<?php

declare(strict_types=1);

namespace app\miniapi\service;

use app\miniapi\auth\Principal;
use app\miniapi\auth\WechatIdentityProvider;
use app\miniapi\auth\IdentityProvider;
use app\miniapi\model\MiniUser;
use app\miniapi\model\MiniSession;
use app\miniapi\http\Fields;
use app\miniapi\exception\ApiException;

final class AuthService
{
    public function __construct(private readonly IdentityProvider $provider = new WechatIdentityProvider())
    {
    }

    public function login(array $input): array
    {
        Fields::only($input, ['code']);
        $identity = $this->provider->exchange(Fields::text($input, 'code', 512));

        return $this->issue($identity);
    }

    /** Internal only. The HTTP controller never accepts provider identity from clients. */
    public function issue(array $identity): array
    {
        return (new MiniUser())->getConnection()->transaction(function () use ($identity) {
            $now = date('Y-m-d H:i:s');
            MiniUser::query()->insertOrIgnore($identity + [
                'nickname' => '',
                'status' => 1,
                'created_at' => $now,
                'updated_at' => $now,
            ]);

            return $this->sessionFor(MiniUser::query()->where($identity)->lockForUpdate()->firstOrFail());
        });
    }

    /**
     * Issues a session for an account that already exists, so a verified phone reaches the same
     * user and therefore the same granted identity as the WeChat login it was bound to.
     */
    public function issueForExisting(MiniUser $user): array
    {
        return (new MiniUser())->getConnection()->transaction(function () use ($user) {
            return $this->sessionFor(MiniUser::query()->where('id', $user->id)->lockForUpdate()->firstOrFail());
        });
    }

    private function sessionFor(MiniUser $user): array
    {
        if ((int) $user->status !== 1) {
            throw new ApiException(40302, '账号已停用', 403);
        }
        $now = date('Y-m-d H:i:s');
        $token = bin2hex(random_bytes(32));
        $expires = date('Y-m-d H:i:s', time() + (int) config('mini_api.session_ttl', 604800));
        MiniSession::query()->insert([
            'user_id' => $user->id,
            'token_hash' => hash('sha256', $token),
            'expires_at' => $expires,
            'created_at' => $now,
        ]);

        return [
            'access_token' => $token,
            'token_type' => 'Bearer',
            'expires_at' => $expires,
            'user_id' => (string) $user->id,
            'identities' => (new Access(new Principal((string) $user->id)))->identities(),
        ];
    }

    public function logout(string $token): array
    {
        MiniSession::query()->where('token_hash', hash('sha256', $token))->whereNull('revoked_at')->update(['revoked_at' => date('Y-m-d H:i:s')]);

        return ['logged_out' => true];
    }
}