<?php
if (!defined('ABSPATH')) exit;

add_action('admin_menu', 'wph_register_menu');
add_action('admin_post_wph_start', 'wph_handle_start');
add_action('admin_post_wph_save_step', 'wph_handle_save_step');
add_action('admin_post_wph_finish', 'wph_handle_finish');
add_action('admin_post_wph_discard', 'wph_handle_discard');
add_action('admin_post_wph_download_report', 'wph_handle_download_report');
add_action('admin_post_wph_refresh_checks', 'wph_handle_refresh_checks');
add_action('admin_post_wph_download_html', 'wph_handle_download_html');
add_action('admin_post_wph_email_report', 'wph_handle_email_report');
add_action('admin_post_wph_step_action', 'wph_handle_step_action');
add_action('admin_enqueue_scripts', 'wph_enqueue_assets');

function wph_register_menu(): void {
    add_management_page(
        'Site Healthcheck',
        'Site Healthcheck',
        'manage_options',
        'site-healthcheck',
        'wph_render_admin_page'
    );
}

function wph_enqueue_assets($hook): void {
    if ($hook !== 'tools_page_site-healthcheck') return;
    wp_register_style('wph-admin', false);
    wp_enqueue_style('wph-admin');
    wp_add_inline_style('wph-admin', wph_inline_css());
}

function wph_inline_css(): string {
    return '
        .wph-card { background:#fff; border:1px solid #c3c4c7; border-radius:6px; padding:1rem 1.25rem; margin-bottom:1rem; }
        .wph-card h2 { margin-top:0; }
        .wph-step-status { display:inline-block; padding:.1rem .55rem; border-radius:10px; font-size:11px; font-weight:600; text-transform:uppercase; letter-spacing:.04em; }
        .wph-status-not_started { background:#f0f0f1; color:#646970; }
        .wph-status-done { background:#def7e3; color:#155724; }
        .wph-status-skipped { background:#fff3cd; color:#856404; }
        .wph-status-blocked { background:#fbeae8; color:#721c24; }
        .wph-status-n_a { background:#e2e3e5; color:#41464b; }
        .wph-step { padding:1rem 1.25rem; border:1px solid #dcdcde; border-radius:6px; margin-bottom:.75rem; background:#fff; }
        .wph-step header { display:flex; justify-content:space-between; align-items:center; gap:1rem; margin-bottom:.5rem; }
        .wph-step header h2 { margin:0; font-size:1.1rem; }
        .wph-sub-items { margin:.5rem 0 .75rem 1.25rem; padding:0; }
        .wph-sub-items li { margin:.15rem 0; }
        .wph-watch-outs { background:#fff8e1; border-left:3px solid #f5b800; padding:.4rem .8rem; margin:.5rem 0; font-size:.92em; }
        .wph-watch-outs strong { display:block; margin-bottom:.2rem; }
        .wph-escalation { background:#fbeae8; border-left:3px solid #c0392b; padding:.4rem .8rem; margin:.5rem 0; font-weight:500; }
        .wph-step textarea { width:100%; min-height:60px; }
        .wph-progress { font-weight:600; }
        .wph-ok { color:#155724; }
        .wph-warn { color:#856404; }
        .wph-bad { color:#721c24; }
        .wph-bootstrap-panel { padding:.6rem 1rem; background:#f6f7f7; border:1px solid #dcdcde; border-radius:6px; margin-bottom:.75rem; }
        .wph-bootstrap-panel h3 { margin:0 0 .35rem; font-size:1rem; }
        .wph-actions { display:flex; gap:.5rem; align-items:center; margin-top:.4rem; }
        .wph-autocheck { background:#f6f7f7; border:1px solid #dcdcde; border-radius:6px; padding:.6rem 1rem; margin:.6rem 0; }
        .wph-autocheck header { display:flex; justify-content:space-between; align-items:center; margin:0 0 .4rem; }
        .wph-autocheck header h3 { margin:0; font-size:.95rem; }
        .wph-autocheck table { width:100%; border-collapse:collapse; }
        .wph-autocheck td { padding:.25rem .4rem; vertical-align:top; border-bottom:1px solid #f0f0f1; }
        .wph-autocheck tr:last-child td { border-bottom:0; }
        .wph-autocheck .lvl { width:1.4rem; text-align:center; font-weight:600; }
        .wph-autocheck .lvl-ok    { color:#1a8917; }
        .wph-autocheck .lvl-warn  { color:#b07a00; }
        .wph-autocheck .lvl-bad   { color:#c0392b; }
        .wph-autocheck .lvl-info  { color:#646970; }
        .wph-autocheck .label { font-weight:600; }
        .wph-autocheck .value { color:#1d1d1f; }
        .wph-autocheck .detail { color:#646970; font-size:.9em; }
        .wph-checked-at { color:#646970; font-size:.85em; }
        .wph-layout { display:grid; grid-template-columns: 220px 1fr; gap:1rem; }
        .wph-sidebar { position:sticky; top:36px; align-self:start; max-height: calc(100vh - 60px); overflow:auto; }
        .wph-sidebar .wph-card { padding:.75rem 1rem; }
        .wph-sidebar h3 { margin:0 0 .4rem; font-size:.9rem; text-transform:uppercase; letter-spacing:.04em; color:#646970; }
        .wph-sidebar ol { margin:0; padding:0; list-style:none; }
        .wph-sidebar li { padding:.18rem 0; }
        .wph-sidebar a { text-decoration:none; }
        .wph-sidebar .dot { display:inline-block; width:.6rem; height:.6rem; border-radius:50%; margin-right:.4rem; background:#dcdcde; vertical-align:middle; }
        .wph-sidebar .dot-done { background:#1a8917; }
        .wph-sidebar .dot-skipped { background:#b07a00; }
        .wph-sidebar .dot-blocked { background:#c0392b; }
        .wph-sidebar .dot-n_a { background:#646970; }
        .wph-diff { background:#eef4fb; border:1px solid #cfe0f3; padding:.6rem 1rem; border-radius:6px; margin:.5rem 0; font-size:.9em; }
        .wph-diff strong { display:inline-block; margin-right:.4rem; }
        .wph-diff .delta-new { color:#c0392b; }
        .wph-diff .delta-resolved { color:#1a8917; }
        .wph-diff .delta-changed { color:#b07a00; }
        @media (max-width: 980px) { .wph-layout { grid-template-columns: 1fr; } .wph-sidebar { position: static; max-height: none; } }
    ';
}

