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

/**
 * Applies an AI-selected composition without asking AI to regenerate content.
 * Existing post HTML is embedded unchanged and all visual tokens come from the
 * shared site-wide Design Contract.
 */
class AIWEST_Visual_Layout_Engine {
    const ENGINE_VERSION = '5';
    const META_PLAN = '_aiwest_visual_layout_plan';

    public static function init() {
        add_action('wp_enqueue_scripts', [__CLASS__, 'enqueue_frontend_styles'], 20);
        add_action('enqueue_block_editor_assets', [__CLASS__, 'enqueue_editor_styles']);
        add_filter('the_content', [__CLASS__, 'apply_current_contract'], 24);
    }

    public static function select_plan($post, $instruction = '', $contract = null) {
        $contract = is_array($contract)
            ? $contract
            : (class_exists('AIWEST_Design_Contract') ? AIWEST_Design_Contract::resolve() : []);
        $default = self::heuristic_plan($post, $instruction, $contract);
        $plan = $default;
        $plan['engine'] = 'deterministic_layout_plan';
        $plan['layout_template'] = sanitize_key((string)($contract['layout']['template'] ?? 'standard_landing'));
        $plan['design_contract_hash'] = sanitize_key((string)($contract['hash'] ?? ''));

        if (!class_exists('AIWEST_OpenAI') || !method_exists('AIWEST_OpenAI', 'chat')) {
            return $plan;
        }

        $content = isset($post->post_content) ? (string)$post->post_content : '';
        $plain = trim(wp_strip_all_tags($content));
        preg_match_all('/<h[1-3]\b/i', $content, $heading_matches);
        preg_match_all('/<(?:ul|ol)\b/i', $content, $list_matches);
        preg_match_all('/<table\b/i', $content, $table_matches);
        preg_match_all('/<img\b/i', $content, $image_matches);

        $messages = [
            [
                'role' => 'system',
                'content' => 'You select a visual presentation preset for existing WordPress content. You never write, quote, summarize, or transform page content. Return JSON only.',
            ],
            [
                'role' => 'user',
                'content' =>
                    "Choose one safe layout preset.\n" .
                    "Allowed profile: documentation, editorial, cards, landing.\n" .
                    "Allowed density: compact, balanced, spacious.\n" .
                    "Title: " . sanitize_text_field((string)($post->post_title ?? '')) . "\n" .
                    "Post type: " . sanitize_key((string)($post->post_type ?? 'post')) . "\n" .
                    "Visible word count: " . self::word_count($plain) . "\n" .
                    "Heading count: " . count($heading_matches[0]) . "\n" .
                    "List count: " . count($list_matches[0]) . "\n" .
                    "Table count: " . count($table_matches[0]) . "\n" .
                    "Image count: " . count($image_matches[0]) . "\n" .
                    "Administrator layout instruction: " . sanitize_textarea_field((string)$instruction) . "\n" .
                    (class_exists('AIWEST_Design_Contract') ? AIWEST_Design_Contract::planner_context($contract) : '') . "\n" .
                    "The composition must obey that contract. Do not select or propose colors, fonts, radii, widths or shadows.\n" .
                    'Return exactly: {"profile":"...","density":"..."}',
            ],
        ];

        $result = AIWEST_OpenAI::chat($messages, 0.1);
        if (is_wp_error($result)) {
            if (class_exists('AIWEST_Logger')) {
                AIWEST_Logger::warning('Visual layout planning failed; deterministic preset used.', [
                    'post_id' => intval($post->ID ?? 0),
                    'error' => $result->get_error_message(),
                ]);
            }
            return $plan;
        }

        $decoded = self::decode_json($result);
        if (!is_array($decoded)) return $plan;

        $plan['profile'] = self::allowed_value($decoded['profile'] ?? '', ['documentation','editorial','cards','landing'], $default['profile']);
        $plan['density'] = self::allowed_value($decoded['density'] ?? '', ['compact','balanced','spacious'], $default['density']);
        $plan['engine'] = 'ai_layout_plan';
        return $plan;
    }

    public static function apply($content, $plan) {
        unset($plan);

        /*
         * Layout is presentation metadata, not post content. Older releases
         * stored a synthetic core/group block around the content, which could
         * trigger Gutenberg's "unexpected or invalid content" warning. Keep
         * the approved content byte-for-byte, except for removing that legacy
         * outer wrapper when the administrator runs Visual Enhancement again.
         */
        $content = self::unwrap((string)$content);
        return class_exists('AIWEST_Semantic_Layout_Composer')
            ? AIWEST_Semantic_Layout_Composer::decompose($content)
            : $content;
    }

    public static function apply_current_contract($content) {
        $content = (string) $content;
        if (is_admin() || is_feed()) return $content;

        $post_id = get_the_ID();
        if (!$post_id) return $content;
        $plan = get_post_meta($post_id, self::META_PLAN, true);
        if (!is_array($plan) || empty($plan)) return $content;

