<?php
declare(strict_types=1);

namespace Soon\Api\Admin\Controllers;

use Soon\Api\Core\Db;
use Soon\Api\Core\Json;
use Soon\Api\Services\AdminPermission;
use Soon\Api\Services\AuditService;
use Soon\Api\Services\MembershipService;

final class UsersController
{
    public function list(int $adminId): void
    {
        $page = max(1, (int)($_GET['page'] ?? 1));
        $size = max(1, min(200, (int)($_GET['size'] ?? 20)));
        $offset = ($page - 1) * $size;
        $q = trim((string)($_GET['q'] ?? ''));
        $baseSql = 'SELECT u.id, u.email, u.role, u.admin_level, u.status, u.created_at, '
            . '(SELECT p.name FROM subscriptions s JOIN plans p ON p.id = s.plan_id '
            . 'WHERE s.user_id = u.id AND s.status = \'active\' AND s.expires_at > NOW() '
            . 'ORDER BY s.expires_at DESC LIMIT 1) AS plan_name '
            . 'FROM users u';
        $pdo = Db::pdo();
        if ($q !== '') {
            $like = '%' . $q . '%';
            $stmt = $pdo->prepare($baseSql . ' WHERE u.email LIKE :q ORDER BY u.id DESC LIMIT :lim OFFSET :off');
            $stmt->bindValue('q', $like);
            $stmt->bindValue('lim', $size, \PDO::PARAM_INT);
            $stmt->bindValue('off', $offset, \PDO::PARAM_INT);
            $stmt->execute();
            $countStmt = $pdo->prepare('SELECT COUNT(*) FROM users WHERE email LIKE :q');
            $countStmt->execute(['q' => $like]);
            $count = (int)$countStmt->fetchColumn();
        } else {
            $stmt = $pdo->prepare($baseSql . ' ORDER BY u.id DESC LIMIT :lim OFFSET :off');
            $stmt->bindValue('lim', $size, \PDO::PARAM_INT);
            $stmt->bindValue('off', $offset, \PDO::PARAM_INT);
            $stmt->execute();
            $count = (int)$pdo->query('SELECT COUNT(*) FROM users')->fetchColumn();
        }
        AuditService::log($adminId, 'users.list', 'users', ['page' => $page, 'size' => $size, 'q' => $q]);
        Json::ok(['items' => $stmt->fetchAll(), 'total' => $count, 'page' => $page, 'size' => $size]);
    }

    public function create(int $adminId): void
    {
        $body = Json::readBody();
        $email = trim((string)($body['email'] ?? ''));
        $password = (string)($body['password'] ?? '');
        $role = (string)($body['role'] ?? 'user');
        if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
            Json::fail('bad_request', '邮箱格式不正确', 400);
        }
        if (strlen($password) < 8) {
            Json::fail('bad_request', '密码至少 8 位', 400);
        }
        if (!in_array($role, ['user', 'admin'], true)) {
            Json::fail('bad_request', 'role 不合法', 400);
        }
        if ($role === 'admin') {
            AdminPermission::requireFull($adminId);
        }
        $adminLevel = null;
        if ($role === 'admin') {
            $adminLevel = (string)($body['admin_level'] ?? 'ops');
            if (!in_array($adminLevel, ['full', 'ops'], true)) {
                Json::fail('bad_request', 'admin_level 不合法', 400);
            }
        }
        $pdo = Db::pdo();
        $dup = $pdo->prepare('SELECT id FROM users WHERE email = :e');
        $dup->execute(['e' => $email]);
        if ($dup->fetch()) {
            Json::fail('conflict', '邮箱已存在', 409);
        }
        $hash = password_hash($password, PASSWORD_BCRYPT, ['cost' => 12]);
        $stmt = $pdo->prepare(
            'INSERT INTO users (email, password_hash, role, admin_level, status, created_at) '
            . 'VALUES (:e, :h, :r, :lv, \'active\', :ts)'
        );
        $stmt->execute([
            'e' => $email,
            'h' => $hash,
            'r' => $role,
            'lv' => $adminLevel,
            'ts' => date('Y-m-d H:i:s'),
        ]);
        $id = (int)$pdo->lastInsertId();
        AuditService::log($adminId, 'users.create', 'user:' . $id, ['email' => $email, 'role' => $role]);
        Json::ok(['id' => $id, 'email' => $email, 'role' => $role]);
    }

    public function detail(int $adminId, int $id): void
    {
        $pdo = Db::pdo();
        $user = self::findUser($pdo, $id);
        if ($user === null) {
            Json::fail('not_found', '用户不存在', 404);
        }