function wph_render_admin_page(): void {
    if (!current_user_can('manage_options')) wp_die('Forbidden');

    $session = WPH_Session::current();

    echo '<div class="wrap">';
    echo '<h1>Site Healthcheck</h1>';

    if (!$session) {
        wph_render_start_panel();
        echo '</div>';
        return;
    }

    if ($session->is_finished()) {
        wph_render_finished_panel($session);
        echo '</div>';
        return;
    }

    wph_render_active_session($session);
    echo '</div>';
}

function wph_render_start_panel(): void {
    ?>
    <div class="wph-card">
        <h2>Start a healthcheck</h2>
        <p>This will create a new in-progress session for <code><?php echo esc_html(get_site_url()); ?></code>. One session per site at a time.</p>
        <form method="post" action="<?php echo esc_url(admin_url('admin-post.php')); ?>">
            <?php wp_nonce_field('wph_start'); ?>
            <input type="hidden" name="action" value="wph_start">
            <button class="button button-primary">Start new healthcheck</button>
        </form>
    </div>
    <?php
    WPH_Recovery_Bootstrap::render_status();
}

function wph_render_active_session(WPH_Session $session): void {
    $progress = $session->progress();
    $tech     = get_userdata($session->technician_id());
    ?>
    <div class="wph-card">
        <p>
            <strong>Session:</strong> <code><?php echo esc_html($session->id()); ?></code> ·
            <strong>Started:</strong> <?php echo esc_html(date('Y-m-d H:i', $session->started_at())); ?> ·
            <strong>Technician:</strong> <?php echo esc_html($tech ? $tech->display_name : '#' . $session->technician_id()); ?> ·
            <span class="wph-progress"><?php echo (int) $progress['done']; ?> / <?php echo (int) $progress['total']; ?> steps</span>
        </p>
        <p>WP <code><?php echo esc_html($session->wp_version()); ?></code> · PHP <code><?php echo esc_html($session->php_version()); ?></code> · Site <code><?php echo esc_html($session->site_url()); ?></code></p>
        <div class="wph-actions">
            <form method="post" action="<?php echo esc_url(admin_url('admin-post.php')); ?>" onsubmit="return confirm('Mark this healthcheck as finished?');" style="display:inline">
                <?php wp_nonce_field('wph_finish'); ?>
                <input type="hidden" name="action" value="wph_finish">
                <button class="button button-primary">Finish &amp; generate report</button>
            </form>
            <form method="post" action="<?php echo esc_url(admin_url('admin-post.php')); ?>" onsubmit="return confirm('Discard this in-progress session? All notes will be lost.');" style="display:inline">
                <?php wp_nonce_field('wph_discard'); ?>
                <input type="hidden" name="action" value="wph_discard">
                <button class="button button-link-delete">Discard</button>
            </form>
        </div>
    </div>
    <?php

