<?php
/**
 * @package AKSRT
 */

namespace AKSRT\Admin;

defined('ABSPATH') || exit;

trait UserControllerInviteOperations {

    /**
     * GET /invite/codes — 邀请码列表（管理后台）
     */
    public function get_invite_codes(\WP_REST_Request $request): \WP_REST_Response {
        global $wpdb;

        $page       = max(1, (int) ($request->get_param('page') ?: 1));
        $per_page   = max(1, min(100, (int) ($request->get_param('per_page') ?: 20)));
        $keyword    = trim(sanitize_text_field((string) $request->get_param('keyword')));
        $status     = sanitize_key((string) $request->get_param('status'));
        $source     = sanitize_key((string) $request->get_param('source'));
        $date_from  = sanitize_text_field((string) $request->get_param('date_from'));
        $date_to    = sanitize_text_field((string) $request->get_param('date_to'));

        $usermeta_table = $wpdb->usermeta;
        $invite_table   = class_exists('\AKSRT\Core\DBMigrator') ? \AKSRT\Core\DBMigrator::table('invite') : '';

        $invite_rows = [];
        if ($invite_table) {
            $records = $wpdb->get_results("SELECT * FROM {$invite_table}", ARRAY_A);
            foreach ((array) $records as $record) {
                $invite_rows[(string) $record['invite_code']] = $record;
            }
        }

        $items = [];
        $user_rows = $wpdb->get_results(
            "SELECT user_id, meta_value AS invite_code FROM {$usermeta_table} WHERE meta_key = 'aksrt_invite_code' ORDER BY umeta_id DESC",
            ARRAY_A
        );

        foreach ((array) $user_rows as $row) {
            $user_id = (int) $row['user_id'];
            $user    = get_userdata($user_id);
            $code    = sanitize_key((string) $row['invite_code']);
            $record  = $invite_rows[$code] ?? null;

            $item = [
                'row_key'             => 'user:' . $user_id,
                'source_type'         => 'user',
                'source_label'        => __('用户邀请码', 'aksrt'),
                'user'                => $this->build_admin_user_summary($user_id, $user),
                'invite_code'         => $code,
                'status'              => $record ? 'used' : 'active',
                'status_label'        => $record ? __('已使用', 'aksrt') : __('可用', 'aksrt'),
                'created_at'          => $user ? (string) $user->user_registered : '',
                'used_at'             => $record['created_at'] ?? '',
                'note'                => '',
                'batch_id'            => '',
                'created_by'          => null,
                'registration_status' => $record['status'] ?? '',
                'invitee'             => $this->build_admin_user_summary((int) ($record['invitee_id'] ?? 0)),
                'can_bulk'            => false,
                'actions'             => ['disable'],
            ];

            if ($this->invite_item_matches_filters($item, $keyword, $status, $source, $date_from, $date_to)) {
                $items[] = $item;
            }
        }

        foreach ($this->load_standalone_invite_codes() as $entry) {
            $code        = sanitize_key((string) ($entry['code'] ?? ''));
            $record      = $invite_rows[$code] ?? null;
            $used_by     = (int) ($entry['used_by'] ?? 0);
            $disabled    = !empty($entry['disabled']);
            $used        = !empty($entry['used']) || $used_by > 0 || !empty($record['invitee_id']);
            $status_key  = $disabled ? 'disabled' : ($used ? 'used' : 'active');
            $status_map  = [
                'active'   => __('可用', 'aksrt'),
                'used'     => __('已使用', 'aksrt'),
                'disabled' => __('已禁用', 'aksrt'),
            ];
            $invitee_id  = $used_by > 0 ? $used_by : (int) ($record['invitee_id'] ?? 0);

