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

/**
 * Resolves the single site-wide visual contract used by Site Builder,
 * Content Development and the Visual Layout Engine.
 *
 * AI may choose an appropriate composition for a page, but it must not invent
 * a separate palette, width, radius or component language for that page.
 */
class AIWEST_Design_Contract {
    const VERSION = '1';

    public static function resolve() {
        $design = class_exists('AIWEST_Design_System')
            ? AIWEST_Design_System::get()
            : self::fallback_design();

        $brand_style = trim((string) get_option(
            'aiwest_visual_brand_style',
            'Modern, clear, expert website: hero, cards, steps, FAQ, CTA, generous spacing and professional tone.'
        ));
        $brand_style = self::normalize_legacy_brand($brand_style);
        $layout_mode = sanitize_key((string) get_option('aiwest_layout_mode', 'ai_independent'));
        if (!in_array($layout_mode, ['ai_independent', 'theme_compatible'], true)) {
            $layout_mode = 'ai_independent';
        }

        $reference = class_exists('AIWEST_Memory')
            ? trim((string) AIWEST_Memory::get('lovable_project_summary', ''))
            : '';
        $reference = self::normalize_legacy_reference($reference);

        $contract = [
            'version' => self::VERSION,
            'tokens' => [
                'primary' => (string) ($design['primary'] ?? '#2563eb'),
                'primary_dark' => (string) ($design['primary_dark'] ?? '#1d4ed8'),
                'accent' => (string) ($design['accent'] ?? '#10b981'),
                'ink' => (string) ($design['ink'] ?? '#111827'),
                'muted' => (string) ($design['muted'] ?? '#4b5563'),
                'border' => (string) ($design['border'] ?? '#e5e7eb'),
                'surface' => (string) ($design['surface'] ?? '#ffffff'),
                'soft' => (string) ($design['soft'] ?? '#f8fafc'),
                'soft_blue' => (string) ($design['soft_blue'] ?? '#eff6ff'),
                'radius' => (string) ($design['radius'] ?? '22px'),
                'button_radius' => (string) ($design['button_radius'] ?? '999px'),
                'shadow' => (string) ($design['shadow'] ?? '0 18px 50px rgba(15,23,42,.08)'),
                'max_width' => (string) ($design['max_width'] ?? '1180px'),
            ],
            'layout' => [
                'template' => sanitize_key((string) ($design['layout_template'] ?? 'standard_landing')),
                'section_count' => (string) ($design['section_count'] ?? '4'),
                'card_count' => (string) ($design['card_count'] ?? '3'),
                'faq_policy' => sanitize_key((string) ($design['faq_policy'] ?? 'optional')),
                'cta_policy' => sanitize_key((string) ($design['cta_policy'] ?? 'always')),
                'related_policy' => sanitize_key((string) ($design['related_policy'] ?? 'optional')),
                'mode' => $layout_mode,
            ],
            'media' => [
                'source' => sanitize_key((string) ($design['media_source'] ?? 'ai_or_library')),
                'position' => sanitize_key((string) ($design['media_position'] ?? 'right_column')),
                'size' => sanitize_key((string) ($design['media_size'] ?? 'medium')),
                'url' => esc_url_raw((string) ($design['media_url'] ?? '')),
                'video_url' => esc_url_raw((string) ($design['video_url'] ?? '')),
            ],
            'canvas' => [
                'background_url' => esc_url_raw((string) get_option('aiwest_canvas_bg_url', '')),
                'background_opacity' => self::opacity(get_option('aiwest_canvas_bg_opacity', 0.16), 0.16),
                'header_background_url' => esc_url_raw((string) get_option('aiwest_header_bg_url', '')),
                'header_background_opacity' => self::opacity(get_option('aiwest_header_bg_opacity', 0.18), 0.18),
            ],
            'brand_style' => sanitize_textarea_field($brand_style),
            'imported_reference' => sanitize_textarea_field($reference),
        ];

