is not a composer. Selecting Y
    must not present the Three-Fin parameters.
    """
    pytest.importorskip("mechcomp.profiles")
    from mechcomp.web.app import build_payload

    y = build_payload("3x", "Y", {})
    offered = {k for _, keys in y["groups"] for k in keys}
    assert any(k.startswith("y_") for k in offered)
    assert not any(k.startswith("three_fin_") for k in offered), sorted(offered)
    assert "strap_width_mm" in offered and "fit_clearance_mm" in offered


def test_every_offered_control_is_a_real_parameter():
    """A control that does nothing is worse than a missing one."""
    pytest.importorskip("mechcomp.profiles")
    from mechcomp.web.app import build_payload, families

    for name, family in families().items():
        for profile in sorted(family.catalogue):
            p = build_payload(name, profile, {})
            for _, keys in p["groups"]:
                for key in keys:
                    assert key in family.defaults, (
                        "%s/%s offers %s, which is not a parameter"
                        % (name, profile, key))