            $item = [
                'row_key'             => 'standalone:' . $code,
                'source_type'         => 'standalone',
                'source_label'        => __('独立邀请码', 'aksrt'),
                'user'                => null,
                'invite_code'         => $code,
                'status'              => $status_key,
                'status_label'        => $status_map[$status_key],
                'created_at'          => (string) ($entry['created_at'] ?? ''),
                'used_at'             => (string) ($entry['used_at'] ?? ($record['created_at'] ?? '')),
                'note'                => (string) ($entry['note'] ?? ''),
                'batch_id'            => (string) ($entry['batch_id'] ?? ''),
                'created_by'          => $this->build_admin_user_summary((int) ($entry['created_by'] ?? 0)),
                'registration_status' => $record['status'] ?? '',
                'invitee'             => $this->build_admin_user_summary($invitee_id),
                'can_bulk'            => true,
                'actions'             => ['disable', 'delete'],
            ];

            if ($this->invite_item_matches_filters($item, $keyword, $status, $source, $date_from, $date_to)) {
                $items[] = $item;
            }
        }

        usort($items, static function ($left, $right) {
            return strcmp((string) ($right['created_at'] ?? ''), (string) ($left['created_at'] ?? ''));
        });

        $total   = count($items);
        $offset  = ($page - 1) * $per_page;
        $paged   = array_slice($items, $offset, $per_page);
        $stats   = $this->build_invite_operation_stats($items, $invite_rows);

        return $this->success([
            'data' => [
                'items'       => array_values($paged),
                'total'       => $total,
                'page'        => $page,
                'per_page'    => $per_page,
                'total_pages' => max(1, (int) ceil(max(1, $total) / $per_page)),
                'stats'       => $stats,
                'options'     => [
                    'statuses' => [
                        ['label' => __('全部状态', 'aksrt'), 'value' => ''],
                        ['label' => __('可用', 'aksrt'), 'value' => 'active'],
                        ['label' => __('已使用', 'aksrt'), 'value' => 'used'],
                        ['label' => __('已禁用', 'aksrt'), 'value' => 'disabled'],
                    ],
                    'sources' => [
                        ['label' => __('全部来源', 'aksrt'), 'value' => ''],
                        ['label' => __('用户邀请码', 'aksrt'), 'value' => 'user'],
                        ['label' => __('独立邀请码', 'aksrt'), 'value' => 'standalone'],
                    ],
                ],
            ],
        ]);
    }

    /**
     * POST /invite/codes — 批量生成邀请码（管理后台）
     * Body: { count: int, length: int, prefix: string }
     * 为指定用户或批量创建邀请码。
     */
    public function generate_invite_codes(\WP_REST_Request $request): \WP_REST_Response {
        if (!class_exists('\AKSRT\Credits\Invite')) {
            return $this->error(__('邀请系统未启用', 'aksrt'), 500);
        }

        $params = $this->get_json_params($request);
        $count    = max(1, min(100, (int) ($params['count'] ?? 1)));
        $length   = max(4, min(12, (int) ($params['length'] ?? 6)));
        $prefix   = sanitize_key((string) ($params['prefix'] ?? ''));
        $note     = sanitize_textarea_field((string) ($params['note'] ?? ''));
        $batch_id = sanitize_text_field((string) ($params['batch_id'] ?? ''));

        if ($batch_id === '') {
            $batch_id = 'INV-' . gmdate('YmdHis') . '-' . wp_generate_password(4, false, false);
        }

        $generated = [];
        $codes     = $this->load_standalone_invite_codes();
        $alphabet  = 'abcdefghjkmnpqrstuvwxyz23456789';

        for ($i = 0; $i < $count; $i++) {
            $code = '';
            for ($attempt = 0; $attempt < 12; $attempt++) {
                $candidate = $prefix;
                for ($j = 0; $j < $length; $j++) {
                    $candidate .= $alphabet[random_int(0, strlen($alphabet) - 1)];
                }
                $candidate = sanitize_key($candidate);
                if (!$this->invite_code_exists_globally($candidate, $codes)) {
                    $code = $candidate;
                    break;
                }
            }

            if ($code === '') {
                continue;
            }

            $codes[] = [
                'code'       => $code,
                'created_at' => current_time('mysql'),
                'used'       => false,
                'used_by'    => 0,
                'used_at'    => '',
                'disabled'   => false,
                'note'       => $note,
                'batch_id'   => $batch_id,
                'created_by' => get_current_user_id(),
            ];
            $generated[] = $code;
        }

