<?php
/**
 * Shared HTML renderers used by blocks, templates and shortcodes:
 * metric maths, case study cards, grids, filters, the listing page and
 * related case studies.
 */

if (!defined('ABSPATH')) {
    exit;
}

/* ------------------------------------------------------------------
 * Numbers and metrics
 * ---------------------------------------------------------------- */

/**
 * Reads a number from values like "1.40%", "$58", "9,400", "12k", "2.1s".
 * Returns null for values that aren't a single number ("1m 42s", "Passed").
 */
function sahcs_parse_number($value) {
    $v = sahcs_trim(wp_strip_all_tags((string) $value));
    if ($v === '') {
        return null;
    }
    $v = str_replace([',', ' ', "\xC2\xA0"], '', $v);
    $v = preg_replace('/^[^\d\-\+\.]+/u', '', $v); // leading currency or symbols
    if (!preg_match('/^([\-\+]?\d*\.?\d+)(k|K|M|x|X|%|s|ms|sec|secs|px|kb|KB|mb|MB)?$/u', $v, $m)) {
        return null;
    }
    $n = (float) $m[1];
    $unit = isset($m[2]) ? $m[2] : '';
    if ($unit === 'k' || $unit === 'K') {
        $n *= 1000;
    } elseif ($unit === 'M') {
        $n *= 1000000;
    }
    return $n;
}

/**
 * Works out the change between "before" and "after".
 * Returns ['pct' => float, 'label' => '+107%', 'improved' => bool] or null.
 */
function sahcs_metric_change(array $item) {
    $before = sahcs_parse_number(isset($item['before']) ? $item['before'] : '');
    $after  = sahcs_parse_number(isset($item['after']) ? $item['after'] : '');
    if ($before === null || $after === null || (float) $before === 0.0) {
        return null;
    }
    $pct = ($after - $before) / abs($before) * 100;
    if (abs($pct) < 0.05) {
        return null;
    }
    $better_lower = isset($item['better']) && $item['better'] === 'lower';
    $improved = $better_lower ? $pct < 0 : $pct > 0;
    $rounded = abs($pct) >= 10 ? round(abs($pct)) : round(abs($pct), 1);
    $label = ($pct > 0 ? '+' : "\u{2212}") . number_format_i18n($rounded, (abs($pct) >= 10 ? 0 : 1)) . '%';
    return ['pct' => $pct, 'label' => $label, 'improved' => $improved];
}

function sahcs_format_value($value, array $item = []) {
    $value = sahcs_trim((string) $value);
    if ($value === '') {
        return '';
    }
    $prefix = isset($item['prefix']) ? (string) $item['prefix'] : '';
    $suffix = isset($item['suffix']) ? (string) $item['suffix'] : '';
    return $prefix . $value . $suffix;
}

/* ------------------------------------------------------------------
 * Small helpers
 * ---------------------------------------------------------------- */

/** Safe list of allowed heading tags for cards and section titles. */
function sahcs_heading_tag($tag, $default = 'h3') {
    return in_array($tag, ['h2', 'h3', 'h4', 'p'], true) ? $tag : $default;
}

/**
 * A short summary of a case study: the manual excerpt if there is one,
 * otherwise the "At a glance" text or the first paragraph.
 */
function sahcs_card_excerpt($post, $words = 24) {
    $post = get_post($post);
    if (!$post) {
        return '';
    }
    if (has_excerpt($post)) {
        return wp_trim_words(get_the_excerpt($post), $words);
    }
    $text = '';
    $walk = function ($blocks) use (&$walk, &$text) {
        foreach ($blocks as $b) {
            if ($text !== '') {
                return;
            }
            if ($b['blockName'] === 'sahcs/hero' && !empty($b['attrs']['intro'])) {
                $text = $b['attrs']['intro'];
                return;
            }
            if ($b['blockName'] === 'core/paragraph') {
                $t = sahcs_trim(wp_strip_all_tags($b['innerHTML']));
                if ($t !== '') {
                    $text = $t;
                    return;
                }
            }
            if (!empty($b['innerBlocks'])) {
                $walk($b['innerBlocks']);
            }
        }
    };
    $walk(parse_blocks($post->post_content));
    return wp_trim_words($text, $words);
}

/** Terms of a case study, cached by WordPress. */
function sahcs_post_terms($post_id) {
    $terms = get_the_terms($post_id, SAHCS_TAX);
    return (is_array($terms)) ? $terms : [];
}

