/**
 * WPpiloot Connector 1.1.0 (snippet-versie) - https://wppiloot.nl
 * Laat WPpiloot ACF-velden lezen en aanpassen, ook als "Show in REST API" uit staat.
 * WordPress-rechten blijven gelden. Staat de plugin ook aan, dan laadt maar één van beide.
 */
if (! defined('WPPILOOT_CONNECTOR_VERSION')) {
    define('WPPILOOT_CONNECTOR_SOURCE', 'snippet');

    define('WPPILOOT_CONNECTOR_VERSION', '1.1.0');

    /**
     * Eindpunten (namespace wppiloot/v1), alleen voor ingelogde gebruikers
     * (applicatiewachtwoord):
     *   GET  /status                 versie, ACF aanwezig?
     *   GET  /acf/overview           optiepagina's en berichttypes met ACF-velden
     *   GET  /acf/fields?target=...  velddefinities + huidige waarden
     *   POST /acf/fields             {target, values: {veldnaam: waarde}}
     * target = "post:123" (elk berichttype) of "options:<menu_slug>".
     */
    add_action('rest_api_init', function () {
        $ns = 'wppiloot/v1';

        register_rest_route($ns, '/status', [
            'methods' => 'GET',
            'permission_callback' => 'is_user_logged_in',
            'callback' => function () {
                return [
                    'version' => WPPILOOT_CONNECTOR_VERSION,
                    'acf' => function_exists('acf_get_field_groups'),
                    'acf_version' => defined('ACF_VERSION') ? ACF_VERSION : null,
                    'acf_pro' => defined('ACF_PRO') && ACF_PRO,
                    'source' => defined('WPPILOOT_CONNECTOR_SOURCE') ? WPPILOOT_CONNECTOR_SOURCE : 'plugin',
                ];
            },
        ]);

        register_rest_route($ns, '/acf/overview', [
            'methods' => 'GET',
            'permission_callback' => 'is_user_logged_in',
            'callback' => 'wppiloot_acf_overview',
        ]);

        register_rest_route($ns, '/acf/fields', [
            [
                'methods' => 'GET',
                'permission_callback' => 'wppiloot_acf_can_edit',
                'callback' => 'wppiloot_acf_get',
                'args' => ['target' => ['required' => true, 'type' => 'string']],
            ],
            [
                'methods' => 'POST',
                'permission_callback' => 'wppiloot_acf_can_edit',
                'callback' => 'wppiloot_acf_update',
                'args' => [
                    'target' => ['required' => true, 'type' => 'string'],
                    'values' => ['required' => true, 'type' => 'object'],
                ],
            ],
        ]);
    });

    /**
     * Zet "post:123" of "options:slug" om naar wat ACF verwacht.
     *
     * @return array{kind: string, acf_id: int|string, post?: WP_Post, page?: array}|WP_Error
     */
    function wppiloot_acf_target($target)
    {
        if (! function_exists('acf_get_field_groups')) {
            return new WP_Error('wppiloot_no_acf', 'Advanced Custom Fields is niet actief op deze site.', ['status' => 400]);
        }

        if (preg_match('/^post:(\d+)$/', (string) $target, $m)) {
            $post = get_post((int) $m[1]);
            if (! $post || $post->post_type === 'revision') {
                return new WP_Error('wppiloot_not_found', 'Dit bericht bestaat niet.', ['status' => 404]);
            }

            return ['kind' => 'post', 'acf_id' => $post->ID, 'post' => $post];
        }

        if (preg_match('/^options:([A-Za-z0-9_-]+)$/', (string) $target, $m)) {
            $page = function_exists('acf_get_options_page') ? acf_get_options_page($m[1]) : null;
            if (! $page) {
                return new WP_Error('wppiloot_not_found', 'Deze optiepagina bestaat niet.', ['status' => 404]);
            }

            return ['kind' => 'options', 'acf_id' => $page['post_id'] ?: 'options', 'page' => $page];
        }

        return new WP_Error('wppiloot_bad_target', 'target moet "post:<id>" of "options:<slug>" zijn.', ['status' => 400]);
    }

    /** Dezelfde rechten als in de WordPress-backend. */
    function wppiloot_acf_can_edit(WP_REST_Request $request)
    {
        if (! is_user_logged_in()) {
            return false;
        }
        $t = wppiloot_acf_target($request['target']);
        if (is_wp_error($t)) {
            return $t;
        }

        return $t['kind'] === 'post'
            ? current_user_can('edit_post', $t['post']->ID)
            : current_user_can($t['page']['capability'] ?: 'edit_posts');
    }

