<?php

namespace App\Console\Commands;

use Illuminate\Console\Command;

class Sm2EncryptCommand extends Command
{
    /**
     * The name and signature of the console command.
     *
     * 用法：php artisan sm2:encrypt "明文" "公钥hex(可含04前缀)" --mode=c1c3c2
     */
    protected $signature = 'sm2:encrypt';

    /**
     * The console command description.
     */
    protected $description = '使用 SM2 公钥加密（硬编码明文与公钥），返回hex密文';

    public function handle(): int
    {
        // 硬编码待加密明文与公钥（hex，含04前缀）
        $message = '{"title": "","district": "","xmlxS":"足球"}';
        $publicKey = 'MFkwEwYHKoZIzj0CAQYIKoEcz1UBgi0DQgAEkecuYCCoPprFvmgZoXTtEXcpYyvJi9rgizj+FMqVIL0OSQ24plc4F8ONugktvjPRbwvRly12ieRK9SGiG+9sjA==';
        $mode = 1; // C1C3C2

        try {
            // 若提供的是 SPKI Base64 公钥，转换为未压缩点HEX(04+x+y)
            $pubHex = $this->normalizePublicKeyToHex($publicKey);

            // RtSm2 缺省返回hex，且加密返回 c1c3c2
            $sm2 = new \Rtgm\sm\RtSm2('hex', true);
            $cipherHex = $sm2->doEncrypt($message, $pubHex, $mode);
            $this->line($cipherHex);
            return self::SUCCESS;
        } catch (\Throwable $e) {
            $this->error('SM2 加密失败：' . $e->getMessage());
            return self::FAILURE;
        }
    }

    private function normalizePublicKeyToHex(string $key): string
    {
        $trimmed = trim($key);
        // 如果已经是 128/130 长度的HEX，直接返回
        if (preg_match('/^(04)?[0-9a-fA-F]{128}$/', $trimmed)) {
            return strtolower($trimmed);
        }

        // 可能是 Base64(SPKI SubjectPublicKeyInfo)
        $bin = base64_decode($trimmed, true);
        if ($bin === false) {
            throw new \InvalidArgumentException('公钥格式不支持：既不是HEX也不是Base64');
        }

        // 优先使用 OpenSSL 解析 SPKI，获取未压缩公钥点
        if (function_exists('openssl_pkey_get_public')) {
            $pem = "-----BEGIN PUBLIC KEY-----\n" . chunk_split($trimmed, 64, "\n") . "-----END PUBLIC KEY-----\n";
            $res = @openssl_pkey_get_public($pem);
            if ($res !== false) {
                $details = openssl_pkey_get_details($res);
                if ($details && isset($details['ec']) && isset($details['ec']['public_key'])) {
                    $pubBin = $details['ec']['public_key']; // binary starting with 0x04
                    if ($pubBin !== '' && ord($pubBin[0]) === 0x04) {
                        return strtolower(bin2hex($pubBin));
                    }
                }
                // 某些 PHP 版本可能在 key 索引中提供公钥
                if ($details && isset($details['key'])) {
                    // 再次从 details['key']（PEM）中提取 BIT STRING
                    $pem2 = $details['key'];
                    $clean = str_replace(["-----BEGIN PUBLIC KEY-----", "-----END PUBLIC KEY-----", "\r", "\n", " "], '', $pem2);
                    $bin2 = base64_decode($clean, true);
                    if ($bin2 !== false) {
                        $found = $this->extractUncompressedPointFromSpki($bin2);
                        if ($found !== null) {
                            return $found;
                        }
                    }
                }
            }
        }

        // 退而求其次：直接从 SPKI 二进制中提取 BIT STRING（不下钻根 SEQUENCE，直接扫描 0x03 标签）
        $found = $this->extractUncompressedPointFromSpki($bin);
        if ($found !== null) {
            return $found;
        }

        throw new \RuntimeException('未找到公钥BIT STRING');
    }

    private function extractUncompressedPointFromSpki(string $spkiBin): ?string
    {
        $len = strlen($spkiBin);
        for ($pos = 0; $pos < $len; $pos++) {
            if (ord($spkiBin[$pos]) !== 0x03) {
                continue;
            }
            $p = $pos + 1;
            if ($p >= $len)
                break;
            $lenByte = ord($spkiBin[$p++]);
            if (($lenByte & 0x80) === 0) {
                $l = $lenByte;
            } else {
                $num = $lenByte & 0x7F;
                if ($num === 0 || $p + $num > $len) {
                    continue;
                }
                $l = 0;
                for ($i = 0; $i < $num; $i++) {
                    $l = ($l << 8) | ord($spkiBin[$p++]);
                }
            }
            if ($p + $l > $len) {
                continue;
            }
            if ($l < 2) {
                continue;
            }
            $unusedBits = ord($spkiBin[$p]);
            if ($unusedBits !== 0) {
                continue;
            }
            $bitString = substr($spkiBin, $p + 1, $l - 1);
            if ($bitString !== '' && ord($bitString[0]) === 0x04) {
                return strtolower(bin2hex($bitString));
            }
        }
        return null;
    }
}