/* ------------------------------------------------------------------
 * Case study card
 * ---------------------------------------------------------------- */

/**
 * @param int   $post_id
 * @param array $args heading (h2|h3|h4), excerpt (bool), eager (bool), stat (bool)
 */
function sahcs_card($post_id, array $args = []) {
    $args = array_merge(['heading' => 'h3', 'excerpt' => true, 'eager' => false, 'priority' => false, 'stat' => true], $args);
    $post = get_post($post_id);
    if (!$post) {
        return '';
    }
    $tag   = sahcs_heading_tag($args['heading'], 'h3');
    $url   = get_permalink($post);
    $title = get_the_title($post);
    $terms = sahcs_post_terms($post->ID);

    $media = '';
    if (has_post_thumbnail($post)) {
        $img_attrs = [
            'class'   => 'sahcs-card__img',
            'loading' => $args['eager'] ? 'eager' : 'lazy',
            'sizes'   => '(max-width: 640px) 100vw, (max-width: 1024px) 50vw, 33vw',
            'alt'     => '',
            // Some themes add inline sizes to every image; these win over them.
            'style'   => 'width:100%;height:100%;max-width:100%',
        ];
        if ($args['priority']) {
            $img_attrs['fetchpriority'] = 'high';
        }
        $media = get_the_post_thumbnail($post, 'medium_large', $img_attrs);
    }
    if ($media === '') {
        $initial = function_exists('mb_substr') ? mb_substr(wp_strip_all_tags($title), 0, 1) : substr(wp_strip_all_tags($title), 0, 1);
        $media = '<span class="sahcs-card__placeholder" aria-hidden="true">' . esc_html($initial) . '</span>';
    }

    $term_slugs = wp_list_pluck($terms, 'slug');

    $out  = '<article class="sahcs-card" data-sahcs-terms="' . esc_attr(implode(' ', $term_slugs)) . '">';
    $out .= '<div class="sahcs-card__media">' . $media . '</div>';
    $out .= '<div class="sahcs-card__body">';
    if ($terms) {
        $out .= '<p class="sahcs-card__meta">';
        foreach (array_slice($terms, 0, 2) as $t) {
            $out .= '<span class="sahcs-chip">' . esc_html($t->name) . '</span>';
        }
        $out .= '</p>';
    }
    $out .= '<' . $tag . ' class="sahcs-card__title"><a class="sahcs-card__link" href="' . esc_url($url) . '">' . esc_html(wp_strip_all_tags($title)) . '</a></' . $tag . '>';

    if ($args['stat']) {
        $hl = get_post_meta($post->ID, '_sahcs_highlight', true);
        if (is_array($hl) && !empty($hl['value'])) {
            $out .= '<p class="sahcs-card__stat"><strong>' . esc_html($hl['value']) . '</strong> ' . esc_html(isset($hl['label']) ? $hl['label'] : '') . '</p>';
        }
    }
    if ($args['excerpt']) {
        $excerpt = sahcs_card_excerpt($post);
        if ($excerpt !== '') {
            $out .= '<p class="sahcs-card__excerpt">' . esc_html($excerpt) . '</p>';
        }
    }
    $out .= '<span class="sahcs-card__more" aria-hidden="true">' . esc_html__('Read case study', 'siteaudithub-case-studies') . '<span class="sahcs-arrow">&rarr;</span></span>';
    $out .= '</div></article>';
    return $out;
}

/* ------------------------------------------------------------------
 * Grid (used by the shortcode, the "Case Studies" block and Related)
 * ---------------------------------------------------------------- */

function sahcs_grid_defaults() {
    return [
        'limit'    => 6,
        'category' => '',
        'ids'      => '',
        'exclude'  => '', // phpcs:ignore WordPressVIPMinimum.Performance.WPQueryParams.PostNotIn_exclude -- shortcode attribute default, not a query argument
        'columns'  => 3,
        'layout'   => 'grid',   // grid | list
        'filters'  => false,
        'orderby'  => 'latest', // latest | oldest | title | random | menu
        'excerpt'  => true,
        'button'   => false,
        'button_text' => '',
        'heading'  => '',       // '' = automatic: h2 without a title, h3 under a title
        'title'    => '',
    ];
}

function sahcs_bool($v) {
    if (is_bool($v)) {
        return $v;
    }
    return in_array(strtolower((string) $v), ['1', 'yes', 'true', 'on'], true);
}

function sahcs_grid(array $args) {
    $a = array_merge(sahcs_grid_defaults(), $args);
    $a['limit']   = max(1, min(60, (int) $a['limit']));
    $a['columns'] = max(1, min(4, (int) $a['columns']));
    $a['layout']  = $a['layout'] === 'list' ? 'list' : 'grid';
    $a['filters'] = sahcs_bool($a['filters']);
    $a['excerpt'] = sahcs_bool($a['excerpt']);
    $a['button']  = sahcs_bool($a['button']);

