<?php
defined('ABSPATH') || exit();

final class APEARI_Plans
{
    public const BLOCKS = [
        'core/paragraph',
        'core/heading',
        'core/button',
        'core/buttons',
        'core/group',
        'core/columns',
        'core/column',
        'core/image',
        'core/gallery',
        'core/spacer',
        'core/separator',
        'core/list',
        'core/list-item',
        'core/quote',
    ];
    public const CONTAINERS = [
        'core/group',
        'core/columns',
        'core/column',
        'core/buttons',
        'core/list',
        'core/quote',
        'core/gallery',
    ];
    public const STYLES = [
        'color',
        'backgroundColor',
        'fontSize',
        'padding',
        'margin',
        'borderRadius',
        'letterSpacing',
        'lineHeight',
        'blockGap',
        'borderWidth',
        'borderColor',
        'minHeight',
    ];

    public static function validate($plan)
    {
        if (
            !is_array($plan) ||
            !isset($plan['summary'], $plan['operations']) ||
            !is_string($plan['summary']) ||
            !is_array($plan['operations']) ||
            count($plan['operations']) < 1 ||
            count($plan['operations']) > 12
        ) {
            return new WP_Error('apeari_plan', __('Serwer zwrócił nieprawidłowy plan zmian.', 'apeari'), [
                'status' => 502,
            ]);
        }
        $clean = ['summary' => sanitize_text_field(mb_substr($plan['summary'], 0, 500)), 'operations' => []];
        $node_count = 0;
        foreach ($plan['operations'] as $op) {
            if (!is_array($op) || empty($op['type'])) {
                return self::invalid();
            }
            switch ($op['type']) {
                case 'remove_block':
                case 'duplicate_block':
                    if ('remove_block' === $op['type'] && count($plan['operations']) !== 1) {
                        return self::invalid();
                    }
                    $clean['operations'][] = ['type' => $op['type']];
                    break;
                case 'move_block':
                    if (!in_array($op['direction'] ?? '', ['up', 'down'], true)) {
                        return self::invalid();
                    }
                    $clean['operations'][] = ['type' => 'move_block', 'direction' => $op['direction']];
                    break;
                case 'set_layout':
                    if (
                        !in_array($op['layout'] ?? '', ['constrained', 'flex', 'grid'], true) ||
                        !in_array($op['orientation'] ?? '', ['horizontal', 'vertical'], true)
                    ) {
                        return self::invalid();
                    }
                    $clean['operations'][] = [
                        'type' => 'set_layout',
                        'layout' => $op['layout'],
                        'orientation' => $op['orientation'],
                    ];
                    break;
                case 'set_alignment':
                    if (!in_array($op['value'] ?? '', ['left', 'center', 'right'], true)) {
                        return self::invalid();
                    }
                    $clean['operations'][] = ['type' => 'set_alignment', 'value' => $op['value']];
                    break;
                case 'set_heading_level':
                    if (!is_int($op['level'] ?? null) || $op['level'] < 1 || $op['level'] > 6) {
                        return self::invalid();
                    }
                    $clean['operations'][] = ['type' => 'set_heading_level', 'level' => $op['level']];
                    break;
                case 'set_link':
                    $url = $op['url'] ?? null;
                    if (
                        !is_string($url) ||
                        strlen($url) > 2000 ||
                        !is_bool($op['newTab'] ?? null) ||
                        !preg_match('~^(?:https?://|/|\#|mailto:|tel:)~i', $url) ||
                        preg_match('/[\x00-\x20<>"\x27]/', $url) ||
                        wp_parse_url($url, PHP_URL_USER) ||
                        wp_parse_url($url, PHP_URL_PASS)
                    ) {
                        return self::invalid();
                    }
                    $clean['operations'][] = ['type' => 'set_link', 'url' => $url, 'newTab' => $op['newTab']];
                    break;
                case 'set_text':
                    if (!isset($op['text']) || !is_string($op['text']) || strlen($op['text']) > 8000) {
                        return self::invalid();
                    }
                    $clean['operations'][] = [
                        'type' => 'set_text',
                        'text' => sanitize_textarea_field($op['text']),
                    ];
                    break;
                case 'set_style':
                    if (
                        !isset($op['property'], $op['value']) ||
                        !in_array($op['property'], self::STYLES, true) ||
