<?php
/**
 * Forum permission/capability service.
 *
 * Extracted from AKSRT_Forum to keep the capability matrix,
 * tier resolution, and cache invalidation in a focused unit.
 *
 * @package AKSRT
 */

defined('ABSPATH') || exit;

class AKSRT_Forum_Permission_Service {

    // ── Tier constants (mirrored from AKSRT_Forum) ───────────────
    const TIER_NONE         = 0;
    const TIER_MODERATOR    = 1;
    const TIER_PLATE_AUTHOR = 2;
    const TIER_CAT_MOD      = 3;
    const TIER_FORUM_ADMIN  = 4;

    /** @var array<string,bool>  cap_key => bool */
    private static array $cap_cache = [];
    /** @var array<string,int>   "uid:plate_id" => tier */
    private static array $tier_cache = [];

    /** @var AKSRT_Forum */
    private $forum;

    public function __construct($forum) {
        $this->forum = $forum;
    }

    // ── Capability matrix ─────────────────────────────────────────

    /**
     * Capability definitions matrix.
     *
     * Keys:
     *   'min_tier'     — minimum TIER_* constant required
     *   'context'      — 'topic'|'plate'|'global'|'any'
     *   'self'         — true = only applies to own content
     *   'logged'       — shorthand: any logged-in user
     *   'settings_key' — optional forum settings permissions key
     */
    private function cap_defs(): array {
        return [
            // ── Topic viewing ─────────────────────────────────────────────
            'topic_view_pending'     => ['min_tier' => self::TIER_MODERATOR,    'context' => 'plate'],
            'topic_view_hidden'      => ['min_tier' => self::TIER_MODERATOR,    'context' => 'plate'],
            'topic_view_deleted'     => ['min_tier' => self::TIER_FORUM_ADMIN,  'context' => 'global'],

            // ── Topic editing ─────────────────────────────────────────────
            'topic_edit'             => ['min_tier' => self::TIER_NONE, 'self' => true,  'context' => 'topic'],
            'topic_edit_other'       => ['min_tier' => self::TIER_MODERATOR,    'context' => 'plate'],
            'topic_delete'           => ['min_tier' => self::TIER_NONE, 'self' => true,  'context' => 'topic'],
            'topic_delete_other'     => ['min_tier' => self::TIER_MODERATOR,    'context' => 'plate'],

            // ── Topic governance ──────────────────────────────────────────
            'topic_sticky_plate'     => ['min_tier' => self::TIER_MODERATOR,    'context' => 'plate'],
            'topic_sticky_super'     => ['min_tier' => self::TIER_PLATE_AUTHOR, 'context' => 'plate'],
            'topic_sticky_global'    => ['min_tier' => self::TIER_FORUM_ADMIN,  'context' => 'global'],
            'topic_featured'         => ['min_tier' => self::TIER_MODERATOR,    'context' => 'plate'],
            'topic_lock'             => ['min_tier' => self::TIER_NONE, 'self' => true,  'context' => 'topic'],
            'topic_lock_other'       => ['min_tier' => self::TIER_MODERATOR,    'context' => 'plate'],
            'topic_highlight'        => ['min_tier' => self::TIER_MODERATOR,    'context' => 'plate'],
            'topic_score_other'      => ['min_tier' => self::TIER_MODERATOR,    'context' => 'plate'],
            'topic_move'             => ['min_tier' => self::TIER_MODERATOR,    'context' => 'plate'],
            'topic_moderate'         => ['min_tier' => self::TIER_MODERATOR,    'context' => 'plate'],

            // ── Topic interaction (logged users) ──────────────────────────
            'topic_vote'             => ['min_tier' => self::TIER_NONE, 'logged' => true],
            'topic_favorite'         => ['min_tier' => self::TIER_NONE, 'logged' => true],
            'topic_score'            => ['min_tier' => self::TIER_NONE, 'logged' => true],
            'topic_report'           => ['min_tier' => self::TIER_NONE, 'logged' => true],

            // ── Reply governance ──────────────────────────────────────────
            'reply_adopt'            => ['min_tier' => self::TIER_NONE, 'self' => true,  'context' => 'topic'],
            'reply_adopt_other'      => ['min_tier' => self::TIER_MODERATOR,    'context' => 'plate'],
            'reply_delete_other'     => ['min_tier' => self::TIER_MODERATOR,    'context' => 'plate'],
            'reply_edit_other'       => ['min_tier' => self::TIER_MODERATOR,    'context' => 'plate'],
            'reply_top'              => ['min_tier' => self::TIER_MODERATOR,    'context' => 'plate'],
            // ── Reply interaction ─────────────────────────────────────────
            'reply_like'             => ['min_tier' => self::TIER_NONE, 'logged' => true],
            'reply_score'            => ['min_tier' => self::TIER_NONE, 'logged' => true],

