import json
import shutil
import subprocess
import sys
from pathlib import Path

from app.api.search_highlight import build_query_tokens, highlight_text


def _run_node_highlight(value: str, query: str):
    """Invoke Node to run client highlight.js and return tokens and html.

    Skips DOM and sanitizer loading by providing a minimal window with an
    escape() function that mirrors server escaping behavior.
    """
    node_path = shutil.which("node")
    if not node_path:
        return None

    repo_root = Path(__file__).resolve().parents[1]
    highlight_js_path = repo_root / "static/js/highlight.js"
    if not highlight_js_path.exists():
        return None

    payload = json.dumps({"value": value, "query": query})
    script = f"""
      const fs = require('fs');
      global.window = {{}};
      // Provide escape that matches server: replace &, <, >, ", '
      window.htmlSanitizer = {{
        escape: function(text) {{
          const str = String(text == null ? '' : text);
          return str
            .replace(/&/g, '&amp;')
            .replace(/</g, '&lt;')
            .replace(/>/g, '&gt;')
            .replace(/"/g, '&quot;')
            .replace(/'/g, '&#39;');
        }}
      }};
      require('{highlight_js_path.as_posix()}');
      const input = JSON.parse(process.argv[2]);
      const tokens = window.highlightUtils.buildTokens(input.query);
      const html = window.highlightUtils.highlight(input.value, tokens);
      process.stdout.write(JSON.stringify({{ tokens, html }}));
    """
    res = subprocess.run(
        [node_path, "-e", script, payload],
        cwd=str(repo_root),
        capture_output=True,
        text=True,
    )
    if res.returncode != 0:
        return None
    return json.loads(res.stdout)


def test_highlight_parity_with_client_when_node_available():
    """Compare tokens and highlighted HTML between server and client implementations.

    This test is skipped when Node is unavailable.
    """
    samples = [
        ("Hello John Smith", "john smith"),
        ("<b>A&B</b> and C", "a b"),
        ("Anna and Ann went", "ann anna"),
        ("He said \"Hello\" & it's fine", "hello"),
        ("Case 12345", "case 123"),
    ]

    for value, query in samples:
        client = _run_node_highlight(value, query)
        if client is None:
            # Skip gracefully if Node not present or script failed
            import pytest
            pytest.skip("Node or client highlight not available")
        server_tokens = build_query_tokens(query)
        server_html = highlight_text(value, server_tokens)
        assert client["tokens"] == server_tokens
        assert client["html"] == server_html