                        !is_string($op['value'])
                    ) {
                        return self::invalid();
                    }
                    $color = in_array($op['property'], ['color', 'backgroundColor', 'borderColor'], true);
                    $pattern = $color
                        ? '/^#[a-fA-F0-9]{6}$/'
                        : ('lineHeight' === $op['property']
                            ? '/^(?:[0-9](?:\.\d{1,2})?|\d{1,3}(?:\.\d{1,2})?(?:px|rem|em|%))$/'
                            : '/^(?:0|(?:\d{1,3}(?:\.\d{1,2})?)(?:px|rem|em|%))$/');
                    if (!preg_match($pattern, $op['value'])) {
                        return self::invalid();
                    }
                    $clean['operations'][] = [
                        'type' => 'set_style',
                        'property' => $op['property'],
                        'value' => $op['value'],
                    ];
                    break;
                case 'set_image':
                case 'insert_image':
                    if (!is_string($op['mediaKey'] ?? null) || !preg_match('/^m[0-7]$/', $op['mediaKey'])) {
                        return self::invalid();
                    }
                    if (
                        'insert_image' === $op['type'] &&
                        !in_array($op['position'] ?? '', ['before', 'after', 'inside'], true)
                    ) {
                        return self::invalid();
                    }
                    $clean['operations'][] = array_filter(
                        [
                            'type' => $op['type'],
                            'mediaKey' => $op['mediaKey'],
                            'position' => $op['position'] ?? null,
                        ],
                        static fn($value) => null !== $value,
                    );
                    break;
                case 'insert_gallery':
                    if (
                        !in_array($op['position'] ?? '', ['before', 'after', 'inside'], true) ||
                        !is_array($op['mediaKeys'] ?? null) ||
                        1 === count($op['mediaKeys']) ||
                        count($op['mediaKeys']) > 16
                    ) {
                        return self::invalid();
                    }
                    if (!in_array($op['presentation'] ?? 'gallery', ['gallery', 'carousel'], true)) {
                        return self::invalid();
                    }
                    foreach ($op['mediaKeys'] as $key) {
                        if (!is_string($key) || !preg_match('/^m[0-7]$/', $key)) {
                            return self::invalid();
                        }
                    }
                    if (count(array_unique($op['mediaKeys'])) !== count($op['mediaKeys'])) {
                        return self::invalid();
                    }
                    $clean['operations'][] = [
                        'type' => 'insert_gallery',
                        'position' => $op['position'],
                        'mediaKeys' => array_values($op['mediaKeys']),
                        'presentation' => $op['presentation'] ?? 'gallery',
                    ];
                    break;
                case 'insert_section':
                    if (
                        !isset($op['title'], $op['body']) ||
                        !is_string($op['title']) ||
                        !is_string($op['body']) ||
                        strlen($op['title']) > 500 ||
                        strlen($op['body']) > 8000
                    ) {
                        return self::invalid();
                    }
                    if (!in_array($op['position'] ?? 'after', ['before', 'after', 'inside'], true)) {
                        return self::invalid();
                    }
                    $clean['operations'][] = [
                        'type' => 'insert_section',
                        'title' => sanitize_text_field($op['title']),
                        'body' => sanitize_textarea_field($op['body']),
                        'position' => $op['position'] ?? 'after',
                    ];
                    break;
                case 'insert_blocks':
                    if (
                        !in_array($op['position'] ?? '', ['before', 'after', 'inside'], true) ||
                        !is_array($op['blocks'] ?? null) ||
                        !$op['blocks']
                    ) {
                        return self::invalid();
                    }
                    $blocks = self::nodes($op['blocks'], 1, $node_count);
                    if (is_wp_error($blocks)) {
                        return $blocks;
                    }
                    $clean['operations'][] = [
                        'type' => 'insert_blocks',
                        'position' => $op['position'],
                        'blocks' => $blocks,
                    ];
                    break;
                default:
                    return self::invalid();
            }
        }
        return $clean;
    }

