"""DFD Гейна–Сарсона: локальный Pillow, без Graphviz."""

from __future__ import annotations

from pathlib import Path
from unittest.mock import patch

import pytest

from md2gost.dfd_gs import (
    SAMPLE,
    DfdGsParseError,
    _arrange,
    parse_dfd_gs,
    render_dfd_gs,
)
from md2gost.diagram_renderer import (
    DIAGRAM_LANGS,
    configure_diagrams,
    is_diagram_lang,
    prepare_source,
    render_diagram,
)


def test_fence_aliases_do_not_steal_yourdon():
    assert is_diagram_lang("dfd-gs")
    assert is_diagram_lang("uml-dfd-gs")
    assert is_diagram_lang("gane-sarson")
    assert is_diagram_lang("uml-gane-sarson")
    assert "dfd-gs" in DIAGRAM_LANGS
    assert prepare_source("dfd-gs", SAMPLE)[1] == "dfd-gs"
    assert prepare_source("gane-sarson", SAMPLE)[1] == "dfd-gs"
    assert prepare_source("uml-dfd-gs", SAMPLE)[1] == "dfd-gs"
    assert prepare_source("dfd", "entity A Клиент\n")[1] == "dfd"
    assert prepare_source("uml-dfd", "entity A Клиент\n")[1] == "dfd"
    assert prepare_source("yourdon", "entity A Клиент\n")[1] == "dfd"


def test_badges_and_colon_label():
    diagram = parse_dfd_gs(
        """
        entity A Художник
        entity B Заказчик
        process Accept Принять заявку
        process 3.1 Проверить срок
        store Orders Заказы
        store D4 Акты
        A --> Accept : файлы работы
        """
    )
    by_id = {node.id: node for node in diagram.nodes}
    assert by_id["A"].badge == "1"
    assert by_id["B"].badge == "2"
    assert by_id["Accept"].badge == "1"
    assert by_id["3.1"].badge == "3.1"
    assert by_id["Orders"].badge == "D1"
    assert by_id["D4"].badge == "D4"
    assert diagram.flows[0].label == "файлы работы"
    assert diagram.form == "kit"
    assert diagram.title == ""


def test_store_code_skips_taken_numbers():
    diagram = parse_dfd_gs(
        """
        store D1 Заказы
        store Orders Журнал
        """
    )
    badges = {node.id: node.badge for node in diagram.nodes}
    assert badges == {"D1": "D1", "Orders": "D2"}


def test_parse_errors():
    with pytest.raises(DfdGsParseError, match="пустой"):
        parse_dfd_gs("  \n\n")
    with pytest.raises(DfdGsParseError, match="без узлов"):
        parse_dfd_gs("# только комментарий\n")
    with pytest.raises(DfdGsParseError, match="без узлов"):
        parse_dfd_gs("title Только шапка\n")
    with pytest.raises(DfdGsParseError, match="повтор"):
        parse_dfd_gs("entity A Один\nprocess A Два\n")
    with pytest.raises(DfdGsParseError, match="неизвестный узел"):
        parse_dfd_gs("entity A Один\nA --> B поток\n")
    with pytest.raises(DfdGsParseError, match="в себя"):
        parse_dfd_gs("entity A Один\nA --> A петля\n")
    with pytest.raises(DfdGsParseError, match="form"):
        parse_dfd_gs("form fancy\nentity A Один\n")
    with pytest.raises(DfdGsParseError, match="нет подписи"):
        parse_dfd_gs("process 1\n")


def test_columns_and_straight_arrow():
    diagram = parse_dfd_gs(
        """
        entity A Художник
        process P Принять
        store S Файлы
        A --> P заявка
        P --> S файл
        """
    )
    layout = _arrange(diagram, 1)
    assert layout.placed["A"].x < layout.placed["P"].x < layout.placed["S"].x
    straight = _arrange(
        parse_dfd_gs("entity A Художник\nprocess P Принять\nA --> P заявка\n"),
        1,
    )
    pts = straight.routes[0].pts
    assert len(pts) == 2
    assert abs(pts[0][1] - pts[1][1]) < 1


def test_opposite_flows_do_not_share_a_port():
    diagram = parse_dfd_gs(
        """
        process P Принять
        store S Заказы
        P --> S статус
        S --> P обновление
        """
    )
    layout = _arrange(diagram, 1)
    y1 = layout.routes[0].pts[0][1]
    y2 = layout.routes[1].pts[0][1]
    assert abs(y1 - y2) > 10


def test_stacked_processes_link_vertically():
    diagram = parse_dfd_gs(
        """
        process A Один
        process B Два
        A --> B дальше
        """
    )
    pts = _arrange(diagram, 1).routes[0].pts
    assert len(pts) == 2
    assert abs(pts[0][0] - pts[1][0]) < 1
    assert pts[0][1] < pts[1][1]


def test_skipped_process_is_an_elbow():
    diagram = parse_dfd_gs(
        """
        process A Один
        process B Два
        process C Три
        A --> C дальше
        """
    )
    pts = _arrange(diagram, 1).routes[0].pts
    assert len(pts) >= 3


def test_render_png_and_svg_without_graphviz():
    png, svg = render_dfd_gs(parse_dfd_gs(SAMPLE), scale=1)
    assert png.startswith(b"\x89PNG")
    assert svg is not None
    assert "USED AT" in svg
    assert "Тарасов" in svg
    assert "A44" in svg
    assert "rx=" in svg
    assert "Художник" in svg
    assert "rotate(-90" in svg
    assert "D2" in svg

    plain = parse_dfd_gs("form plain\nentity A Художник\nprocess P Принять\nA --> P заявка\n")
    _png, svg_plain = render_dfd_gs(plain, scale=1)
    assert "USED AT" not in (svg_plain or "")
    assert "rx=" in (svg_plain or "")


def test_render_diagram_skips_jar_and_kroki(tmp_path):
    calls = {"jar": 0, "kroki": 0}

    def fake_jar(*_args, **_kwargs):
        calls["jar"] += 1
        return False

    def fake_kroki(*_args, **_kwargs):
        calls["kroki"] += 1
        return False

    configure_diagrams(fallback="off", cache_dir=str(tmp_path), diagram_scale=1, diagram_format="svg")
    with patch("md2gost.diagram_renderer._render_plantuml_jar", side_effect=fake_jar), \
         patch("md2gost.diagram_renderer._render_kroki", side_effect=fake_kroki):
        result = render_diagram(
            "dfd-gs", SAMPLE, cache_dir=str(tmp_path), diagram_scale=1, diagram_format="svg",
        )
    assert calls["jar"] == 0
    assert calls["kroki"] == 0
    assert Path(result.png_path).read_bytes().startswith(b"\x89PNG")
    assert result.svg_path and Path(result.svg_path).read_text(encoding="utf-8").startswith("<svg")
    assert result.pixel_scale == 1


def test_render_diagram_bad_source(tmp_path):
    configure_diagrams(fallback="off", cache_dir=str(tmp_path))
    with pytest.raises(RuntimeError, match="пустой"):
        render_diagram("gane-sarson", "   ", cache_dir=str(tmp_path))