<?php
namespace Zadex\Dynamic;

defined('ABSPATH') || exit;

/**
 * Base class for dynamic tags. A tag renders a value (string, number, or `{url,id,alt}` for images) for a
 * Context. Register custom tags with the `zadex/dynamic/tags` filter:
 *
 *   add_filter('zadex/dynamic/tags', function (array $tags) { $tags['my-tag'] = new My_Tag(); return $tags; });
 */
abstract class Tag
{
    public const CATEGORIES = ['text', 'url', 'image', 'number', 'color'];

    /** Unique slug (`post-title`). */
    abstract public function name(): string;

    abstract public function title(): string;

    /** Group key shown as a heading in the picker (post, archive, site, media, user, other, acf …). */
    public function group(): string
    {
        return 'post';
    }

    /** @return string[] subset of self::CATEGORIES: which control types can use this tag */
    public function categories(): array
    {
        return ['text'];
    }

    /**
     * Tag settings, in the manifest control format (`id`, `type`, `label`, `default`, `options`).
     * A text control with `"dynamicOptions": true` gets suggestions from GET /dynamic/options.
     *
     * @return array<int, array<string, mixed>>
     */
    public function controls(): array
    {
        return [];
    }

    /**
     * Option list for a control (GET /dynamic/options), e.g. meta keys or ACF fields.
     *
     * @return array<int, array{value: string, label: string}>
     */
    public function options(string $control, string $search, Context $ctx): array
    {
        return [];
    }

    /**
     * @param array<string, mixed> $settings tag settings merged with control defaults
     * @return string|int|float|array|null
     */
    abstract public function render(array $settings, Context $ctx);

    /** @return array<string, mixed> control defaults */
    public function defaults(): array
    {
        $out = [];
        foreach ($this->controls() as $control) {
            if (isset($control['id']) && array_key_exists('default', $control)) {
                $out[$control['id']] = $control['default'];
            }
        }
        return $out;
    }

    public function group_title(): string
    {
        $titles = [
            'post'     => __('Post', 'zadex'),
            'archive'  => __('Archive', 'zadex'),
            'site'     => __('Site', 'zadex'),
            'media'    => __('Media', 'zadex'),
            'user'     => __('User', 'zadex'),
            'other'    => __('Other', 'zadex'),
            'acf'      => 'ACF',
            'pods'     => 'Pods',
            'toolset'  => 'Toolset',
            'meta-box' => 'Meta Box',
        ];
        return $titles[$this->group()] ?? ucfirst($this->group());
    }

    /** @return array<string, mixed> editor payload (window.ZADEX.dynamicTags) */
    public function to_array(): array
    {
        return [
            'name'       => $this->name(),
            'title'      => $this->title(),
            'group'      => $this->group(),
            'groupTitle' => $this->group_title(),
            'categories' => array_values(array_intersect($this->categories(), self::CATEGORIES)),
            'controls'   => array_values($this->controls()),
        ];
    }

    /** Filters a {value,label} list by a search string (case-insensitive, value or label). */
    protected static function filter_options(array $options, string $search, int $limit = 50): array
    {
        $search = strtolower(trim($search));
        $out = [];
        foreach ($options as $opt) {
            if ($search !== '' && !str_contains(strtolower($opt['value'] . ' ' . $opt['label']), $search)) {
                continue;
            }
            $out[] = $opt;
            if (count($out) >= $limit) {
                break;
            }
        }
        return $out;
    }

    /** Turns an attachment id into the media shape. */
    protected static function attachment(int $id, string $size = 'full'): array
    {
        if ($id <= 0) {
            return ['id' => 0, 'url' => '', 'alt' => ''];
        }
        $url = function_exists('wp_get_attachment_image_url') ? (string) wp_get_attachment_image_url($id, $size) : '';
        $alt = function_exists('get_post_meta') ? (string) get_post_meta($id, '_wp_attachment_image_alt', true) : '';
        return ['id' => $id, 'url' => $url, 'alt' => $alt];
    }

    /** Normalises a plugin field value (string, number, image array, list) into a tag result. */
    protected static function field_value($value)
    {
        if (is_bool($value)) {
            return $value ? '1' : '';
        }
        if (is_scalar($value) || $value === null) {
            return $value;
        }
        if (is_object($value)) {
            $value = (array) $value;
        }
        if (!is_array($value)) {
            return '';
        }
        // Image-like field: { url, id|ID, alt }.
        if (isset($value['url']) && is_string($value['url'])) {
            return ['id' => (int) ($value['id'] ?? $value['ID'] ?? 0), 'url' => $value['url'], 'alt' => is_string($value['alt'] ?? null) ? $value['alt'] : ''];
        }
        // Meta Box image lists: first item. Plain lists: comma separated.
        if (array_is_list($value)) {
            if (isset($value[0]) && is_array($value[0]) && isset($value[0]['url'])) {
                return self::field_value($value[0]);
            }
            return implode(', ', array_filter(array_map(static fn($v) => is_scalar($v) ? (string) $v : '', $value), 'strlen'));
        }
        return '';
    }
}