<?php

namespace app\controller\api;

use app\model\UploadFile;
use app\service\PermissionService;
use think\exception\HttpResponseException;

class Upload extends BaseApi
{
    public function upload()
    {
        $user = $this->authUser();
        $file = $this->request->file('file');

        if (!$file) {
            return $this->error('请选择文件');
        }

        try {
            $ext = strtolower($file->extension() ?: pathinfo($file->getOriginalName(), PATHINFO_EXTENSION));
            $ext = $ext ?: 'bin';
            $mime = $this->resolveMime($file, $ext);
            $fileType = $this->detectFileType($mime, $ext);

            if (!empty($user['is_guest']) && $fileType === 'image') {
                return $this->error('游客模式不支持发送图片，请登录后再上传', 403);
            }

            if ($fileType === 'document' && !in_array($mime, config('upload.allowed_documents'), true)) {
                $mime = self::DOCUMENT_MIME_BY_EXT[$ext] ?? $mime;
            }

            if (!PermissionService::canUpload($user, $fileType)) {
                return $this->error('您没有权限上传此类型文件或功能未开启', 403);
            }

            $maxSize = PermissionService::getMaxUploadSizeMb($user) * 1024 * 1024;
            if ($file->getSize() > $maxSize) {
                return $this->error('文件大小超出限制');
            }

            if (!$this->isAllowedMime($mime, $fileType, $ext)) {
                return $this->error('不支持的文件类型: ' . $mime);
            }

            $originalName = $file->getOriginalName();
            $fileSize = $file->getSize();

            $uploadPath = rtrim(config('upload.path'), '/\\');
            $this->ensureUploadDir($uploadPath);

            $subdir = date('Y/m/d');
            $storedBase = uniqid('', true) . '.' . $ext;
            $storedName = $subdir . '/' . $storedBase;
            $fullDir = $uploadPath . DIRECTORY_SEPARATOR . str_replace('/', DIRECTORY_SEPARATOR, $subdir);

            if (!is_dir($fullDir) && !mkdir($fullDir, 0755, true) && !is_dir($fullDir)) {
                return $this->error('无法创建上传目录，请检查 uploads 权限', 500);
            }

            if (!is_writable($fullDir)) {
                return $this->error('上传目录不可写，请执行: chmod -R 775 uploads && chown -R www-data:www-data uploads', 500);
            }

            $moved = $file->move($fullDir, $storedBase);
            if (!$moved) {
                return $this->error('文件保存失败: ' . ($file->getError() ?: '未知错误'), 500);
            }

            $record = UploadFile::create([
                'user_id'       => $user['id'],
                'original_name' => $originalName,
                'stored_name'   => $storedBase,
                'file_path'     => $storedName,
                'mime_type'     => $mime,
                'file_size'     => $fileSize,
                'file_type'     => $fileType,
            ]);

            return $this->success([
                'id'   => $record->id,
                'url'  => '/api/uploads/' . rawurlencode($storedBase),
                'name' => $originalName,
                'type' => $fileType,
                'mime' => $mime,
                'size' => $fileSize,
            ]);
        } catch (\think\exception\FileException $e) {
            return $this->error('文件保存失败: ' . $e->getMessage(), 500);
        } catch (\Throwable $e) {
            return $this->error('上传失败: ' . $e->getMessage(), 500);
        }
    }

    public function serve($filename)
    {
        $filename = basename($filename);
        $upload = UploadFile::where('stored_name', $filename)
            ->whereOr('file_path', 'like', '%/' . $filename)
            ->find();

        if (!$upload) {
            throw new HttpResponseException(json([
                'code'    => 1,
                'message' => '文件不存在',
                'data'    => null,
            ], 404));
        }

        $path = rtrim(config('upload.path'), '/\\') . DIRECTORY_SEPARATOR . str_replace('/', DIRECTORY_SEPARATOR, $upload->file_path);
        if (!is_file($path)) {
            throw new HttpResponseException(json([
                'code'    => 1,
                'message' => '文件不存在',
                'data'    => null,
            ], 404));
        }