            // ── Plate management ──────────────────────────────────────────
            'plate_follow'           => ['min_tier' => self::TIER_NONE, 'logged' => true],
            'plate_create'           => ['min_tier' => self::TIER_FORUM_ADMIN,  'context' => 'global'],
            'plate_manage'           => ['min_tier' => self::TIER_PLATE_AUTHOR, 'context' => 'plate'],
            'plate_delete'           => ['min_tier' => self::TIER_FORUM_ADMIN,  'context' => 'global'],

            // ── Moderator system ──────────────────────────────────────────
            'moderator_manage'       => ['min_tier' => self::TIER_CAT_MOD,      'context' => 'plate'],
            'moderator_apply'        => ['min_tier' => self::TIER_NONE, 'logged' => true],
            'moderator_review'       => ['min_tier' => self::TIER_CAT_MOD,      'context' => 'plate'],

            // ── User governance ───────────────────────────────────────────
            'user_ban'               => ['min_tier' => self::TIER_CAT_MOD,      'context' => 'global'],
            'user_report'            => ['min_tier' => self::TIER_NONE, 'logged' => true],

            // ── Compose capabilities ──────────────────────────────────────
            'compose_post'           => ['min_tier' => self::TIER_NONE, 'logged' => true, 'settings_key' => ''],
            'compose_post_no_review' => ['min_tier' => self::TIER_MODERATOR,    'context' => 'plate'],
            'compose_upload_image'   => ['min_tier' => self::TIER_NONE, 'logged' => true, 'settings_key' => 'posts_upload_img'],
            'compose_upload_video'   => ['min_tier' => self::TIER_NONE, 'logged' => true, 'settings_key' => 'posts_upload_video'],
            'compose_upload_file'    => ['min_tier' => self::TIER_NONE, 'logged' => true, 'settings_key' => 'posts_upload_file'],
            'compose_iframe_video'   => ['min_tier' => self::TIER_NONE, 'logged' => true, 'settings_key' => 'posts_iframe_video'],
            'compose_set_type'       => ['min_tier' => self::TIER_NONE, 'logged' => true],
            'compose_set_visibility' => ['min_tier' => self::TIER_NONE, 'logged' => true],
            'compose_set_cover'      => ['min_tier' => self::TIER_NONE, 'logged' => true, 'settings_key' => 'posts_upload_img'],
            'compose_set_vote'       => ['min_tier' => self::TIER_NONE, 'logged' => true],
            'compose_set_paid'       => ['min_tier' => self::TIER_PLATE_AUTHOR, 'context' => 'plate', 'settings_key' => 'paid_content'],
            'compose_set_hide'       => ['min_tier' => self::TIER_PLATE_AUTHOR, 'context' => 'plate', 'settings_key' => 'paid_content'],
        ];
    }

    // ── Tier resolution ───────────────────────────────────────────

    /**
     * Return the user's highest tier for a given plate.
     *
     * Result is cached per request on "$user_id:$plate_id".
     */
    public function get_user_plate_tier(int $user_id, int $plate_id): int {
        if ($user_id <= 0) {
            return self::TIER_NONE;
        }

        $cache_key = "$user_id:$plate_id";
        if (isset(self::$tier_cache[$cache_key])) {
            return self::$tier_cache[$cache_key];
        }

        $tier = $this->compute_user_plate_tier($user_id, $plate_id);
        self::$tier_cache[$cache_key] = $tier;
        return $tier;
    }

    private function compute_user_plate_tier(int $user_id, int $plate_id): int {
        // Tier 4: WP admin or bbs_admin_users list
        if ($this->forum->is_forum_admin($user_id)) {
            return self::TIER_FORUM_ADMIN;
        }

        // Tier 3: category moderator (plate_cat term meta 'moderator')
        $cats = get_the_terms($plate_id, 'aksrt_plate_cat');
        if ($cats && !is_wp_error($cats)) {
            foreach ($cats as $cat) {
                if ($this->forum->is_cat_moderator($user_id, (int) $cat->term_id)) {
                    return self::TIER_CAT_MOD;
                }
            }
        }

        // Tier 2: plate_author (plate CPT post_author)
        if ($this->forum->is_plate_cpt_active()) {
            $post = get_post($plate_id);
            if ($post && (int) $post->post_author === $user_id) {
                return self::TIER_PLATE_AUTHOR;
            }