    WPH_Recovery_Bootstrap::render_status();
    wph_render_blocked_summary($session);
    wph_render_diff_summary($session);

    echo '<div class="wph-layout">';
    wph_render_sidebar($session);
    echo '<div>';
    foreach (WPH_Steps::instance()->all() as $step) {
        wph_render_step_card($session, $step);
    }
    echo '</div></div>';
}

function wph_render_sidebar(WPH_Session $session): void {
    echo '<aside class="wph-sidebar"><div class="wph-card"><h3>Steps</h3><ol>';
    foreach (WPH_Steps::instance()->all() as $step) {
        $state = $session->step_state($step->id());
        $cls = 'dot-' . $state['status'];
        printf(
            '<li><span class="dot %s"></span><a href="#step-%s">%s</a></li>',
            esc_attr($cls),
            esc_attr($step->id()),
            esc_html($step->title())
        );
    }
    echo '</ol></div></aside>';
}

function wph_render_blocked_summary(WPH_Session $session): void {
    $blocked = [];
    foreach (WPH_Steps::instance()->all() as $step) {
        $state = $session->step_state($step->id());
        if ($state['status'] === WPH_Session::STATUS_BLOCKED) {
            $blocked[] = ['step' => $step, 'state' => $state];
        }
    }
    if (!$blocked) return;
    echo '<div class="wph-card" style="border-left:4px solid #c0392b">';
    echo '<h2 style="color:#721c24">Stop &amp; escalate</h2>';
    echo '<p>The following steps are blocked. Resolve or escalate before continuing:</p>';
    echo '<ul style="margin-left:1.25rem">';
    foreach ($blocked as $b) {
        $esc = $b['step']->escalation();
        echo '<li><a href="#step-' . esc_attr($b['step']->id()) . '"><strong>' . esc_html($b['step']->title()) . '</strong></a>';
        if ($esc) echo ' — ' . esc_html($esc);
        if (!empty($b['state']['notes'])) echo '<br><em>' . esc_html($b['state']['notes']) . '</em>';
        echo '</li>';
    }
    echo '</ul></div>';
}

function wph_render_diff_summary(WPH_Session $session): void {
    $prev = WPH_Session::previous();
    if (!$prev) return;

    // Aggregate findings by step+id from each session
    $current_idx = [];
    foreach (WPH_Steps::instance()->all() as $step) {
        $r = $session->get_autocheck($step->id());
        if (!$r) continue;
        foreach ($r['findings'] as $f) {
            $current_idx[$step->id() . '|' . $f['id']] = $f;
        }
    }
    $prev_idx = [];
    foreach (WPH_Steps::instance()->all() as $step) {
        $r = $prev->get_autocheck($step->id());
        if (!$r) continue;
        foreach ($r['findings'] as $f) {
            $prev_idx[$step->id() . '|' . $f['id']] = $f;
        }
    }
    $new = $resolved = $changed = [];
    foreach ($current_idx as $k => $f) {
        if (!isset($prev_idx[$k])) {
            if (in_array($f['level'], ['warn', 'bad'], true)) $new[] = $f;
        } elseif ($prev_idx[$k]['level'] !== $f['level'] || $prev_idx[$k]['value'] !== $f['value']) {
            $changed[] = ['was' => $prev_idx[$k], 'now' => $f];
        }
    }
    foreach ($prev_idx as $k => $f) {
        if (!isset($current_idx[$k]) && in_array($f['level'], ['warn', 'bad'], true)) {
            $resolved[] = $f;
        }
    }
    if (!$new && !$resolved && !$changed) return;
    echo '<div class="wph-diff"><strong>Δ vs. previous session</strong> (finished ' . esc_html(date('Y-m-d', (int) $prev->finished_at())) . ')';
    if ($new)      echo ' · <span class="delta-new">' . count($new) . ' new issue(s)</span>';
    if ($resolved) echo ' · <span class="delta-resolved">' . count($resolved) . ' resolved</span>';
    if ($changed)  echo ' · <span class="delta-changed">' . count($changed) . ' changed</span>';
    echo '</div>';
}

