<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Support\Facades\Storage;

class File extends Model
{
    use HasFactory;

    protected $fillable = [
        'user_id',
        'original_name',
        'storage_name',
        'path',
        'url',
        'mime_type',
        'size',
        'extension',
        'disk',
        'module',
        'purpose',
        'description',
        'status',
    ];

    protected $casts = [
        'size' => 'integer',
    ];

    /**
     * 关联用户
     */
    public function user(): BelongsTo
    {
        return $this->belongsTo(User::class);
    }

    /**
     * 获取文件完整路径
     */
    public function getFullPathAttribute(): string
    {
        return $this->path . '/' . $this->storage_name;
    }

    /**
     * 获取文件大小（可读格式）
     */
    public function getSizeFormattedAttribute(): string
    {
        $size = $this->size;
        $units = ['B', 'KB', 'MB', 'GB', 'TB'];
        
        for ($i = 0; $size >= 1024 && $i < 4; $i++) {
            $size /= 1024;
        }
        
        return round($size, 2) . ' ' . $units[$i];
    }

    /**
     * 获取文件图标
     */
    public function getIconAttribute(): string
    {
        $extension = strtolower($this->extension);
        
        $icons = [
            // 图片
            'jpg' => 'image', 'jpeg' => 'image', 'png' => 'image', 'gif' => 'image',
            'bmp' => 'image', 'svg' => 'image', 'webp' => 'image',
            
            // 文档
            'pdf' => 'picture_as_pdf',
            'doc' => 'description', 'docx' => 'description',
            'xls' => 'table_chart', 'xlsx' => 'table_chart',
            'ppt' => 'slideshow', 'pptx' => 'slideshow',
            
            // 文本
            'txt' => 'text_fields', 'md' => 'text_fields',
            'json' => 'code', 'xml' => 'code', 'html' => 'code',
            
            // 压缩文件
            'zip' => 'folder_zip', 'rar' => 'folder_zip', '7z' => 'folder_zip',
            'tar' => 'folder_zip', 'gz' => 'folder_zip',
            
            // 其他
            'csv' => 'table_rows',
        ];
        
        return $icons[$extension] ?? 'insert_drive_file';
    }

    /**
     * 检查文件是否存在
     */
    public function exists(): bool
    {
        return Storage::disk($this->disk)->exists($this->getFullPathAttribute());
    }

    /**
     * 获取文件内容
     */
    public function getContent(): string
    {
        return Storage::disk($this->disk)->get($this->getFullPathAttribute());
    }

    /**
     * 删除物理文件
     */
    public function deletePhysicalFile(): bool
    {
        if ($this->exists()) {
            return Storage::disk($this->disk)->delete($this->getFullPathAttribute());
        }
        return false;
    }

    /**
     * 获取文件URL
     */
    public function getUrl(): string
    {
        if ($this->url) {
            return $this->url;
        }
        
        return Storage::disk($this->disk)->url($this->getFullPathAttribute());
    }

    /**
     * 获取缩略图URL（如果是图片）
     */
    public function getThumbnailUrl($width = 200, $height = 200): ?string
    {
        if (strpos($this->mime_type, 'image/') === 0) {
            // 这里可以集成图片处理库生成缩略图
            // 暂时返回原图URL
            return $this->getUrl();
        }
        
        return null;
    }

    /**
     * 获取文件统计
     */
    public static function getStatistics($userId = null)
    {
        $query = self::query();
        
        if ($userId) {
            $query->where('user_id', $userId);
        }
        
        $total = $query->count();
        $totalSize = $query->sum('size');
        $byModule = $query->selectRaw('module, COUNT(*) as count, SUM(size) as size')
            ->groupBy('module')
            ->orderBy('count', 'desc')
            ->get();
        $byType = $query->selectRaw('mime_type, COUNT(*) as count')
            ->groupBy('mime_type')
            ->orderBy('count', 'desc')
            ->limit(10)
            ->get();
        
        return [
            'total' => $total,
            'total_size' => $totalSize,
            'total_size_formatted' => self::formatSize($totalSize),
            'by_module' => $byModule,
            'by_type' => $byType,
        ];
    }

    /**
     * 格式化文件大小
     */
    private static function formatSize($bytes): string
    {
        $units = ['B', 'KB', 'MB', 'GB', 'TB'];
        
        for ($i = 0; $bytes >= 1024 && $i < 4; $i++) {
            $bytes /= 1024;
        }
        
        return round($bytes, 2) . ' ' . $units[$i];
    }

    /**
     * 根据模块获取文件
     */
    public static function getByModule($module, $purpose = null, $limit = 20)
    {
        $query = self::where('module', $module)->where('status', 'active');
        
        if ($purpose) {
            $query->where('purpose', $purpose);
        }
        
        return $query->orderBy('created_at', 'desc')->limit($limit)->get();
    }

    /**
     * 清理过期文件
     */
    public static function cleanupExpired($days = 30)
    {
        $expiredDate = now()->subDays($days);
        
        $files = self::where('created_at', '<', $expiredDate)
            ->where('status', '!=', 'permanent')
            ->get();
        
        $deletedCount = 0;
        $failedFiles = [];
        
        foreach ($files as $file) {
            try {
                // 删除物理文件
                $file->deletePhysicalFile();
                
                // 删除数据库记录
                $file->delete();
                
                $deletedCount++;
            } catch (\Exception $e) {
                $failedFiles[] = [
                    'id' => $file->id,
                    'name' => $file->original_name,
                    'error' => $e->getMessage(),
                ];
            }
        }
        
        return [
            'deleted_count' => $deletedCount,
            'failed_files' => $failedFiles,
        ];
    }
}