<?php
/**
 * AKSRT Signin
 *
 * 每日签到服务：
 *   - REST GET  /signin/today  返回今日是否签到 + 连续天数 + 今日奖励 + 明日奖励
 *   - REST POST /signin        执行签到
 *
 * 签到日期使用站点时区当日 0 点为切换点。
 *
 * @package AKSRT
 */

defined('ABSPATH') || exit;

class AKSRT_Signin {

    private static $instance = null;

    private function __construct() {}

    public static function get_instance(): self {
        if (null === self::$instance) self::$instance = new self();
        return self::$instance;
    }

    public function init(): void {
        add_action('rest_api_init', [$this, 'register_routes']);
    }

    public function register_routes(): void {
        register_rest_route('aksrt/v1', '/signin/today', [
            'methods'             => 'GET',
            'callback'            => [$this, 'rest_today'],
            'permission_callback' => function () {
                return is_user_logged_in();
            },
        ]);
        register_rest_route('aksrt/v1', '/signin', [
            'methods'             => 'POST',
            'callback'            => [$this, 'rest_signin'],
            'permission_callback' => function () {
                return is_user_logged_in();
            },
        ]);
    }

    /** GET /signin/today */
    public function rest_today(WP_REST_Request $request) {
        $user_id = get_current_user_id();
        $signin_cfg = class_exists('AKSRT_Settings')
            ? AKSRT_Settings::get_signin_reward_settings()
            : [
                'enabled' => false,
                'base'    => 0,
                'streak'  => [],
            ];

        $today_str = $this->today_date();
        $rec = $this->get_record($user_id, $today_str);

        $current_streak = $this->compute_current_streak($user_id, $today_str);
        $next_streak    = $current_streak + ($rec ? 0 : 1);

        return new WP_REST_Response([
            'enabled'          => !empty($signin_cfg['enabled']),
            'signed'           => (bool) $rec,
            'streak'           => $current_streak,
            'reward_today'     => $rec ? (int) $rec['reward'] : 0,
            'reward_if_signin' => $rec ? 0 : $this->calc_reward($next_streak, $signin_cfg),
            'date'             => $today_str,
        ], 200);
    }

    /** POST /signin */
    public function rest_signin(WP_REST_Request $request) {
        global $wpdb;

        $user_id = get_current_user_id();
        $signin_cfg = class_exists('AKSRT_Settings')
            ? AKSRT_Settings::get_signin_reward_settings()
            : [
                'enabled' => false,
                'base'    => 0,
                'streak'  => [],
            ];

        if (empty($signin_cfg['enabled'])) {
            return new WP_Error('aksrt_signin_disabled', __('签到功能未启用', 'aksrt'), ['status' => 403]);
        }

        $today_str = $this->today_date();
        if ($this->get_record($user_id, $today_str)) {
            return new WP_Error('aksrt_signin_dup', __('今日已签到', 'aksrt'), ['status' => 409]);
        }

        // 人机验证（若启用）
        if (function_exists('aksrt_require_captcha')) {
            $body        = $request->get_json_params();
            $cap_payload = is_array($body) && isset($body['captcha']) && is_array($body['captcha'])
                ? $body['captcha']
                : (is_array($body) ? $body : []);
            $verify = aksrt_require_captcha('signin', $cap_payload);
            if ($verify !== true) {
                $msg = is_string($verify) ? $verify : __('人机验证失败', 'aksrt');
                return new WP_Error('aksrt_captcha_failed', $msg, ['status' => 400]);
            }
        }

        $current_streak = $this->compute_current_streak($user_id, $today_str);
        $new_streak     = $current_streak + 1;
        $reward         = $this->calc_reward($new_streak, $signin_cfg);

        $table = AKSRT_DB_Migrator::table('signin_log');
        if (!$table) {
            return new WP_Error('aksrt_signin_db', __('数据表不存在', 'aksrt'), ['status' => 500]);
        }