function wph_render_step_card(WPH_Session $session, WPH_Step $step): void {
    $state  = $session->step_state($step->id());
    $status = $state['status'];
    $notes  = $state['notes'];
    ?>
    <form method="post" action="<?php echo esc_url(admin_url('admin-post.php')); ?>" class="wph-step" id="step-<?php echo esc_attr($step->id()); ?>">
        <?php wp_nonce_field('wph_save_step_' . $step->id()); ?>
        <input type="hidden" name="action" value="wph_save_step">
        <input type="hidden" name="step" value="<?php echo esc_attr($step->id()); ?>">
        <header>
            <h2><?php echo esc_html($step->title()); ?></h2>
            <span class="wph-step-status wph-status-<?php echo esc_attr($status); ?>"><?php echo esc_html(str_replace('_', ' ', $status)); ?></span>
        </header>
        <?php if ($blurb = $step->blurb()): ?>
            <p><?php echo esc_html($blurb); ?></p>
        <?php endif; ?>
        <?php if ($items = $step->sub_items()): ?>
            <ul class="wph-sub-items">
                <?php foreach ($items as $item): ?>
                    <li><?php echo esc_html($item); ?></li>
                <?php endforeach; ?>
            </ul>
        <?php endif; ?>
        <?php if ($watch = $step->watch_outs()): ?>
            <div class="wph-watch-outs">
                <strong>Watch out for:</strong>
                <ul style="margin:.2rem 0 0 1rem;">
                    <?php foreach ($watch as $w): ?>
                        <li><?php echo esc_html($w); ?></li>
                    <?php endforeach; ?>
                </ul>
            </div>
        <?php endif; ?>
        <?php if ($status === WPH_Session::STATUS_BLOCKED && ($esc = $step->escalation())): ?>
            <div class="wph-escalation"><?php echo esc_html($esc); ?></div>
        <?php endif; ?>
        <?php wph_render_autocheck($session, $step); ?>
        <?php $step->render_extra($session->data()); ?>
        <p>
            <label>
                <strong>Status:</strong>
                <select name="status">
                    <?php foreach (WPH_Session::VALID_STATUSES as $s): ?>
                        <option value="<?php echo esc_attr($s); ?>" <?php selected($status, $s); ?>><?php echo esc_html(str_replace('_', ' ', $s)); ?></option>
                    <?php endforeach; ?>
                </select>
            </label>
        </p>
        <p>
            <label><strong>Notes:</strong></label>
            <textarea name="notes" placeholder="What did you check, find, fix, or flag?"><?php echo esc_textarea($notes); ?></textarea>
        </p>
        <p>
            <button class="button">Save step</button>
            <?php if ($state['updated_at']): ?>
                <span class="description">Last saved <?php echo esc_html(human_time_diff($state['updated_at'], time())); ?> ago</span>
            <?php endif; ?>
        </p>
    </form>
    <?php
}

function wph_render_finished_panel(WPH_Session $session): void {
    $report = wph_build_markdown_report($session);
    $admin_email = get_option('admin_email');
    ?>
    <div class="wph-card">
        <h2>Healthcheck finished</h2>
        <p>Started <?php echo esc_html(date('Y-m-d H:i', $session->started_at())); ?> · Finished <?php echo esc_html(date('Y-m-d H:i', (int) $session->finished_at())); ?></p>
        <div class="wph-actions">
            <form method="post" action="<?php echo esc_url(admin_url('admin-post.php')); ?>" style="display:inline">
                <?php wp_nonce_field('wph_download_report'); ?>
                <input type="hidden" name="action" value="wph_download_report">
                <button class="button button-primary">Download Markdown</button>
            </form>
            <form method="post" action="<?php echo esc_url(admin_url('admin-post.php')); ?>" style="display:inline">
                <?php wp_nonce_field('wph_download_html'); ?>
                <input type="hidden" name="action" value="wph_download_html">
                <button class="button">Download HTML</button>
            </form>
            <button class="button" onclick="navigator.clipboard.writeText(document.getElementById('wph-report-md').textContent);this.textContent='Copied!';setTimeout(()=>this.textContent='Copy Markdown',2000)">Copy Markdown</button>
            <form method="post" action="<?php echo esc_url(admin_url('admin-post.php')); ?>" style="display:inline">
                <?php wp_nonce_field('wph_email_report'); ?>
                <input type="hidden" name="action" value="wph_email_report">
                <input type="email" name="to" placeholder="recipient@example.com" value="<?php echo esc_attr($admin_email); ?>" required style="min-width:14em">
                <button class="button">Email report</button>
            </form>
            <form method="post" action="<?php echo esc_url(admin_url('admin-post.php')); ?>" onsubmit="return confirm('Discard this finished session?');" style="display:inline">
                <?php wp_nonce_field('wph_discard'); ?>
                <input type="hidden" name="action" value="wph_discard">
                <button class="button button-link-delete">Discard</button>
            </form>
        </div>
    </div>
    <div class="wph-card">
        <h2>Report preview</h2>
        <pre id="wph-report-md" style="white-space:pre-wrap;background:#f6f7f7;padding:1rem;border-radius:6px;max-height:30em;overflow:auto"><?php echo esc_html($report); ?></pre>
    </div>
    <?php
}

