<?php
if (!defined('ABSPATH')) exit;
// phpcs:disable WordPress.DB.PreparedSQL.NotPrepared, WordPress.DB.PreparedSQL.InterpolatedNotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter -- Every table name is $wpdb->prefix plus a fixed suffix from a private helper (never user input); all runtime values go through $wpdb->prepare() placeholders.

/**
 * Autobraid — automatic linking rules: phrase -> target page.
 *
 * Rules do NOT insert links through the the_content filter. A scan creates ordinary
 * suggestions (Knots, method=autobraid), and saving goes through
 * Linkbraid_Link_Manager::apply_suggestion — the same validator, link limit,
 * content hash, history and undo as the AI suggestions. Cluster-level rules
 * (Strands) are planned for the next stage.
 */
class Linkbraid_Autobraid {

    private static function rules_table() { global $wpdb; return $wpdb->prefix . 'lbraid_autobraid_rules'; }
    private static function suggestions_table() { global $wpdb; return $wpdb->prefix . 'lbraid_link_suggestions'; }

    /** Rule list with suggestion statistics. */
    public static function rules() {
        global $wpdb;
        $rules = $wpdb->get_results(
            "SELECT r.*, p.post_title, p.post_status,
                (SELECT COUNT(*) FROM " . self::suggestions_table() . " s WHERE s.rule_id = r.id AND s.status = 'pending') AS pending,
                (SELECT COUNT(*) FROM " . self::suggestions_table() . " s WHERE s.rule_id = r.id AND s.status = 'accepted') AS accepted
             FROM " . self::rules_table() . " r
             LEFT JOIN {$wpdb->posts} p ON p.ID = r.target_post_id
             ORDER BY r.id DESC", ARRAY_A);
        foreach ($rules as &$rule) {
            $rule['target_url'] = get_permalink($rule['target_post_id']);
            $rule['target_title'] = $rule['post_title'] ?: ('#' . $rule['target_post_id']);
            $rule['target_missing'] = $rule['post_status'] !== 'publish';
        }
        return $rules;
    }

    public static function save_rule($phrase, $target_post_id, $flexible = 0) {
        global $wpdb;
        $phrase = trim(preg_replace('/\s+/u', ' ', (string) $phrase));
        $target_post_id = absint($target_post_id);
        if (mb_strlen($phrase) < 2 || mb_strlen($phrase) > 190) return ['error' => __( 'The phrase must be between 2 and 190 characters.', 'linkbraid' )];
        $target = get_post($target_post_id);
        if (!$target || $target->post_status !== 'publish' || !in_array($target->post_type, lbraid_post_types(), true)) return ['error' => __( 'Pick a published page from the enabled content types.', 'linkbraid' )];
        if (!Linkbraid_Anchors::allows($target_post_id, $phrase)) return ['error' => __( 'The target page only allows anchors from its assigned list — add this phrase to its anchors or change the mode.', 'linkbraid' )];
        $exists = $wpdb->get_var($wpdb->prepare(
            'SELECT id FROM ' . self::rules_table() . ' WHERE phrase = %s AND target_post_id = %d', $phrase, $target_post_id));
        if ($exists) return ['error' => __( 'That rule already exists.', 'linkbraid' )];
        if (false === $wpdb->insert(self::rules_table(), ['phrase' => $phrase, 'target_post_id' => $target_post_id, 'enabled' => 1, 'flexible' => $flexible ? 1 : 0, 'created_at' => current_time('mysql')])) {
            return ['error' => __( 'The rule could not be saved.', 'linkbraid' )];
        }
        return ['success' => true, 'id' => (int) $wpdb->insert_id];
    }

    public static function set_enabled($id, $enabled) {
        global $wpdb;
        return false !== $wpdb->update(self::rules_table(), ['enabled' => $enabled ? 1 : 0], ['id' => absint($id)]);
    }

    /** Deletes a rule together with its unresolved suggestions (applied ones stay). */
    public static function delete_rule($id) {
        global $wpdb;
        $id = absint($id);
        $wpdb->delete(self::suggestions_table(), ['rule_id' => $id, 'status' => 'pending']);
        return false !== $wpdb->delete(self::rules_table(), ['id' => $id]);
    }