    $query = [
        'post_type'           => SAHCS_CPT,
        'post_status'         => 'publish',
        'posts_per_page'      => $a['limit'],
        'ignore_sticky_posts' => true,
        'no_found_rows'       => true,
    ];

    $ids = array_values(array_unique(array_filter(array_map('sahcs_localize_id', array_map('absint', explode(',', (string) $a['ids']))))));
    if ($ids) {
        $query['post__in'] = $ids;
        $query['orderby']  = 'post__in';
        $query['posts_per_page'] = count($ids);
    } else {
        switch ($a['orderby']) {
            case 'oldest':
                $query['orderby'] = 'date';
                $query['order'] = 'ASC';
                break;
            case 'title':
                $query['orderby'] = 'title';
                $query['order'] = 'ASC';
                break;
            case 'random':
                $query['orderby'] = 'rand';
                break;
            case 'menu':
                $query['orderby'] = ['menu_order' => 'ASC', 'date' => 'DESC'];
                break;
            default:
                $query['orderby'] = 'date';
                $query['order'] = 'DESC';
        }
    }

    $cats = array_filter(array_map('sanitize_title', explode(',', (string) $a['category'])));
    if ($cats) {
        $query['tax_query'] = [[ // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_tax_query
            'taxonomy' => SAHCS_TAX,
            'field'    => 'slug',
            'terms'    => $cats,
        ]];
    }

    $exclude = array_filter(array_map('absint', explode(',', (string) $a['exclude'])));
    if ($exclude && (int) $query['posts_per_page'] > 0) {
        // Ask for a few extra and drop the excluded ones here (faster than NOT IN).
        $query['posts_per_page'] = (int) $query['posts_per_page'] + count($exclude);
    }

    $q = new WP_Query($query);
    if ($exclude) {
        $keep = (int) $a['limit'];
        $q->posts = array_values(array_filter($q->posts, function ($p) use ($exclude) {
            return !in_array((int) $p->ID, $exclude, true);
        }));
        if ($keep > 0 && empty($ids)) {
            $q->posts = array_slice($q->posts, 0, $keep);
        }
        $q->post_count = count($q->posts);
    }
    sahcs_enqueue_front();

    if (!$q->have_posts()) {
        return '';
    }

    // Heading levels follow the page outline: the page title is the H1, a grid
    // title is an H2 and its cards H3; without a grid title the cards are H2.
    $card_heading = (isset($a['heading']) && $a['heading'] !== '')
        ? sahcs_heading_tag($a['heading'], 'h3')
        : ($a['title'] !== '' ? 'h3' : 'h2');
    $out = '<div class="sahcs-scope sahcs-grid-wrap" data-sahcs-grid>';
    if ($a['title'] !== '') {
        $out .= '<h2 class="sahcs-grid-wrap__title">' . esc_html($a['title']) . '</h2>';
    }

    if ($a['filters'] && !$ids) {
        $terms = [];
        foreach ($q->posts as $p) {
            foreach (sahcs_post_terms($p->ID) as $t) {
                $terms[$t->slug] = $t->name;
            }
        }
        if (count($terms) > 1) {
            asort($terms);
            $out .= '<div class="sahcs-filters" role="group" aria-label="' . esc_attr__('Filter case studies', 'siteaudithub-case-studies') . '"><ul class="sahcs-filters__list">';
            $out .= '<li><button type="button" class="sahcs-filter sahcs-filter--active" data-sahcs-filter="*" aria-pressed="true">' . esc_html__('All', 'siteaudithub-case-studies') . '</button></li>';
            foreach ($terms as $slug => $name) {
                $out .= '<li><button type="button" class="sahcs-filter" data-sahcs-filter="' . esc_attr($slug) . '" aria-pressed="false">' . esc_html($name) . '</button></li>';
            }
            $out .= '</ul></div>';
        }
    }