            // Tier 1: in plate _aksrt_moderators list
            $mods = get_post_meta($plate_id, '_aksrt_moderators', true);
            if (is_array($mods) && in_array($user_id, $mods, true)) {
                return self::TIER_MODERATOR;
            }

            return self::TIER_NONE;
        }
        // Fallback: taxonomy board
        $roles = get_term_meta($plate_id, '_aksrt_moderator_roles', true);
        $roles = is_array($roles) ? $roles : [];
        $role  = $roles[$user_id] ?? '';
        if ($role === 'super_moderator' || $role === 'plate_author') {
            return self::TIER_PLATE_AUTHOR;
        }
        $mods = get_term_meta($plate_id, '_aksrt_moderators', true);
        if (is_array($mods) && in_array($user_id, $mods, true)) {
            return self::TIER_MODERATOR;
        }

        return self::TIER_NONE;
    }

    // ── Capability check ──────────────────────────────────────────

    /**
     * Unified capability resolver.
     *
     * @param int    $user_id     User to check (0 = guest).
     * @param string $cap         Capability id from cap_defs().
     * @param int    $context_id  topic_id for 'topic' context, plate_id for 'plate' context.
     * @return bool
     */
    public function forum_user_can(int $user_id, string $cap, int $context_id = 0): bool {
        $cache_key = "$user_id:$cap:$context_id";
        if (array_key_exists($cache_key, self::$cap_cache)) {
            return self::$cap_cache[$cache_key];
        }

        $result = $this->compute_forum_cap($user_id, $cap, $context_id);
        self::$cap_cache[$cache_key] = $result;
        return $result;
    }

    private function compute_forum_cap(int $user_id, string $cap, int $context_id): bool {
        $defs = $this->cap_defs();
        if (!isset($defs[$cap])) {
            return false;
        }
        $def = $defs[$cap];

        $logged_only = !empty($def['logged']) && ($def['min_tier'] ?? self::TIER_NONE) === self::TIER_NONE;
        $self_only   = !empty($def['self']);
        $context     = $def['context'] ?? 'any';
        $min_tier    = (int) ($def['min_tier'] ?? self::TIER_NONE);
        $settings_key = $def['settings_key'] ?? '';
        // Guest short-circuit
        if ($user_id <= 0) {
            return false;
        }

        // Forum-wide admin bypasses everything
        if ($this->forum->is_forum_admin($user_id)) {
            // Honour settings-gated compose caps even for admins when the feature is globally off
            if ($settings_key !== '') {
                $perms = $this->forum->get_config()['permissions'] ?? [];
                if (isset($perms[$settings_key]) && $perms[$settings_key] === false) {
                    return false;
                }
            }
            return true;
        }

        // 'logged' / any-user caps: just need to be logged in
        if ($logged_only || ($min_tier === self::TIER_NONE && $context === 'any')) {
            if ($settings_key !== '') {
                $perms = $this->forum->get_config()['permissions'] ?? [];
                if (array_key_exists($settings_key, $perms) && empty($perms[$settings_key])) {
                    return false;
                }
            }
            return true;
        }

        // 'self' caps: caller passes topic_id as context; check authorship
        if ($self_only) {
            if ($context_id <= 0) {
                return false;
            }
            $post = get_post($context_id);
            return $post && (int) $post->post_author === $user_id;
        }

        // Global caps (no specific plate/topic context)
        if ($context === 'global') {
            if ($min_tier <= self::TIER_CAT_MOD) {
                return $this->is_cat_moderator_anywhere($user_id);
            }
            return false;
        }

        // Plate-context caps
        if ($context === 'plate') {
            $plate_id = $this->resolve_plate_id($context_id, $cap);
            if ($plate_id <= 0) {
                return false;
            }
            $tier = $this->get_user_plate_tier($user_id, $plate_id);

            // Check optional settings gate
            if ($settings_key !== '') {
                $perms = $this->forum->get_config()['permissions'] ?? [];
                if (array_key_exists($settings_key, $perms) && empty($perms[$settings_key])) {
                    return $tier >= self::TIER_PLATE_AUTHOR;
                }
            }

            return $tier >= $min_tier;
        }

        return false;
    }

    // ── Helper methods ────────────────────────────────────────────

    /**
     * Resolve a plate_id from either a plate_id or topic_id, depending on the cap context.
     */
    private function resolve_plate_id(int $context_id, string $cap): int {
        if ($context_id <= 0) {
            return 0;
        }
        $post = get_post($context_id);
        if (!$post) {
            return 0;
        }
        if ($post->post_type === 'aksrt_forum_plate') {
            return $context_id;
        }
        if ($post->post_type === 'aksrt_forum_topic') {
            return $this->forum->get_topic_plate_id($context_id);
        }
        return 0;
    }