        $contract['hash'] = self::fingerprint($contract);
        return $contract;
    }

    public static function planner_context($contract = null) {
        $contract = is_array($contract) ? $contract : self::resolve();
        $layout = $contract['layout'] ?? [];
        $media = $contract['media'] ?? [];

        return "SITE-WIDE DESIGN CONTRACT (mandatory):\n"
            . "- Use the global WordPress design tokens exposed as --aiwest-* CSS variables. Never invent a page-specific palette.\n"
            . "- Layout template: " . ($layout['template'] ?? 'standard_landing') . ".\n"
            . "- Layout mode: " . ($layout['mode'] ?? 'ai_independent') . ".\n"
            . "- Target sections: " . ($layout['section_count'] ?? '4') . "; cards per card section: " . ($layout['card_count'] ?? '3') . ".\n"
            . "- FAQ: " . ($layout['faq_policy'] ?? 'optional') . "; CTA: " . ($layout['cta_policy'] ?? 'always') . "; related content: " . ($layout['related_policy'] ?? 'optional') . ".\n"
            . "- Media: " . ($media['source'] ?? 'ai_or_library') . ", " . ($media['position'] ?? 'right_column') . ", " . ($media['size'] ?? 'medium') . ".\n"
            . "- Brand direction: " . (($contract['brand_style'] ?? '') ?: 'No additional brand direction.') . "\n"
            . "- Imported design reference: " . (($contract['imported_reference'] ?? '') ?: 'No imported design reference.') . "\n"
            . "- Contract fingerprint: " . ($contract['hash'] ?? '') . ".";
    }

    public static function default_profile($contract = null) {
        $contract = is_array($contract) ? $contract : self::resolve();
        $template = sanitize_key((string) ($contract['layout']['template'] ?? 'standard_landing'));
        $map = [
            'standard_landing' => 'landing',
            'guide' => 'documentation',
            'comparison' => 'cards',
            'directory' => 'cards',
            'product' => 'landing',
            'minimal' => 'editorial',
        ];
        return $map[$template] ?? 'editorial';
    }

    public static function fingerprint($contract) {
        if (!is_array($contract)) return '';
        unset($contract['hash']);
        $json = wp_json_encode($contract, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
        return substr(hash('sha256', (string) $json), 0, 16);
    }

    protected static function opacity($value, $fallback) {
        return is_numeric($value) ? max(0, min(1, (float) $value)) : (float) $fallback;
    }

    protected static function normalize_legacy_reference($reference) {
        if ($reference === '') return '';
        return strtr($reference, [
            'Zaimportowany wzorzec projektu.' => 'Imported project design reference.',
            'Data importu:' => 'Import date:',
            'Pliki:' => 'Files:',
            'Komponenty:' => 'Components:',
            'Strony/widoki:' => 'Pages/views:',
            'Pliki danych:' => 'Data files:',
            'Wykryte ścieżki/menu/linki:' => 'Detected routes/menu/links:',
            'Ważne pliki stron:' => 'Important page files:',
            'Ważne komponenty:' => 'Important components:',
            'Pliki danych/treści:' => 'Data/content files:',
            'Fragmenty treści i klas:' => 'Content and class excerpts:',
        ]);
    }

    protected static function normalize_legacy_brand($brand_style) {
        $legacy = [
            'Nowoczesny, jasny, ekspercki portal budowlany: hero, karty, kroki, FAQ, CTA, dużo przestrzeni, profesjonalny ton.',
            'Nowoczesny, jasny, ekspercki serwis: hero, karty, kroki, FAQ, CTA, dużo przestrzeni, profesjonalny ton.',
        ];
        return in_array($brand_style, $legacy, true)
            ? 'Modern, clear, expert website: hero, cards, steps, FAQ, CTA, generous spacing and professional tone.'
            : $brand_style;
    }

    protected static function fallback_design() {
        return [
            'primary' => '#2563eb', 'primary_dark' => '#1d4ed8', 'accent' => '#10b981',
            'ink' => '#111827', 'muted' => '#4b5563', 'border' => '#e5e7eb',
            'surface' => '#ffffff', 'soft' => '#f8fafc', 'soft_blue' => '#eff6ff',
            'radius' => '22px', 'button_radius' => '999px',
            'shadow' => '0 18px 50px rgba(15,23,42,.08)', 'max_width' => '1180px',
            'layout_template' => 'standard_landing', 'section_count' => '4', 'card_count' => '3',
            'faq_policy' => 'optional', 'cta_policy' => 'always', 'related_policy' => 'optional',
            'media_source' => 'ai_or_library', 'media_position' => 'right_column', 'media_size' => 'medium',
        ];
    }
}