<?php

namespace App\Services\Esign;

use Illuminate\Support\Facades\Http;
use JsonException;
use RuntimeException;

final class EsignClient
{
    private readonly string $baseUrl;

    private readonly EsignRequestSigner $signer;

    public function __construct(?EsignConfiguration $configuration = null)
    {
        $configuration ??= EsignConfiguration::fromConfig();
        $configuration->assertReadyForApi();

        $this->baseUrl = $configuration->baseUrl();
        $this->signer = new EsignRequestSigner($configuration->appId(), $configuration->appSecret());
    }

    public static function configured(): bool
    {
        $configuration = EsignConfiguration::fromConfig();

        if (! $configuration->isConfigured()) {
            return false;
        }

        try {
            $configuration->assertReadyForApi();
        } catch (RuntimeException) {
            return false;
        }

        return true;
    }

    public function uploadPdf(string $bytes, string $fileName): string
    {
        if (! str_starts_with($bytes, '%PDF-')) {
            throw new RuntimeException('只能向 E 签宝上传有效 PDF 文件。');
        }

        if (strlen($bytes) > 50 * 1024 * 1024) {
            throw new RuntimeException('E 签宝单文件不能超过 50 MB。');
        }

        if (preg_match('/[\\/:*"<>|？?\x00-\x1F]/u', $fileName) === 1 || ! str_ends_with(strtolower($fileName), '.pdf')) {
            throw new RuntimeException('E 签宝文件名必须是安全的 PDF 文件名。');
        }

        $contentMd5 = base64_encode(md5($bytes, true));
        $data = $this->request('POST', '/v3/files/file-upload-url', [
            'contentMd5' => $contentMd5,
            'contentType' => 'application/pdf',
            'fileName' => $fileName,
            'fileSize' => strlen($bytes),
            'convertToPDF' => false,
        ]);
        $fileId = (string) ($data['fileId'] ?? '');
        $uploadUrl = (string) ($data['fileUploadUrl'] ?? '');

        if ($fileId === '' || $uploadUrl === '') {
            throw new RuntimeException('E 签宝未返回文件 ID 或上传地址。');
        }

        $uploadResponse = Http::timeout($this->timeout())
            ->withHeaders(['Content-MD5' => $contentMd5])
            ->withBody($bytes, 'application/pdf')
            ->send('PUT', $uploadUrl);

        if (! $uploadResponse->successful()) {
            throw new RuntimeException('报价 PDF 上传到 E 签宝文件服务失败。');
        }

        $this->waitUntilFileReady($fileId);

        return $fileId;
    }

    public function createSignFlow(string $fileId, string $fileName, array $signer, int $expiresAtMs): string
    {
        $flowConfig = [
            'signFlowTitle' => $signer['flow_title'],
            'signFlowExpireTime' => $expiresAtMs,
            'autoStart' => true,
            'autoFinish' => true,
            'identityVerify' => true,
        ];
        $notifyUrl = EsignConfiguration::fromConfig()->notifyUrl();

        if ($notifyUrl !== '') {
            $flowConfig['notifyUrl'] = $notifyUrl;
        }

        $signers = $signer['signers'] ?? null;
        $signerPayload = is_array($signers) && $signers !== []
            ? array_map(fn (array $item, int $index): array => $this->signerPayload($fileId, $item, $index), array_values($signers), array_keys(array_values($signers)))
            : [[
                'signerType' => 1,
                'signConfig' => ['signOrder' => 1],
                'noticeConfig' => ['noticeTypes' => $signer['notice_types']],
                'orgSignerInfo' => [
                    'orgName' => $signer['organization_name'],
                    'transactorInfo' => [
                        'psnAccount' => $signer['operator_account'],
                        'psnInfo' => ['psnName' => $signer['operator_name']],
                    ],
                ],
                'signFields' => [[
                    'fileId' => $fileId,
                    'normalSignFieldConfig' => [
                        'freeMode' => true,
                        'movableSignField' => true,
                        'signFieldSize' => '159',
                    ],
                ]],
            ]];

        $docs = [[
                'fileId' => $fileId,
                'fileName' => $fileName,
        ]];
        foreach ($signer['additional_docs'] ?? [] as $document) {
            $index = (int) $document['signer_index'];
            if (! isset($signerPayload[$index]) || blank($document['fileId'])) {
                throw new RuntimeException('证件推送单的签署方或文件 ID 无效。');
            }
            if (($document['stamp_only'] ?? false) && $signerPayload[$index]['signerType'] !== 1) {
                throw new RuntimeException('营业执照需要企业盖章，请选择企业签署方。');
            }
            $docs[] = ['fileId' => $document['fileId'], 'fileName' => $document['fileName']];
            // Each credential PDF is one page, with exactly one field assigned
            // to the chosen recipient. Other signers only sign the main file.
            $signerPayload[$index]['signFields'][] = [
                'fileId' => $document['fileId'],
                'normalSignFieldConfig' => [
                    'freeMode' => false,
                    'movableSignField' => false,
                    'signFieldStyle' => 1,
                    'signFieldSize' => '120',
                    'signFieldPosition' => ['positionPage' => '1', 'positionX' => 420.0, 'positionY' => 725.0],
                ],
            ];
        }
        $data = $this->request('POST', '/v3/sign-flow/create-by-file', [
            'docs' => $docs,
            'signFlowConfig' => $flowConfig,
            'signers' => $signerPayload,
        ]);
        $signFlowId = (string) ($data['signFlowId'] ?? '');