        $inserted = $wpdb->insert(
            $table,
            [
                'user_id'     => $user_id,
                'signin_date' => $today_str,
                'streak'      => $new_streak,
                'reward'      => $reward,
            ],
            ['%d', '%s', '%d', '%d']
        );
        if ($inserted === false) {
            return new WP_Error('aksrt_signin_dup', __('签到失败', 'aksrt'), ['status' => 409]);
        }

        if ($reward > 0) {
            if (class_exists('AKSRT_Points_Free')) {
                $granted = AKSRT_Points_Free::grant_amount($user_id, $reward, 'sign_in', ['type' => 'user', 'id' => $user_id]);
                if (is_wp_error($granted)) {
                    if (class_exists('AKSRT_Credits')) {
                        AKSRT_Credits::add($user_id, $reward, 'signin', ['type' => 'user', 'id' => $user_id]);
                    }
                } else {
                    $reward = (int) $granted;
                }
            } elseif (class_exists('AKSRT_Credits')) {
                AKSRT_Credits::add($user_id, $reward, 'signin', ['type' => 'user', 'id' => $user_id]);
            }
        }

        return new WP_REST_Response([
            'success' => true,
            'streak'  => $new_streak,
            'reward'  => $reward,
            'balance' => class_exists('AKSRT_Credits') ? AKSRT_Credits::balance($user_id) : 0,
        ], 200);
    }

    // ---------- 工具方法 ----------

    /** 站点时区下的今日日期 'Y-m-d' */
    private function today_date(): string {
        return (new DateTimeImmutable('today', wp_timezone()))->format('Y-m-d');
    }

    /** 取签到记录 */
    private function get_record(int $user_id, string $date): ?array {
        global $wpdb;
        $table = AKSRT_DB_Migrator::table('signin_log');
        if (!$table) return null;
        $row = $wpdb->get_row($wpdb->prepare(
            "SELECT * FROM {$table} WHERE user_id = %d AND signin_date = %s",
            $user_id,
            $date
        ), ARRAY_A);
        return $row ?: null;
    }

    /**
     * 获取最近 N 天的签到记录
     *
     * @param int $user_id
     * @param int $days
     * @return array
     */
    public function get_recent_signins(int $user_id, int $days = 30): array {
        global $wpdb;
        $table = AKSRT_DB_Migrator::table('signin_log');
        if (!$table) return [];

        $from_date = (new DateTimeImmutable("-{$days} days", wp_timezone()))->format('Y-m-d');

        $rows = $wpdb->get_results($wpdb->prepare(
            "SELECT signin_date FROM {$table} WHERE user_id = %d AND signin_date >= %s ORDER BY signin_date ASC",
            $user_id,
            $from_date
        ), ARRAY_A);

        return $rows ?: [];
    }

    /**
     * 算"今天之前"的连续签到天数。
     */
    private function compute_current_streak(int $user_id, string $today_str): int {
        global $wpdb;
        $table = AKSRT_DB_Migrator::table('signin_log');
        if (!$table) return 0;

        // 拿最近 60 天的签到记录降序
        $rows = $wpdb->get_results($wpdb->prepare(
            "SELECT signin_date FROM {$table} WHERE user_id = %d AND signin_date <= %s ORDER BY signin_date DESC LIMIT 60",
            $user_id,
            $today_str
        ), ARRAY_A);
        if (empty($rows)) return 0;

        $dates = array_map(fn($r) => $r['signin_date'], $rows);
        $today = new DateTimeImmutable($today_str);
        $tz = wp_timezone();

        // 起点：若今天已签则从今天回看，否则从昨天回看
        $cursor = in_array($today_str, $dates, true)
            ? $today
            : $today->sub(new DateInterval('P1D'));

        $count = 0;
        foreach ($dates as $d) {
            if ($d === $cursor->format('Y-m-d')) {
                $count++;
                $cursor = $cursor->sub(new DateInterval('P1D'));
            } else {
                break;
            }
        }
        return $count;
    }

    /**
     * 根据连续天数计算奖励 = base + streak 段额外奖励。
     */
    private function calc_reward(int $streak, array $cfg): int {
        $base = (int) ($cfg['base'] ?? 1);
        $extra = 0;
        $streak_table = is_array($cfg['streak'] ?? null) ? $cfg['streak'] : [];

        // streak_table 是 { N: extra } —— 当 streak 恰好命中 N 时给 extra
        // 对 array_keys 不稳定的存储格式做容错
        $normalized = [];
        foreach ($streak_table as $k => $v) {
            $normalized[(int) $k] = (int) $v;
        }
        if (isset($normalized[$streak])) {
            $extra = $normalized[$streak];
        }
        return max(0, $base + $extra);
    }
}