    $cols_class = $a['layout'] === 'list' ? '' : ' sahcs-cols-' . (int) $a['columns'];
    $out .= '<div class="sahcs-grid sahcs-grid--' . esc_attr($a['layout']) . $cols_class . '">';
    foreach ($q->posts as $p) {
        $out .= sahcs_card($p->ID, ['heading' => $card_heading, 'excerpt' => $a['excerpt']]);
    }
    $out .= '</div>';
    $out .= '<p class="sahcs-grid__empty" hidden>' . esc_html__('No case studies in this category yet.', 'siteaudithub-case-studies') . '</p>';

    if ($a['button']) {
        $text = $a['button_text'] !== '' ? $a['button_text'] : __('View all case studies', 'siteaudithub-case-studies');
        $out .= '<p class="sahcs-grid__more"><a class="sahcs-button sahcs-button--ghost" href="' . esc_url(get_post_type_archive_link(SAHCS_CPT)) . '">' . esc_html($text) . '</a></p>';
    }
    $out .= '</div>';

    wp_reset_postdata();
    return $out;
}

/* ------------------------------------------------------------------
 * Listing page (archive and category pages)
 * ---------------------------------------------------------------- */

function sahcs_render_archive() {
    global $wp_query;
    $s = sahcs_get_settings();
    sahcs_enqueue_front();

    $term = is_tax(SAHCS_TAX) ? get_queried_object() : null;

    if ($term) {
        /* translators: %s: category name, e.g. Shopify */
        $title = sprintf(__('%s case studies', 'siteaudithub-case-studies'), $term->name);
        $intro = $term->description !== '' ? $term->description : $s['archive_intro'];
    } else {
        $title = $s['archive_title'] !== '' ? $s['archive_title'] : __('Case Studies', 'siteaudithub-case-studies');
        $intro = $s['archive_intro'];
    }

    $out  = '<div class="sahcs-scope sahcs-archive">' . sahcs_page_script();
    $out .= '<div class="sahcs-archive__header">';
    if ($term) {
        $out .= '<nav class="sahcs-breadcrumb" aria-label="' . esc_attr__('Breadcrumb', 'siteaudithub-case-studies') . '"><a href="' . esc_url(get_post_type_archive_link(SAHCS_CPT)) . '">' . esc_html($s['archive_title'] !== '' ? $s['archive_title'] : __('Case Studies', 'siteaudithub-case-studies')) . '</a><span aria-hidden="true"> / </span><span aria-current="page">' . esc_html($term->name) . '</span></nav>';
    }
    $out .= '<h1 class="sahcs-archive__title">' . esc_html($title) . '</h1>';
    if ($intro !== '') {
        $out .= '<div class="sahcs-archive__intro">' . wpautop(esc_html($intro)) . '</div>';
    }
    $out .= '</div>';

    if (!empty($s['show_filters'])) {
        $out .= sahcs_archive_filters($term);
    }

    $out .= '<div class="sahcs-archive__results" data-sahcs-results aria-live="polite">';
    if (have_posts()) {
        $layout = (isset($s['archive_layout']) && $s['archive_layout'] === 'list') ? 'list' : 'grid';
        $out .= '<div class="sahcs-grid sahcs-grid--' . $layout . ($layout === 'grid' ? ' sahcs-cols-' . (int) $s['columns'] : '') . '">';
        $i = 0;
        while (have_posts()) {
            the_post();
            $out .= sahcs_card(get_the_ID(), ['heading' => 'h2', 'eager' => $i < (int) $s['columns'], 'priority' => $i === 0]);
            $i++;
        }
        $out .= '</div>';
        $links = paginate_links([
            'type'      => 'list',
            'prev_text' => '<span class="sahcs-arrow" aria-hidden="true">&larr;</span> ' . esc_html__('Previous', 'siteaudithub-case-studies'),
            'next_text' => esc_html__('Next', 'siteaudithub-case-studies') . ' <span class="sahcs-arrow" aria-hidden="true">&rarr;</span>',
            'total'     => (int) $wp_query->max_num_pages,
        ]);
        if ($links) {
            $out .= '<nav class="sahcs-pagination" aria-label="' . esc_attr__('Case studies pages', 'siteaudithub-case-studies') . '">' . $links . '</nav>';
        }
        wp_reset_postdata();
    } else {
        $out .= '<p class="sahcs-archive__empty">' . esc_html__('No case studies found yet.', 'siteaudithub-case-studies') . '</p>';
    }
    $out .= '</div></div>';
    return $out;
}

