<?php
defined('IS_INITPHP') || die('Access Denied!');

/**
 * 扩展类库-验证码
 */
class captchaInit {
	
	// 验证码位数
	private $mCheckCodeNum = 4;
	// 产生的验证码
	private $mCheckCode = '';
	
	// 验证码的图片
	private $mCheckImage = '';
	// 干扰像素
	private $mDisturbColor = '';
	// 验证码的图片宽度
	private $mCheckImageWidth = '60';
	// 验证码的图片宽度
	private $mCheckImageHeight = '20';
	/**
	 * @brief 输出头
	 */
	private function OutFileHeader() {
		header( "Content-type: image/png" );
	}
	/**
	 * * @brief 产生验证码
	 */
	public function CreateCheckCode() {
		$this->mCheckCode = $this->mKey( $this->mCheckCodeNum, 'ALNUM' );
		return $this->mCheckCode;
	}
	private function mKey($len = 4, $type = 'ALNUM') {
		// Register the lower case alphabet array
		$alpha = array(
				'a',
				'b',
				'c',
				'd',
				'e',
				'f',
				'g',
				'h',
				'i',
				'j',
				'k',
				'l',
				'm',
				'n',
				'o',
				'p',
				'q',
				'r',
				's',
				't',
				'u',
				'v',
				'w',
				'x',
				'y',
				'z' 
		);
		
		// Register the upper case alphabet array
		$ALPHA = array(
				'A',
				'B',
				'C',
				'D',
				'E',
				'F',
				'G',
				'H',
				'J',
				'K',
				'L',
				'M',
				'N',
				'P',
				'Q',
				'R',
				'S',
				'T',
				'U',
				'V',
				'W',
				'X',
				'Y',
				'Z' 
		);
		
		// Register the numeric array
		$num = array(
				'0',
				'1',
				'2',
				'3',
				'4',
				'5',
				'6',
				'7',
				'8',
				'9' 
		);
		
		// Initialize the keyVals array for use in the for loop
		$keyVals = array();
		
		// Initialize the key array to register each char
		$key = array();
		
		// Loop through the choices and register
		// The choice to keyVals array
		switch($type) {
			case 'lower' :
				$keyVals = $alpha;
				break;
			case 'upper' :
				$keyVals = $ALPHA;
				break;
			case 'numeric' :
				$keyVals = $num;
				break;
			case 'ALPHA' :
				$keyVals = array_merge( $alpha, $ALPHA );
				break;
			case 'ALNUM' :
				$keyVals = array_merge( $ALPHA, $num );
				break;
		}
		
		// Loop as many times as specified
		// Register each value to the key array
		for($i = 0; $i <= $len - 1; $i ++) {
			$r = rand( 0, count( $keyVals ) - 1 );
			$key [$i] = $keyVals [$r];
		}
		
		// Glue the key array into a string and return it
		return join( "", $key );
	}
	/**
	 * @brief 产生验证码图片
	 */
	private function CreateImage() {
		$this->mCheckImage = @imagecreate( $this->mCheckImageWidth, $this->mCheckImageHeight );
		imagecolorallocate( $this->mCheckImage, 200, 200, 200 );
		return $this->mCheckImage;
	}
	/**
	 * @brief 设置图片的干扰像素
	 */
	private function SetDisturbColor() {
		for($i = 0; $i <= 128; $i ++) {
			$this->mDisturbColor = imagecolorallocate( $this->mCheckImage, rand( 0, 255 ), rand( 0, 255 ), rand( 0, 255 ) );
			imagesetpixel( $this->mCheckImage, rand( 2, 128 ), rand( 2, 38 ), $this->mDisturbColor );
		}
	}
	/**
	 *
	 *
	 * @brief 设置验证码图片的大小
	 *
	 * @param $width 宽        	
	 *
	 * @param $height 高        	
	 *
	 */
	public function SetCheckImageWH($width, $height) {
		if($width == '' || $height == '')
			return false;
		$this->mCheckImageWidth = $width;
		$this->mCheckImageHeight = $height;
		return true;
	}
	/**
	 * @brief 在验证码图片上逐个画上验证码
	 */
	private function WriteCheckCodeToImage() {
		for($i = 0; $i <= $this->mCheckCodeNum; $i ++) {
			$bg_color = imagecolorallocate( $this->mCheckImage, rand( 0, 255 ), rand( 0, 128 ), rand( 0, 255 ) );
			$x = floor( $this->mCheckImageWidth / $this->mCheckCodeNum ) * $i;
			$y = rand( 0, $this->mCheckImageHeight - 15 );
			imagechar( $this->mCheckImage, 5, $x, $y, $this->mCheckCode [$i], $bg_color );
		}
	}
	/**
	 * @brief 输出验证码图片
	 */
	public function OutCheckImage() {
		$this->OutFileHeader();
		$this->CreateImage();
		$this->SetDisturbColor();
		$this->WriteCheckCodeToImage();
		imagepng( $this->mCheckImage );
		imagedestroy( $this->mCheckImage );
	}
}