        if ($signFlowId === '') {
            throw new RuntimeException('E 签宝未返回签署流程 ID。');
        }

        return $signFlowId;
    }

    private function signerPayload(string $fileId, array $signer, int $index): array
    {
        $type = (int) ($signer['signer_type'] ?? 1);
        $payload = [
            'signerType' => $type,
            'signConfig' => ['signOrder' => $index + 1],
            'noticeConfig' => ['noticeTypes' => (string) ($signer['notice_types'] ?? '1')],
            'signFields' => [[
                'fileId' => $fileId,
                'normalSignFieldConfig' => [
                    'freeMode' => true,
                    'movableSignField' => true,
                    'signFieldSize' => '159',
                ],
            ]],
        ];

        if ($type === 0) {
            $payload['psnSignerInfo'] = [
                'psnAccount' => $signer['operator_account'],
                'psnInfo' => ['psnName' => $signer['operator_name']],
            ];
        } else {
            $payload['orgSignerInfo'] = [
                'orgName' => $signer['organization_name'],
                'transactorInfo' => [
                    'psnAccount' => $signer['operator_account'],
                    'psnInfo' => ['psnName' => $signer['operator_name']],
                ],
            ];
        }

        return $payload;
    }

    /**
     * 获取签署人的签署页面链接（免登录，扫码或点开即可签署）。企业签署时带上企业名称，直接进入以该企业身份签署的页面。
     */
    public function signUrl(string $signFlowId, string $psnAccount, ?string $orgName = null): string
    {
        $payload = [
            'needLogin' => false,
            'urlType' => 2,
            'operator' => ['psnAccount' => $psnAccount],
            'clientType' => 'ALL',
        ];
        if ($orgName !== null && $orgName !== '') {
            $payload['organization'] = ['orgName' => $orgName];
        }

        $data = $this->request('POST', "/v3/sign-flow/{$signFlowId}/sign-url", $payload);
        $url = (string) ($data['shortUrl'] ?? '') ?: (string) ($data['url'] ?? '');

        if ($url === '') {
            throw new RuntimeException('E 签宝未返回签署链接。');
        }

        return $url;
    }

    /** 撤回还没签完的签署流程（签署人那边的待签任务随之失效）。 */
    public function revokeSignFlow(string $signFlowId, string $reason): void
    {
        $this->request('POST', "/v3/sign-flow/{$signFlowId}/revoke", [
            'revokeReason' => mb_substr($reason, 0, 50),
        ]);
    }

    public function signFlowDetail(string $signFlowId): array
    {
        return $this->request('GET', "/v3/sign-flow/{$signFlowId}/detail");
    }

    public function downloadUrls(string $signFlowId): array
    {
        return $this->request('POST', "/v3/sign-flow/{$signFlowId}/file-download-url", [
            'urlAvailableDate' => '3600',
        ]);
    }

    public function downloadUploadedPdf(string $fileId): string
    {
        $data = $this->request('GET', "/v3/files/{$fileId}");
        $downloadUrl = (string) ($data['fileDownloadUrl']
            ?? $data['downloadUrl']
            ?? data_get($data, 'files.0.downloadUrl', ''));

        if ($downloadUrl === '') {
            throw new RuntimeException('E 签宝未返回历史原文件下载地址。');
        }

        return $this->download($downloadUrl);
    }

    public function download(string $url): string
    {
        $response = Http::timeout($this->timeout())->get($url);

        if (! $response->successful()) {
            throw new RuntimeException('无法从 E 签宝下载签署归档文件。');
        }

        return $response->body();
    }

    private function waitUntilFileReady(string $fileId): void
    {
        for ($attempt = 0; $attempt < 8; $attempt++) {
            $data = $this->request('GET', "/v3/files/{$fileId}");
            $status = (string) ($data['fileStatus'] ?? $data['status'] ?? '');

            if (in_array($status, ['2', '5'], true)) {
                return;
            }

            if ($attempt < 7) {
                usleep(400000);
            }
        }

        throw new RuntimeException('E 签宝文件处理超时，请稍后重试。');
    }

    private function request(string $method, string $path, array $payload = []): array
    {
        $method = strtoupper($method);
        $body = $method === 'GET' ? '' : $this->encodeJson($payload);
        $request = Http::timeout($this->timeout())
            ->withHeaders($this->signer->headers($method, $path, $body));

        if ($body !== '') {
            $request = $request->withBody($body, EsignRequestSigner::CONTENT_TYPE);
        }

        $response = $request->send($method, $this->baseUrl . $path);

        if (! $response->successful()) {
            throw new RuntimeException("E 签宝接口请求失败（HTTP {$response->status()}）。");
        }

        $decoded = $response->json();

        if (! is_array($decoded)) {
            throw new RuntimeException('E 签宝接口返回了无法识别的数据。');
        }

        if ((int) ($decoded['code'] ?? -1) !== 0) {
            $code = (string) ($decoded['code'] ?? 'unknown');
            $message = mb_substr((string) ($decoded['message'] ?? '未知错误'), 0, 300);

            throw new RuntimeException("E 签宝接口返回业务错误（{$code}）：{$message}");
        }

        return is_array($decoded['data'] ?? null) ? $decoded['data'] : [];
    }

    private function encodeJson(array $payload): string
    {
        try {
            return json_encode($payload, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_THROW_ON_ERROR);
        } catch (JsonException $exception) {
            throw new RuntimeException('E 签宝请求数据无法编码。', previous: $exception);
        }
    }

    private function timeout(): int
    {
        return EsignConfiguration::fromConfig()->timeout();
    }
}