"""Tests for pure helpers in mytoolkit.md_to_pdf (no pandoc/typst needed)."""

import shutil

import pytest

from mytoolkit.md_to_pdf import (
    _consume_balanced,
    _longest_backtick_run,
    _odd_fenced_code_before,
    _typst_raw_fence,
    preprocess_typst_callouts,
    resolve_markdown_image_paths,
)


class TestResolveMarkdownImagePaths:
    def test_relative_path_resolved_when_file_exists(self, tmp_path):
        (tmp_path / "figs").mkdir()
        (tmp_path / "figs" / "a.png").write_bytes(b"png")
        out = resolve_markdown_image_paths("![alt](figs/a.png)", tmp_path)
        assert out == f"![alt]({tmp_path / 'figs' / 'a.png'})"

    def test_missing_file_left_unchanged(self, tmp_path):
        md = "![alt](figs/nope.png)"
        assert resolve_markdown_image_paths(md, tmp_path) == md

    @pytest.mark.parametrize(
        "src",
        ["https://x.com/a.png", "http://x.com/a.png", "data:image/png;base64,AA", "#frag"],
    )
    def test_urls_and_anchors_untouched(self, tmp_path, src):
        md = f"![alt]({src})"
        assert resolve_markdown_image_paths(md, tmp_path) == md

    def test_absolute_path_untouched(self, tmp_path):
        md = "![alt](/abs/path/a.png)"
        assert resolve_markdown_image_paths(md, tmp_path) == md

    def test_html_img_tag_resolved(self, tmp_path):
        (tmp_path / "a.png").write_bytes(b"png")
        out = resolve_markdown_image_paths('<img src="a.png" width="50%">', tmp_path)
        assert out == f'<img src="{tmp_path / "a.png"}" width="50%">'


class TestBacktickFenceHelpers:
    @pytest.mark.parametrize(
        ("s", "expected"),
        [("", 0), ("a`b", 1), ("``x```y", 3), ("````", 4)],
    )
    def test_longest_backtick_run(self, s, expected):
        assert _longest_backtick_run(s) == expected

    def test_raw_fence_at_least_three(self):
        assert _typst_raw_fence("plain") == "```"

    def test_raw_fence_exceeds_inner_run(self):
        assert _typst_raw_fence("has ``` inside") == "````"


class TestBalancedConsume:
    def test_simple(self):
        assert _consume_balanced("(a(b)c)", 0, "(", ")") == 7

    def test_not_open_char(self):
        assert _consume_balanced("x()", 0, "(", ")") is None

    def test_unbalanced(self):
        assert _consume_balanced("(a(b)", 0, "(", ")") is None

    def test_quoted_chars_ignored(self):
        assert _consume_balanced('(")")x', 0, "(", ")") == 5


class TestOddFencedCode:
    def test_inside_fence(self):
        md = "```\ncode\n"
        assert _odd_fenced_code_before(md, len(md)) is True

    def test_outside_fence(self):
        md = "```\ncode\n```\n"
        assert _odd_fenced_code_before(md, len(md)) is False


@pytest.mark.skipif(not shutil.which("pandoc"), reason="pandoc not installed")
class TestPreprocessTypstCallouts:
    def test_info_box_wrapped_in_raw_typst(self):
        md = "#info-box[\nHello **world**\n]\n"
        out = preprocess_typst_callouts(md)
        assert "{=typst}" in out
        assert "#info-box[" in out

    def test_callout_inside_code_fence_untouched(self):
        md = "```\n#info-box[\nx\n]\n```\n"
        assert preprocess_typst_callouts(md) == md