    /** Veldgroepen die bij dit doel horen (zoals ACF ze in de editor toont). */
    function wppiloot_acf_groups(array $t)
    {
        if ($t['kind'] === 'post') {
            $args = ['post_id' => $t['post']->ID, 'post_type' => $t['post']->post_type];
            $template = get_page_template_slug($t['post']);
            if ($template) {
                $args['page_template'] = $template;
            }
        } else {
            $args = ['options_page' => $t['page']['menu_slug']];
        }

        return array_values(array_filter(acf_get_field_groups($args), function ($g) {
            return ! empty($g['active']);
        }));
    }

    /** Beknopte definitie van een veld, voor het taalmodel. */
    function wppiloot_acf_describe(array $field)
    {
        $d = [
            'name' => $field['name'],
            'label' => $field['label'],
            'type' => $field['type'],
        ];
        if (! empty($field['instructions'])) {
            $d['instructions'] = wp_strip_all_tags($field['instructions']);
        }
        if (! empty($field['required'])) {
            $d['required'] = true;
        }
        if (! empty($field['choices']) && is_array($field['choices'])) {
            $d['choices'] = $field['choices'];
        }
        if (! empty($field['multiple'])) {
            $d['multiple'] = true;
        }
        if (! empty($field['max'])) {
            $d['max'] = $field['max'];
        }
        if (in_array($field['type'], ['image', 'file', 'gallery'], true)) {
            $d['value_format'] = 'media-id (gallery: lijst van media-id\'s)';
        } elseif (in_array($field['type'], ['post_object', 'relationship', 'page_link'], true)) {
            $d['value_format'] = 'bericht-id (of lijst van id\'s)';
        } elseif ($field['type'] === 'taxonomy') {
            $d['value_format'] = 'term-id (of lijst van id\'s)';
        } elseif ($field['type'] === 'link') {
            $d['value_format'] = '{"title","url","target"}';
        } elseif ($field['type'] === 'true_false') {
            $d['value_format'] = '0 of 1';
        }
        if (! empty($field['sub_fields'])) {
            $d['sub_fields'] = array_map('wppiloot_acf_describe', $field['sub_fields']);
        }
        if (! empty($field['layouts'])) {
            $d['layouts'] = array_values(array_map(function ($l) {
                return [
                    'name' => $l['name'],
                    'label' => $l['label'],
                    'sub_fields' => array_map('wppiloot_acf_describe', $l['sub_fields'] ?? []),
                ];
            }, $field['layouts']));
        }

        return $d;
    }

    /**
     * Ruwe waarde (zoals opgeslagen, zonder opmaak) met veldnamen in plaats van
     * veldsleutels in repeaters, groepen en flexibele inhoud. Zo komt het weer
     * terug in update_field().
     */
    function wppiloot_acf_export(array $field, $value)
    {
        switch ($field['type']) {
            case 'repeater':
                if (! is_array($value)) {
                    return [];
                }

                return array_values(array_map(function ($row) use ($field) {
                    return wppiloot_acf_export_row($field['sub_fields'] ?? [], (array) $row);
                }, $value));

            case 'group':
                return wppiloot_acf_export_row($field['sub_fields'] ?? [], (array) $value);

            case 'flexible_content':
                if (! is_array($value)) {
                    return [];
                }
                $layouts = [];
                foreach ($field['layouts'] ?? [] as $l) {
                    $layouts[$l['name']] = $l;
                }

                return array_values(array_map(function ($row) use ($layouts) {
                    $row = (array) $row;
                    $name = $row['acf_fc_layout'] ?? '';
                    $out = ['acf_fc_layout' => $name];
                    if (isset($layouts[$name])) {
                        $out += wppiloot_acf_export_row($layouts[$name]['sub_fields'] ?? [], $row);
                    }

                    return $out;
                }, $value));

            default:
                return $value;
        }
    }

    function wppiloot_acf_export_row(array $sub_fields, array $row)
    {
        $out = [];
        foreach ($sub_fields as $sub) {
            $raw = $row[$sub['key']] ?? $row[$sub['name']] ?? null;
            $out[$sub['name']] = wppiloot_acf_export($sub, $raw);
        }

        return $out;
    }

    function wppiloot_acf_get(WP_REST_Request $request)
    {
        $t = wppiloot_acf_target($request['target']);
        if (is_wp_error($t)) {
            return $t;
        }

        $groups = [];
        foreach (wppiloot_acf_groups($t) as $group) {
            $fields = [];
            foreach (acf_get_fields($group) ?: [] as $field) {
                if (in_array($field['type'], ['tab', 'message', 'accordion'], true) || $field['name'] === '') {
                    continue;
                }
                $fields[] = wppiloot_acf_describe($field) + [
                    'value' => wppiloot_acf_export($field, get_field($field['key'], $t['acf_id'], false)),
                ];
            }
            $groups[] = ['title' => $group['title'], 'fields' => $fields];
        }

        return [
            'target' => $request['target'],
            'title' => $t['kind'] === 'post' ? get_the_title($t['post']) : $t['page']['page_title'],
            'post_type' => $t['kind'] === 'post' ? $t['post']->post_type : null,
            'groups' => $groups,
        ];
    }