        $subStmt = $pdo->prepare(
            'SELECT s.id AS subscription_id, s.plan_id, s.status, s.started_at, s.expires_at, p.name AS plan_name, p.code AS plan_code '
            . 'FROM subscriptions s JOIN plans p ON p.id = s.plan_id '
            . 'WHERE s.user_id = :uid ORDER BY (s.status = \'active\') DESC, s.id DESC LIMIT 1'
        );
        $subStmt->execute(['uid' => $id]);
        $subscription = $subStmt->fetch() ?: null;

        $usageStmt = $pdo->prepare(
            'SELECT COUNT(*) AS files_count, COALESCE(SUM(size), 0) AS storage_bytes '
            . 'FROM soon_files WHERE user_id = :uid AND deleted_at IS NULL'
        );
        $usageStmt->execute(['uid' => $id]);
        $usage = $usageStmt->fetch() ?: ['files_count' => 0, 'storage_bytes' => 0];

        $orderStmt = $pdo->prepare(
            'SELECT id, order_no, amount_cents, status, channel, created_at FROM pay_orders '
            . 'WHERE user_id = :uid ORDER BY id DESC LIMIT 5'
        );
        $orderStmt->execute(['uid' => $id]);
        $recentOrders = $orderStmt->fetchAll();

        AuditService::log($adminId, 'users.detail', 'user:' . $id);
        Json::ok([
            'user' => $user,
            'subscription' => $subscription,
            'usage' => [
                'files_count' => (int)$usage['files_count'],
                'storage_bytes' => (int)$usage['storage_bytes'],
            ],
            'recent_orders' => $recentOrders,
        ]);
    }

    public function update(int $adminId, int $id): void
    {
        $pdo = Db::pdo();
        $user = self::findUser($pdo, $id);
        if ($user === null) {
            Json::fail('not_found', '用户不存在', 404);
        }
        $body = Json::readBody();
        $email = array_key_exists('email', $body) ? trim((string)$body['email']) : null;
        $role = array_key_exists('role', $body) ? (string)$body['role'] : null;
        $adminLevel = array_key_exists('admin_level', $body) ? (string)$body['admin_level'] : null;

        if ($email !== null) {
            if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
                Json::fail('bad_request', '邮箱格式不正确', 400);
            }
            $dup = $pdo->prepare('SELECT id FROM users WHERE email = :e AND id != :id');
            $dup->execute(['e' => $email, 'id' => $id]);
            if ($dup->fetch()) {
                Json::fail('conflict', '邮箱已被使用', 409);
            }
        }
        if ($role !== null && !in_array($role, ['user', 'admin'], true)) {
            Json::fail('bad_request', 'role 不合法', 400);
        }
        if ($role === 'user' && $user['role'] === 'admin') {
            self::assertAdminRemovable($pdo, $id);
        }
        if ($role === 'admin' || $user['role'] === 'admin' || $adminLevel !== null) {
            AdminPermission::requireFull($adminId);
        }
        if ($adminLevel !== null && !in_array($adminLevel, ['full', 'ops'], true)) {
            Json::fail('bad_request', 'admin_level 不合法', 400);
        }
        if ($role !== null && $role !== 'admin' && $adminLevel !== null) {
            Json::fail('bad_request', '仅管理员账号可设置 admin_level', 400);
        }

        $sets = [];
        $params = ['id' => $id];
        if ($email !== null) {
            $sets[] = 'email = :e';
            $params['e'] = $email;
        }
        if ($role !== null) {
            $sets[] = 'role = :r';
            $params['r'] = $role;
            if ($role === 'user') {
                $sets[] = 'admin_level = NULL';
            }
        }
        if ($adminLevel !== null) {
            $sets[] = 'admin_level = :lv';
            $params['lv'] = $adminLevel;
        }
        if ($sets === []) {
            Json::fail('bad_request', '无更新字段', 400);
        }
        $pdo->prepare('UPDATE users SET ' . implode(', ', $sets) . ' WHERE id = :id')->execute($params);
        AuditService::log($adminId, 'users.update', 'user:' . $id, [
            'email' => $email,
            'role' => $role,
            'admin_level' => $adminLevel,
        ]);
        Json::ok(['id' => $id]);
    }

    public function delete(int $adminId, int $id): void
    {
        if ($id === $adminId) {
            Json::fail('bad_request', '不能删除自己的账号', 400);
        }
        $pdo = Db::pdo();
        $user = self::findUser($pdo, $id);
        if ($user === null) {
            Json::fail('not_found', '用户不存在', 404);
        }
        if ($user['role'] === 'admin') {
            AdminPermission::requireFull($adminId);
            self::assertAdminRemovable($pdo, $id);
        }
        $pdo->beginTransaction();
        try {
            $pdo->prepare('UPDATE soon_files SET deleted_at = :ts WHERE user_id = :u AND deleted_at IS NULL')
                ->execute(['ts' => date('Y-m-d H:i:s'), 'u' => $id]);
            $pdo->prepare('DELETE FROM subscriptions WHERE user_id = :u')->execute(['u' => $id]);
            $pdo->prepare('DELETE FROM users WHERE id = :id')->execute(['id' => $id]);
            $pdo->commit();
        } catch (\Throwable $e) {
            if ($pdo->inTransaction()) {
                $pdo->rollBack();
            }
            throw $e;
        }
        AuditService::log($adminId, 'users.delete', 'user:' . $id, ['email' => $user['email']]);
        Json::ok(['id' => $id]);
    }

