package cn.gygxzc.envir.utils

import org.slf4j.LoggerFactory
import java.security.MessageDigest


/**
 *
 * @author NorthLan
 * @date 2018/3/5
 * @url https://noahlan.com
 */
class MD5Salt {
    companion object {
        private val logger = LoggerFactory.getLogger(MD5Salt::class.java)
        private const val ALGORITHM = "MD5"
        private const val CUT_SYMBOL = "#"

        /**
         * md5 盐值加密字符串
         * @param salt
         * 				盐值
         * @param rawText
         *				需要加密的字符串
         * @return
         */
        fun md5SaltEncode(salt: String, rawText: String): String? {
            return MD5Salt(salt, ALGORITHM).encode(rawText)
        }

        /**
         * 判断md5 盐值加密内容是否正确
         * @param salt
         * 盐值
         * @param encodeText
         * 加密后的文本内容
         * @param rawText
         * 加密前的文本内容
         * @return
         */
        fun md5SaltValid(salt: String, encodeText: String, rawText: String): Boolean {
            return MD5Salt(salt, ALGORITHM).isValid(encodeText, rawText)
        }
    }

    private var salt: String? = null
    private var algorithm: String? = null

    private constructor()

    constructor(salt: String, algorithm: String) {
        this.salt = salt
        this.algorithm = algorithm
    }

    /**
     * 字符串盐值加密
     * @param rawText
     * 需要加密的字符串
     * @return
     */
    fun encode(rawText: String): String? {
        try {
            val md = MessageDigest.getInstance(this.algorithm)
            //加密后的字符串
            return Byte2Hex.byte2Hex(md.digest(mergeRawTextAndSalt(rawText).toByteArray()))
        } catch (e: Exception) {
            logger.error(" MD5Salt encode exception.")
            e.printStackTrace()
        }
        return null
    }

    /**
     *
     *
     *
     * 判断加密内容是否正确
     *
     *
     * @param encodeText
     * 加密后的文本内容
     * @param rawText
     * 加密前的文本内容
     * @return
     */
    fun isValid(encodeText: String, rawText: String): Boolean {
        return this.encode(rawText).equals(encodeText)
    }

    /**
     *
     *
     *
     * 合并混淆盐值至加密内容
     *
     *
     * @param rawText
     * 需要加密的字符串
     * @return
     */
    private fun mergeRawTextAndSalt(rawText: String?): String {
        var tmp = rawText
        if (tmp == null) {
            tmp = ""
        }

        return if (this.salt == null || "" == this.salt) {
            tmp
        } else {
            val mt = StringBuffer()
            mt.append(tmp)
            mt.append(CUT_SYMBOL)
            mt.append(this.salt)
            mt.toString()
        }
    }

}