        $content = self::unwrap($content);
        $contract = class_exists('AIWEST_Design_Contract') ? AIWEST_Design_Contract::resolve() : [];
        $fallback_profile = class_exists('AIWEST_Design_Contract')
            ? AIWEST_Design_Contract::default_profile($contract)
            : 'editorial';
        $profile = self::allowed_value($plan['profile'] ?? '', ['documentation','editorial','cards','landing'], $fallback_profile);
        $density = self::allowed_value($plan['density'] ?? '', ['compact','balanced','spacious'], 'balanced');
        $contract_hash = sanitize_key((string)($contract['hash'] ?? ($plan['design_contract_hash'] ?? '')));
        $classes = 'aiwest-visual-layout aiwest-visual-contract-v2 aiwest-visual-profile-' . $profile . ' aiwest-visual-density-' . $density;
        if (class_exists('AIWEST_Semantic_Layout_Composer')) {
            $raw_content = AIWEST_Semantic_Layout_Composer::decompose($content);
            $composed = AIWEST_Semantic_Layout_Composer::compose($raw_content, $profile);
            $content = AIWEST_Semantic_Layout_Composer::identity_preserved($raw_content, $composed)
                ? $composed
                : $raw_content;
        }

        return '<div class="' . esc_attr($classes) . '" data-aiwest-visual-layout="' . esc_attr(self::ENGINE_VERSION) . '" data-aiwest-design-contract="' . esc_attr($contract_hash) . '">'
            . '<div class="aiwest-visual-layout-inner">'
            . $content
            . '</div></div>';
    }

    public static function save_plan($post_id, $plan) {
        $post_id = absint($post_id);
        if (!$post_id) return false;

        $safe_plan = [
            'profile' => self::allowed_value($plan['profile'] ?? '', ['documentation','editorial','cards','landing'], 'editorial'),
            'density' => self::allowed_value($plan['density'] ?? '', ['compact','balanced','spacious'], 'balanced'),
            'layout_template' => sanitize_key((string)($plan['layout_template'] ?? 'standard_landing')),
            'design_contract_hash' => sanitize_key((string)($plan['design_contract_hash'] ?? '')),
            'engine' => sanitize_key((string)($plan['engine'] ?? 'deterministic_layout_plan')),
            'engine_version' => self::ENGINE_VERSION,
        ];

        update_post_meta($post_id, self::META_PLAN, $safe_plan);
        return $safe_plan;
    }

    public static function unwrap($content) {
        $content = (string)$content;
        if (strpos($content, 'aiwest-visual-layout') === false || strpos($content, 'data-aiwest-visual-layout-content') === false) {
            return $content;
        }

        if (!preg_match('/<div\b(?=[^>]*\bdata-aiwest-visual-layout-content\s*=\s*(["\'])1\1)[^>]*>/i', $content, $start, PREG_OFFSET_CAPTURE)) {
            return $content;
        }
        if (!preg_match('/<\/div>\s*<!--\s*\/wp:group\s*-->\s*<\/div>\s*<!--\s*\/wp:group\s*-->\s*$/is', $content, $end, PREG_OFFSET_CAPTURE)) {
            return $content;
        }

        $start_offset = $start[0][1] + strlen($start[0][0]);
        $end_offset = $end[0][1];
        if ($end_offset < $start_offset) return $content;

        $inner = substr($content, $start_offset, $end_offset - $start_offset);
        if (substr($inner, 0, 1) === "\n") $inner = substr($inner, 1);
        if (substr($inner, -1) === "\n") $inner = substr($inner, 0, -1);
        return $inner;
    }

    public static function enqueue_frontend_styles() {
        wp_enqueue_style(
            'aiwest-visual-layout',
            AIWEST_URL . 'assets/visual-layout.css',
            [],
            defined('AIWEST_VERSION') ? AIWEST_VERSION : null
        );
    }

    public static function enqueue_editor_styles() {
        wp_enqueue_style(
            'aiwest-visual-layout-editor',
            AIWEST_URL . 'assets/visual-layout.css',
            [],
            defined('AIWEST_VERSION') ? AIWEST_VERSION : null
        );
    }


    protected static function heuristic_plan($post, $instruction, $contract) {
        $context = is_array($contract)
            ? (($contract['brand_style'] ?? '') . ' ' . ($contract['imported_reference'] ?? ''))
            : '';
        $haystack = self::lower((string)($post->post_title ?? '') . ' ' . (string)$instruction . ' ' . $context);
        $profile = class_exists('AIWEST_Design_Contract')
            ? AIWEST_Design_Contract::default_profile(is_array($contract) ? $contract : null)
            : 'editorial';
        if (preg_match('/documentation|docs|security|privacy|policy|terms|api|changelog|roadmap|support|faq|dokument|prywat|bezpieczeń|regulamin/u', $haystack)) $profile = 'documentation';
        elseif (preg_match('/landing|hero|homepage|home page|strona główna/u', $haystack)) $profile = 'landing';
        elseif (preg_match('/cards|grid|features|services|karty|siatka/u', $haystack)) $profile = 'cards';

        $density = preg_match('/spacious|generous spacing|dużo przestrzeni|przestronn/u', $haystack) ? 'spacious' : (preg_match('/compact|dense|kompakt/u', $haystack) ? 'compact' : 'balanced');
        return ['profile' => $profile, 'density' => $density];
    }

    protected static function decode_json($result) {
        $clean = trim((string)$result);
        $clean = preg_replace('/^```(?:json)?\s*/i', '', $clean);
        $clean = preg_replace('/\s*```$/', '', $clean);
        $data = json_decode($clean, true);
        if (is_array($data)) return $data;
        $first = strpos($clean, '{');
        $last = strrpos($clean, '}');
        return ($first !== false && $last !== false && $last > $first) ? json_decode(substr($clean, $first, $last - $first + 1), true) : null;
    }

    protected static function allowed_value($value, $allowed, $fallback) {
        $value = sanitize_key((string)$value);
        return in_array($value, $allowed, true) ? $value : $fallback;
    }

    protected static function word_count($text) {
        preg_match_all('/[\p{L}\p{N}][\p{L}\p{N}\p{M}\x{2019}\'\-]*/u', (string)$text, $matches);
        return count($matches[0]);
    }

    protected static function lower($text) {
        return function_exists('mb_strtolower') ? mb_strtolower((string)$text, 'UTF-8') : strtolower((string)$text);
    }
}

AIWEST_Visual_Layout_Engine::init();