    public function setPassword(int $adminId, int $id): void
    {
        $pdo = Db::pdo();
        if (self::findUser($pdo, $id) === null) {
            Json::fail('not_found', '用户不存在', 404);
        }
        $password = (string)(Json::readBody()['password'] ?? '');
        if (strlen($password) < 8) {
            Json::fail('bad_request', '密码至少 8 位', 400);
        }
        $hash = password_hash($password, PASSWORD_BCRYPT, ['cost' => 12]);
        $pdo->prepare('UPDATE users SET password_hash = :h WHERE id = :id')->execute(['h' => $hash, 'id' => $id]);
        AuditService::log($adminId, 'users.setPassword', 'user:' . $id);
        Json::ok(['id' => $id]);
    }

    public function setSubscription(int $adminId, int $id): void
    {
        $pdo = Db::pdo();
        if (self::findUser($pdo, $id) === null) {
            Json::fail('not_found', '用户不存在', 404);
        }
        $body = Json::readBody();
        $planId = (int)($body['plan_id'] ?? 0);
        $days = (int)($body['days'] ?? 0);
        if ($planId <= 0) {
            Json::fail('bad_request', 'plan_id 必填', 400);
        }
        $planStmt = $pdo->prepare('SELECT * FROM plans WHERE id = :id');
        $planStmt->execute(['id' => $planId]);
        $plan = $planStmt->fetch();
        if (!$plan) {
            Json::fail('not_found', '套餐不存在', 404);
        }
        $durationDays = $days > 0 ? $days : (int)$plan['duration_days'];
        $pdo->beginTransaction();
        try {
            $pdo->prepare('UPDATE subscriptions SET status = \'expired\' WHERE user_id = :u AND status = \'active\'')
                ->execute(['u' => $id]);
            if ($plan['code'] !== 'free') {
                $now = date('Y-m-d H:i:s');
                $expires = MembershipService::subscriptionExpiresAt($durationDays);
                $pdo->prepare(
                    'INSERT INTO subscriptions (user_id, plan_id, status, started_at, expires_at) '
                    . 'VALUES (:u, :p, \'active\', :sa, :ea)'
                )->execute(['u' => $id, 'p' => $planId, 'sa' => $now, 'ea' => $expires]);
            }
            $pdo->commit();
        } catch (\Throwable $e) {
            if ($pdo->inTransaction()) {
                $pdo->rollBack();
            }
            throw $e;
        }
        AuditService::log($adminId, 'users.setSubscription', 'user:' . $id, [
            'plan_id' => $planId,
            'days' => $durationDays,
        ]);
        Json::ok(['id' => $id, 'plan_id' => $planId]);
    }

    public function setStatus(int $adminId, int $id): void
    {
        $body = Json::readBody();
        $status = (string)($body['status'] ?? '');
        if (!in_array($status, ['active', 'disabled'], true)) {
            Json::fail('bad_request', 'status 必须为 active 或 disabled', 400);
        }
        if ($id === $adminId && $status === 'disabled') {
            Json::fail('bad_request', '不能停用自己的账号', 400);
        }
        $pdo = Db::pdo();
        $user = self::findUser($pdo, $id);
        if ($user === null) {
            Json::fail('not_found', '用户不存在', 404);
        }
        if ($status === 'disabled' && $user['role'] === 'admin') {
            self::assertAdminRemovable($pdo, $id);
        }
        $pdo->prepare('UPDATE users SET status = :s WHERE id = :id')->execute(['s' => $status, 'id' => $id]);
        AuditService::log($adminId, 'users.setStatus', 'user:' . $id, ['status' => $status]);
        Json::ok(['id' => $id, 'status' => $status]);
    }

    /** @return array<string, mixed>|null */
    private static function findUser(\PDO $pdo, int $id): ?array
    {
        $stmt = $pdo->prepare('SELECT id, email, role, admin_level, status, created_at FROM users WHERE id = :id');
        $stmt->execute(['id' => $id]);
        $row = $stmt->fetch();
        return $row ?: null;
    }

    private static function assertAdminRemovable(\PDO $pdo, int $excludeId): void
    {
        $stmt = $pdo->prepare('SELECT COUNT(*) FROM users WHERE role = \'admin\' AND status = \'active\' AND id != :id');
        $stmt->execute(['id' => $excludeId]);
        if ((int)$stmt->fetchColumn() < 1) {
            Json::fail('bad_request', '至少保留一名活跃管理员', 400);
        }
    }
}