        $this->save_standalone_invite_codes($codes);

        return $this->success([
            'message' => sprintf(__('已生成 %d 个邀请码', 'aksrt'), count($generated)),
            'data'    => [
                'codes'    => $generated,
                'batch_id' => $batch_id,
            ],
        ]);
    }

    /**
     * POST /invite/codes/{id}/disable — 禁用邀请码
     */
    public function disable_invite_code(\WP_REST_Request $request): \WP_REST_Response {
        $user_id = (int) $request->get_param('id');

        if ($user_id <= 0) {
            return $this->error(__('参数无效', 'aksrt'));
        }

        $removed = $this->remove_user_invite_code($user_id);
        if (!$removed) {
            return $this->error(__('邀请码不存在或已禁用', 'aksrt'));
        }

        return $this->success(['message' => __('邀请码已禁用', 'aksrt')]);
    }

    public function bulk_update_invite_codes(\WP_REST_Request $request): \WP_REST_Response {
        $params  = $this->get_json_params($request);
        $action  = sanitize_key((string) ($params['action'] ?? ''));
        $targets = isset($params['targets']) && is_array($params['targets']) ? $params['targets'] : [];

        if (!in_array($action, ['disable', 'delete'], true) || empty($targets)) {
            return $this->error(__('批量操作参数无效', 'aksrt'));
        }

        $codes     = $this->load_standalone_invite_codes();
        $processed = 0;

        foreach ($targets as $target) {
            $source_type = sanitize_key((string) ($target['source_type'] ?? ''));
            if ($source_type === 'user') {
                $user_id = (int) ($target['user_id'] ?? 0);
                if ($action === 'disable' && $this->remove_user_invite_code($user_id)) {
                    $processed++;
                }
                continue;
            }

            if ($source_type !== 'standalone') {
                continue;
            }

            $code = sanitize_key((string) ($target['code'] ?? $target['invite_code'] ?? ''));
            foreach ($codes as $index => $entry) {
                $entry_code = sanitize_key((string) ($entry['code'] ?? ''));
                if ($entry_code !== $code) {
                    continue;
                }

                if ($action === 'delete' && empty($entry['used']) && empty($entry['used_by'])) {
                    unset($codes[$index]);
                } else {
                    $entry['disabled'] = true;
                    $codes[$index]     = $entry;
                }
                $processed++;
                break;
            }
        }

        $this->save_standalone_invite_codes($codes);

        return $this->success([
            'message' => sprintf(__('已处理 %d 条邀请码记录', 'aksrt'), $processed),
        ]);
    }

    /**
     * GET /invite/stats — 邀请系统统计
     */
    public function get_invite_stats(): \WP_REST_Response {
        global $wpdb;

        $items        = [];
        $user_records = $wpdb->get_results(
            "SELECT user_id, meta_value AS invite_code FROM {$wpdb->usermeta} WHERE meta_key = 'aksrt_invite_code'",
            ARRAY_A
        );

        foreach ((array) $user_records as $row) {
            $items[] = [
                'source_type' => 'user',
                'status'      => 'active',
            ];
        }

        foreach ($this->load_standalone_invite_codes() as $entry) {
            $used     = !empty($entry['used']) || !empty($entry['used_by']);
            $disabled = !empty($entry['disabled']);
            $items[]  = [
                'source_type' => 'standalone',
                'status'      => $disabled ? 'disabled' : ($used ? 'used' : 'active'),
            ];
        }

        $stats = $this->build_invite_operation_stats($items);
        return $this->success(['data' => $stats]);
    }

    private function load_standalone_invite_codes(): array {
        $codes = get_option('aksrt_standalone_invite_codes', []);
        return is_array($codes) ? array_values($codes) : [];
    }

    private function save_standalone_invite_codes(array $codes): void {
        update_option('aksrt_standalone_invite_codes', array_values($codes), false);
    }

    private function invite_code_exists_globally(string $candidate, array $standalone_codes = []): bool {
        if ($candidate === '') {
            return true;
        }

        global $wpdb;