    /** Alle velden (op het hoogste niveau) die bij het doel horen, op naam. */
    function wppiloot_acf_field_map(array $t)
    {
        $map = [];
        foreach (wppiloot_acf_groups($t) as $group) {
            foreach (acf_get_fields($group) ?: [] as $field) {
                if ($field['name'] !== '' && ! in_array($field['type'], ['tab', 'message', 'accordion'], true)) {
                    $map[$field['name']] = $field;
                }
            }
        }

        return $map;
    }

    /** Tekst zonder unfiltered_html-recht door wp_kses_post, net als in de editor. */
    function wppiloot_acf_clean($value)
    {
        if (is_array($value)) {
            return array_map('wppiloot_acf_clean', $value);
        }
        if (is_string($value) && ! current_user_can('unfiltered_html')) {
            return wp_kses_post($value);
        }

        return $value;
    }

    function wppiloot_acf_update(WP_REST_Request $request)
    {
        $t = wppiloot_acf_target($request['target']);
        if (is_wp_error($t)) {
            return $t;
        }

        $values = (array) $request['values'];
        if (! $values) {
            return new WP_Error('wppiloot_empty', 'Geen waarden meegegeven.', ['status' => 400]);
        }

        $map = wppiloot_acf_field_map($t);
        $unknown = array_diff(array_keys($values), array_keys($map));
        if ($unknown) {
            return new WP_Error('wppiloot_unknown_field', 'Onbekende velden voor dit doel: '.implode(', ', $unknown).'. Bestaande velden: '.implode(', ', array_keys($map)).'.', ['status' => 400]);
        }

        foreach ($values as $name => $value) {
            $field = $map[$name];
            if (in_array($field['type'], ['select', 'radio', 'button_group', 'checkbox'], true) && ! empty($field['choices']) && $value !== '' && $value !== null) {
                foreach ((array) $value as $v) {
                    if (! array_key_exists((string) $v, $field['choices'])) {
                        return new WP_Error('wppiloot_bad_choice', "Waarde \"{$v}\" is niet toegestaan voor {$name}. Kies uit: ".implode(', ', array_keys($field['choices'])).'.', ['status' => 400]);
                    }
                }
            }
        }

        $updated = [];
        foreach ($values as $name => $value) {
            $field = $map[$name];
            update_field($field['key'], wppiloot_acf_clean($value), $t['acf_id']);
            $updated[$name] = wppiloot_acf_export($field, get_field($field['key'], $t['acf_id'], false));
        }

        if ($t['kind'] === 'post') {
            // Wijzigingsdatum bijwerken (caches, sitemaps), zonder de inhoud aan te raken.
            wp_update_post(['ID' => $t['post']->ID]);
        }

        return ['target' => $request['target'], 'updated' => $updated];
    }

    function wppiloot_acf_overview()
    {
        if (! function_exists('acf_get_field_groups')) {
            return new WP_Error('wppiloot_no_acf', 'Advanced Custom Fields is niet actief op deze site.', ['status' => 400]);
        }

        $options = [];
        foreach (function_exists('acf_get_options_pages') ? (acf_get_options_pages() ?: []) : [] as $page) {
            if (current_user_can($page['capability'] ?: 'edit_posts')) {
                $options[] = ['target' => 'options:'.$page['menu_slug'], 'title' => $page['page_title']];
            }
        }

        $post_types = [];
        foreach (acf_get_field_groups() as $group) {
            if (empty($group['active'])) {
                continue;
            }
            foreach ($group['location'] as $rules) {
                foreach ($rules as $rule) {
                    if ($rule['param'] === 'post_type' && $rule['operator'] === '==') {
                        $post_types[$rule['value']][] = $group['title'];
                    } elseif ($rule['param'] === 'page_template' && $rule['operator'] === '==') {
                        $post_types['page'][] = $group['title'].' (sjabloon '.$rule['value'].')';
                    }
                }
            }
        }

        $types = [];
        foreach ($post_types as $slug => $titles) {
            $obj = get_post_type_object($slug);
            if ($obj && current_user_can($obj->cap->edit_posts)) {
                $types[] = [
                    'post_type' => $slug,
                    'label' => $obj->labels->name,
                    'rest_base' => $obj->show_in_rest ? ($obj->rest_base ?: $slug) : null,
                    'field_groups' => array_values(array_unique($titles)),
                ];
            }
        }

        return ['options_pages' => $options, 'post_types' => $types];
    }
}