    /**
     * Check if the user is a cat_moderator on ANY plate category (for global caps).
     */
    private function is_cat_moderator_anywhere(int $user_id): bool {
        if ($user_id <= 0) {
            return false;
        }
        if ($this->forum->is_forum_admin($user_id)) {
            return true;
        }
        $cats = get_terms(['taxonomy' => 'aksrt_plate_cat', 'hide_empty' => false, 'fields' => 'ids']);
        if (is_wp_error($cats) || empty($cats)) {
            return false;
        }
        foreach ((array) $cats as $cat_id) {
            if ($this->forum->is_cat_moderator($user_id, (int) $cat_id)) {
                return true;
            }
        }
        return false;
    }

    // ── Compose capabilities ──────────────────────────────────────

    /**
     * Get per-feature capabilities for the compose/edit form.
     *
     * @return array<string,bool>
     */
    public function get_compose_capabilities(int $user_id): array {
        $keys = [
            'can_post', 'can_set_type', 'can_set_visibility',
            'can_set_cover', 'can_set_cover_image', 'can_set_cover_slide', 'can_set_cover_video',
            'can_set_vote', 'can_set_paid', 'can_set_hide',
            'can_upload_image', 'can_upload_video', 'can_upload_file',
            'can_iframe_video',
        ];
        if ($user_id <= 0) {
            return array_fill_keys($keys, false);
        }

        return [
            'can_post'             => $this->forum_user_can($user_id, 'compose_post'),
            'can_set_type'         => $this->forum_user_can($user_id, 'compose_set_type'),
            'can_set_visibility'   => $this->forum_user_can($user_id, 'compose_set_visibility'),
            'can_set_cover'        => $this->forum_user_can($user_id, 'compose_set_cover'),
            'can_set_cover_image'  => $this->forum_user_can($user_id, 'compose_set_cover'),
            'can_set_cover_slide'  => $this->forum_user_can($user_id, 'compose_set_cover'),
            'can_set_cover_video'  => $this->forum_user_can($user_id, 'compose_upload_video'),
            'can_set_vote'         => $this->forum_user_can($user_id, 'compose_set_vote'),
            'can_set_paid'         => $this->forum_user_can($user_id, 'compose_set_paid'),
            'can_set_hide'         => $this->forum_user_can($user_id, 'compose_set_hide'),
            'can_upload_image'     => $this->forum_user_can($user_id, 'compose_upload_image'),
            'can_upload_video'     => $this->forum_user_can($user_id, 'compose_upload_video'),
            'can_upload_file'      => $this->forum_user_can($user_id, 'compose_upload_file'),
            'can_iframe_video'     => $this->forum_user_can($user_id, 'compose_iframe_video'),
        ];
    }

    // ── Cache invalidation ────────────────────────────────────────

    public function flush_cap_cache(int $user_id = 0): void {
        if ($user_id > 0) {
            foreach (array_keys(self::$cap_cache) as $k) {
                if (strncmp($k, "$user_id:", strlen("$user_id:")) === 0) {
                    unset(self::$cap_cache[$k]);
                }
            }
            foreach (array_keys(self::$tier_cache) as $k) {
                if (strncmp($k, "$user_id:", strlen("$user_id:")) === 0) {
                    unset(self::$tier_cache[$k]);
                }
            }
        } else {
            self::$cap_cache  = [];
            self::$tier_cache = [];
        }
    }

    public function cap_cache_on_login(string $user_login, \WP_User $user): void {
        $this->flush_cap_cache((int) $user->ID);
    }

    /** Flush cache when plate moderator meta changes. */
    public function cap_cache_on_plate_meta(int $meta_id, int $object_id, string $meta_key): void {
        if (in_array($meta_key, ['_aksrt_moderators', '_aksrt_moderator_roles'], true)) {
            self::$cap_cache  = [];
            self::$tier_cache = [];
        }
    }

    /** Flush cache when plate_cat moderator term meta changes. */
    public function cap_cache_on_cat_meta(int $meta_id, int $object_id, string $meta_key): void {
        if ($meta_key === 'moderator') {
            self::$cap_cache  = [];
            self::$tier_cache = [];
        }
    }

    /** Flush cache when a plate CPT post is saved (plate_author may change). */
    public function cap_cache_on_plate_save(int $post_id): void {
        foreach (array_keys(self::$tier_cache) as $k) {
            if (substr($k, -strlen(":$post_id")) === ":$post_id") {
                unset(self::$tier_cache[$k]);
            }
        }
        self::$cap_cache = [];
    }
}