// --- Handlers ----------------------------------------------------------------

function wph_handle_start(): void {
    if (!current_user_can('manage_options')) wp_die('Forbidden');
    check_admin_referer('wph_start');
    WPH_Session::start(get_current_user_id());
    wp_safe_redirect(admin_url('tools.php?page=site-healthcheck'));
    exit;
}

function wph_handle_save_step(): void {
    if (!current_user_can('manage_options')) wp_die('Forbidden');
    $step_id = isset($_POST['step']) ? sanitize_key((string) $_POST['step']) : '';
    check_admin_referer('wph_save_step_' . $step_id);
    $session = WPH_Session::current();
    if (!$session || $session->is_finished()) wp_die('No active session.');
    if (!WPH_Steps::instance()->get($step_id)) wp_die('Unknown step.');
    $status = isset($_POST['status']) ? sanitize_key((string) $_POST['status']) : WPH_Session::STATUS_NOT_STARTED;
    $notes  = isset($_POST['notes'])  ? wp_unslash((string) $_POST['notes'])    : '';
    $session->update_step($step_id, $status, $notes);
    wp_safe_redirect(admin_url('tools.php?page=site-healthcheck#step-' . rawurlencode($step_id)));
    exit;
}

function wph_handle_finish(): void {
    if (!current_user_can('manage_options')) wp_die('Forbidden');
    check_admin_referer('wph_finish');
    $session = WPH_Session::current();
    if (!$session) wp_die('No active session.');
    $session->finish();
    wp_safe_redirect(admin_url('tools.php?page=site-healthcheck'));
    exit;
}

function wph_handle_discard(): void {
    if (!current_user_can('manage_options')) wp_die('Forbidden');
    check_admin_referer('wph_discard');
    WPH_Session::discard();
    wp_safe_redirect(admin_url('tools.php?page=site-healthcheck'));
    exit;
}

function wph_render_autocheck(WPH_Session $session, WPH_Step $step): void {
    if (!$step->has_autocheck()) return;
    $result = $session->get_autocheck($step->id());
    ?>
    <div class="wph-autocheck">
        <header>
            <h3>Automated checks</h3>
            <form method="post" action="<?php echo esc_url(admin_url('admin-post.php')); ?>" style="display:inline">
                <?php wp_nonce_field('wph_refresh_checks_' . $step->id()); ?>
                <input type="hidden" name="action" value="wph_refresh_checks">
                <input type="hidden" name="step" value="<?php echo esc_attr($step->id()); ?>">
                <button class="button button-small"><?php echo $result ? 'Refresh' : 'Run checks'; ?></button>
            </form>
        </header>
        <?php if (!$result): ?>
            <p class="description">No automated checks have been run for this step yet.</p>
        <?php else: ?>
            <table>
                <?php foreach ($result['findings'] as $finding):
                    $icon = ['ok' => '✓', 'warn' => '⚠', 'bad' => '✗', 'info' => '·'][$finding['level']] ?? '·';
                ?>
                <tr>
                    <td class="lvl lvl-<?php echo esc_attr($finding['level']); ?>"><?php echo esc_html($icon); ?></td>
                    <td class="label"><?php echo esc_html($finding['label']); ?></td>
                    <td class="value"><?php echo esc_html($finding['value']); ?></td>
                    <td class="detail"><?php echo esc_html($finding['detail']); ?></td>
                </tr>
                <?php endforeach; ?>
            </table>
            <p class="wph-checked-at">Checked <?php echo esc_html(human_time_diff((int) $result['checked_at'], time())); ?> ago (<?php echo esc_html(date('Y-m-d H:i', (int) $result['checked_at'])); ?>)</p>
        <?php endif; ?>
    </div>
    <?php
}

function wph_handle_step_action(): void {
    if (!current_user_can('manage_options')) wp_die('Forbidden');
    $step_id     = isset($_POST['step'])        ? sanitize_key((string) $_POST['step'])        : '';
    $action_name = isset($_POST['step_action']) ? sanitize_key((string) $_POST['step_action']) : '';
    check_admin_referer('wph_step_action_' . $step_id . '_' . $action_name);
    $session = WPH_Session::current();
    if (!$session || $session->is_finished()) wp_die('No active session.');
    $step = WPH_Steps::instance()->get($step_id);
    if (!$step) wp_die('Unknown step.');