        $existing_user_code = $wpdb->get_var($wpdb->prepare(
            "SELECT umeta_id FROM {$wpdb->usermeta} WHERE meta_key = 'aksrt_invite_code' AND meta_value = %s LIMIT 1",
            $candidate
        ));
        if ($existing_user_code) {
            return true;
        }

        foreach ($standalone_codes as $entry) {
            if (sanitize_key((string) ($entry['code'] ?? '')) === $candidate) {
                return true;
            }
        }

        $invite_table = class_exists('\AKSRT\Core\DBMigrator') ? \AKSRT\Core\DBMigrator::table('invite') : '';
        if ($invite_table) {
            $existing_invite = $wpdb->get_var($wpdb->prepare(
                "SELECT id FROM {$invite_table} WHERE invite_code = %s LIMIT 1",
                $candidate
            ));
            if ($existing_invite) {
                return true;
            }
        }

        return false;
    }

    private function invite_item_matches_filters(array $item, string $keyword, string $status, string $source, string $date_from, string $date_to): bool {
        if ($status !== '' && ($item['status'] ?? '') !== $status) {
            return false;
        }
        if ($source !== '' && ($item['source_type'] ?? '') !== $source) {
            return false;
        }

        $created_at = (string) ($item['created_at'] ?? '');
        if ($date_from !== '' && $created_at !== '' && strcmp($created_at, $date_from . ' 00:00:00') < 0) {
            return false;
        }
        if ($date_to !== '' && $created_at !== '' && strcmp($created_at, $date_to . ' 23:59:59') > 0) {
            return false;
        }

        if ($keyword === '') {
            return true;
        }

        $haystack = implode(' ', array_filter([
            (string) ($item['invite_code'] ?? ''),
            (string) ($item['status_label'] ?? ''),
            (string) ($item['note'] ?? ''),
            (string) ($item['batch_id'] ?? ''),
            (string) ($item['user']['display_name'] ?? ''),
            (string) ($item['invitee']['display_name'] ?? ''),
            (string) ($item['invitee']['email'] ?? ''),
        ]));

        return mb_stripos($haystack, $keyword) !== false;
    }

    private function build_invite_operation_stats(array $items, array $invite_rows = []): array {
        $stats = [
            'total_codes'       => count($items),
            'active_codes'      => 0,
            'used_codes'        => 0,
            'disabled_codes'    => 0,
            'user_codes'        => 0,
            'standalone_codes'  => 0,
            'total_invites'     => count($invite_rows),
            'total_rewarded'    => 0,
        ];

        foreach ($items as $item) {
            $status = $item['status'] ?? '';
            if ($status === 'active') {
                $stats['active_codes']++;
            } elseif ($status === 'used') {
                $stats['used_codes']++;
            } elseif ($status === 'disabled') {
                $stats['disabled_codes']++;
            }

            if (($item['source_type'] ?? '') === 'user') {
                $stats['user_codes']++;
            } elseif (($item['source_type'] ?? '') === 'standalone') {
                $stats['standalone_codes']++;
            }
        }

        foreach ($invite_rows as $row) {
            if (($row['status'] ?? '') === 'rewarded') {
                $stats['total_rewarded']++;
            }
        }

        return $stats;
    }

    private function remove_user_invite_code(int $user_id): bool {
        $user_id = (int) $user_id;
        if ($user_id <= 0) {
            return false;
        }

        $code = get_user_meta($user_id, 'aksrt_invite_code', true);
        if (!$code) {
            return false;
        }

        delete_user_meta($user_id, 'aksrt_invite_code');

        $map = get_option('aksrt_invite_code_map', []);
        if (is_array($map) && isset($map[$code])) {
            unset($map[$code]);
            update_option('aksrt_invite_code_map', $map, false);
        }

        return true;
    }
}