    /**
     * Scan of a single post (one queue unit): for every enabled rule it creates
     * at most one suggestion, when the phrase can be inserted safely and the target
     * is not linked yet.
     */
    public static function scan_post($post_id) {
        global $wpdb;
        // Ignored content gets no rule matches (Settings → Linking rules).
        if (in_array((int) $post_id, lbraid_ignored_posts(), true)) return ['success' => true, 'count' => 0];
        $rules = $wpdb->get_results('SELECT * FROM ' . self::rules_table() . ' WHERE enabled = 1');
        if (!$rules) return ['success' => true, 'count' => 0];

        $fragments = null; // lazy - only once a rule passes the cheap filters
        $created = 0;
        foreach ($rules as $rule) {
            $target = (int) $rule->target_post_id;
            if ($target === (int) $post_id) continue;
            if (get_post_status($target) !== 'publish') continue;
            if (get_option('lbraid_exclude_home', 1) && $target === (int) get_option('page_on_front')) continue;
            if (in_array($target, lbraid_excluded_targets(), true)) continue;
            if (!Linkbraid_Anchors::allows($target, $rule->phrase)) continue;
            if (Linkbraid_Anchors::phrase_ignored($rule->phrase)) continue;
            if ($wpdb->get_var($wpdb->prepare(
                "SELECT 1 FROM {$wpdb->prefix}lbraid_existing_links WHERE source_post_id = %d AND target_post_id = %d LIMIT 1", $post_id, $target))) continue;
            if ($wpdb->get_var($wpdb->prepare(
                'SELECT 1 FROM ' . self::suggestions_table() . " WHERE source_post_id = %d AND target_post_id = %d AND status = 'pending' LIMIT 1", $post_id, $target))) continue;

            if ($fragments === null) $fragments = Linkbraid_Content::fragments($post_id);
            $url = get_permalink($target);
            $found = false; $anchor = $rule->phrase;
            foreach ($fragments as $fragment) {
                if (!empty($rule->flexible)) {
                    // Flexible rule: inflected forms match too; the SURFACE form
                    // found in the text becomes the anchor, so everything
                    // downstream (plan, preview, apply) stays a literal match.
                    $match = Linkbraid_Content::insert_flexible($fragment['html'], $rule->phrase, $url);
                    if ($match !== null) { $anchor = $match['anchor']; $found = true; break; }
                } elseif (Linkbraid_Content::insert($fragment['html'], $rule->phrase, $url) !== null) { $found = true; break; }
            }
            if (!$found) continue;
            // The surface form must pass the same anchor rules as the phrase itself.
            if (!Linkbraid_Anchors::allows($target, $anchor) || Linkbraid_Anchors::phrase_ignored($anchor) || !Linkbraid_Anchors::available_for($anchor, $target)) continue;

            $inserted = $wpdb->insert(self::suggestions_table(), [
                'source_post_id'  => (int) $post_id,
                'target_post_id'  => $target,
                'anchor_text'     => mb_substr($anchor, 0, 500),
                'context_snippet' => '',
                'confidence'      => 1,
                'status'          => 'pending',
                'is_new_content'  => 0,
                'source_hash'     => Linkbraid_Content::hash($post_id),
                /* translators: %1$s, %2$s: dynamic values in display order. */
                'reason'          => sprintf( __( 'Autobraid rule: “%1$s” → %2$s', 'linkbraid' ), $rule->phrase, get_the_title($target) ),
                'method'          => 'autobraid',
                'rule_id'         => (int) $rule->id,
                'created_at'      => current_time('mysql'),
            ]);
            if ($inserted) $created++;
        }
        return ['success' => true, 'count' => $created];
    }

    /** Applies a batch of pending matches (through the full validator). */
    public static function apply_batch($limit = 25) {
        global $wpdb;
        $ids = $wpdb->get_col($wpdb->prepare(
            'SELECT id FROM ' . self::suggestions_table() . " WHERE method = 'autobraid' AND status = 'pending' ORDER BY id ASC LIMIT %d", max(1, min(50, (int) $limit))));
        $out = Linkbraid_Link_Manager::apply_bulk($ids);
        $out['remaining'] = (int) $wpdb->get_var(
            'SELECT COUNT(*) FROM ' . self::suggestions_table() . " WHERE method = 'autobraid' AND status = 'pending'");
        return $out;
    }

    public static function pending_count() {
        global $wpdb;
        return (int) $wpdb->get_var('SELECT COUNT(*) FROM ' . self::suggestions_table() . " WHERE method = 'autobraid' AND status = 'pending'");
    }
}