    private static function nodes(array $nodes, int $depth, int &$count)
    {
        if ($depth > 5) {
            return self::invalid();
        }
        $result = [];
        foreach ($nodes as $node) {
            if (
                ++$count > 40 ||
                !is_array($node) ||
                !in_array($node['blockName'] ?? '', array_diff(self::BLOCKS, ['core/image']), true) ||
                !is_string($node['text'] ?? null) ||
                strlen($node['text']) > 8000 ||
                !is_array($node['children'] ?? null)
            ) {
                return self::invalid();
            }
            if ($node['children'] && !in_array($node['blockName'], self::CONTAINERS, true)) {
                return self::invalid();
            }
            $children = $node['children'] ? self::nodes($node['children'], $depth + 1, $count) : [];
            if (is_wp_error($children)) {
                return $children;
            }
            foreach ($children as $child) {
                if (!self::allowed_parent($child['blockName'], $node['blockName'])) {
                    return self::invalid();
                }
            }
            $result[] = [
                'blockName' => $node['blockName'],
                'text' => sanitize_textarea_field($node['text']),
                'children' => $children,
            ];
        }
        return $result;
    }

    public static function allowed_parent(string $child, ?string $parent): bool
    {
        $required = [
            'core/column' => 'core/columns',
            'core/button' => 'core/buttons',
            'core/list-item' => 'core/list',
        ];
        $only = [
            'core/columns' => 'core/column',
            'core/buttons' => 'core/button',
            'core/list' => 'core/list-item',
            'core/gallery' => 'core/image',
        ];
        return (!isset($required[$child]) || $required[$child] === $parent) &&
            (!isset($only[$parent ?? '']) || $only[$parent] === $child);
    }

    public static function for_context(array $plan, array $context)
    {
        $placement = $context['target']['placement'];
        $parents = $context['ancestors'];
        $parent = $parents ? end($parents)['blockName'] : null;
        foreach ($plan['operations'] as $op) {
            if (in_array($op['type'], ['remove_block', 'duplicate_block', 'move_block'], true)) {
                $attrs = $context['attributes'] ?? [];
                if (
                    !empty($attrs['templateLock']) ||
                    !empty($attrs['lock']['remove']) ||
                    ('move_block' === $op['type'] && !empty($attrs['lock']['move']))
                ) {
                    return self::invalid();
                }
            }
            if ('set_layout' === $op['type'] && 'core/group' !== $context['blockName']) {
                return self::invalid();
            }
            if ('set_heading_level' === $op['type'] && 'core/heading' !== $context['blockName']) {
                return self::invalid();
            }
            if ('set_link' === $op['type'] && 'core/button' !== $context['blockName']) {
                return self::invalid();
            }
            if (
                'set_alignment' === $op['type'] &&
                !in_array($context['blockName'], ['core/paragraph', 'core/heading', 'core/button'], true)
            ) {
                return self::invalid();
            }
            if (
                'set_text' === $op['type'] &&
                !in_array(
                    $context['blockName'],
                    ['core/paragraph', 'core/heading', 'core/button', 'core/list-item'],
                    true,
                )
            ) {
                return self::invalid();
            }
            if ('set_image' === $op['type'] && 'core/image' !== $context['blockName']) {
                return self::invalid();
            }
            if (
                'set_style' === $op['type'] &&
                !in_array($op['property'], APEARI_Providers::allowed_styles($context['blockName']), true)
            ) {
                return self::invalid();
            }
            $insertion = in_array(
                $op['type'],
                ['insert_section', 'insert_blocks', 'insert_image', 'insert_gallery'],
                true,
            );
            if ('edit' !== $placement && (!$insertion || $op['position'] !== $placement)) {
                return new WP_Error(
                    'apeari_placement',
                    __(
                        'Plan AI nie odpowiada wybranemu miejscu wstawienia. Nie zastosowano zmian.',
                        'apeari',
                    ),
                    ['status' => 422],
                );
            }
            if (!$insertion) {
                continue;
            }
            $destination = 'inside' === $op['position'] ? $context['blockName'] : $parent;
            if ('inside' === $op['position'] && !in_array($destination, self::CONTAINERS, true)) {
                return self::invalid();
            }
            $nodes =
                'insert_section' === $op['type']
                    ? [['blockName' => 'core/group']]
                    : ('insert_image' === $op['type']
                        ? [['blockName' => 'core/image']]
                        : ('insert_gallery' === $op['type']
                            ? [['blockName' => 'core/gallery']]
                            : $op['blocks']));
            foreach ($nodes as $node) {
                if (!self::allowed_parent($node['blockName'], $destination)) {
                    return self::invalid();
                }
            }
        }
        return $plan;
    }

