md_to_gost/tests/test_mermaid_renderer.py

"""Tests for local Mermaid rendering chain."""

from __future__ import annotations

from pathlib import Path
from unittest.mock import patch

import pytest

from md2gost.diagram_renderer import configure_diagrams, render_diagram
from md2gost.mermaid_renderer import (
    CACHE_KEY_PREFIX,
    render_mermaid_local,
    write_mermaid_outputs,
)


def test_cache_key_prefix_stable():
    assert CACHE_KEY_PREFIX.startswith("mmd-local")


def test_prepare_mermaid_source_injects_init():
    from md2gost.mermaid_renderer import prepare_mermaid_source

    out = prepare_mermaid_source("flowchart LR\nA-->B", html_labels=True)
    assert out.startswith("%%{init")
    assert "htmlLabels': true" in out
    assert "flowchart LR" in out
    assert prepare_mermaid_source(out) == out

    qj = prepare_mermaid_source("flowchart LR\nA-->B", html_labels=False)
    assert "htmlLabels': false" in qj


def test_quickjs_cyrillic_no_foreign_object():
    """QuickJS uses htmlLabels:false → SVG text; resvg can paint Cyrillic."""
    from md2gost.mermaid_renderer import _render_quickjs

    got = _render_quickjs('flowchart LR\nA["Акционеры"] --> B["Тест"]', scale=1)
    assert got is not None
    svg, png = got
    assert "Акционеры" in svg
    assert "foreignObject" not in svg
    assert "<text" in svg
    assert png.startswith(b"\x89PNG")
    assert len(png) > 2000



def test_write_mermaid_outputs_quickjs(tmp_path, monkeypatch):
    png = b"\x89PNG\r\n\x1a\n" + b"\x00" * 40
    svg = '<svg xmlns="http://www.w3.org/2000/svg"><rect/></svg>'

    def fake_local(source, *, scale=1.0):
        assert "flowchart" in source
        return svg, png, "quickjs"

    monkeypatch.setattr(
        "md2gost.mermaid_renderer.render_mermaid_local", fake_local,
    )
    out_png = tmp_path / "a.png"
    out_svg = tmp_path / "a.svg"
    assert write_mermaid_outputs("flowchart LR\nA-->B", out_png, out_svg, scale=2)
    assert out_png.read_bytes().startswith(b"\x89PNG")
    assert "<svg" in out_svg.read_text(encoding="utf-8")


def test_render_mermaid_local_order_browser_then_quickjs(monkeypatch):
    calls = []

    def fake_browser(source, *, scale=1.0):
        calls.append("browser")
        return None

    def fake_qj(source, *, scale=1.0):
        calls.append("quickjs")
        return (
            '<svg xmlns="http://www.w3.org/2000/svg"/>',
            b"\x89PNG\r\n\x1a\n" + b"\x00" * 20,
        )

    monkeypatch.setattr("md2gost.mermaid_renderer._render_browser", fake_browser)
    monkeypatch.setattr("md2gost.mermaid_renderer._render_quickjs", fake_qj)
    got = render_mermaid_local("flowchart LR\nA-->B")
    assert got is not None
    assert got[2] == "quickjs"
    assert calls == ["browser", "quickjs"]


def test_render_diagram_uses_local_before_kroki(tmp_path):
    png = b"\x89PNG\r\n\x1a\n" + b"\x00" * 20
    svg = b'<svg xmlns="http://www.w3.org/2000/svg"/>'
    kroki_calls = []

    def fake_write(source, out_png, out_svg, *, scale=1.0):
        Path(out_png).write_bytes(png)
        if out_svg is not None:
            Path(out_svg).write_bytes(svg)
        return True

    def fake_kroki(source, diagram_type, base_url, out_path, fmt="png"):
        kroki_calls.append((diagram_type, fmt, base_url))
        return False

    configure_diagrams(fallback="remote", cache_dir=str(tmp_path), diagram_scale=2)
    with patch("md2gost.diagram_renderer._render_plantuml_jar", return_value=False), \
         patch("md2gost.mermaid_renderer.write_mermaid_outputs", side_effect=fake_write), \
         patch("md2gost.diagram_renderer._render_kroki", side_effect=fake_kroki):
        result = render_diagram(
            "mermaid", "flowchart LR\nA-->B", cache_dir=str(tmp_path),
        )
    assert kroki_calls == []
    assert Path(result.png_path).read_bytes().startswith(b"\x89PNG")
    assert result.pixel_scale == 2.0


def test_render_diagram_falls_to_kroki_if_local_fails(tmp_path):
    png = b"\x89PNG\r\n\x1a\n" + b"\x00" * 20
    kroki_calls = []

    def fake_write(*args, **kwargs):
        return False

    def fake_kroki(source, diagram_type, base_url, out_path, fmt="png"):
        kroki_calls.append((diagram_type, fmt, base_url))
        if fmt == "png":
            out_path.write_bytes(png)
        else:
            out_path.write_bytes(b"<svg xmlns='http://www.w3.org/2000/svg'/>")
        return True

    configure_diagrams(fallback="remote", cache_dir=str(tmp_path))
    with patch("md2gost.diagram_renderer._render_plantuml_jar", return_value=False), \
         patch("md2gost.mermaid_renderer.write_mermaid_outputs", side_effect=fake_write), \
         patch("md2gost.diagram_renderer._render_kroki", side_effect=fake_kroki):
        result = render_diagram("mermaid", "flowchart LR\nA-->B", cache_dir=str(tmp_path))
    assert any(t == "mermaid" and f == "png" for t, f, _ in kroki_calls)
    assert Path(result.png_path).read_bytes().startswith(b"\x89PNG")
    assert result.pixel_scale == 1.0


@pytest.mark.skipif(
    __import__("importlib").util.find_spec("mermaidx") is None,
    reason="mermaidx not installed",
)
def test_quickjs_real_render():
    from md2gost.mermaid_renderer import _render_quickjs

    got = _render_quickjs("flowchart LR\nA-->B", scale=1)
    assert got is not None
    svg, png = got
    assert "<svg" in svg.lower()
    assert png.startswith(b"\x89PNG")