"""Return the actual assembled embedded Overview HTML to simulated-browser tests."""
from pathlib import Path


def render_admin_index(root: Path) -> str:
    web = root / 'src/admin/web'
    html = (web / 'index.html').read_text(encoding='utf-8')
    metrics = (web / 'partials/overview-metrics.html').read_text(encoding='utf-8').split('<!-- RP_METRICS_SPLIT -->')
    charts = (web / 'partials/overview-charts.html').read_text(encoding='utf-8').split('<!-- RP_CHARTS_SPLIT -->')
    assert len(metrics) == len(charts) == 2
    for key, fragment in (
        ('METRICS_MAIN', metrics[0]), ('CHARTS_MAIN', charts[0]),
        ('METRICS_WEB', metrics[1]), ('CHARTS_WEB', charts[1]),
    ):
        marker = '<!-- RP_' + key + ' -->'
        assert html.count(marker) == 1
        html = html.replace(marker, fragment)
    return html