function sahcs_archive_filters($current_term = null) {
    $terms = get_terms(['taxonomy' => SAHCS_TAX, 'hide_empty' => true]);
    if (is_wp_error($terms) || count($terms) < 1) {
        return '';
    }
    $all_url = get_post_type_archive_link(SAHCS_CPT);
    $out  = '<nav class="sahcs-filters" aria-label="' . esc_attr__('Filter case studies by category', 'siteaudithub-case-studies') . '" data-sahcs-archive-filters><ul class="sahcs-filters__list">';
    $active = !$current_term;
    $out .= '<li><a class="sahcs-filter' . ($active ? ' sahcs-filter--active' : '') . '" href="' . esc_url($all_url) . '"' . ($active ? ' aria-current="page"' : '') . '>' . esc_html__('All', 'siteaudithub-case-studies') . '</a></li>';
    foreach ($terms as $t) {
        $active = $current_term && (int) $current_term->term_id === (int) $t->term_id;
        $out .= '<li><a class="sahcs-filter' . ($active ? ' sahcs-filter--active' : '') . '" href="' . esc_url(get_term_link($t)) . '"' . ($active ? ' aria-current="page"' : '') . '>' . esc_html($t->name) . '</a></li>';
    }
    $out .= '</ul></nav>';
    return $out;
}

/* ------------------------------------------------------------------
 * Related case studies
 * ---------------------------------------------------------------- */

/**
 * Related case studies.
 * $args['ids']    - chosen case studies in this order (empty = automatic: same category first).
 * $args['layout'] - 'grid' or 'list'; empty = the Settings choice.
 */
function sahcs_related($post_id, $count, $title, $args = []) {
    $count  = max(1, min(12, (int) $count));
    $chosen = isset($args['ids']) ? array_values(array_unique(array_filter(array_map('intval', (array) $args['ids'])))) : [];
    $layout = isset($args['layout']) && in_array($args['layout'], ['grid', 'list'], true) ? $args['layout'] : sahcs_get_settings('related_layout');
    $layout = $layout === 'list' ? 'list' : 'grid';

    $ids = [];
    if ($chosen) {
        // Only published case studies, never the one being viewed, in the chosen order.
        foreach ($chosen as $id) {
            $id = sahcs_localize_id($id); // same case study in the page's language
            if ($id !== (int) $post_id && get_post_type($id) === SAHCS_CPT && get_post_status($id) === 'publish') {
                $ids[] = $id;
            }
        }
    }
    if (!$ids) {
        $term_ids = wp_list_pluck(sahcs_post_terms($post_id), 'term_id');

        $query = [
            'post_type'           => SAHCS_CPT,
            'post_status'         => 'publish',
            'posts_per_page'      => $count + 1,
            'fields'              => 'ids',
            'ignore_sticky_posts' => true,
            'no_found_rows'       => true,
        ];
        $ids = [];
        if ($term_ids) {
            $query['tax_query'] = [[ // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_tax_query
                'taxonomy' => SAHCS_TAX,
                'field'    => 'term_id',
                'terms'    => $term_ids,
            ]];
            $ids = array_diff(array_map('intval', (new WP_Query($query))->posts), [(int) $post_id]);
            $ids = array_slice(array_values($ids), 0, $count);
            unset($query['tax_query']);
        }
        // Top up with the latest case studies if the category has too few.
        if (count($ids) < $count) {
            $skip = array_merge([(int) $post_id], $ids);
            $query['posts_per_page'] = $count + count($skip);
            $more = array_diff(array_map('intval', (new WP_Query($query))->posts), $skip);
            $ids = array_merge($ids, array_slice(array_values($more), 0, $count - count($ids)));
        }

    }
    if (!$ids) {
        return '';
    }
    // Columns follow the number asked for ("How many"), not the number found,
    // so one related case study keeps its normal card size and the other
    // places stay empty instead of one card stretching across the row.
    $cols = min(3, max(count($ids), $count));
    $grid_class = $layout === 'list' ? 'sahcs-grid sahcs-grid--list' : 'sahcs-grid sahcs-grid--grid sahcs-cols-' . (int) $cols;
    $out  = '<section class="sahcs-related sahcs-related--' . $layout . '" aria-labelledby="sahcs-related-title-' . (int) $post_id . '">';
    $out .= '<h2 class="sahcs-related__title" id="sahcs-related-title-' . (int) $post_id . '">' . esc_html($title) . '</h2>';
    $out .= '<div class="' . esc_attr($grid_class) . '">';
    foreach ($ids as $id) {
        $out .= sahcs_card($id, ['heading' => 'h3', 'excerpt' => $layout === 'list']);
    }
    $out .= '</div></section>';
    return $out;
}