        $mime = $upload->mime_type ?: (@mime_content_type($path) ?: 'application/octet-stream');

        return response(file_get_contents($path), 200, [
            'Content-Type'  => $mime,
            'Content-Length' => (string) filesize($path),
            'Cache-Control' => 'public, max-age=604800',
        ]);
    }

    /**
     * 文档扩展名 -> 常见但不同系统上可能检测出不一致的 MIME 兜底表。
     * .doc/.docx 等 Office 文档在不同服务器 fileinfo 版本下识别出的 MIME 差异很大，
     * 仅靠 MIME 白名单很容易误判为“不支持的文件类型”，因此这里用扩展名兜底放行。
     */
    private const IMAGE_EXTENSIONS = ['jpg', 'jpeg', 'png', 'gif', 'webp', 'bmp'];

    private const VIDEO_EXTENSIONS = ['mp4', 'webm', 'mov'];

    private const DOCUMENT_EXTENSIONS = ['pdf', 'doc', 'docx', 'txt', 'md'];

    private const IMAGE_MIME_BY_EXT = [
        'jpg'  => 'image/jpeg',
        'jpeg' => 'image/jpeg',
        'png'  => 'image/png',
        'gif'  => 'image/gif',
        'webp' => 'image/webp',
        'bmp'  => 'image/bmp',
    ];

    private const DOCUMENT_MIME_BY_EXT = [
        'pdf'  => 'application/pdf',
        'doc'  => 'application/msword',
        'docx' => 'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
        'txt'  => 'text/plain',
        'md'   => 'text/markdown',
    ];

    private function resolveMime($file, string $ext): string
    {
        $mime = $file->getMime();
        if (!$mime && is_file($file->getPathname())) {
            $mime = @mime_content_type($file->getPathname()) ?: '';
        }

        $mime = strtolower(trim((string) $mime));
        if ($mime === 'image/jpg') {
            $mime = 'image/jpeg';
        }

        if ($mime === '' || $mime === 'application/octet-stream') {
            $mime = self::IMAGE_MIME_BY_EXT[$ext] ?? self::DOCUMENT_MIME_BY_EXT[$ext] ?? $mime;
        }

        return $mime ?: 'application/octet-stream';
    }

    private function ensureUploadDir(string $uploadPath): void
    {
        if (is_dir($uploadPath)) {
            return;
        }

        if (!mkdir($uploadPath, 0755, true) && !is_dir($uploadPath)) {
            throw new \RuntimeException('无法创建 uploads 目录: ' . $uploadPath);
        }
    }

    private function detectFileType(string $mime, string $ext = ''): string
    {
        $ext = strtolower($ext);

        if (in_array($ext, self::IMAGE_EXTENSIONS, true)) {
            return 'image';
        }
        if (in_array($ext, self::VIDEO_EXTENSIONS, true)) {
            return 'video';
        }
        if (str_starts_with($mime, 'image/')) {
            return 'image';
        }
        if (str_starts_with($mime, 'video/')) {
            return 'video';
        }
        if (str_starts_with($mime, 'audio/')) {
            return 'audio';
        }
        if (in_array($mime, config('upload.allowed_documents'), true)) {
            return 'document';
        }
        if (in_array(strtolower($ext), self::DOCUMENT_EXTENSIONS, true)) {
            return 'document';
        }
        return 'other';
    }

    private function isAllowedMime(string $mime, string $fileType, string $ext = ''): bool
    {
        $config = config('upload');
        return match ($fileType) {
            'image'    => in_array($mime, $config['allowed_images'], true)
                || in_array(strtolower($ext), self::IMAGE_EXTENSIONS, true),
            'video'    => in_array($mime, $config['allowed_videos'], true)
                || in_array(strtolower($ext), self::VIDEO_EXTENSIONS, true),
            'audio'    => in_array($mime, $config['allowed_audios'], true),
            'document' => in_array($mime, $config['allowed_documents'], true)
                || in_array(strtolower($ext), self::DOCUMENT_EXTENSIONS, true),
            default    => false,
        };
    }
}