<?php
/*
 * Image handle class
 * by lijg 20181031 
 */

class ImageLib{
    public function __construct(){
        //TODO
    }
    
    public function setImageType($imgPath='', $type=''){
        if(empty($imgPath) || empty($type)){
            return false;
        }
        
        $im = null;
        switch($type){
            case 1:
                $im = imagecreatefromgif($imgPath);
                break;
            case 2:
                $im = imagecreatefromjpeg($imgPath);
                break;
            case 3:
                $im = imagecreatefrompng($imgPath);
                break;
            default:
                return false;
        }
        
        return $im;
    }
    
    public function exportImage($imgPath='', $dim, $suf='thumb'){
        if(empty($imgPath) || empty($dim)){
            return false;
        }
        
        $imgInfo = getimagesize($imgPath);
        $path = pathinfo($imgPath);
        $imgName = "{$path['dirname']}/{$suf}/{$path['filename']}_{$suf}.{$path['extension']}";
        switch($imgInfo[2]){
            case 1:
                imagegif($dim, $imgName);
                break;
            case 2:
                imagejpeg($dim, $imgName);
                break;
            case 3:
                imagepng($dim, $imgName);
                break;
            default:
                return false;
        }
        return $imgName;
    }
    
    public function scaleImage($imgPath='', $setWidth='100', $setHeight='100', $suf ='thumb'){
        if(empty($imgPath)){
            return false;
        }
        
        $imgInfo = getimagesize($imgPath);
        $width = $imgInfo[0];
        $height = $imgInfo[1];
        $rate = ($setWidth/$width)>($setHeight/$height)?$setHeight/$height:$setWidth/$width;
        $newWidth = floor($width*$rate);
        $newHeight = floor($height*$rate);
        
        $sim = $this->setImageType($imgPath, $imgInfo[2]);
        $dim = imagecreatetruecolor($newWidth, $newHeight);
        
        imagecopyresampled($dim, $sim, 0, 0, 0, 0, $newWidth, $newHeight, $width, $height);
        $image = $this->exportImage($imgPath, $dim, $suf);
        
        imagedestroy($sim);
        imagedestroy($dim);
        return $image;
    }
    
    
    
    public function __destruct(){
        //TODO
    }
}