    private static function invalid(): WP_Error
    {
        return new WP_Error(
            'apeari_operation',
            __('Plan zawiera nieobsługiwaną lub niebezpieczną operację.', 'apeari'),
            [
                'status' => 422,
            ],
        );
    }

    public static function demo(string $instruction)
    {
        $lower = mb_strtolower($instruction);
        $ops = [];
        if (
            preg_match(
                '/(?:tekst|treść|tresc|napis|nagłówek|naglowek).*?[„"“](.+?)[”"“]/us',
                $instruction,
                $m,
            )
        ) {
            $ops[] = ['type' => 'set_text', 'text' => $m[1]];
        }
        $colors = [
            'niebiesk' => '#2563eb',
            'zielon' => '#16a34a',
            'czerwon' => '#dc2626',
            'czarn' => '#111827',
            'biał' => '#ffffff',
            'bial' => '#ffffff',
            'fiolet' => '#7c3aed',
            'pomarańcz' => '#ea580c',
            'pomarancz' => '#ea580c',
        ];
        $color = null;
        if (preg_match('/#[a-f0-9]{6}\b/i', $instruction, $m)) {
            $color = $m[0];
        }
        if (!$color) {
            foreach ($colors as $word => $hex) {
                if (str_contains($lower, $word)) {
                    $color = $hex;
                    break;
                }
            }
        }
        if ($color) {
            $ops[] = [
                'type' => 'set_style',
                'property' => preg_match('/tło|tlo|background/u', $lower) ? 'backgroundColor' : 'color',
                'value' => $color,
            ];
        }
        foreach (
            [
                'fontSize' =>
                    '/(?:font|czcionk|rozmiar\s+tekstu)[^\d]{0,25}(\d{1,3}(?:\.\d{1,2})?\s*(?:px|rem|em))/u',
                'padding' =>
                    '/(?:padding|odstęp\s+wewn|odstep\s+wewn)[^\d]{0,25}(\d{1,3}(?:\.\d{1,2})?\s*(?:px|rem|em))/u',
                'borderRadius' =>
                    '/(?:zaokrągl|zaokragl|radius)[^\d]{0,25}(\d{1,3}(?:\.\d{1,2})?\s*(?:px|rem|em))/u',
            ]
            as $property => $regex
        ) {
            if (preg_match($regex, $lower, $m)) {
                $ops[] = [
                    'type' => 'set_style',
                    'property' => $property,
                    'value' => preg_replace('/\s/', '', $m[1]),
                ];
            }
        }
        if (preg_match('/dodaj.*sekcj/u', $lower)) {
            $ops = [
                [
                    'type' => 'insert_blocks',
                    'position' => 'after',
                    'blocks' => [
                        [
                            'blockName' => 'core/group',
                            'text' => '',
                            'children' => [
                                [
                                    'blockName' => 'core/heading',
                                    'text' => __('Porozmawiajmy o Twoim projekcie', 'apeari'),
                                    'children' => [],
                                ],
                                [
                                    'blockName' => 'core/paragraph',
                                    'text' => __(
                                        'Opisz swój pomysł. Wspólnie znajdziemy rozwiązanie dopasowane do Twoich potrzeb.',
                                        'apeari',
                                    ),
                                    'children' => [],
                                ],
                            ],
                        ],
                    ],
                ],
            ];
        }
        if (!$ops) {
            return new WP_Error(
                'apeari_demo',
                __(
                    'Tryb demo rozpoznaje przykłady: Zmień tekst na „Witaj”, Ustaw tło #2563eb, Ustaw rozmiar tekstu 32px, Ustaw padding 24px, Dodaj sekcję. Swobodne polecenia wymagają podłączenia API AI.',
                    'apeari',
                ),
                ['status' => 422],
            );
        }
        return self::validate([
            'summary' => __('Zmiana demonstracyjna — sprawdź rezultat w podglądzie.', 'apeari'),
            'operations' => $ops,
        ]);
    }
}