    // Pass POST through unslashed so handlers see the raw user input.
    $input = wp_unslash($_POST);
    @set_time_limit(60);
    $finding = $step->handle_action($action_name, is_array($input) ? $input : []);

    if (is_array($finding)) {
        // Append (or replace by id) onto this step's stored findings.
        $existing = $session->get_autocheck($step_id);
        $findings = $existing['findings'] ?? [];
        $replaced = false;
        foreach ($findings as $i => $f) {
            if (($f['id'] ?? '') === ($finding['id'] ?? '')) {
                $findings[$i] = $finding;
                $replaced = true;
                break;
            }
        }
        if (!$replaced) $findings[] = $finding;
        $session->set_autocheck($step_id, $findings);
    }

    wp_safe_redirect(admin_url('tools.php?page=site-healthcheck#step-' . rawurlencode($step_id)));
    exit;
}

function wph_handle_refresh_checks(): void {
    if (!current_user_can('manage_options')) wp_die('Forbidden');
    $step_id = isset($_POST['step']) ? sanitize_key((string) $_POST['step']) : '';
    check_admin_referer('wph_refresh_checks_' . $step_id);
    $session = WPH_Session::current();
    if (!$session || $session->is_finished()) wp_die('No active session.');
    $step = WPH_Steps::instance()->get($step_id);
    if (!$step) wp_die('Unknown step.');
    @set_time_limit(60);
    $findings = $step->autocheck($session->data());
    $session->set_autocheck($step_id, $findings);
    wp_safe_redirect(admin_url('tools.php?page=site-healthcheck#step-' . rawurlencode($step_id)));
    exit;
}

function wph_handle_download_report(): void {
    if (!current_user_can('manage_options')) wp_die('Forbidden');
    check_admin_referer('wph_download_report');
    $session = WPH_Session::current();
    if (!$session) wp_die('No session.');
    wph_stream_report($session, 'md');
}

function wph_handle_download_html(): void {
    if (!current_user_can('manage_options')) wp_die('Forbidden');
    check_admin_referer('wph_download_html');
    $session = WPH_Session::current();
    if (!$session) wp_die('No session.');
    wph_stream_report($session, 'html');
}

function wph_stream_report(WPH_Session $session, string $format): void {
    $host = parse_url(get_site_url(), PHP_URL_HOST) ?: 'site';
    $host = preg_replace('/[^a-z0-9.-]/i', '', (string) $host);
    $stamp = date('Ymd', $session->started_at() ?: time());
    nocache_headers();
    if ($format === 'html') {
        header('Content-Type: text/html; charset=UTF-8');
        header('Content-Disposition: attachment; filename="wph-report-' . $host . '-' . $stamp . '.html"');
        echo wph_build_html_report($session);
    } else {
        header('Content-Type: text/markdown; charset=UTF-8');
        header('Content-Disposition: attachment; filename="wph-report-' . $host . '-' . $stamp . '.md"');
        echo wph_build_markdown_report($session);
    }
    exit;
}

function wph_handle_email_report(): void {
    if (!current_user_can('manage_options')) wp_die('Forbidden');
    check_admin_referer('wph_email_report');
    $session = WPH_Session::current();
    if (!$session) wp_die('No session.');
    $to = isset($_POST['to']) ? sanitize_email((string) wp_unslash($_POST['to'])) : '';
    if (!is_email($to)) wp_die('Bad email address.');
    $host = parse_url(get_site_url(), PHP_URL_HOST) ?: 'site';
    $subject = 'Site Healthcheck — ' . $host . ' — ' . date('Y-m-d', $session->started_at() ?: time());
    $html = wph_build_html_report($session);
    $ok = wp_mail($to, $subject, $html, ['Content-Type: text/html; charset=UTF-8']);
    wp_safe_redirect(admin_url('tools.php?page=site-healthcheck&wph_mail=' . ($ok ? '1' : '0')));
    exit;
}